To determine if comparing alpha angle measurements of the outer cortical margin (preoperative alpha angle) and the inner cortical margin (theoretical postoperative alpha angle) on magnetic resonance imaging (MRI) can estimate the amount of sclerotic bone that needs to be resected to restore the alpha angle to normative values (<55⁰) in patients with symptomatic femoroacetabular impingement (FAI).

A retrospective review was conducted on patients with FAI undergoing primary hip arthroscopy and CAM osteoplasty from June 2013 to February 2017. Inclusion criteria were radiologist-measured alpha angles >70° on 3T oblique axial MRI, unilateral primary hip arthroscopy, and age ≥18. Exclusions included previous hip surgery, hip trauma, avascular necrosis, advanced osteoarthritis, dysplasia, poor quality images, or missing MRI images. Alpha angles were measured preoperatively using the outer cortical margin and postoperatively using the inner cortical margin of femur. Surgeries were performed by the senior surgeon. Paired t-tests compared preoperative and postoperative alpha angles, and intraclass correlation coefficients (ICC) were used to assess inter-rater and intra-rater reliability.

One hundred patients (100 hips) were included with an average age of 40.8 years (range, 18.7-64.9), with 75 % being male (n = 75). The average BMI was 24.7 ± 3.9 (range, 17.1-38.8). The average maximum alpha angle at the outer cortical margin was 77.0 ± 4.2° (range, 70.0-90.8), with an ICC for inter-rater reliability of 0.861, indicating excellent agreement. The average inner cortical alpha angle was 46.4 ± 3.4° (range, 36.5-55.4), significantly less than 55° (p<0.001). The mean difference between the outer and inner cortical alpha angles was -30.6 ± 5.1° (p< 0.001).

The difference between outer and inner cortical alpha angles on MRI can accurately estimate the amount of sclerotic bone resection needed to restore the alpha angle to normative values in patients with FAI. This information may be directly applied clinically marker to assess adequacy of CAM resection.

The purpose of this study was to (1) evaluate preoperative pelvic tilt utilizing the sacro-femoral-pubic (SFP) angle on standing pelvic x-rays, and (2) determine if the SFP angle changes after a unilateral or bilateral PAO.

A retrospective review was conducted of PAOs performed by a single hip preservation surgeon from November 2018 to November 2023. Standing x-rays were reviewed at 4 time points: preoperative, subacute postoperative, 6-month follow-up, and 12-month follow-up. Data collected included demographics, lateral center-edge angle (LCEA), Tönnis angle, and sacro-femoral-pubic (SFP) angle (a surrogate metric for pelvic tilt). Linear mixed models and Wilcoxon signed-rank tests were used to evaluate preoperative to postoperative differences in pelvic tilt for the unilateral and bilateral PAO groups, respectively.

Seventy-four patients met inclusion criteria, consisting of 53 unilateral and 21 bilateral PAO patients (18.5±4.1 vs. 21.3±5.1 y, 90.6% vs. 95.2% female, LCEA 17.5 deg±6.5 deg vs. 18.0 deg±5.5 deg and 18.0 deg±6.3 deg, respectively). The Average preoperative pelvic tilt, calculated from the SFP angle, for the unilateral and bilateral PAO patients were 9.1 degrees±5.5 degrees and 8.1 degrees±5.6 degrees, respectively. These values increased postoperatively at average 7-week (-0.3 deg±3.4 deg and 1.3 deg±3.7 deg), 6-month (1.1 deg±3.8 deg and 2.7 deg±3.4 deg), and 12-month (1.0 deg±4.1 deg and 2.7 deg±3.0 deg) follow-up. Significant differences in pelvic tilt were observed from preoperative x-rays to 6 months ( P =0.002) and 12 months ( P =0.001) for the bilateral PAO patients, whereas the unilateral group demonstrated similar pelvic tilt at all time points ( P =0.09).

Patients undergoing bilateral PAO demonstrated an average increase in pelvic tilt of 2.7 degrees as measured by SFP angle at 6 months and 12 months postoperatively, suggesting a compensatory adaptation after surgery that may have implications in rehabilitation regimens and planned surgical corrections.

Level III-therapeutic study.

To compare patient-reported outcomes (PROs), achievement of clinically significant outcomes, and reoperation-free survivorship between primary and revision hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS) in propensity-matched borderline hip dysplasia (BHD) patients at a minimum 5-year follow-up.

Patients with BHD, characterized by a lateral center-edge angle 18° to 25°, who underwent HA for FAIS with capsular repair by a single surgeon between January 2012 and June 2018 with a minimum 5-year follow-up were identified. Cases of revision HA were propensity-matched 1:2 to cases of primary HA, controlling for age, sex, and body mass index. A 1:2 ratio was chosen to maximize the number of included patients. Collected PROs included Hip Outcome Score-Activities of Daily Living and Sport Subscales, International Hip Outcome Score 12, modified Harris Hip Score, and Visual Analog Scale for Pain. Achievement of minimal clinically important difference, patient acceptable symptom state, and substantial clinical benefit for any measured PRO was compared between groups along with reoperation-free survivorship using Kaplan-Meier analysis.

Thirty-six revision HA hips (34 patients) were propensity-matched to 72 primary HA hips (70 patients). The groups were similar in age (31.5 ± 10.3 years vs 30.5 ± 11.2, P = .669), sex (69.4% female vs 70.8%, P = .656), and body mass index (25.7 ± 4.0 vs 25.5 ± 3.7, P = .849). The revision group showed a greater prevalence of prolonged preoperative pain (50.0% vs 27.8%, P = .032) compared with the primary group. A significant improvement in all PROs was observed for both groups with comparable PROs preoperatively and at the 5-year follow-up between groups (P ≥ .086). The revision and primary groups showed comparable minimal clinically important difference (95.0% vs 95.7%, P ≥ .999), patient acceptable symptom state (80.0% vs 83.6%, P = .757), and substantial clinical benefit (62.5% vs 70.7%, P = .603) achievement for any PRO. Comparable reoperation-free survivorship was observed (P = .151).

Propensity-matched patients with BHD undergoing primary and revision hip arthroscopy for FAIS achieved similar minimum 5-year PROs, clinically significant outcomes, and reoperation-free survivorship.

Level III, retrospective comparative case series.

Studies evaluating the long-term survival rate, patient satisfaction, and conversion to total hip arthroplasty (THA) are limited. The aim of this study was to evaluate satisfaction and hip survival at a minimum 10-year follow-up in patients following hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

A total of 164 patients underwent hip arthroscopy for FAIS between 2007 and 2012; of these, 76 (49 men and 27 women; mean age, 40.7 ± 11.2 years; range, 15-69 years) patients could be clinically examined or reached by phone or email and included in the study. Prospectively collected data of these patients who followed for a minimum of 10 years were retrospectively analysed. Patients who had previous trauma or surgery on the hip or were younger than 15 years were excluded. Of the 76 patients, 37 (48.7%) had mixed type, where 29 (38.2%) had cam and 10 (13.2%) had pincer type FAIS. Patient demographics, Tonnis grade for osteoarthritis and intraoperative findings were reviewed. Outcome measures of interest included reoperations (re-arthroscopy, conversion to THA), patient satisfaction, ability to return to sports, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), modified Harris Hip Score (mHHS) and some possible factors associated with conversion to THA.

The mean follow-up was 12.4 ± 1.8 (10-16 years). Twenty-one per cent required conversion to THA, with a mean time requiring THA of 4.8 ± 1.7 years (2-8 years). Mean age of the patients requiring THA was 47.8 ± 8.2 years. Two (2.6%) patients required re-arthroscopy. Fifty-eight (76.3%) patients did not undergo any revision surgery or other treatments. Forty-seven (61.8%) patients were completely satisfied with the results, where 5 (6.6%) patients were very satisfied and 4 (5.3%) patients were satisfied. Overall satisfaction rate was 73.7%. Mean postoperative mHHS score was 76.5 ± 15.5 and the mean WOMAC score was 84.0 ± 16.0. Return-to-sports rate was 85%, and the return to the old sport level was 67.1%. Age over 40 years (p = 0.004), a Tonnis Grade >1 (p < 0.001) and a full-thickness acetabular chondral lesion (p = 0.001) were identified as factors for failure and conversion to THA.

Hip arthroscopy for FAIS resulted in high satisfaction of patients who did not eventually require THA. Higher rates of conversion to THA were seen in older patients, patients treated with higher Tonnis grade and full-thickness acetabular chondral lesions.

Level IV, case series.

To explore the application of a new three-dimensional computed tomography measurement (maximum-inscribed-sphere method) in female DDH (developmental dysplasia of the hip) patients with gynecoid and anthropoid type pelvis on measuring the bony birth canal before and after unilateral PAO (periacetabular osteotomy).

A total of 19 female DDH patients of childbearing age were included in this study. The pelvis types were classified as gynecoid (11 patients) and anthropoid (8 patients). The maximum-inscribed-sphere method was applied to measure the bony birth canal. The lateral central edge angle (LCE), the anterior central edge angle (ACE), the Tönnis angle, and the distance between the femoral head and Koher's line were measured.

For the gynecoid type, the narrowest part of the bony birth canal before and after the surgery occurred both at the 21st layer of bilateral ischial spines and the 4th sacrum (107.39 mm ± 4.33 mm; 106.27 mm ± 4.76 mm). In anthropoid patients, the narrowest part of the bony birth canal was found at the 21st layer before surgery (105.89 mm ± 6.58 mm), and the 19th layer after surgery (103.48 mm ± 7.36 mm). The most significant narrowing was found at the 8th layer (4.25 mm ± 3.51 mm p < 0.05) in those with gynecoid type pelvis, and at the 9th layer (5.8 mm ± 3.15 mm p < 0.001) in those with anthropoid type pelvis after PAO. There was no statistical significant difference between acetabular dysplasia and bony birth canal in the two type groups before surgery. For the anthropoid type, the increment of LCE angle and the narrowing of bony birth canal from the 13th to 19th layer after PAO was also more significant. As the impact of unilateral PAO on the gynecoid type pelvis was caused by a decreased distance between the femoral head and Kohler's line, resulting in the narrowing of bony birth canal between the 1st and 12th layer.

Unilateral PAO did not affect the narrowest part of the bony birth canal in either pelvis type but caused mild narrowing above the ischial spine, with notable effects in the anthropoid group. In gynecoid pelvis patients, it led to narrowing through changes in the relation between the femoral head and Kohler's line.

Score cutoffs of clinically important outcome values such as the minimal clinically important improvement (MCII), substantial clinical benefit (SCB), and Patient Acceptable Symptom State (PASS) are population and treatment specific. In patients with nonarthritic hip-related pain, numerous score cutoffs have been calculated for use after surgical treatment, but they have not been established for patients who pursue nonoperative care.

To determine the MCII, SCB, and PASS score cutoffs for the 12-item International Hip Outcome Tool (iHOT-12), the Hip Disability and Osteoarthritis Outcome Score (HOOS), and an 8-item abbreviated version of the HOOS (HOOSglobal) among patients with nonarthritic hip-related pain who were managed nonoperatively.

Cohort study; Level of evidence, 4.

The cohort included 15- to 40-year-old patients who were diagnosed with nonarthritic hip-related pain by a surgical or nonsurgical orthopaedic clinician and were advised to pursue nonoperative management at the time of evaluation. At baseline and 12-month follow-up, patients completed the iHOT-12, HOOS, and HOOSglobal. Receiver operating characteristic curves were used to generate MCII, SCB, and PASS score cutoffs using an anchor-based approach as well as score changes between baseline and 12 months. The anchor question for the MCII and SCB utilized a 9-item global rating of change scale. The anchor question for the PASS was as follows ("yes"/"no" response): "Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?"

Among 61 patients (mean age, 28 ± 8 years; 50 [82%] female), for the iHOT-12, the MCII score cutoff was 14, the SCB score cutoff was 18, and the PASS score cutoff was 63. For the HOOS subscales, the MCII score cutoffs ranged from 4 (Activities of Daily Living) to 13 (Sport and Recreation), the SCB score cutoffs ranged from 10 (Symptoms and Activities of Daily Living) to 25 (Quality of Life), and the PASS score cutoffs ranged from 50 (Quality of Life) to 87 (Activities of Daily Living). For the HOOSglobal, the MCII score cutoff was 5, the SCB score cutoff was 12, and the PASS score cutoff was 65. The models mostly had good responsiveness (area under the curve = 0.73-0.94).

These clinically important outcome values can assist clinicians and researchers with interpreting patients' clinical change during nonoperative treatment for nonarthritic hip-related pain.

Adolescent hip dysplasia represents a unique challenge for pediatric orthopaedic surgeons. The disease spectrum is broad and the complications of untreated disease can be severe. The purpose of this review is to provide a framework for understanding and treating adolescent hip dysplasia and when to consider nonoperative versus operative interventions.

Combined hip arthroscopy and periacetabular osteotomy may be considered for patients with concomitant symptomatic labral tears, which is often diagnosed by history and advanced imaging. Hip dysplasia in adolescent patients is an important diagnosis. There are various clinical and radiographic parameters and the most important ones are lateral center edge angle, Tonnis grade, and joint congruency. Management is based on symptoms and radiographic findings. Nonoperative management is typically recommended for patients with symptomatic borderline dysplasia. Surgical management includes periacetabular osteotomy for patients with symptomatic hip dysplasia that have failed nonoperative treatment. Concomitant hip arthroscopy may be considered for patients with symptomatic labral tear, but is generally not recommended in isolation if there is evidence of dysplasia. Outcomes are generally good after operative management of hip dysplasia in adolescent patients.

A subchondral stress fracture of the femoral head (SSFFH) is managed with nonoperative treatment. There is a lack of knowledge regarding whether hip arthroscopic management is effective for active patients with SSFFHs.

To elucidate whether arthroscopic management of SSFFHs enables active patients to return to sports activity.

Cohort study; Level of evidence, 3.

A total of 22 patients undergoing hip arthroscopic management (labral repair/reconstruction and fragment fixation with hydroxyapatite and poly-L-lactic acid [HA/PLLA]-threaded pins) were enrolled and divided into 2 groups. The active group was defined as patients who participated in any kind of sports, regardless of the level of competition. The inactive group was defined as patients who did not participate in sports or any activity. Patient-reported outcome measure (PROM) scores, including the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS), were collected preoperatively and at 6 months, 12 months, and the final follow-up (mean, 70.0 ± 36.6 months [range, 24-144 months]) after surgery. The authors performed chi-square and Mann-Whitney U tests to compare the PROM scores between the 2 groups.

There were 10 patients in the active group and 12 patients in the inactive group in the final analysis. Overall, 14 SSFFHs underwent internal fixation with HA/PLLA-threaded pins. The PROM scores significantly improved from preoperatively to the final follow-up. The active group had significantly better PROM scores than the inactive group at 6 months (mHHS: 96.6 ± 5.0 vs 85.3 ± 13.6, respectively [P = .033]; NAHS: 74.3 ± 6.4 vs 57.0 ± 15.6, respectively [P = .008]) and 1 year (mHHS: 98.8 ± 1.8 vs 92.7 ± 8.6, respectively [P = .040]; NAHS: 78.0 ± 2.1 vs 65.9 ± 11.7, respectively [P = .007]). Additionally, 9 of 10 patients in the active group returned to their sports activity.

The study showed that arthroscopic management (femoroacetabular impingement correction, labral preservation, and stabilization with HA/PLLA-threaded pins) provided favorable clinical outcomes and a high rate of return to sports activity in active patients with SSFFHs. Active patients with SSFFHs had better postoperative results than inactive patients.

People with Marfan syndrome (MFS) have clinical symptoms of hip pain, but to date, there is limited knowledge about hip-related structural abnormalities in these patients. Therefore, the purpose of this cross-sectional study was to assess hip-related structural abnormalities and patient-reported outcomes (PRO) in a cohort of patients with MFS compared to healthy controls.

Nineteen individuals with MFS (17 females, 39.8±11.5 years) and 19 age, sex, and body mass index-matched healthy, asymptomatic individuals (17 females, 36.2±12.5 years) underwent radiographic imaging and unilateral hip MRI. The Scoring Osteoarthritis with MRI (SHOMRI) technique was used to assess hip-related morphological abnormalities between the MFS and control groups. All participants completed the Hip disability and Osteoarthritis Outcome Score (HOOS) to assess hip-related symptoms, pain, and function during activities of daily living (ADL) and quality of life (QOL).

The MFS group exhibited higher lateral center edge angles (p < .001). Despite similar severity of femoral cartilage damage (p = 1.0), the MFS group exhibited a higher severity (p = 0.046) of acetabular cartilage degeneration (1.21±1.08) compared to the controls (0.53±1.02). There were no between-group differences in severity of labral pathology, subchondral cysts, or edema. Individuals with MFS also self-reported significantly lower HOOS symptoms (p = 0.003), pain (p = 0.014), ADL (p = 0.028), and QOL (p = 0.014) sub-scores, indicating worse hip-related PRO in MFS.

Our study results suggest that individuals with MFS exhibit early signs of acetabular cartilage degeneration and poor hip-related clinical outcomes compared to healthy individuals. Future work should investigate the underlying biomechanical mechanisms associated with hip joint degeneration in the MFS population.

Developmental dysplasia of the hip reduces hip stability due to insufficient femoral head coverage. Periacetabular osteotomy surgery aims to increase this coverage. Typically measured using radiographs, most coverage assessments are limited to static hip positions and cannot capture 3D anatomy. This study quantified how dynamic 3D femoral coverage changes during gait and squat after periacetabular osteotomy surgery and compared dynamic coverage to static measures.

Pre- and post-surgery CT scans from 38 patients with hip dysplasia were used to reconstruct 3D femur and pelvis bones with which gait and squat were simulated. Models of 38 control subjects were also created. The femoral head was divided into anteromedial, anterolateral, posteromedial, and posterolateral regions. Regional coverage was compared pre- and post-surgery, and against controls, in a static neutral position, during the stance phase of gait, and throughout the squat cycle.

Lateral coverage increased post-surgery in the static neutral position (anterolateral: 4.9 ± 3.6 % to 13.8 ± 5.6 %; posterolateral: 22.9 ± 15.4 % to 39.8 ± 15.2 % (p ≤ 0.001)) and throughout gait and squat (p ≤ 0.001). Average changes in neutral anterolateral coverage (+8.9 ± 4.5 %) were similar to average changes during gait (+8.1 ± 3.0 %), but not squat (+12.0 ± 1.9 %). Static neutral coverage post-surgery differed significantly from dynamic coverage in every region of the femoral head during all of gait, and most of squat.

While static measures follow some patterns of dynamic coverage after surgery, they miss important variations that can impact joint loading. Understanding how periacetabular osteotomy changes dynamic femoral head coverage can aid with operative planning and assessment to optimize outcomes during daily activities.

The severity of hip dysplasia is characterized by radiographic measurements that require user definition of the acetabular sourcil edge, a bony landmark for which the corresponding three-dimensional (3D) anatomy is not well defined in any imaging plane.

To use digitally reconstructed radiographs to determine: (1) What 3D anatomy is contributing to the "acetabular sourcil" location used to make lateral center-edge angle (LCEA) and anterior center-edge angle (ACEA) measurements in standing AP and false-profile radiographic views, respectively? (2) How do intraobserver and interobserver agreement in LCEA and ACEA translate into agreement of the 3D anatomy being evaluated? (3) How distinct are regions around the acetabular rim circumference that are evaluated by LCEA and ACEA measurements on radiographs?

Between January 2018 and May 2019, 72 patients were indicated for periacetabular osteotomy to treat hip dysplasia or acetabular retroversion at our institution. From these patients, a series of 10 patients were identified of the first 12 patients in 2018 who were treated with periacetabular osteotomy, excluding two with missing or low-quality clinical imaging. A second series of 10 patients was identified of the first 11 patients in 2019 who were treated with periacetabular osteotomy and concurrent hip arthroscopy, excluding one who was missing clinical imaging. Pelvis and femoral bone surface models were generated from CT scans of these two series of 10 patients. There were 15 female and five male patients, with a median patient age of 18 years (IQR 17 to 23 years), a preoperative LCEA of 22° (IQR 18° to 24°), and a preoperative ACEA of 23° (IQR 18° to 27°). Exclusion criteria included missing preoperative CT or standard clinical radiographic imaging or severe joint incongruity. To address our first study question, digitally reconstructed radiographs matching each patient's standing AP and false-profile clinical radiographs were created from the segmented CT volumes. A board-certified orthopaedic surgeon and three trained researchers measured LCEA and ACEA on the digitally reconstructed radiographs, and the selected sourcil points were projected back into coordinates in the 3D anatomic space. To address our second study question, intraobserver and interobserver agreement in radiographic coverage angles were related to variations in 3D coordinates of the selected bony anatomy. Lastly, to address our third study question, 3D locations around the acetabular rim identified as contributing to the lateral and anterior sourcil points were summarized across patients in a clockface coordinate system, and statistical analysis of the "time" separating the 3D acetabular contributions of the sourcil edges was performed.

The 3D anatomy contributing to the lateral sourcil was a variable length (27 mm [IQR 15 to 34 mm]) span of the laterosuperior acetabular edges, with contributions by the anterior inferior iliac spine in 35% (7 of 20) of hips. The anterior sourcil reflected a 28-mm (IQR 25 to 31 mm) span of bone from the medial ilium (posterior-medial to the anterior-inferior iliac spine and anterior-lateral to the arcuate line) to the anterior and lateral edges of the acetabulum. Interobserver variability was good for LCEA (intraclass correlation coefficient [ICC] 0.82 to 0.83) and moderate to good for ACEA (ICC 0.73 to 0.79), whereas the agreement in identified 3D sourcil locations varied widely (ICC 0.32 to 0.95). The acetabular edge of the 3D anatomy contributing to the anterior sourcil overlapped the circumferential range of the acetabular rim contributing to the lateral sourcil.

Projection of two-dimensional radiographic landmarks contributing to the diagnosis of structural hip deformity into 3D allowed for the identification of the overlapping bony anatomy contributing to radiographically visible anterior and lateral sourcil edges.

This work leveraging digitally reconstructed radiographs and 3D pelvis anatomy has found that bone outside the joint contributes to the radiographic appearance of the sourcil and may variably confound estimates of joint coverage. Furthermore, the substantial overlap between the acetabular bone contributing to measurement of the LCEA and ACEA would indicate that these angles measure similar acetabular deformity, and that additional measures are needed to assess anterior coverage independent of lateral coverage.

Hip arthroscopy has become the preferred method for surgical management of numerous hip pathologies. Traditionally, arthroscopic access to the hip has mainly been performed by starting in the central compartment first, which commonly requires capsulotomy and subsequent closure to access the hip joint. This technique is both technically challenging and has been associated with iatrogenic damage to the hip cartilage, as well as the labrum, potentially compromising the integrity of the hip capsule. In this Technical Note, we present our approach to hip arthroscopy that accesses the hip through the peripheral compartment first, with minimal periportal capsulotomies, using a post-less traction bed. This technique can decrease the risk of iatrogenic damage, decrease surgical time, and improve visualization and accessibility for both novice and advanced hip arthroscopy surgeons.

Decreased acetabular version and posterior acetabular coverage of the femoral head have been regarded as the leading causes of sport-related posterior hip dislocation or subluxation. This study aimed to examine the posterior acetabular coverage of the femoral head in 21 patients who sustained posterior hip dislocation or subluxation during sport activities.

The anterior and posterior acetabular rims on 3-dimensional computed tomography (3D-CT) images were delineated on the normal side in these patients. Radiologic signs, including crossover and posterior wall signs, were examined. The fracture center level (FCL) of the posterior acetabular wall was identified on axial CT images of the injured hip and the level was marked on the normal side. The difference in the femoral head coverage by posterior and anterior acetabular rims was measured by measuring the horizontal distance between anterior and posterior acetabular rims at the FCL (posterior-anterior [P-A] index). The acetabular version was measured at the femoral head and FCL using axial CT images of the normal side. Femoral head coverage by the posterior acetabular wall on the normal side was measured using 3D-CT (areal coverage).

The crossover and posterior wall signs were positive in 14 and 10 patients, respectively, in 3D-CT images. The FCL was evenly distributed in the proximal half of the posterior acetabular wall. Seven patients had a P-A index of ≤ 0, and all were positive for the crossover sign. The anterior acetabular rim was relatively prominent in these patients. The acetabular version was lower at the FCL than at the femoral head center (p < 0.001). The proximal half areal coverage of the posterior acetabular wall was significantly smaller than the whole areal coverage (p = 0.003).

Superior-posterior coverage of the femoral head by the posterior acetabular wall was insufficient in patients who sustained hip posterior dislocation or subluxation during sports activities.

Sex has been associated with different pathologic characteristics in painful hips undergoing hip arthroscopic surgery.

To compare minimum 10-year patient-reported outcomes (PROs) and survivorship in patients who underwent primary hip arthroscopic surgery for femoroacetabular impingement syndrome and labral tears according to sex.

Cohort study; Level of evidence, 3.

Data from patients who underwent primary hip arthroscopic surgery between March 2009 and May 2011 were reviewed. Patients with minimum 10-year PROs for the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sports-Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain were eligible. Exclusion criteria included previous ipsilateral hip conditions or surgical procedures, Tönnis grade >1, or dysplasia (lateral center-edge angle <25°). In the subanalysis, female patients were matched to male patients using a 1:1 ratio by age, sex, and body mass index.

A total of 375 hips had a minimum 10-year follow-up. There were 249 female (mean age, 36.8 ± 13.1 years) and 126 male (mean age, 38.9 ± 13.1 years) hips. Survivorship was defined as no conversion to total hip arthroplasty. Female and male hips exhibited similarly high rates of survivorship (80.3% vs 72.2%, respectively; P = .076). Female hips underwent secondary arthroscopic surgery at a statistically higher rate of 14.5% (P = .021) and had higher rates of capsular repair and iliopsoas fractional lengthening (P < .0001 and P < .001, respectively). Male hips had a significantly higher rate of acetabular labrum articular disruption/Outerbridge grade 3 and 4 damage at 54.0% compared with female hips (both P < .001) and underwent femoroplasty and acetabular microfracture at significantly higher rates of 88.1% versus 51.0%, respectively, and 16.7% versus 4.8%, respectively (both P < .001). In the subanalysis, both groups showed significant improvements in all PROs from baseline (all P < .001). Even though female patients demonstrated a higher rate of secondary arthroscopic surgery, they had a higher self-reported mean satisfaction score of 9.0 compared with 8.4 (P = .003) and a greater magnitude of improvement in 10-year PROs (ΔmHHS: 29.3 ± 17.5 vs 23.1 ± 19.8, respectively [P = .036]; ΔNAHS: 33.2 ± 21.3 vs 25.1 ± 19.5, respectively [P = .012]; ΔHOS-SSS: 47.0 ± 32.0 vs 32.7 ± 31.9, respectively [P = .008]; and ΔVAS: -4.6 ± 2.7 vs -3.5 ± 2.0, respectively [P = .009]). However, all PROs at a minimum 10-year follow-up were similar between the groups.

After undergoing hip arthroscopic surgery for femoroacetabular impingement syndrome, both female and male patients reported significant improvements in all PROs at a minimum 10-year follow-up and high patient satisfaction, with similar final functional scores. Even though female patients demonstrated a higher rate of secondary arthroscopic surgery, they had a higher satisfaction score and a greater magnitude of improvement in PROs postoperatively.

Accurate assessment of hip morphology is crucial for the diagnosis and management of hip pathologies. Traditional manual measurements are prone to mistakes and inter- and intra-reader variability. Artificial intelligence (AI) could mitigate such issues by providing accurate and reproducible measurements. The aim of this study was to compare the performance of BoneMetrics (Gleamer, Paris, France) in measuring pelvic and hip parameters on anteroposterior (AP) and false profile radiographs to expert manual measurements.

This retrospective study included AP and false profile pelvic radiographs collected from private practices in France. Pelvic and hip measurements included the femoral neck shaft angle, lateral center edge angle, acetabular roof angle, pelvic obliquity, and vertical center anterior angle. AI measurements were compared to a ground truth established by two expert radiologists. Performance metrics included mean absolute error (MAE), Bland-Altman analysis, and intraclass correlation coefficients (ICC).

AI measurements were performed on AP views from 88 patients and on false profile views from 60 patients. They demonstrated high accuracy, with MAE values inferior to 0.5 mm for pelvic obliquity and inferior to 4.2° for all pelvic angles on both views. ICC values indicated good to excellent agreement between AI measurements and the ground truth (0.78-0.99). Notably, no significant differences were found in AI measurement accuracy between patients with normal and abnormal acetabular coverage.

The application of AI in measuring pelvic and hip parameters on AP and false profile radiographs demonstrates promising outcomes. The results reveal that these AI-powered measurements provide accurate estimations and show strong agreement with expert manual measurements. Ultimately, the use of AI has the potential to enhance the reproducibility of measurements as part of comprehensive hip assessments, thereby improving diagnostic accuracy.

To evaluate rates of achieving meaningful outcomes and clinical failure at 2 years after undergoing microfracture augmented with allograft cartilage with autologous platelet-rich plasma and to identify predictors of conversion to total hip arthroplasty (THA).

Data from a prospective series of consecutive patients with Outerbridge grade 4 chondromalacia of the acetabulum or femoral head who underwent hip microfracture augmented with allograft cartilage between January 2017 and June 2022 were analyzed. Patient-reported outcomes were collected preoperatively and at a minimum of 2 years postoperatively. The Hip Outcome Score-Activities of Daily Living Subscale, Hip Outcome Score-Sports-Specific Subscale, modified Harris Hip Score, and Non-arthritic Hip Score thresholds for achieving the minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit at 2 years after surgery were calculated. Logistic regression analysis was performed to identify any association between nonmodifiable variables and clinical failure.

A total of 108 hips (80.6% follow-up) among 106 patients had 2-year follow-up and were included in the final analysis. The mean age and body mass index (BMI) were 37.9 ± 10.1 years and 26.8 ± 4.7, respectively, with a mean follow-up time of 31.9 ± 8.4 months (range, 24-53 months). There was a statistically significant improvement in all functional score averages over the 2-year period (P < .05). A total of 84.7%, 75.5%, and 70.4% of patients reached at least 1 threshold for achieving the minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit, respectively. There were 11 patients (10.2%) who underwent conversion to THA, with increased age, BMI, and preoperative pain duration increasing the likelihood of requiring THA (P < .05 for all). Finally, chondromalacia size or chondromalacia index (e.g., Outerbridge grade × surface area) was not associated with clinical failure or achievement of meaningful outcomes (P > .05 for all).

Patients undergoing microfracture with allograft cartilage and autologous platelet-rich plasma augmentation for acetabular or femoral head chondromalacia showed a statistically significant improvement in outcome scores and high rates of achieving meaningful outcomes at 2-year follow-up regardless of chondromalacia defect size. The rate of conversion to THA was 10.2%, with increased age, BMI, and preoperative pain duration increasing the likelihood of requiring THA.

Level IV, therapeutic study.

The relationship between sagittal lumbopelvic alignment and the bony pathomorphology of hip dysplasia is currently at the forefront of clinical and scientific interest. The aim of this study was to determine whether there is a compensatory lumbopelvic aspect associated with the two major acetabular phenotypes in dysplastic hips.

From September 2022 to March 2024, a total of 145 patients with symptomatic bilateral hip dysplasia were included in the study. Hips were categorized into either anterolateral or posterolateral morphologies based on anteroposterior pelvic x-rays. Additionally, the lumbopelvic sagittal alignment was determined radiographically. Furthermore, a multivariable linear regression analysis was conducted to assess the association of lumbopelvic sagittal alignment with additional independent factors.

Pelvic tilt (PT) significantly differed between the anterolateral and posterolateral phenotypes of hip dysplasia (16.84° ± 8.75° vs. 11.51° ± 6.63°, respectively; p < 0.001). Similar significant findings were observed for pelvic incidence (57.19° ± 12.96° vs. 50.75° ± 13.1°, respectively; p < 0.001). A PT of >14.5° was identified as the most likely factor associated with anterolateral dysplasia.

The results of this study reveal a paradox in the hip-spine association in hip dysplasia. Contrary to previous theories, it seems that PT constitutes a component of the corresponding phenotype of dysplastic pathology, rather than functioning as a compensatory tilt.

Level III.

While often used, Hilgenreiner's line may not always be a reliable reference plane following triple innominate pelvic osteotomy or trauma to the triradiate cartilage. The inferior sacral-iliac line is a horizontal line connecting the sclerotic corners of the inferior sacral-iliac joints. This is a consistent landmark in the ossifying infant pelvis as well as the fully developed adult pelvis. The goal of this study was to determine if there is a difference in measurements between the inferior sacral-iliac line and Hilgenreiner's line in order to identify an alternative horizontal reference plane.

3 reviewers (fellowship-trained paediatric orthopaedic surgeon, junior orthopaedic resident, senior orthopaedic resident) reviewed 100 paediatric non-osteotomized pelvises. The difference between Hilgenreiner's line and the inferior sacral-iliac line were measured and reported. Measurements were repeated a minimum of 48 hours apart, resulting in 600 comparisons between Hilgenreiner's line and the inferior sacral-iliac line. The standard error of measurement was calculated to assess the variation in measurements between each individual observer and the group as a whole.

The mean standard error of measurement between Hilgenreiner's line and the inferior sacral-iliac line was 0.44° (95% CI, ± 0.86). Reviewers 1-3 demonstrated a mean standard error of measurement of 0.38, 0.28, and 0.35 (95% CI, ± 0.74, 0.55, and 0.86) respectively. There was no statistically significant difference between reviewers (p > 0.05). Intra-observer reliability for reviewers 1, 2, and 3 was 0.64 (0.47-0.76), 0.75 (0.63-0.83), and 0.54 (0.32-0.69) respectively, with an inter-observer reliability of 0.42 (0.20-0.60) degrees.

In this proof-of-concept study, the inferior sacral-iliac line was found to be an appropriate alternative to Hilgenreiner's line that is easily identifiable for all levels of orthopaedic training. Future inferior sacral-iliac line studies should demonstrate the reliability of multiple acetabular measurements, both pre- and post-osteotomy.

To compare pre- and postoperative findings between patients undergoing hip arthroscopy for femoroacetabular impingement syndrome with lateral impingement versus those without lateral impingement METHODS: Patients who underwent primary hip arthroscopy for femoroacetabular impingement syndrome between 2012 and 2017 with minimum 5-year follow-up were included. Alpha angle (AA) was measured on preoperative anteroposterior (AP) and 90° Dunn radiographs. Patients with AA >60° on Dunn view but not AP view (no lateral impingement) were propensity matched by sex, age, and body mass index in a 1:3 ratio to patients with AA >60° on both views (lateral impingement). Demographic characteristics, radiographic and intraoperative findings, reoperation rates, and patient-reported outcomes (PROs) were compared between groups. Categorical variables were compared using the Fisher exact testing and continuous variable using 2-tailed Student t tests.

Sixty patients with lateral impingement (65.0% female, age: 35.3 ± 13.0 years) were matched to 180 patients without lateral impingement (65.0% female, age: 34.7 ± 12.5 years, P ≥ .279). Patients with lateral impingement had larger preoperative AAs on both Dunn (71.0° ± 8.8° vs 67.6° ± 6.1°, P = .001) and AP radiographs (79.0° ± 12.1° vs 48.2° ± 6.5°, P < .001). However, there were no differences in postoperative AAs on either view (Dunn: 39.0° ± 6.1° vs 40.5° ± 5.3°, AP: 45.8° ± 9.0° vs 44.9° ± 7.0°, P ≥ .074). Labral tears began more superiorly in patients with lateral impingement (12:00 ± 0:49 vs 12:17 ± 0:41, P = .030), and they demonstrated greater rates of acetabular and femoral cartilage damage (P = .030 for both); however, there were no differences in PROs or reoperation rates between the groups at 5-year follow-up.

Although cam deformities located laterally and anterolaterally are larger than those located anterolaterally alone, both can be resected adequately, resulting in similar postoperative radiographic measurements, PROs, and survivorship.

Level III, retrospective cohort study.

Salter osteotomy (SO) and Pemberton acetabuloplasty (PA) are procedures to treat skeletally immature patients with developmental dysplasia of the hip (DDH). The purpose of this study was to compare the radiographic results and rate of residual dysplasia (RD) after treatment with SO and with PA.

This was a retrospective analysis of pediatric patients treated with either SO or PA for DDH between 1980 and 2013 who were skeletally mature at the time of follow-up. The preoperative and postoperative acetabular index (AI) and postoperative lateral center-edge angle (LCEA) and anterior center-edge angle (ACEA) were collected. RD was defined as an LCEA or ACEA of <20° or an acetabular inclination (AIn) of >15° at skeletal maturity. Continuous variables were compared between treatment groups with 2-sample t tests, and categorical variables were compared using chi-square tests. Multivariable analysis was used to identify risk factors for RD with p < 0.05.

The study included 113 hips in 102 patients with a mean follow-up of 10.5 years. The SO group had 73 hips treated at a mean patient age of 5.4 years, and the PA group had 40 hips treated at a mean age of 5.3 years. The preoperative AI did not differ between the treatment groups (32.2° versus 31.3°, p = 0.658), nor did the immediate postoperative AI (20.0° versus 20.2°, p = 0.459). At the time of final follow-up, the SO group had a significantly smaller AIn (8.6° versus 13.2°, p = 0.001), a trend toward a greater LCEA (26.2° versus 21.6°, p = 0.056), and a similar ACEA (24.1° versus 26.1°, p = 0.808). By the abovementioned definition, 36 hips (31.9%) had evidence of RD, with a lower rate in the SO group (26.0% versus 42.5%, p = 0.07). Patients who had a positive family history of hip dysplasia were more likely to have RD (odds ratio = 4.311, 95% confidence interval = 1.125 to 16.528).

Patients with RD could be effectively treated with either SO or PA, with overall good radiographic outcomes. However, SO achieved a better AI and may thus yield better long-term health of the affected hip.

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Hip dysplasia (HD) is characterized by insufficient acetabular coverage of the femoral head, leading to a predisposition for osteoarthritis. While radiographic measurements such as the lateral center edge angle (LCEA) and Tönnis angle are essential in evaluating HD severity, patient-reported outcome measures (PROMs) offer insights into the subjective health impact on patients.

To investigate the correlations between machine-learning automated and manual radiographic measurements of HD and PROMs with the hypothesis that artificial intelligence (AI)-generated HD measurements indicating less severe dysplasia correlate with better PROMs.

Retrospective study evaluating 256 hips from 130 HD patients from a hip preservation clinic database. Manual and AI-derived radiographic measurements were collected and PROMs such as the Harris hip score (HHS), international hip outcome tool (iHOT-12), short form (SF) 12 (SF-12), and Visual Analogue Scale of the European Quality of Life Group survey were correlated using Spearman's rank-order correlation.

The median patient age was 28.6 years (range 15.7-62.3 years) with 82.3% of patients being women and 17.7% being men. The median interpretation time for manual readers and AI ranged between 4-12 minutes per patient and 31 seconds, respectively. Manual measurements exhibited weak correlations with HHS, including LCEA (r = 0.18) and Tönnis angle (r = -0.24). AI-derived metrics showed similar weak correlations, with the most significant being Caput-Collum-Diaphyseal (CCD) with iHOT-12 at r = -0.25 (P = 0.042) and CCD with SF-12 at r = 0.25 (P = 0.048). Other measured correlations were not significant (P > 0.05).

This study suggests AI can aid in HD assessment, but weak PROM correlations highlight their continued importance in predicting subjective health and outcomes, complementing AI-derived measurements in HD management.

This study aimed to determine the acetabular position to optimize hip biomechanics after transposition osteotomy of the acetabulum (TOA), a specific form of periacetabular osteotomy, in patients with hip dysplasia.

We created patient-specific finite-element models of 46 patients with hip dysplasia to simulate 12 virtual TOA scenarios: lateral rotation to achieve a lateral center-edge angle (LCEA) of 30°, 35°, and 40° combined with anterior rotation of 0°, 5°, 10°, and 15°. Joint contact pressure (CP) on the acetabular cartilage during a single-leg stance and simulated hip range of motion without osseous impingement were calculated. The optimal acetabular position was defined as satisfying both normal joint CP and the required range of motion for activities of daily living. Multivariable logistic regression analysis was used to identify preoperative morphological predictors of osseous impingement after virtual TOA with adequate acetabular correction.

The prevalence of hips in the optimal position was highest (65.2%) at an LCEA of 30°, regardless of the amount of anterior rotation. While the acetabular position minimizing peak CP varied among patients, approximately 80% exhibited normalized peak CP at an LCEA of 30° and 35° with 15° of anterior rotation, which were the 2 most favorable configurations among the 12 simulated scenarios. In this context, the preoperative head-neck offset ratio (HNOR) at the 1:30 clock position (p = 0.018) was an independent predictor of postoperative osseous impingement within the required range of motion. Specifically, an HNOR of <0.14 at the 1:30 clock position predicted limitation of required range of motion after virtual TOA (sensitivity, 57%; specificity, 81%; and area under the receiver operating characteristic curve, 0.70).

Acetabular reorientation to an LCEA of between 30° and 35° with an additional 15° of anterior rotation may serve as a biomechanics-based target zone for surgeons performing TOA in most patients with hip dysplasia. However, patients with a reduced HNOR at the 1:30 clock position may experience limited range of motion in activities of daily living postoperatively.

This study provides a biomechanics-based target for refining acetabular reorientation strategies during TOA while considering morphological factors that may limit the required range of motion.

Developmental dysplasia of the hip (DDH) can cause pain and premature osteoarthritis. The risk factors and timing for disease progression in adolescents and young adults have not been fully defined. This study aimed to determine the prevalence of and risk factors for contralateral hip pain and surgery after periacetabular osteotomy (PAO) on a dysplastic hip.

Patients undergoing unilateral PAO for DDH were followed for at least 2 years and categorized into contralateral pain and no-pain groups and contralateral surgery and no-surgery groups. Pain was defined with the modified Harris hip score. Univariate analysis tested group differences in demographics, radiographic measures, and range of motion. Kaplan-Meier survival analysis was used to assess pain development and surgery in the contralateral hip over time. Multivariable regression identified risk factors for contralateral pain and surgery. Contralateral pain and surgery predictors were secondarily assessed after categorization of the contralateral hips as dysplastic, borderline, and non-dysplastic and in subgroups based on the lateral center-edge angle (LCEA) and acetabular inclination (AI) in 5° increments.

One hundred and eighty-four patients were followed for a mean of 4.6 ± 1.6 years (range, 2.0 to 8.8 years), during which 51% (93) reported contralateral hip pain and 33% (60) underwent contralateral surgery. Kaplan-Meier analysis predicted 5-year survivorship of 49% with contralateral pain development as the end point and 66% with contralateral surgery as the end point. Painful hips exhibited more severe dysplasia compared with no-pain hips (LCEA = 16.5° versus 20.3°, p < 0.001; AI = 13.2° versus 10.0°, p < 0.001). AI was the sole predictor of pain, with every 1° increase in the AI raising the risk by 11%. Surgically treated hips also had more severe dysplasia (LCEA = 14.9° versus 20.0°, p < 0.001; AI = 14.7° versus 10.2°, p < 0.001) and were in younger patients (21.6 versus 24.1 years, p = 0.022). AI and a maximum alpha angle of ≥55° were predictors of contralateral surgery.

At 5 years after hip PAO, approximately 50% of contralateral hips will have pain and approximately 35% can be expected to need surgery. More severe dysplasia, based on the LCEA and AI, increases the risk of contralateral hip pain and surgery, with AI being a predictor of both outcomes. Knowing these risks can inform patient counseling and treatment planning.

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The purpose of this systematic review was to compare patient populations and outcomes in studies treating borderline hip dysplasia (BHD) with either hip arthroscopy or periacetabular osteotomy (PAO). We hypothesized that studies would show significant postoperative improvement following both PAO and arthroscopy for BHD, and that subjects undergoing arthroscopy would have a higher rate of Cam morphology.

A literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted to identify studies published after 2014 that reported patient-reported outcome measures (PROMs) following hip arthroscopy or PAO for BHD. Preoperative demographics, radiographic variables, operative findings, procedures, postoperative outcomes, and complications were recorded. Forest plots were constructed of disaggregated data to identify study heterogeneity using the I2 statistic.

26 studies (8 PAO; 18 Arthroscopy) were included. Acetabular morphology was comparable between the PAO and arthroscopy studies while the arthroscopy studies reported higher alpha angles (range 48.3-75.3°) compared to the PAO studies (range 47.6-55°). No PAO studies reported an average alpha angle greater than 60° while this was reported in 71% of arthroscopy studies. The most common PROMs were the modified Harris Hip Score (mHHS), with average improvement ranging from 20-29 for PAO and 17.9-34.4 for arthroscopy, and the International Hip Outcome Tool-12 (iHOT-12), with mean postoperative scores ranging from 73.3-74.3 for PAO and 67.5-85.4 for arthroscopy. Postoperative PROM improvement was significant for all studies with significant heterogeneity for the mHHS (I2=0.90) and iHOT-12 (I2=0.98).

There was significant postoperative improvement following both PAO and modern hip arthroscopy for the surgical management of BHD with high levels of heterogeneity limiting comparability between study groups. Hip arthroscopy studies recorded higher alpha angles suggesting that cam deformities in the setting of BHD can be managed arthroscopically, however further study on optimizing indications between procedures is required.

As the field of hip preservation evolves, the diagnosis of borderline dysplasia (defined as a lateral center edge angle between 18°-25°) has shown itself to be one of the more challenging diagnoses to treat. As the nuances of acetabular coverage have come to light, the question of whether borderline hip dysplasia is best treated with isolated hip arthroscopy, periacetabular osteotomy, or whether a combined procedure is best, is now top of mind. The goal of these procedures is to not only improve patient symptoms, but to correct underlying pathology and ideally slow the development of hip osteoarthritis. The purpose of this review is to summarize the recent literature and clinical findings regarding both isolated hip arthroscopy and periacetabular osteotomy in the surgical management of borderline hip dysplasia.

Current research demonstrates improved postoperative clinical outcome scores for both patients who had isolated hip arthroscopy in the setting of borderline hip dysplasia and for those patients who underwent periacetabular osteotomy. Mid-term outcomes for patients in both groups have showed low rates of conversion to total hip arthroplasty. No gold standard in the surgical management of borderline hip arthroscopy exists. Improved clinical outcomes have been seen postoperatively in patients who undergo hip arthroscopy and in patients who undergo periacetabular osteotomy. Successful clinical outcomes seem to rely on treatment of the underlying clinical pathology and are largely based on the appropriate surgical indications and appropriate surgical techniques. Surgical decision making in this patient population should be individualized based on a comprehensive evaluation of the patient.

Etiology of hip osteoarthritis (OA) and survival of hip arthroplasty in the young (below 40-years-old) remains poorly described. Furthermore, joint survivorship mid to long-term and PROMs according to the etiology are unclear. The study aims were to 1) identify the indications for arthroplasty in the below 40-years-old cohort; 2) define hip arthroplasty outcomes in the young and 3) test whether patients with sequelae of pediatrics hip disease have inferior outcome compared to other patients.

Our hypothesis was that hip arthroplasty is a viable option for managing hip disease in patients under 40, with excellent survival rates and outcomes.

This is an IRB approved, retrospective, consecutive, multi-surgeon, cohort study from a single academic center. Indication for hip arthroplasty of 346 patients (410 hips) below 40-years-old were studied; 239 underwent THA (58%) and 171 hip resurfacing (42%). Patient, surgical and implant factors were tested for association with implant survivorship and functional outcome for hip arthroplasty performed with a follow-up of more than two years. Pediatric hip sequelae patients were compared for survival and PROMs with the rest of the cohort.

The most common etiology of OA was FAI (47%), followed by pediatric hip sequelae (18%). The 10-year survivorship was 97.2% ± 1.2, mean OHS was 45.1 ± 6.3 and mean HHS was 93.4 ± 12.6. The pediatric hip sequelae subgroup demonstrated no differences in 10-year survivorship and better PROMs compared to rest (OHS: 46.6 ± 3.8; HHS: 96.0 ± 8.5).

The most common aetiologies amongst the young with hip OA is FAI and pediatric hip sequelae. Hip arthroplasty in the young presents excellent 10-year survivorship and PROMs. Excellent survival and PROMs in the young with pediatric hip sequelae provide important information for decision-making in this challenging population.

III; retrospective cohort study.

To report minimum 2-year follow-up patient-reported outcomes (PROs), clinical benefit, and survivorship in patients who underwent concomitant hip arthroscopy and periacetabular osteotomy (PAO) for the surgical treatment of the developmental dysplasia of the hip (DDH).

Prospectively collected data were retrospectively reviewed for patients who underwent hip arthroscopy with concomitant PAO between December 2015 and September 2022. Patients with baseline and minimum 2-year PROs were included. Exclusion criteria included those who underwent an isolated PAO or had a history of ipsilateral prior surgery. The PROs collected were Hip Outcome Score-Activities of Daily Living (HOS-ADL) and Hip Outcome Score-Sport-Specific Subscale (HOS-SSS). The minimal clinically important difference (MCID) was reported. Survivorship was defined as nonconversion to total hip arthroplasty (THA).

Thirty patients were included (29 females and 1 male). The average age at the time of surgery was 27.48 ± 8.57 years, and the average body mass index was 23.97 ± 4.05. Further, 86.67%, 73.33%, and 100% underwent labral treatment, femoroplasty, and capsular closure, respectively. The preoperative lateral center-edge angle increased from 17.07° ± 4.40 to 33.24° ± 3.40 postoperatively (P < .001). At a minimum of 2-year follow-up, all PROs significantly improved from baseline (P < .001): HOS-ADL improved from 62.68 ± 16.18 to 91.66 ± 15.13, HOS-SSS from 38.96 ± 21.39 to 86.82 ± 19.56. Moreover, 90% and 93.33% achieved MCID for the HOS-ADL and HOS-SSS, respectively. No conversions to THA were reported.

At a minimum 2-year follow-up, the surgical management of DDH with PAO and concomitant hip arthroscopy demonstrated significant improvement in all PROs collected, with a high achievement rate for the MCID, and survivorship of 100%. These results suggest that, at short-term follow-up, this surgical approach seems to be safe and effective.

Level IV, retrospective case-series.

The understanding and treatment of prearthritic hip disease has evolved remarkably over the past 20 years. The principal investigator and the multicenter Academic Network of Conservational Hip Outcomes Research (ANCHOR) group have had a key role in improving the quality of care for these patients suffering from the three most common prearthritic conditions: femoroacetabular impingement, developmental dysplasia of the hip, and residual Legg-Calve-Perthes Disease. We aim to demonstrate that based on the six quality of care dimensions as defined by Donabedian, our 20-year academic journey has markedly improved the quality of care for young patients with prearthritic hip disease.

Patients with increased pelvic tilt (PT) are at risk for instability following total hip arthroplasty (THA). Identification of increased PT using anteroposterior (AP) pelvic radiographs could avoid additional spinopelvic radiographs. This study aimed to (1) describe which AP pelvic parameters most accurately estimate sagittal PT, and (2) determine thresholds for these parameters that can identify patients with increased PT.

This was a retrospective, consecutive, cohort study in a tertiary referral hospital on 225 patients (age: 66 ± 12 years-old; 52% female) listed for THA. Patients underwent pre-operative standing AP pelvic radiographs to measure distance- and angular- based parameters from several anatomical landmarks. Sagittal PT was measured on a standing lateral spinopelvic radiograph and considered high when ≥ 20°.

No AP pelvic parameters correlated strongly with sagittal PT. Ratio between horizontal and vertical diameter of the pelvic foramen (C/D ratio) (rho - 0.341; p < 0.001); and vertical distance between trans-SIJ and trans-ASIS line (SITA) (rho 0.307; p < 0.001) correlated moderately with sagittal PT. Sacro-femoral-pubic (SFP) angle < 60° had highest sensitivity (85%), but lowest specificity (52%) to differentiate between patients with and without increased PT. If SITA > 62 mm, C/D ratio < 0.5 and SFP < 60°, specificity increased (88%), but sensitivity was low (49%).

In the absence of computerized models, AP pelvic parameters cannot accurately predict sagittal PT. However, an SFP < 60° should alert a hip surgeon that a patient may have an increased PT, and would benefit from additional lateral spinopelvic imaging prior to THA.

Level II, diagnostic study.

Acetabular dysplasia has been theorized as a risk factor instability amongst common acetabular fractures, such as posterior wall (PW) fractures. However, common radiographic measurements often cannot be acquired in trauma patients. We evaluated axial computed tomography (CT) scans to identify novel, easily-obtained measurements that correlate with acetabular dysplasia for use in surgical indications and planning.

Patients with known acetabular dysplasia undergoing elective periacetabular osteotomy were selected. A different group of patients without pelvic ring or acetabular fractures from an institutional trauma registry were selected as a comparison group. Standard indices of dysplasia were collected, such as center-edge angle (CEA). Acetabular geometric measurements were taken at three axial levels: 0 - cranial CT slice at the dome; 1 - cranial CT where the dome is an incomplete circle; 2 - cranial CT with femoral head visible. Distances between levels were also calculated: Levels 0-1 (Dome Height; DH), Levels 1-2 (Head Height; HH), and Dome-Head Difference (DH - HH = DHD).

DH, HH, and DHD were all significantly correlated with CEA, Tonnis angle, and Sharp's angle in dysplastic hips. All dysplastic hips had DH ≤ 2.5 mm and HH ≥ 1.25 mm. DHD ≤ 0 mm was most specific (93.6 % sensitive, 77.3 % specific) for predicting dysplasia.

DH ≤ 2.5 mm, HH ≥ 1.25 mm, and DHD ≤ 0 mm were independently associated with dysplasia on axial CT scans. These measurements may be quickly and easily used by trauma surgeons to assess a trauma-based axial CT scan for acetabular dysplasia.

To investigate the return to sport (RTS) rate and the sex-based difference of collegiate athletes after arthroscopic treatment for femoroacetabular impingement (FAI).

Patients who were collegiate athletes at the time of surgery and underwent hip arthroscopy for treatment of FAI between January 2009 and June 2020 were included. Patients were excluded if they were in their final year of eligibility, graduated, retired, or had plans to retire from collegiate play before surgery. Publicly available data were collected regarding each patient's collegiate team and division and RTS status after surgery. Comparisons were made based on the RTS status and gender.

Of the 181 hips (144 athletes) who met the inclusion criteria, 114 were male (63%) and 67 were female (37%), with a median age of 20.4 (range: 18.0-24.5). Eighty-six percent (155 hips) returned to sport at the collegiate level after hip arthroscopy. Males were significantly less likely to return to sport compared with females (82% vs 93%, odds ratio = 2.8, 95% confidence interval: 1.003-7.819, P = .042). Males participated in more contact sports (26% vs 1.5%, P < .001) and had more mixed-type FAI (95.6% vs 80.6%, P = .003) compared with females. In addition, males had more grade 3/4 chondral defects (28% vs 13%, P = .023) and underwent microfracture more frequently (11% vs 3%, P = .047). Further, males had significantly larger postoperative alpha angles (46.2 vs 43.6, P < .001).

Collegiate athletes were found to have a high RTS rate of 86% after arthroscopy for the treatment of FAI; however, males were less likely to RTS compared with females. Sex-based differences were identified in the type of sports, type of FAI, prevalence of severe cartilage damage, and postoperative alpha angle.

Level IV, retrospective case series.

To investigate the clinical outcomes after arthroscopic chondral nail fixation for acetabular cartilage delamination (ACD) in patients with femoroacetabular impingement syndrome (FAIS), as well as the presentation of ACD on magnetic resonance imaging (MRI), at follow-up.

A retrospective review was performed between March 2021 and March 2022 at our institute. Patients undergoing primary hip arthroscopy for FAIS in whom ACD was diagnosed intraoperatively were included. The exclusion criteria were incomplete data or loss to minimum 2-year follow-up and concomitant hip conditions including hip osteoarthritis with a Tönnis grade greater than 1, avascular necrosis, Legg-Calvé-Perthes disease, osteoid osteoma, synovial chondromatosis, pigmented villonodular synovitis, and developmental dysplasia of the hip. Patients who underwent chondral nail fixation were matched 1:1 to a control cohort of patients who only underwent simple debridement. Preoperative and minimum 2-year postoperative patient-reported outcome scores, including the visual analog scale (VAS) pain score and modified Harris Hip Score (mHHS), as well as percentage achieving the minimal clinically important difference and patient acceptable symptom state (PASS), were collected and compared. MRI was performed preoperatively and at final follow-up to assess ACD.

Fifty-eight patients were included in the study (29 patients in each group). Both groups showed improved VAS pain scores and mHHS values after surgery (all P < .05). The chondral nail group showed better postoperative VAS pain scores (P = .022) than the control group, whereas the postoperative mHHS values were comparable between the 2 groups (P = .852). No significant differences in achievement of the minimal clinically important difference were found between the 2 groups (all P > .05). More patients in the chondral nail group achieved the PASS for the VAS pain score compared with the control group (75.9% vs 48.3%, P = .030). No patient underwent revision surgery or conversion to total hip arthroplasty. The chondral nail group showed a significantly higher rate of ACD healing on MRI compared with the control group (P < .001).

Patients undergoing arthroscopic chondral nail fixation for the treatment of ACD showed significant pain relief, greater achievement of the PASS for the VAS pain score, and a higher rate of ACD healing on MRI compared with those undergoing simple debridement.

Level III, retrospective cohort study.

Joint hypermobility may be associated with developmental dysplasia of the hip (DDH), but no definite conclusion has been reached. On the basis of long-term clinical observations, we hypothesized that joint hypermobility was associated with the occurrence, imaging findings, and clinical symptoms of DDH.

We conducted a case-control study that included 175 Chinese Han patients between 13 and 45 years of age with Hartofilakidis type-A hip dysplasia. All of these patients underwent periacetabular osteotomy (PAO) between November 2021 and February 2023. An additional 76 individuals of comparable age and sex but without hip dysplasia were selected from the general population to serve as healthy controls. The Beighton 9-point scoring system was used to evaluate joint hypermobility, and a score of ≥4 was defined as generalized joint hypermobility. Standing anteroposterior pelvic radiographs were reviewed. For patients with DDH, the lateral center-edge angle, Tönnis angle, Sharp angle, lateralization of the femoral head, and patient-reported outcomes (iHOT-12, HHS, and WOMAC) were also collected to determine the radiographic severity or clinical symptoms of DDH.

Patients with DDH had an elevated prevalence of generalized joint hypermobility compared with that in the healthy population (27% versus 12%; p = 0.009). Among patients with DDH, those with concomitant generalized joint hypermobility had lower lateral center-edge angles (3.55° versus 9.36°; p = 0.012), greater lateralization of the femoral head (13.78 versus 12.17 mm; p = 0.020), greater standardized lateralization of the femoral head (0.64 versus 0.54; p = 0.009), and lower iHOT-12 scores (35.22 versus 40.96; p = 0.009) than did those without concomitant generalized joint hypermobility. Further multivariable linear regression analysis revealed that higher Beighton scores and younger age were predictive of more severe hip dysplasia. However, the Beighton score was not found to be independently associated with patient-reported outcomes according to multivariable linear regression analysis.

The prevalence of generalized joint hypermobility was greater in patients with DDH than in healthy controls. A higher degree of joint hypermobility was also correlated with more severe hip dysplasia. These results suggest that joint laxity, in addition to bone or cartilage factors, is an important factor related to DDH.

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

➢ The alpha angle was originally defined on magnetic resonance imaging (MRI) scans, using a plane, parallel to the axis of the femoral neck. However, much of the literature on the alpha angle has used radiographs or other imaging modalities to quantify the alpha angle.➢ The measurement of the alpha angle can be unreliable, particularly on radiographs and ultrasound.➢ If radiographs are used to measure the alpha angle, the circle of best-fit method should be used on multiple different views to capture various locations of the cam lesion, and "eyeballing" or estimating the alpha angle should be avoided.➢ The cam lesion is a dynamic and 3-dimensional (3D) problem and is unlikely to be adequately defined or captured by a single angle.➢ Modern technology, including readily available 3D imaging modalities, as well as intraoperative and dynamic imaging options, provides novel, and potentially more clinically relevant, ways to quantify the alpha angle.

Traditional management of moderate to severe stable slipped capital femoral epiphysis (SCFE) has been in situ fixation followed by reconstructive surgery if symptoms arise. This delayed approach may lead to irreversible intra-articular damage of the hip over time. The purpose of this study was to compare radiographic and clinical outcomes of the modified Dunn procedure (MDP) versus in situ fixation followed by delayed Imhauser osteotomy (DIO).

This was a retrospective study from a single institution between 2001 and 2021. Among 250 patients diagnosed with SCFE, a total of 18 (18 hips) treated with MDP and 16 (18 hips) treated with DIO for moderate to severe stable SCFE were included. Most patients who underwent DIO either had concomitant (11/18 hips) or subsequent (2/18 hips) open osteochondroplasty. Mean follow up was 4.7 years (range: 1 to 12.8 y). Radiographs were reviewed to measure Southwick angle, anteroposterior and lateral alpha (α) angles, and femoral head-neck offset ratio preoperatively and at latest follow up. Charts were reviewed for demographics, subsequent surgeries, complications, and Heyman-Herndon clinical outcomes.

The amount of deformity correction was greater in the MDP than DIO group based on anteroposterior α angles (mean: 22.3 vs. 11.9 degrees, P =0.046) and femoral head-neck offset ratios (mean: 0.26 vs. 0.12, P =0.001). There was no significant difference in Heyman-Herndon scores (both 16/18, 88.9% good to excellent outcomes, P >0.999). Less reoperations were performed in the MDP than DIO group (2/18, 11.1% vs. 9/18, 50%; P =0.004). AVN occurred in 2/18 hips (11.1%) in the MDP group with both surgeries performed early in the series and underwent prior in situ screw fixation compared with 0/18 hips (0%) in the DIO group ( P =0.486). One patient in the DIO group was later diagnosed with osteoarthritis.

MDP resulted in more anatomic coronal and sagittal plane deformity correction, less reoperations, and similar Heyman-Herndon clinical outcomes compared with DIO. AVN occurred in the MDP group whereas osteoarthritis occurred in the DIO group. These complications must be weighed against improved long-term clinical results for patients who would otherwise be at risk for premature degenerative joint disease due to residual proximal femoral deformity.

Level III-retrospective comparative study.

Hip injuries in elite athletes are an increasingly recognized problem and range from chronic overuse injuries, such as adductor strains and labral tears, to acute traumatic injuries such as hip dislocations. In this article, we review common hip pathology experienced by elite athletes and sideline management of emergent hip injuries.

Elite athletes are subject to unique physical and mental stresses and therefore must be evaluated and treated in a unique manner. Hip and groin injuries account for approximately 6% of sport injuries overall and 3-15% of all injuries in professional sports. Hip sideline emergencies were rare but can include hip dislocations, subluxations, and avulsion fractures. Hip and groin injuries represent an important subset of injuries which can greatly impact an athlete's ability to perform. Understanding the physiology and types of hip/groin injuries, which athletes are prone to injuries, the impact on recovery time, recurrence risk, and the potential need for surgery aid sports medicine physicians in decision-making.

The horizontal beam lateral (HBL) position technique for X-ray imaging has been used for nearly a century; however, this can be challenging for the patient and the practitioner, as it potentially compromises patient dignity. This study explores student radiographers' knowledge and experience of lateral hip positions and their impact on diagnostic quality and patient dignity.

A cross-sectional mixed-method online survey of undergraduate diagnostic radiography students was completed. Likert scale assessments, rank ordering questions, and free-test qualitative responses were utilised for questions on knowledge and experience of different positioning, ease to obtain, patient dignity, diagnostic quality, and need for repeats. Data analysis included descriptive statistics and cross-tabulation non-parametric analysis against variables of age, gender and year of study.

Responses were received by n = 42/158 students, a response rate of 27%. The HBL position was the most commonly repeated image (76.6%); the qualitative themes included HBL image quality issues and difficulty in the HBL positioning for elderly or frail patients, often in discomfort and pain. Analysis of student responses to perceived patient dignity in positioning identified 73.8% found the HBL undignified, and 85.7% agreed the Clements-Nakayama (CN) position would be more dignified for patients. The diagnostic image quality of the HBL position (64.2%) was compared to the CN alternative axiolateral (66.6%). Comparison of ease of obtaining the correct position for HBL (47.6%) was higher than CN position (28.6%); this could be due to the lack of experience n = 3/42 (7.1%) of this position.

Overall, student radiographers' experience and knowledge of various lateral hip positions observed in clinical practice was good. The CN position scored high for diagnostic image (66.6%) and dignity for the patient (85.7%), over the often repeated HBL position (76.6%), which scored lower for image quality (64.2%) and dignity (76.6%).

Radiographers should advocate for professional autonomy and explore alternative positioning techniques. Further investigation into the CN position's utilisation, image quality and radiation dose in England is recommended.

Hip arthroscopy is a rapidly evolving field in orthopedics, offering diagnostic and therapeutic benefits for a range of hip pathologies. This review outlines a comprehensive guide to initiating hip arthroscopy safely and effectively using evidence-based practices. Optimal surgical outcomes depend on correct indications for surgery, in particular in the presence of borderline dysplasia and degenerative joint diseases. Proper patient counseling and setting realistic expectations are crucial for satisfactory outcomes and recovery. Physical examination, radiographs, MRI, and CT scans are essential for accurate diagnosis. In case of diagnostic uncertainty, the use of intra-articular injections can help confirm the diagnosis before surgery. Techniques for hip arthroscopy include central compartment first, peripheral compartment first, and outside-in approaches. Each technique has advantages, and the optimal approach depends on the specific case. Finally, Proper operating room setup, meticulous patient positioning, and precise portal placement are critical for a successful procedure. A thorough understanding of the safe zone anatomy for portal placement is essential to minimize the risk of neurovascular complications. In conclusion, this manuscript provides a detailed, evidence-based framework for starting hip arthroscopy, emphasizing the importance of technical proficiency, patient selection, and a multidisciplinary approach to ensure patient safety and procedure efficacy.

The primary objective of this study was to develop a custom algorithm to assess three-dimensional (3D) acetabular coverage of the femoral head based on surface models generated from computed tomography (CT) imaging. The secondary objective was to apply this algorithm to asymptomatic young adult hip joints to assess the regional 3D acetabular coverage variability and understand how these novel 3D metrics relate to traditional two-dimensional (2D) radiographic measurements of coverage. The algorithm developed automatically identifies the lateral- and medial-most edges of the acetabular lunate at one-degree intervals around the acetabular rim based on local radius of curvature. The acetabular edges and the center of a best-fit sphere to the femoral head are then used to compute the mean 3D subchondral arc angles and hip joint coverage angles in five acetabular octants. This algorithm was applied to hip models generated from pelvis/hip CT imaging or abdomen/pelvis CT angiograms of 50 patients between 17 and 25 years of age who had no history of congenital or developmental hip pathology, neuromuscular conditions, or bilateral pelvic and/or femoral fractures. Corresponding 2D acetabular coverage measures of lateral center edge angle (LCEA) and acetabular arc angle (AAA) were assessed on the patients' clinical or digitally reconstructed radiographs. The 3D subchondral arc angle in the superior region (58.0 [54.6-64.8] degrees) was significantly higher (p < 0.001) than all other acetabular subregions. The 3D hip joint coverage angle in the superior region (26.2 [20.7-28.5] degrees) was also significantly higher (p < 0.001) than all other acetabular subregions. 3D superior hip joint coverage angle demonstrated the strongest correlation with 2D LCEA (r = 0.649, p < 0.001), while 3D superior-anterior subchondral arc angle demonstrated the strongest correlation with 2D AAA (r = 0.718, p < 0.001). The 3D coverage metrics in the remaining acetabular regions did not strongly correlate with typical 2D radiographic measures. The discrepancy between standard 2D measures of radiographic acetabular coverage and actual 3D coverage identified on advanced imaging indicates potential discord between anatomic coverage and the standard clinical measures of coverage on 2D imaging. As 2D measurement of acetabular coverage is increasingly used to guide surgical decision-making to address acetabular deformities, this work would suggest that 3D measures of acetabular coverage may be important to help discriminate local coverage deficiencies, avoid inconsistencies resulting from differences in radiographic measurement techniques, and provide a better understanding of acetabular coverage in the hip joint, potentially altering surgical planning and guiding surgical technique.

To compare clinical outcomes and rates of secondary surgery, including revision hip arthroscopy and conversion to total hip arthroplasty (THA), after primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) in patients ≥40 years of age at minimum 10-year follow-up compared with a propensity-matched control group of patients <40 years.

A retrospective cohort study was performed for patients who underwent primary hip arthroscopy for FAIS between January 2012 and February 2013. Patients ≥40 years old were propensity matched in a 1:1 ratio by sex and body mass index to patients <40 years old. Patient-reported outcomes (PROs) including Hip Outcome Score for Activities of Daily Living and Sports-Specific subscales, modified Harris Hip, International Hip Outcome Tool-12, and Visual Analog Scale for Pain and Satisfaction were collected. Rates of minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) achievement at 10 years were evaluated and compared between groups. Rates of secondary surgery including revision hip arthroscopy and conversion to THA were evaluated. Gross survivorship between cohorts was evaluated using a Kaplan-Meier curve.

Fifty-three patients aged ≥40 (age 48.3 ± 5.8 years) were successfully matched to 53 patients aged <40 (age: 28.9 ± 7.2, <0.001). There were no other preoperative group differences regarding patient demographics, characteristics, or radiographic findings. Both groups demonstrated significant improvement regarding all PROs at a minimum of 10 years' follow-up (P < .001 for all). No significant difference was noted between cohorts regarding any delta (preoperative to 10-year postoperative) scores (P > .05 for all). High rates of MCID and PASS achievement were achieved in both cohorts, with no significant differences in any PRO measure (P > .05 for all). No significant differences in rates of complications (age ≥40: 2.0%, age <40: 7.7%, P = .363), rates of revision (age ≥40: 7.5%, age <40: 9.4%, P = .999), or conversion to THA (age ≥40: 13.2%, age <40: 3.8%, P = .161) were identified. On Kaplan-Meier analysis, no significant difference (P = .321) was demonstrated in overall gross survivorship between cohorts.

Patients with age ≥40 with FAIS undergoing primary hip arthroscopy demonstrated durable and comparable 10-year PRO and rates of MCID and PASS achievement compared with a propensity-matched cohort of age <40 counterparts.

Level III, retrospective comparative prognostic trial.

Acetabular retroversion is associated with impingement and instability. An adequate interpretation of acetabular version and coverage on radiographs is essential to determine the optimal treatment strategy (periacetabular osteotomy vs hip arthroscopic surgery). The crossover sign (COS) has been associated with the presence of acetabular retroversion, and the anterior wall index (AWI) and posterior wall index (PWI) assess anteroposterior acetabular coverage. However, the radiographic appearance of the acetabulum is sensitive to anterior inferior iliac spine (AIIS) morphology and pelvic tilt (PT), which differs between the supine and standing positions.

To (1) identify differences in the acetabular appearance between the supine and standing positions among patients presenting with hip pain; (2) determine factors (acetabular version, AIIS morphology, and spinopelvic characteristics) associated with the crossover ratio (COR), AWI, and PWI; and (3) define relevant clinical thresholds to guide management.

Cross-sectional study; Level of evidence, 3.