Knee osteoarthritis (OA), affecting both tibiofemoral and patellofemoral compartments, causes pain and reduced quality of life. The Mulligan Concept of mobilization with movement (MWM) may relieve symptoms by modifying sensory input, enhancing central inhibition, and improving motor activation. This study conducted a systematic review and meta-analysis with subgroup analysis to evaluate MWM's efficacy in improving pain and disability in knee OA.

Electronic databases were searched from inception to January 2025 for randomized controlled trials (RCTs) on the effects of MWM on knee OA. Pain intensity and disability improvement, standardized using Hedges' g, were the primary and secondary outcomes. Two reviewers independently assessed study quality, extracted data, and performed a meta-analysis using a random-effects model. Subgroup analyses considered intervention regimens, technique including weight-bearing or not, Kellgren-Lawrence (K-L) classification grades, and control group comparisons.

From 23 RCTs (996 participants; mean age 37-61 years), MWM significantly reduced pain (Hedges' g = -0.984, 95% CI = -1.375 to -0.593) and improved disability (Hedges' g = -1.041, 95% CI = -1.477 to - 0.606).. Greater effect sizes were observed when MWM was combined with other therapies, including weight-bearing positions, and among participants without advanced K-L grades. MWM also demonstrated significant effects in comparison with active controls.

This meta-analysis showed that MWM reduces pain and disability in individuals with knee osteoarthritis, especially when incorporated into treatment protocols featuring weight-bearing positions and combined physical therapies. Clinically, MWM could be incorporated into rehabilitation programs to enhance pain relief and functional recovery. Future studies should extend follow-ups and address bias.

The knee is meniscus-dependent, relying on the tissue's biomechanical properties to maintain joint health and function. Meniscus dysfunction has primarily been assessed by measuring tibiofemoral articular contact areas and pressures, which entail important limitations. Meniscus extrusion, excursion, and hoop strain are dynamic measures of meniscal function, which have potential advantages for clinically applicable biomechanical testing of meniscus. The objective of this study was to quantify meniscus extrusion, excursion, and hoop strain under clinically relevant loading and motion conditions in meniscus-intact and meniscus-deficient cadaveric knees using a novel model. Cadaveric knees (n = 8) were dynamically tested through a functional range of motion under 30 N of compressive load in a robotic testing system to determine meniscus translations at full extension and 30, 60, 90, and 100 degrees of flexion through 10 cycles. For meniscus-intact and meniscus-deficient (posterior meniscus root release) states, measurements for medial and lateral meniscus excursion, extrusion, and hoop strain were determined by calculating respective translations of fiducial tracking markers and were compared for statistically significant differences. In the meniscus-intact state, medial and lateral meniscus extrusion, excursion, and hoop strain metrics corresponded well to previously reported measurements, suggesting that this model has translational validity for assessing functional kinematics for clinical application. For both medial and lateral menisci, posterior root release was associated with significantly more meniscus extrusion and significantly less maximum meniscus hoop strain compared with the meniscus-intact status. For meniscus excursion, medial root release showed significant differences from the intact status only at a knee flexion angle of 100 degrees, whereas lateral root release differed significantly from the intact status at 60 and 90 degrees of knee flexion. Taken together, this study verifies that this model can effectively quantify meniscus extrusion, excursion, and hoop strain under clinically relevant loading and motion conditions in meniscus-intact and meniscus-deficient knees for use in preclinical studies aimed at assessing the severity of meniscus deficiency, as well as surgical interventions and postoperative management strategies intended to optimize meniscus preservation.

The objectives were to determine the prevalence of meeting criteria for symptoms suggestive of early osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) and to characterize the longitudinal changes in these symptoms during the first two years post-ACLR.

We analyzed data from 10,231 patients aged 14 to 40 years in the New Zealand ACL Registry who completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 6, 12, and 24 months post-ACLR. Symptoms suggestive of early OA were defined as scoring ≤85% on at least two of four KOOS subscales. Longitudinal patterns of change were categorized as persistent, resolution, new, inconsistent, or no symptoms across the three visits. Prevalence and odds ratios (ORs) of symptoms were compared across visits, sex, and age groups using generalized estimating equations, and longitudinal patterns of symptom change were analyzed using multinomial logistic regression.

Prevalence of meeting criteria of symptoms suggestive of early OA was 68% at 6 months, 54% at 12 months, and 46% at 24 months post-ACLR. Longitudinally, 33% had persistent symptoms, 23% had no symptoms, 29% showed symptom resolution, 6% developed new symptoms, and 9% had inconsistent symptoms. Women consistently showed higher odds of symptoms (OR range 1.17-1.52). Older age groups demonstrated higher odds of symptoms, particularly at 6 months (OR range 1.64-2.45).

Symptoms suggestive of early OA are highly prevalent within two years post-ACLR, with one third of patients experiencing persistent symptoms. These findings indicate that symptoms are more likely to persist rather than newly develop, emphasizing the importance of early identification and targeted interventions.

To investigate the differences in clinical and radiographic knee OA markers between injured and uninjured UK service personnel.

This study was a cross-sectional analysis, 8 years post-injury, of a prospective cohort study. The Knee Injury and Osteoarthritis Outcome Scores (KOOS), radiographic Kellgren and Lawrence (KL) scores and Osteoarthritis Research Society International scores (joint space narrowing, sclerosis, osteophytes) were obtained from 565 uninjured and 579 matched (on sex, age, rank, regiment and role on deployment) major combat injured participants from the Armed Services Trauma Rehabilitation Outcome study; 35 had a knee injury and 142 had an amputation without knee injury. Kruskal-Wallis tests were used to compare between groups for KOOS and radiographic measures. A multiple logistic regression was performed on the effects of injury on radiographic features.

The mean age at injury was 25.7 years (s.d. 5.2). Injured participants demonstrated worse KOOS values for pain {median 89 [interquartile range (IQR) 72-100] vs 94 [83-100]} and symptoms [median 80 (IQR 60-90) vs 85 (70-95), P < 0.001] and higher scores for radiographic variables than uninjured participants. Injured non-amputated/non-knee-injured participants had worse KOOS values than uninjured participants [pain: 92 (IQR 75-100) vs 94 (83-100); symptoms: 80 (IQR 60-90) vs 85 (70-95), P < 0.01]. Knee-injured participants had worse KOOS values [pain: 67 (IQR 55-85), symptoms: 55 (IQR 35-73), P < 0.001] than all subgroups and worse radiographic measures than injured non-amputated participants. KL score (≥1) and sclerosis were worse for amputees than injured non-amputated participants. Amputees had 4.04-fold increased odds (95% CI 2.45, 6.65) vs uninjured participants and knee-injured participants had 4.06-fold increased odds (95% CI 1.89-8.74) than uninjured participants of knee osteoarthritis (KOA; KL ≥1). Injured participants (without knee injury/amputation) had 1.74-fold (95% CI 1.27, 2.69) increased odds of KOA than uninjured participants.

Major combat trauma (in addition to knee injury or amputation) has a substantial effect on the development of KOA.

Meniscectomy is a common knee surgery for meniscal tear, and is associated with progressive osteoarthritis (OA). There are few literatures focus on the use of lateral unicompartmental knee arthroplasty (UKA) for lateral post-meniscectomy knee osteoarthritis (PMKO). Therefore, the purpose of this study is to compare the outcomes of lateral UKA performed for lateral PMKO and primary lateral compartment knee osteoarthritis (LCKO).

A total of 38 consecutive patients (38 knees) who received lateral UKAs for isolated lateral PMKO between September 2013 and September 2019 were retrospectively analyzed. Other thirty-eight patients (38 knees) with primary LCKO were allocated into control group by 1:1 matching according to age, gender, and body mass index. The clinical outcomes were evaluated using the American Knee Society Score, range of motion, Forgotten Joint Score, and EuroQol-5D (EQ-5D) Score. The radiographic assessments included hip-knee-ankle (HKA) angle, mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and posterior tibial slope angle (PTSA).

With a mean 7 years follow-up, there was no significant difference in functional and radiographic outcomes between groups. However, the PMKO group showed severe lateral OA (p = 0.02) preoperatively and less OA progression in the medial compartment postoperatively (p = 0.046). The preoperative mLDFA was significantly more valgus in the LCKO group (p < 0.001). No case of revision occurred in either group.

Lateral UKA is a valid procedure for lateral PMKO. The clinical and radiographic results are similar in patients underwent lateral UKA for lateral PMKO and for LCKO. Patients with lateral PMKO exhibited severe lateral OA preoperatively and less OA progression in the medial compartment compared to those with LCKO. It is crucial to prevent ascension of the lateral femoral joint-line and maintain proper valgus alignment during lateral UKA.

The graft tension applied during anterior cruciate ligament (ACL) graft fixation (subsequently referred to as initial graft tension) could potentiate posttraumatic osteoarthritis (PTOA) and influence other outcomes.

The purpose of this study was to analyze the effects of initial graft tension on imaging and patient-reported outcomes related to PTOA 15 years postreconstruction surgery. Clinical and functional outcomes were also assessed. It was hypothesized that (1) the high-tension group would have improved imaging findings and outcomes compared with the low-tension group at 15-year follow-up and (2) the imaging findings and outcomes for the high-tension group would be equivalent to the sex-, race-, age-, and activity level matched control group.

Randomized controlled trial; Level of evidence, 1.

Consented patients underwent ACL reconstruction (ACLR) with bone-patellar tendon-bone or a 4-strand hamstring tendon autograft. A matched uninjured control group was assembled for comparison. Two laxity-based tensioning procedures were randomized: (1) tension set to restore normal anteroposterior (AP) laxity at time of surgery relative to the contralateral uninjured knee (low-tension group) or (2) tension set to overconstrain AP laxity at time of surgery relative to the contralateral knee (high-tension group). Baseline outcome measures, radiographs, and magnetic resonance imaging (MRI) scans were collected prior to surgery and at 15 years postoperatively.

For medial joint space width, the differences between limbs across the 3 groups were not significant. Within the tension groups, the Whole Organ MRI Score was significantly higher in the surgical knee relative to the contralateral knee in both groups, while the Osteoarthritis Research Society International radiographic scores were higher in the surgical knee in the low-tension group only. A total of 43% of patients in both tension groups met the Knee injury and Osteoarthritis Outcome Score composite criteria for a symptomatic knee compared with controls (10%; P = .01). Most other outcomes, including AP laxity, International Knee Documentation Committee knee examination score, and single-leg hop test were not significantly different between the 3 groups.

The results do not support the hypotheses that patients in the high-tension group would have better chondroprotection compared with the low-tension group and have equivalent outcomes with the matched controls. Overall, the results show that patients undergoing ACLR are more likely to develop PTOA and display inferior outcomes compared with the uninjured matched control group, regardless of graft tension.

To describe the SHIELD cohort in terms of symptoms indicative of early knee osteoarthritis (OA) and to investigate associations between patient characteristics (demographics, activity/injury-related) and these symptoms at 1 (cross-sectional) and 3 years (longitudinal) post anterior cruciate ligament reconstruction (ACLR).

106 participants (50 ​% women, mean [SD] age 25 [5] years) were included. Symptoms indicative of early knee OA were evaluated by the Knee injury and Osteoarthritis Outcome Score (KOOS) subscale pain, KOOS subscale pain ≤72 (KOOSpain ≤72), and ≤85 on two out of four KOOS subscales (pain, symptoms, activity of daily living, quality of life) (modified Luyten).

Mean (SD) KOOS pain scores were 83.2 (15.7) and 87.3 (12.7) at 1 and 3 years, respectively. At 1 year and 3 years post ACLR, 18/101 (18 ​%) and 14/86 (16 ​%) participants met the KOOSpain ≤72 criterion, whereas 83/101 (82 ​%) and 67/86 (78 ​%) met the modified Luyten criterion. 7/15 (47 ​%) (KOOSpain ≤72) and 59/70 (84 ​%) (modified Luyten) classified as having knee OA symptoms 1 year post ACLR were still classified as having OA symptoms after 3 years. Lower activity level at 1 year was the sole variable consistently associated with all three outcomes 3 years post ACLR.

The proportion of participants fulfilling existing classification criteria for symptoms indicative of early OA after ACLR is highly dependent on the criteria applied and different criteria seem to capture varying aspects of early OA symptoms. Future studies will reveal if these symptoms will persist long-term or just reflect more transient issues.

Anterior cruciate ligament injury increases the risk of knee osteoarthritis, possibly via early onset of knee pain and changes in musculoskeletal function. This study compared knee muscle strength and movement biomechanics during walking and forward lunge between individuals with and without knee pain after anterior cruciate ligament reconstruction.

Cross-sectional study including participants at least 3 years post anterior cruciate ligament reconstruction, aged 18-40 at the time of surgery, and body mass index ≤30. Symptomatic participants were defined by a knee pain score (reconstructed knee) of ≥3 on a 0-10 scale during activities of daily living in the past week. Asymptomatic participants were defined by a pain score of 0. Maximal isometric quadriceps and hamstring muscle strength (Nm/kg) and 3D walking, and forward lunge movement biomechanics were measured.

A total of 122 participants (30% females) were included: 33 symptomatic and 89 asymptomatic (average age: 33.7, range 23.7-51.3 years). The average post-surgery time was 6 (range 3-10) years. The symptomatic group exhibited lower isometric quadriceps and hamstring strength with mean group differences (95% confidence interval [CI]) of 0.33 (0.10 to 0.56) Nm/kg and 0.19 (0.07 to 0.31) Nm/kg, respectively. There were no important group differences in the walking and forward lunge movement biomechanics.

Symptomatic individuals with anterior cruciate ligament reconstruction demonstrated weaker knee muscles compared to their asymptomatic counterparts. The comparable walking and forward lunge biomechanics suggest that knee pain has no substantial impact on movement biomechanics up to 10 years post-surgery.

Level III.

Clinicians use imaging studies to help gauge the degree to which structural factors within the knee account for patients' pain and symptoms. We aimed to determine the degree to which commonly used structural features predict a patient's knee pain and symptoms.

Using Osteoarthritis Initiative data, a 10-year study of 4,796 patients with knee osteoarthritis (KOA), participants' KOA was characterized by radiographs and MRI scans of the knee. Salient features were quantified with two established grading systems: (1) individual radiographic features (IRFs) and (2) MRI Osteoarthritis Knee Scores (MOAKS) from MRI scans. We paired participants' IRFs (24,256 readings) and MOAKS (2,851 readings) with side-specific Knee Injury and Osteoarthritis Outcome Scores (KOOS). We trained generalized linear models to predict KOOS from features measured in IRF and MOAKS. We repeated the analysis on four subsets of the cohort. The models' predictive performance was evaluated using root mean square errors and coefficient of determination (R2).

Neither radiographic features used to determine IRF grades nor MOAKS were predictive of patient pain or symptoms. MOAKS's performance was slightly more predictive of KOOS than IRF's. IRF's prediction of KOOS achieved a maximum R2 of 0.15 and 0.28 for MOAKS, indicating a low level of accuracy in predicting the target variable.

Commonly used structural features from radiographs and MRI scans cannot predict KOA pain and symptoms-even when imaging features are codified by established grading systems like IRF or MOAKS. The predictive performance of these models is even worse as symptom severity worsens.

IV.

To assess the 5-year effects of arthroscopic partial meniscectomy (APM) vs. placebo surgery on the development of the structural changes of the knee by magnetic resonance imaging (MRI).

This multicentre, randomized, participant- and outcome-assessor-blinded, placebo-surgery-controlled trial was carried out in Finland. We randomized 146 adults, mean age 52 years (range 35 to 65) to undergo either APM or placebo surgery. The subjects had symptoms of degenerative medial meniscus tear, a tear verified in MRI and arthroscopy, and no advanced osteoarthritis at baseline. We compared the baseline and 5-year follow-up MRIs using MRI Osteoarthritis Knee Score scoring to derive subregional data on cartilage damage, osteophytes and bone marrow lesions (BMLs). Progression of structural cartilage changes analyzed per subregion was the main outcome, that of osteophytes and BMLs secondary outcomes. We analyzed the progression with multilevel logistic regression model on subregion-level data, adjusted for randomization stratification factors, and using robust standard errors.

Sixty-three (90%) subjects in the APM and 73 (96%) in the placebo-surgery group had MRI at both time points. The adjusted odds ratio (APM vs. placebo-surgery) was 1.31 (95% confidence interval 0.81, 1.94) for progression of cartilage damage, 2.86 (1.16, 6.21) for osteophytes, and 1.43 (0.84, 2.43) for BMLs.

We found a slightly greater risk for progression of osteophytes in the APM group compared to the placebo-surgery group at 5 years after surgery.

ClinicalTrials.gov (NCT01052233 and NCT00549172).

Slower habitual walking speed and aberrant gait biomechanics are linked to clinically significant knee-related symptoms and articular cartilage composition changes linked to posttraumatic osteoarthritis after anterior cruciate ligament reconstruction (ACLR).

To (1) determine whether specific gait biomechanical variables can accurately identify individuals with clinically significant knee-related symptoms post-ACLR and (2) determine the corresponding threshold values, sensitivity, specificity, and odds ratios for each biomechanical variable.

Cross-sectional study.

Laboratory.

A total of 71 individuals (38 female, 33 male; age = 21 ± 4 years, height = 1.76 ± 0.11 m, mass = 75.38 ± 13.79 kg, time after primary unilateral ACLR = 6.2 ± 0.4 months).

Three-dimensional motion capture of 5 overground walking trials was used to calculate discrete gait biomechanical variables of interest during stance phase (first and second peak vertical ground reaction force [vGRF], midstance minimum vGRF, peak internal knee-abduction and -extension moments, and peak knee-flexion angle), along with habitual walking speed. Previously established Knee Injury and Osteoarthritis Outcome Score cutoff scores were used to define patients with (ie, symptomatic; n = 51) and those without (ie, asymptomatic; n = 20) clinically significant knee-related symptoms. Separate receiver operating characteristic curves and respective areas under the curve (AUCs) were used to evaluate the capability of each biomechanical variable of interest to identify individuals with clinically significant knee-related symptoms.

Habitual walking speed (AUC = 0.66), vGRF at midstance (AUC = 0.69), and second peak vGRF (AUC = 0.76) demonstrated low to moderate accuracy for identifying individuals with clinically significant knee-related symptoms. Individuals who exhibited habitual walking speeds ≤ 1.27 m/s, midstance minimum vGRF ≥ 0.82 body weights, and second peak vGRF ≤ 1.11 body weights demonstrated 3.13, 6.36, and 9.57 times higher odds of experiencing clinically significant knee-related symptoms, respectively.

Critical thresholds for gait variables may be used to identify individuals with increased odds of clinically significant knee-related symptoms and potential targets for future interventions.

Limited biomechanical evidence exists describing how horizontal meniscus tears (HMTs), meniscal repair (MR), and meniscectomy alter the knee's biomechanical environment.

To evaluate changes in knee contact mechanics following HMTs, MR, and meniscectomy.

Systematic review; Level of evidence, 5.

PubMed, EMBASE, and CINAHL databases were systematically searched for biomechanical cadaveric studies of HMTs up to January 16, 2023, using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies that (1) did not examine MRs or meniscectomies, (2) did not report contact area (CA) or pressure, (3) involved concomitant injuries (eg, anterior cruciate ligament tear), (4) were nonbiomechanical studies (eg, review, technique, and clinical), and (5) were non-English language articles were excluded. The endpoints were peak contact pressure (PCP) and mean CA.

Out of 1526 initial results, 6 studies were included for final review. PCP and CA were measured in 59 intact menisci, 59 HMTs, 59 partial meniscectomies (PM), 59 complete meniscectomies (CM), and 33 MR. Among all HMTs versus the intact state, pooled PCP increased by 14.2%, and pooled CA decreased by 7.1%. Among all PMs versus the intact state, 4 of 6 studies found significantly increased PCP (27.1%), and 5 found significantly reduced CA (22.1%). Among all CMs versus the intact state, all 6 studies found significantly increased PCP (54.5%), and 5 found significantly reduced CA (33%). Among the 3 studies directly comparing PM to CM, 2 studies found PM to have significantly smaller increases in PCP (23.3% vs 52.4%) and significantly smaller reductions in CA (16.7% vs 28.1%) from the intact state.) The 3 studies evaluating MR versus the intact state found no significant difference in PCP or CA.

After an HMT, MR had the smallest deviations in contact mechanics; only MR restored contact mechanics to the uninjured state. These findings support MR's superiority, illustrate that maintaining contact mechanics requires preserving meniscal tissue, and are consistent with clinical evidence. More clinical comparisons are needed to understand the differences among treatments.

To evaluate radiographic knee osteoarthritis (OA) progression, development of knee OA, patient-reported outcomes and knee muscle strength at 10-year follow-up after arthroscopic partial meniscectomy (APM) or exercise therapy for degenerative meniscal tears.

Randomised controlled trial including 140 participants, with a degenerative meniscal tear and no or minimal radiographic OA changes. Participants were randomised to either APM or 12 weeks of exercise therapy (1:1 ratio). The primary outcome was knee OA progression assessed by the Osteoarthritis Research Society International (OARSI) atlas sum score (sum of medial and lateral compartment joint space narrowing and osteophyte score). Secondary outcomes included incidence of radiographic and symptomatic knee OA, patient-reported pain and knee function and isokinetic knee muscle strength.

The adjusted mean difference in change in the OARSI sum score was 0.39 (95% CI -0.19 to 0.97), with more progression in the APM group. The incidence of radiographic knee OA was 23% in the APM group and 20% in the exercise group (adjusted risk difference 3% (95% CI -13% to 19%)). No clinically relevant differences were found in patient-reported outcomes or isokinetic knee muscle strength.

No differences in radiographic knee OA progression and comparable rates of knee OA development were observed 10 years following APM and exercise therapy for degenerative meniscal tears. Both treatments were associated with improved patient-reported pain and knee function.

NCT01002794.

To investigate if hip and knee alignment assessed 2 years after anterior cruciate ligament (ACL) injury is associated with compartment-specific radiographic knee osteoarthritis (OA) 3 years later.

An exploratory analysis was conducted in the knee ACL, nonsurgical versus surgical treatment (KANON) trial (ISRCTN84752559); 115 subjects with acute ACL injury were assessed at the 2-year follow-up; full-limb images of the injured leg were acquired, and the neck-shaft angle (NSA) and hip-knee-ankle angle (HKA) were measured. At the 5-year follow-up, weight-bearing tibiofemoral and patellofemoral radiographs were obtained. Radiographs were graded according to the OA Research Society International Atlas and Radiographic OA was defined as approximating Kellgren & Lawrence grade 2 or worse. Analysis of covariance adjusting for sex, age, body mass index, randomization and partial meniscectomy recorded at the 2-year follow-up was performed.

In patients who had developed medial tibiofemoral OA at the 5-year follow-up, the NSA and the HKA at the 2-year follow-up were smaller (NSA, mean difference = -4.6° [95% confidence interval {CI} -7.9° to -1.1°]; HKA, mean difference = -2.3° [95% CI -4.2° to -0.4°]). No association was observed between the NSA or HKA at the 2-year follow-up and lateral tibiofemoral OA, nor patellofemoral OA at the 5-year follow-up.

A smaller NSA and HKA angle of the ACL injured leg (i.e., more varus hip and varus knee alignment) 2 years after the injury was associated with medial tibiofemoral radiographic OA 3 years later.

Level II exploratory post hoc analysis of an RCT.

Meniscus is vital for maintaining the anatomical and functional integrity of knee. Injuries to meniscus, commonly caused by trauma or degenerative processes, can result in knee joint dysfunction and secondary osteoarthritis, while current conservative and surgical interventions for meniscus injuries bear suboptimal outcomes. In the past decade, there has been a significant focus on advancing meniscus tissue engineering, encompassing isolated scaffold strategies, biological augmentation, physical stimulus, and meniscus organoids, to improve the prognosis of meniscus injuries. Despite noteworthy promising preclinical results, translational gaps and inconsistencies in the therapeutic efficiency between preclinical and clinical studies exist. This review comprehensively outlines the developments in meniscus tissue engineering over the past decade (Scheme 1). Reasons for the discordant results between preclinical and clinical trials, as well as potential strategies to expedite the translation of bench-to-bedside approaches are analyzed and discussed.

We present a case of rapid chondrolysis after the repair of a lateral meniscus (LM) radial tear. An 18-year-old male competitive skier sustained an anterior cruciate ligament (ACL) injury associated with a Segond fracture and LM radial tear in the posterior segment. The patient underwent a two-stage surgery, LM repair and internal fixation of the fracture fragment, followed by ACL reconstruction. Although the postoperative course was uneventful, the patient experienced persistent joint effusion after starting ski practice six months postoperatively. An arthroscopic examination was performed one year after ACL reconstruction, and severe cartilage damage was observed in the lateral femoral condyle and tibial plateau, whereas complete healing of the repaired LM was observed. Despite complete arthroscopic healing of the meniscus, meniscal function may not be fully restored by isolated meniscal repair of radial tears associated with ACL injury. The development of new surgical methods may be necessary to improve functional restoration.

The ArmeD SerVices TrAuma RehabilitatioN OutComE (ADVANCE) study is investigating long-term combat-injury outcomes; this sub-study aims to understand the association of osteoarthritis (OA) biomarkers with knee radiographic OA (rOA), pain and function in this high-risk population for post-traumatic OA.

ADVANCE compares combat-injured participants with age, rank, deployment and job-role frequency-matched uninjured participants. Post-injury immunoassay-measured serum biomarkers, knee radiographs, Knee Injury and Osteoarthritis Outcome Scale, and six-minute walk tests are reported. The primary analysis, adjusted for age, body mass, socioeconomic status, and ethnicity, was to determine any differences in biomarkers between those with/without combat injury, rOA and pain. Secondary analyses were performed to compare post-traumatic/idiopathic OA, painful/painfree rOA and injury patterns.

A total of 1145 male participants were recruited, aged 34.1 ± 5.4, 8.9 ± 2.2 years post-injury (n = 579 trauma-exposed, of which, traumatic-amputation n = 161) or deployment (n = 566 matched). Cartilage oligomeric matrix protein (COMP) was significantly higher in the combat-injured group compared to uninjured (p = 0.01). Notably, COMP was significantly lower in the traumatic-amputation group compared to non-amputees (p < 0.001), decreasing relative to number of amputations (p < 0.001). Leptin was higher (p = 0.005) and adiponectin lower (p = 0.017) in those with v without knee pain, associated with an increased risk of 22% and 17% for pain, and 46% and 34% for painful rOA, respectively. There were no significant differences between trauma-exposed and unexposed participants with rOA.

The most notable findings of this large, unique study are the similarities between those with rOA regardless of trauma-exposure, the injury-pattern and traumatic-amputation-associated differences in COMP, and the relationship between adipokines and pain.

Meniscal tears affect patients of all ages, with varying presentations, influence on function, and treatment requirements. Classic dogma suggests that older patients should be treated nonoperatively or offered meniscectomy when conservative treatment fails. However, recent data suggest improved subjective outcomes and reduced rates of degenerative change after meniscal repair, even in patients older than 40 years. Controversy exists regarding the comparative reoperation rates of meniscectomy and meniscal repair in the older cohort. Although higher levels of evidence are lacking, it is unlikely that chronological age should be the major driver of surgical decision making for meniscal repair. Patient-, joint-, limb-, and meniscus-specific factors, including physiological age, better guide the surgeon toward successful treatment.

Finite element modeling has served as a cornerstone in understanding knee joint mechanics post-meniscectomy, yet the influence of varying knee geometries remains unknown. The present study aimed to fill that gap by employing statistical shape modeling to generate knee models from MRI data of 31 human knees, capturing the population's knee size and shape variations. Finite element simulations were conducted to replicate intact, partial, and total medial meniscectomy conditions during standing. The results revealed a substantial shift in load distribution from the medial to lateral compartment following medial meniscectomy with its magnitude depending on knee geometry. Cartilages experienced variable degrees of pressure changes at different sites, which could also be different for fluid and contact pressures. While changes in joint size led to somewhat predictable alterations in contact pressure, variations in joint shape resulted in unexpected changes in contact and fluid pressures, emphasizing the need for computational simulations. The average knee geometry exhibited the lowest contact and fluid pressures under the given loading and boundary conditions, in contrast to knees with shapes deviating from the average. This study highlights the significance of individual knee shape in the biomechanical outcome of meniscectomy, potentially explaining the variability in clinical outcomes observed post-surgery.

Platelet-rich plasma (PRP) is gaining popularity across various medical fields, including orthopedics, for its potential in tissue regeneration and wound healing. As intra-articular treatments evolve, PRP has emerged as a promising option for managing knee osteoarthritis, meniscus, and ligament injuries. This review aims to provide an update on the current applications of PRP in treating knee osteoarthritis and its clinical implications in orthopedic and sports medicine. We reviewed 180 eligible studies, and our findings suggest that PRP injections significantly improve knee joint function compared to alternative treatments. The use of PRP across various medical fields has been growing in popularity recently. PRP is a biological product derived from the plasma portion of a patient's own blood, containing a higher concentration of platelets than normal. Its potential for tissue regeneration and wound healing has drawn significant attention from orthopedic surgeons, especially as intra-articular treatment options continue to evolve. The benefits of PRP in treating various osteoarticular conditions have sparked considerable interest within the orthopedic community, particularly for managing knee osteoarthritis, meniscus tears, and ligament injuries. This review aims to provide an updated overview of the current applications of PRP in the treatment of knee osteoarthritis and to offer clinical insights into its use in orthopedic and sports medicine practices. We reviewed 180 relevant titles and abstracts that met the inclusion criteria. Compared to other treatment options, PRP injections significantly enhance knee joint function.

To evaluate the clinical outcomes in the use of a synthetic medial meniscus implant in patients symptomatic after medial meniscectomy and not responsive to nonoperative treatment.

This single-arm, multicenter, prospective study enrolled subjects between ages 30 and 75 with postmeniscectomy pain. Changes from baseline to 24 months were measured in the pain subscale of the knee injury and osteoarthritis outcome score (KOOS) and in KOOS overall (average of all 5 subscales) in patients that had received a medial meniscus implant. Success was a 20-point improvement at 24 months, and reoperation rates and implant failures were recorded. Visual Analog Scale, International Knee Documentation Committee, and Western Ontario Meniscal Evaluation Tool scores were also measured.

Of the 115 treated patients, 3 (2.6%) were either lost to follow-up or missed the 24-month visit, 48 (43%) patients had at least 1 subsequent surgery, and 12 (10.7%) had the implant permanently removed. Of the remaining 100 patients, the mean KOOS pain improved 28.4 points at 24 months (P < .001), and the mean KOOS overall improved 28.3 points (P < .001). Of the subjects, 76% had mean scores for KOOS pain above the minimal clinically important difference threshold, and 72% of subjects met or exceeded this threshold for KOOS overall. There were 29 patients (25.9%) who underwent implant exchange. The 24-month clinical outcomes were similar between subjects who had an implant exchange and patients who did not have any subsequent implant procedure (P < .2).

The synthetic medial meniscus implant shows high reoperation and failure rates. Patients who retained the implant or required implant exchange showed improved pain and function.

Individuals with anterior cruciate ligament reconstruction (ACLR) exhibit less knee kinematic variability while walking than uninjured controls, associated with deleterious changes in cartilage composition linked to an increased risk for early knee osteoarthritis (KOA). It is unknown whether less knee kinematic variability is also associated with worse knee-related patient-reported outcomes (PROs) consistent with KOA development. This study examined associations between kinematic variability during gait and PROs in individuals post-ACLR. Gait kinematics and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were collected from 45 participants 6-months post-ACLR (67% Females; 21.45 ± 4.56 years). Overground gait biomechanics using 3D motion capture were collected, and knee kinematics were extracted for post-processing. Sample entropy (SampEn) was used to calculate knee kinematic variability. Pearson's product-moment correlations were conducted to determine the associations between SampEn and KOOS sub-scores. Additionally, independent samples t-tests were performed to evaluate potential differences in SampEn outcomes between individuals with and without clinically relevant symptoms (defined in the introduction). Less sagittal plane kinematic variability is associated with greater pain (r = 0.37, p = 0.01) and symptoms (r = 0.32, p = 0.03). Symptomatic participants demonstrated less sagittal plane knee kinematic variability compared to asymptomatic participants (p = 0.01). The findings suggest less variable gait patterns 6-months post-ACLR may be linked to KOA-related symptoms.

To investigate the occurrence of meniscal calcifications in individuals with and without knee osteoarthritis (OA). Additionally, we aim to identify the specific types of calcifications: basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP).

We analyzed 82 meniscal posterior horn samples (medial and lateral) collected from 41 human subjects. Among them, 20 individuals underwent total knee replacement due to medial compartment OA, while 21 deceased donors had no known knee OA. The assessment of meniscal calcifications and Pauli's histopathological scoring was conducted using histological sections. Furthermore, adjacent sections underwent measurement using Raman spectroscopy to characterize BCP and CPP calcifications based on their distinct spectral fingerprints.

All OA individuals exhibited calcifications in at least one meniscus, compared to 9.5% (95%CI 1%, 30%) of donors. Among 35 OA menisci with calcifications, 28(80%) had BCP, 5(14%) had CPP and 2(6%) had both types. In 4 donor menisci, 3(75%) had CPP while 1(25%) had both types. We estimated the association between Pauli score and presence of BCP in OA individuals, yielding an odds ratio of 2.1 (95%CI 0.8, 5.3) per 1 Pauli score. The association between Pauli score and presence of CPP (in whole study sample) seemed weaker, with odds ratio of 1.3 (95%CI 1.1, 1.7).

The presence of BCP was predominant in menisci of OA individuals, whereas CPP exhibited similar prevalence in individuals with and without OA. The formation of BCP crystals in menisci may represent an important and specific characteristic of OA disease process that warrants further attention.

To compare the clinical outcomes, failure rates, surgical complications, and postoperative radiographic changes following partial meniscectomy versus meniscal repair for horizontal cleavage tears (HCTs).

A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the Scopus, PubMed, and Embase computerized databases. Clinical studies evaluating partial meniscectomy or meniscal repair for HCTs were included. Demographic characteristics, surgical techniques, clinical outcomes, failure rates, complications, and radiographic assessments were recorded.

A total of 18 studies comprising 833 patients with HCTs were included, of which 562 patients (67.5%) were treated with partial meniscectomy and 271 (32.5%) with meniscal repair. Both types of treatments reported improved clinical outcomes, including International Knee Documentation Committee, Lysholm, Knee injury and Osteoarthritis Outcome Score, and Tegner scores. Failure rates were reported to range between 0% and 15% following partial meniscectomy and from 0% to 17.6% following repair; complications were 7.5% after partial meniscectomy and between 3.8% and 21.4% following meniscal repair. Patients undergoing meniscectomy demonstrated progression of degenerative changes on radiographic assessments.

Repair of HCTs in the appropriately indicated patient can result in similar patient outcomes and failure rates compared to partial meniscectomy. However, especially in patients aged 42 years and younger, a greater complication rate can be expected with repair, while a greater degree of ipsilateral compartment degeneration is seen after partial meniscectomy.

Level IV, systematic review of Level I to IV studies.

The meniscus tissue is crucial for knee joint biomechanics and is frequently susceptible to injuries resulting in early-onset osteoarthritis. Consequently, the need for meniscal substitutes spurs ongoing development. The meniscus is a composite tissue reinforced with circumferential and radial collagenous fibers; the mechanical role of the latter has yet to be fully unveiled. Here, we investigated the role of radial fibers using a synergistic methodology combining meniscal tissue structure imaging, a computational knee joint model, and the fabrication of simple biomimetic composite laminates. These laminates mimic the basic structural units of the meniscus, utilizing longitudinal and transverse fibers equivalent to the circumferential and radial fibers in meniscal tissue. In the computational model, the absence of radial fibers resulted in stress concentration within the meniscus matrix and up to 800 % greater area at the same stress level. Furthermore, the contact pressure on the tibial cartilage increased drastically, affecting up to 322 % larger areas. Conversely, in models with radial fibers, we observed up to 25 % lower peak contact pressures and width changes of less than 0.1 %. Correspondingly, biomimetic composite laminates containing transverse fibers exhibited minor transverse deformations and smaller Poisson's ratios. They demonstrated structural shielding ability, maintaining their mechanical performance with the reduced amount of fibers in the loading direction, similar to the ability of the torn meniscus to carry and transfer loads to some extent. These results indicate that radial fibers are essential to distribute contact pressure and tensile stresses and prevent excessive deformations, suggesting the importance of incorporating them in novel designs of meniscal substitutes. STATEMENT OF SIGNIFICANCE: The organization of the collagen fibers in the meniscus tissue is crucial to its biomechanical function. Radially oriented fibers are an important structural element of the meniscus and greatly affect its mechanical behavior. However, despite their importance to the meniscus mechanical function, radially oriented fibers receive minor attention in meniscal substitute designs. Here, we used a synergistic methodology that combines imaging of the meniscal tissue structure, a structural computational model of the knee joint, and the fabrication of simplistic biomimetic composite laminates that mimic the basic structural units of the meniscus. Our findings highlight the importance of the radially oriented fibers, their mechanical role in the meniscus tissue, and their importance as a crucial element in engineering novel meniscal substitutes.

The purpose of this study was to evaluate the impact that obesity, smoking, and older age have on 30-day postoperative complications, reoperations, and readmissions of patients undergoing arthroscopic meniscectomy or meniscus repair.

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried to identify meniscus surgeries and operative outcomes between 2008 and 2016. Controlled regression analysis was then performed to evaluate for an association between obesity, age, and smoking and these outcomes.

While obesity showed no influence on adverse postoperative complications or reoperations, class I obesity was associated with a lower rate of readmission. Older age, smoking, and comorbidity burden were significant predictors of postoperative complications, reoperations, and/or readmissions. Age 80 years or older was particularly predictive of 30-day complications (odds ratio, 3.5; P<.001) and readmissions (odds ratio, 2.5; P=.004).

Obesity is not a major risk factor for complications when undergoing meniscus surgery, while age older than 70 years predicts negative short-term postoperative outcomes. [Orthopedics. 20XX;4X(X):XXX-XXX.].

Meniscal lesions in vascularized regions are known to regenerate while lack of vascular supply leads to poor healing. Here, we developed and validated a novel methodology for three-dimensional structural analysis of meniscal vascular structures with high-resolution microcomputed tomography (µCT). We collected porcine medial menisci from 10 neonatal (not-developed meniscus, n-) and 10 adults (fully developed meniscus, a-). The menisci were cut into anatomical regions (anterior horn (n-AH and a-AH), central body (n-CB and a-CB), and posterior horn (n-PH and a-PH). Specimens were cut in half, fixed, and one specimen underwent critical point drying and µCT imaging, while other specimen underwent immunohistochemistry and vascularity biomarker CD31 staining for validation of µCT. Parameters describing vascular structures were calculated from µCT. The vascular network in neonatal spread throughout meniscus, while in adult was limited to a few vessels in outer region, mostly on femoral side. n-AH, n-CB, and n-PH had 20, 17, and 11 times greater vascular volume fraction than adult, respectively. Moreover, thickness of blood vessels, in three regions, was six times higher in adults than in neonatal. a-PH appeared to have higher vascular fraction, longer and thicker blood vessels than both a-AH and a-CB. Overall, neonatal regions had a higher number of blood vessels, more branching, and higher tortuosity compared to adult regions. For the first time, critical point drying-based µCT imaging allowed detailed three-dimensional visualization and quantitative analysis of vascularized meniscal structures. We showed more vascularity in neonatal menisci, while adult menisci had fewer and thicker vascularity especially limited to the femoral surface.

Knee osteoarthritis (OA) typically presents with joint pain that is exacerbated by use and alleviated with rest. There is relatively brief, self-limited morning stiffness and absence of constitutional symptoms. Overweight and obesity are the most important modifiable risk factors. Although pharmacologic and nonpharmacologic interventions are generally effective at alleviating pain and improving physical function, they do not fundamentally reverse the pathologic and radiographic process of knee OA. As the severity of disease increases, the magnitude of pain and functional impairment intensifies. Surgical intervention should be pursued to relieve pain and restore functionality only when nonpharmacologic approaches and pharmacologic agents fail to control pain.

The objective of this study was to determine the optimal meniscal radiomic features to classify people who will develop an incident destabilizing medial meniscal tear. We used magnetic resonance (MR) images from an existing case-control study that includes images from the first 4 years of the Osteoarthritis Initiative (OAI). For this exploratory analysis (n = 215), we limited our study sample to people with (1) intact menisci at the OAI baseline visit, (2) 4-year meniscal status data, and (3) complete meniscal data from each region of interest. Incident destabilizing meniscal tear was defined as progressing from an intact meniscus to a destabilizing tear by the 48-month visit using intermediate-weighted fat-suppressed MR images. One reader manually segmented each participant's anterior and posterior horn of the medial menisci at the OAI baseline visit. Next, 61 different radiomic features were extracted from each medial meniscus horn. We performed a classification and regression tree (CART) analysis to determine the classification rules and important variables that predict incident destabilizing meniscal tear. The CART correctly classified 24 of the 34 cases and 172 out of 181 controls with a sensitivity of 70.6% and a specificity of 95.0%. The CART identified large zone high gray level emphasis (i.e., more coarse texture) from the posterior horn as the most important variable to classify who would develop an incident destabilizing medial meniscal tear. The use of radiomic features provides sensitive and quantitative measures of meniscal alterations, allowing us to intervene and prevent destabilizing meniscal tears.

The use of platelet-rich plasma (PRP) in all medical fields is currently gaining popularity (1). PRP is a biological product that can be defined as a segment of the plasma fraction of autologous blood with a platelet concentration level above the baseline (2). The fact that it has uses in tissue regeneration and wound healing has caught the eye of orthopedic surgeons as well, as intra-articular treatments have continued to evolve. Its benefits in the treatment of different osteoarticular pathologies are of great interest in the evolving orthopedic community, targeting mostly knee osteoarthritis, meniscus and ligament injuries (3). The purpose of this review is to update the reader on the current uses of platelet-rich plasma (PRP) in the treatment of knee osteoarthritis pathology and to provide clinical feedback on its uses in the fields of orthopedic and sports medicine practice (4). We proceeded in studying 180 titles and abstracts eligible for inclusion. Compared to alternative treatments, PRP injections greatly improve the function of the knee joint.

Anterior cruciate ligament injury and anterior cruciate ligament reconstruction (ACLR) are risk factors for symptomatic posttraumatic osteoarthritis (PTOA). After ACLR, individuals demonstrate altered joint tissue metabolism indicative of increased inflammation and cartilage breakdown. Serum biomarker changes have been associated with tibiofemoral cartilage composition indicative of worse knee joint health but not with PTOA-related symptoms.

The purpose of this study was to determine associations between changes in serum biomarker profiles from the preoperative sample collection to 6 months after ACLR and clinically relevant knee PTOA symptoms at 12 months after ACLR. It was hypothesized that increases in biomarkers of inflammation, cartilage metabolism, and cartilage degradation would be associated with clinically relevant PTOA symptoms after ACLR.

Case-control study; Level of evidence, 3.

Individuals undergoing primary ACLR were included (N = 30). Serum samples collected preoperatively and 6 months after ACLR were processed to measure markers indicative of changes in inflammation (ie, monocyte chemoattract protein 1 [MCP-1]) and cartilage breakdown (ie, cartilage oligomeric matrix protein [COMP], matrix metalloproteinase 3, ratio of type II collagen breakdown to type II collagen synthesis). Knee injury and Osteoarthritis Outcome Score surveys were completed at 12 months after ACLR and used to identify participants with and without clinically relevant PTOA-related symptoms. K-means cluster analyses were used to determine serum biomarker profiles. One-way analyses of variance and logistic regressions were used to assess differences in Knee injury and Osteoarthritis Outcome Score subscale scores and clinically relevant PTOA-related symptoms between biomarker profiles.

Two profiles were identified and characterized based on decreases (profile 1: 67% female; age, 21.4 ± 5.1 years; body mass index, 24.4 ± 2.4) and increases (profile 2: 33% female; age, 21.3 ± 3.2 years; body mass index, 23.4 ± 2.6) in sMCP-1 and sCOMP preoperatively to 6 months after ACLR. Participants with profile 2 did not demonstrate differences in knee pain, symptoms, activities of daily living, sports function, or quality of life at 12 months after ACLR compared to those with profile 1 (P = .56-.81; η2 = 0.002-0.012). No statistically significant associations were noted between biomarker profiles and clinically relevant PTOA-related symptoms (odds ratio, 1.30; 95% CI, 0.23-6.33).

Serum biomarker changes in MCP-1 and sCOMP within the first 6 months after ACLR were not associated with clinically relevant PTOA-related symptoms.

The self-repair ability after meniscal tears is poor, leading to the development of posttraumatic osteoarthritis. Promoting the repair of meniscal injuries remains a great challenge, especially in the avascular region.

Local delivery of skeletal stem cell (SSC)-derived exosomes (SSC-Exos) would promote meniscal healing and prevent secondary osteoarthritis progression.

Controlled laboratory study.

SSCs were isolated from bone marrow and exosomes were extracted via ultracentrifugation. The cell migration capabilities after incubation with exosomes were validated through in vitro cell culture. Full-thickness longitudinal medial meniscal tears were performed in the avascular region of 40 male Sprague-Dawley rats and 20 male New Zealand White rabbits, which were randomly divided into 2 groups: group treated with phosphate-buffered saline (GCON) and group treated with exosomes (GExosome). The effects of these treatments on meniscal healing and secondary osteoarthritis were evaluated by gross inspection, biomechanical testing, and histological assessment. RNA sequencing of in vitro cell cultures was performed to explore the underlying mechanisms.

Exosomes were successfully extracted and identified. These exosomes significantly promoted cell migration capabilities in vitro (P < .01). The GExosome exhibited greater cell proliferation and tissue regeneration with type 2 collagen secretion, and a significantly higher meniscal repair score than that of the GCON at 8 weeks postoperatively (P < .05). In contrast to the degenerative changes in both the meniscus and articular cartilage of the GCON, meniscal tissue in the GExosome exhibited restoration of normal morphology with a smooth and glossy white surface and better mechanical strength at 8 weeks after meniscal repair. Both degeneration scores and synovitis scores were significantly higher in the GCON than in the GExosome (P < .05). Compared with the GCON, the expression of key genes related to cell migration, such as the chemokine family, was enhanced by exosome injection, leading to an upregulation of extracellular matrix expression while downregulating the expression of inflammation-related genes such as CD68 and the matrix metalloproteinase family.

The administration of SSC-Exos effectively promoted meniscal healing in the avascular region and ameliorated secondary osteoarthritis. The effect might be attributed to inflammation modulation, promotion of cell migration, and secretion of extracellular matrix components.

Injection of SSC-Exos represents a promising therapeutic option for promoting meniscal healing in the avascular region.

Knee osteoarthritis is common in older people. Serum cartilage oligomeric matrix protein (sCOMP) is a biomarker of knee articular cartilage metabolism. The purpose of this study was 2-fold: to (1) determine acute effects of running and swimming on sCOMP concentration in older people; and (2) investigate relationships between sCOMP concentration change due to running and swimming and measures of knee health in older people.

Running would result in greater increase in sCOMP concentration than swimming, and increase in sCOMP concentration due to running and swimming would associate positively with measures of poor knee health.

Cross-sectional.

Level 3.

A total of 20 participants ran 5 km and 19 participants swam 1500 m. sCOMP concentration was measured immediately before, immediately after, and 15, 30, and 60 minutes after running or swimming. sCOMP concentration change due to running and swimming was compared. Correlations between sCOMP concentration change due to running and swimming, and other measures of knee health were evaluated, including the Tegner Activity Scale and Knee injury and Osteoarthritis Outcome Score.

sCOMP concentration increased 29% immediately after running, relative to baseline, but only 6% immediately after swimming (P < 0.01). No significant relationship was observed between acute sCOMP change due to running and swimming, and observed measures of knee health (P > 0.05). Participants with clinically relevant knee symptoms exhibited greater sCOMP concentration before and after running and swimming (P = 0.03) and had greater body mass (P = 0.04).

Running results in greater acute articular cartilage metabolism than swimming; however, the chronic effects of this are unclear. Older people with clinically relevant knee symptoms possess greater sCOMP concentration and are heavier, independent of exercise mode and physical activity level.

These results describe the effects of exercise (running and swimming) for older physically active persons, with and without knee pain.

Most studies regarding medial meniscus posterior root tear (MMPRT) report total Knee injury and Osteoarthritis Outcome Score (KOOS) subscale values as important patient-reported outcomes, but there are few symptom-specific characterizations of patients with MMPRT.

The purpose of this study was to characterize the prevalence and severity of symptoms and functional limitations among patients with MMPRT based on item-level KOOS responses. It was hypothesized that patients with MMPRT would show similar symptoms to those of other meniscal tear types, with items from the KOOS pain subscale forming a majority of the most severe and prevalent symptoms.

Cross-sectional study; Level of evidence, 3.

The records of 1466 patients with medial meniscus root tear between January 2017 and December 2021 at a single institution were reviewed. KOOS subscale scores and item-specific responses from initial evaluation were collected for each patient. Each KOOS item was scored on a scale from 1 (none/least severe) to 5 (extreme/most severe). Median and mean item-level responses were calculated and ranked in order of most to least severe. For statistical analysis, item-level prevalence rates were calculated as the proportion of patients reporting at least mild symptoms and ranked from most to least prevalent.

Included were 61 patients with MMPRT verified on magnetic resonance imaging (MRI). The most severe items according to item-level KOOS response were as follows: awareness of knee problem (mean, 4.62 [95% CI, 4.47-4.78]), difficulty jumping (mean, 4.06 [95% CI, 3.73-4.39]), difficulty twisting or pivoting (mean, 4.04 [95% CI, 3.76-4.32]), difficulty kneeling (mean, 3.98 [95% CI, 3.65-4.31]), and modification of lifestyle (mean, 3.94 [95% CI, 3.69-4.20]). The most prevalent items were knee stiffness later in the day, pain going up- or downstairs, difficulty ascending stairs, difficulty getting in and out of the car, difficulty twisting or pivoting, awareness of knee problem, and modification of lifestyle, with all patients reporting at least mild symptoms for each. Of the 11 most severe and prevalent symptoms, 8 came from the KOOS-Pain item-specific responses.

Pain-related items made up a majority of the most severe and most prevalent symptoms as identified by the item-specific KOOS responses. However, meniscal symptoms commonly seen in other tear types, such as clicking and knee stiffness, were still quite prevalent in patients with MMPRT.

The objective of this study was to compare the vertical (vGRF), anterior-posterior (apGRF), and medial-lateral (mlGRF) ground reaction force (GRF) profiles throughout the stance phase of gait (1) between individuals 6 to 12 months post-anterior cruciate ligament reconstruction (ACLR) and uninjured matched controls and (2) between ACLR and individuals with differing radiographic severities of knee osteoarthritis (KOA), defined as Kellgren and Lawrence (KL) grades KL2, KL3, and KL4.

A total of 196 participants were included in this retrospective cross-sectional analysis. Gait biomechanics were collected from individuals 6 to 12 months post-ACLR (n = 36), uninjured controls matched to the ACLR group (n = 36), and individuals with KL2 (n = 31), KL3 (n = 67), and KL4 osteoarthritis (OA) (n = 26). Between-group differences in vGRF, apGRF, and mlGRF were assessed in reference to the ACLR group throughout each percentage of stance phase using a functional linear model.

The ACLR group demonstrated lower vGRF and apGRF in early and late stance compared to the uninjured controls, with large effects (Cohen's d range: 1.35-1.66). Conversely, the ACLR group exhibited greater vGRF (87%-90%; 4.88% body weight [BW]; d = 0.75) and apGRF (84%-94%; 2.41% BW; d = 0.79) than the KL2 group in a small portion of late stance. No differences in mlGRF profiles were observed between the ACLR and either the uninjured controls or the KL2 group. The magnitude of difference in GRF profiles between the ACLR and OA groups increased with OA disease severity.

Individuals 6 to 12 months post-ACLR exhibit strikingly similar GRF profiles as individuals with KL2 KOA, suggesting both patient groups may benefit from targeted interventions to address aberrant GRF profiles.

Osteoarthritis (OA) can cause disability and reduce quality of life (QoL).

This study aimed to determine whether GreenShell mussel (GSM) powder (PERNAULTRA) consumption was more effective than placebo at improving physical performance and subjective measures of symptoms and function in adults with early signs of knee OA.

The Researching Osteoarthritis and GSM study was a 6-mo randomized, double-blind, placebo-controlled trial in adults aged 55-80 y, screened for signs of OA (n = 120, 65.9 ± 6.43 y, 63% female). Participants consumed either 3 g of powdered whole GSM or placebo (pea protein) daily. Baseline and end data collection included 30-s chair stand, stair test, 40-m fast-paced walk test, Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire categorized into 5 subscales [pain (P), symptoms except pain (S), function in activities of daily living (ADL), function in sports/recreation (SP), and QoL], a measure of Intermittent and Constant Osteoarthritis Pain, and visual analog scale of pain and symptoms.

Visual analog scale symptoms showed a significantly greater reduction in percentage change for GSM than that for placebo [-28.1 (-59.2, 43.2) compared with 0.00 (-28.6, 100); P = 0.03]. Further, a trend for improvement in percentage change for GSM compared with placebo was seen in 40m fast-paced walk [2.51 (-3.55, 8.12) compared with 0.20 (-6.58, 4.92); P = 0.09], KOOS-SP [11.4 (-4.48, 27.0) compared with 0.00 (-11.1, 17.7); P = 0.09], and Intermittent and Constant Osteoarthritis Pain intermittent pain scale [-27.7 (-77.3, 0.00) compared with -14.6 (-50.0, 36.4); P = 0.08]. In those with body mass index (BMI; in kg/m2) <25, GSM consumption significantly improved KOOS-S compared with placebo [6.35 (3.49, 12.7) compared with 0.00 (-4.65, 4.49); P = 0.03] and showed a trend for improvement in KOOS-ADL [3.29 (1.01, 8.79) compared with 1.01 (-5.75, 4.30); P = 0.07]. Those with BMI of ≥25, consuming GSM showed a trend for improvement in KOOS-SP [13.6 (-4.76, 33.3) compared with 0.00 (-12.5, 20.0); P = 0.07].

This research suggests consumption of GSM has potential to alleviate symptoms and improve functionality in OA.This trial was registered at Clinical Trial Registry as ACTRN12620001112954p (https://www.anzctr.org.au/ACTRN12620001112954p.aspx).

Individuals who sustain an ACL injury and undergo reconstruction (ACLR) are at risk for the development of osteoarthritis. Recent investigations have applied the Englund criteria to categorize people with a history of ACLR as someone with a symptomatic or asymptomatic knee.

The purpose of this study was to examine differences in health-related quality of life (HRQL) and psychological outcomes in people with a history of ACLR who were categorized as symptomatic or non-symptomatic by application of the Englund criteria. The authors' hypothesized participants classified as symptomatic would have lower HRQL, increased fear-avoidance beliefs, and decreased resilience compared to participants classified as non-symptomatic.

Cross-sectional, survey.

Participants at least one-year after ACLR were recruited for the study and completed the Tegner Activity Scale, the Brief Resilience Scale (BRS), the modified Disablement in the Physically Active Scale (mDPA), and the Fear-Avoidance Belief Questionnaire (FABQ) at one time-point. Descriptive statistics were summarized using median [interquartile range] and differences between groups were examined using separate Mann-Whitney U tests.

Participants with symptomatic knees had a significantly higher BMI (24.8 [6.4]) than the non-symptomatic group (21.2 [4.3], p=0.013). Participants in the symptomatic group had worse HRQL on the physical subscale (12.5 [16.3] vs. 0.0 [2.5], p<0.001) and mental subscale (2.0 [1] vs. 0.0 [1], p=0.031), higher scores on the FABQ-Sport (14.5 [11] vs. 0.0 [6], p<0.001) and FABQ-Physical Activity (20 [24] vs. 1 [4], p<0.001) and less resilience (3.7[0.42] vs. 4.0 [0.83], p=0.028) compared to those participants in the non-symptomatic group. There were no differences in current physical activity (p=0.285) or change in physical activity (p=0.124) levels between the two groups.

This series of differences may represent a cascade of events that can continue to negatively impact health outcomes across the lifespan for individuals with a history of ACLR. Future research should consider longitudinal investigations of these outcomes after injury and throughout the post-surgical and post-rehabilitation timeframe.

Level 3b.

It is unclear how anterior cruciate ligament (ACL) reconstruction (ACLR) affects the development of osteoarthritis (OA). This uncertainty is partly caused by the lack of long-term studies on ACL injuries treated primarily without reconstruction and the underreporting of symptomatic OA.

To determine (1) the knee function, symptoms, and activity level, as well as the presence of radiographic and symptomatic OA; (2) how these clinical outcomes have changed over time; and (3) the frequency of subsequent knee surgeries after the index ACL injury in a cohort of patients with ACL injuries treated primarily without reconstruction.

Case series; Level of evidence, 4.

A total of 100 patients underwent initial nonoperative treatment >30 years ago (mean, 33.2 ± 1.4 years). Of these, 81 patients (mean age, 59 ± 8 years) completed the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, and Tegner Activity Scale. Seventy-three patients underwent radiography to evaluate tibiofemoral and patellofemoral OA in the ACL-injured knee. Patients only underwent late ACLR if they experienced insufficient knee stability.

At 33 years after the ACL injury, the KOOS Activities of Daily Living subscore was better than population-based reference values, but scores were similar for the remaining KOOS subscales. Furthermore, 65% of patients had a good or excellent Lysholm score (≥84 points). The Tegner score decreased 4 points from before the injury to 33-year follow-up (P < .001). Most patients (75%) had evidence of radiographic tibiofemoral and/or patellofemoral OA, but only 38% were classified as having symptomatic OA (defined as radiographic OA in combination with a symptomatic knee according to cutoffs on the KOOS). Approximately 50% underwent meniscal surgery, and 29% subsequently underwent ACLR for recurrent instability. There were 2 patients who underwent total knee replacement.

Despite a high prevalence of radiographic OA, patients achieved acceptable subjective knee function and had a relatively low prevalence of symptomatic OA at >30 years after an ACL injury when an initial nonoperative treatment strategy was employed.

This review provides insights at the molecular level into the current and old methods for treating meniscal injuries. Meniscal injuries have been found to have a substantial impact on the progression of osteoarthritis. In line with the "save the meniscus" approach, meniscectomy is considered a last-resort treatment. Nevertheless, it is important to note that mechanical repair alone may not achieve the complete restoration of the meniscus. A deep understanding of the healing pathways could lead to future improvements in meniscal healing. The inclusion of cytokines and chemokines has the potential to facilitate the process of tear repair or impede the inflammatory catabolic cascade. MicroRNA (miRNA) could serve as a potential biomarker for meniscal degeneration, and RNA injections might promote collagen and growth factor production. The critical aspect of the healing process is angiogenesis within the inner zone of the meniscus. The use of collagen scaffolds and the implantation of autologous meniscus fragments have been successfully integrated into clinical settings. These findings are encouraging and underscore the need for well-designed clinical trials to explore the most effective factors that can enhance the process of meniscal repair.

Meniscal tears are common and may impair knee function and biomechanics. This meta-analysis compared meniscal repair versus resection in patients with symptomatic meniscal tears in terms of patient-reported outcomes measures (PROMs), joint width, surgical failure, and rate of progression to osteoarthritis (OA) at conventional radiography.

This study was conducted according to the 2020 PRISMA statement. In August 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, and Embase. Two reviewers independently performed the analysis and a methodological quality assessment of the included studies. All the clinical investigations which compared repair versus resection of meniscal tears were accessed.

Data from 20 studies (31,783 patients) were collected. The mean BMI was 28.28 ± 3.2 kg/m2, and the mean age was 37.6 ± 14.0 years. The mean time elapsed from injury to surgery was 12.1 ± 10.2 months and the mean medial joint width was 4.9 ± 0.8 mm. Between studies comparability at baseline was found in age, women, BMI, time from injury to surgery and length of the follow-up, PROMs, medial joint width, and stage of OA. The resection group demonstrated a greater Lysholm score (P = 0.02). No difference was found in the International Knee Documentation Committee (P = 0.2). Nine studies reported data on the rate of failures at a mean of 63.00 ± 24.7 months. No difference was found between the two groups in terms of persistent meniscal symptoms (P = 0.8). Six studies reported data on the rate of progression to total knee arthroplasty at a mean of 48.0 ± 14.7 months follow-up. The repair group evidenced a lower rate of progression to knee arthroplasty (P = 0.0001). Six studies reported data on the rate of advanced knee OA at a mean of 48.0 ± 14.7 months of follow-up. The repair group evidenced a lower rate of advanced knee OA (P = 0.0001). No difference was found in the mean joint space width (P = 0.09).

Meniscal repair is associated with a lower progression to knee osteoarthritis at approximately six years of follow-up compared to partial meniscectomy. No difference in PROMs, medial joint width, and failures were evidenced.

Level III, meta-analysis.

Mesenchymal stem cell (MSC)-based exosomes have garnered attention as a viable therapeutic for post-traumatic cartilage injury and osteoarthritis of the knee; however, efforts for application have been limited due to issues with variable dosing and rapid clearance in vivo. Scaffolds laden with MSC-based exosomes have recently been investigated as a solution to these issues. Here, we review in vivo studies and highlight key strengths and potential clinical uses of exosome-scaffold therapeutics for treatment of post-traumatic cartilage injury and osteoarthritis. In vivo animal studies were gathered using keywords related to the topic, revealing 466 studies after removal of duplicate papers. Inclusion and exclusion criteria were applied for abstract screening and full-text review. Thirteen relevant studies were identified for analysis and extraction. Three predominant scaffold subtypes were identified: hydrogels, acellular extracellular matrices, and hyaluronic acid. Each scaffold-exosome design showcased unique properties with relation to gross findings, tissue histology, biomechanics, and gene expression. All designs demonstrated a reduction in inflammation and induction of tissue regeneration. The results of our review show that current exosome-scaffold therapeutics demonstrate the capability to halt and even reverse the course of post-traumatic cartilage injury and osteoarthritis. While this treatment modality shows incredible promise, future research should aim to characterize long-term biocompatibility and optimize scaffold designs for human treatment.