Outcome of meniscal repairs in paediatric population: A tertiary centre experience

Abstract

BACKGROUND

Meniscal sparing surgery is a widely utilised treatment option for unstable meniscal tears with the aim of minimising the risk of progression towards osteoarthritis. However, there is limited data in the literature on meniscal repair outcomes in skeletally immature patients.

AIM

To evaluate the re-operation rate and functional outcomes of meniscal repairs in children and adolescents.

METHODS

We performed a retrospective review of all patients who underwent arthroscopic meniscal repair surgery between January 2007 and January 2018. All patients were under the age of 18 at the time of surgery. Procedures were all performed by a single surgeon. Information was gathered from our hospital Electronic Patient Records system. The primary outcome measure was re-operation rate (need for further surgery on the same meniscus). Secondary outcome measures were surgical complications and patient reported outcome measures that were International Knee Documentation Committee (IKDC), Tegner and Lysholm scores.

RESULTS

We identified 59 patients who underwent 66 All-inside meniscal repairs (32 medial meniscus and 34 Lateral meniscus). Meniscal repairs were performed utilizing FasT-Fix (Smith and Nephew) implants. There were 37 males and 22 females with an average age of 14 years (range 6-16). The average follow-up time was 53 months (range 26-140). Six patients had concomitant anterior cruciate ligament reconstruction surgery along with the meniscal repair. There were no intra-operative complications. The re-operation rate for meniscal repairs was 16.6% (11 cases) with 2 patients requiring further meniscal repairs and 9 patients underwent partial meniscectomies. The mean postoperative IKDC score was 88 (44-100), Tegner score was 7(2-10) and Lysholm score was 94 (57-100).

CONCLUSION

Our results showed that arthroscopic repair of meniscal tears in the paediatric population is an effective treatment option that has a low failure rate and good postoperative clinical with the advantage of preserving meniscal tissues.

Key Words: Meniscus, Meniscal repair, Outcome, Meniscal preservation

Core Tip: There has been a significant shift towards meniscal preservation surgery, recognizing the crucial role of the menisci in knee joint function. Although clinical outcomes of meniscal repairs are well-documented in the literature, data on pediatric outcomes are limited. This study demonstrates that meniscal repair in pediatric and adolescent patients has a low re-operation rate and satisfactory postoperative functional outcomes, as measured by Patient-Reported Outcome Measures. This indicates that arthroscopic repair of meniscal tears is a safe and effective treatment option for this specific age group.

INTRODUCTION

Meniscal tears are widely prevalent in adult population, yet their incidence is steadily rising among children and adolescence[1]. This could be attributed to the improvement in knee imaging modalities and increased sports participation among paediatric population[2-4]. The menisci have a vital role in load transmission, joint lubrication, proprioception and knee stability[5-7]. Surgical management of meniscal tears has evolved from total and partial meniscectomy to meniscal repair with emphasis on meniscal preservation. There is well documented evidence in the literature that meniscal resection leads to increased contact stresses and accelerated degenerative changes in the knee[8-11]. Consequently, there has been a growing trend towards meniscal preservation surgery[12]. Arthroscopic meniscal repair has evolved over the last two decades with improvement in surgical techniques and devices[13]. Several studies have reported satisfactory short and long term results following meniscal repair surgery with a re-operation rate between 16.5% and 20.7% respectively, failure of meniscal repair in around 20%[14-16].

However, most of these studies have focused on the adult population with limited data available in the literature on clinical outcomes following meniscal repair in the children and adolescent population[17]. The aim of this study was to assess the functional outcomes and re-operation rate of arthroscopic all-inside meniscus repair in children and adolescents. We sought to determine the clinical outcomes and return to sports after arthroscopic meniscal repair in this age group.

MATERIALS AND METHODS

Following approval by our institutional review board, a retrospective review was performed for all patients under the age of 18 who underwent arthroscopic meniscal repair at our tertiary centre for paediatric orthopaedics. All procedures were performed by a single paediatric knee surgeon. All patients were assessed clinically for symptomatic meniscal tear and diagnosis was confirmed with magnetic resonance imaging (MRI) of the knee prior to surgery. Patient with discoid meniscus, multiligaments injury, concomitant periarticular fractures, or full-thickness osteochondral lesions were excluded from this study. Information was gathered from our hospital Electronic Patient Records system as well as telephone interviews with patients.

Study population

We identified 59 patients who underwent 66 All-inside meniscal repairs (32 medial meniscus and 34 lateral meniscus). There were 37 males and 22 females with an average age of 14 years (range 6-16). There were 37 right and 29 left knees involved. The most common meniscal tear type was longitudinal tears (62%) followed by bucket handle tears (21%; Table 1). Of the 66 meniscal tears, 59 tears were in the red zone, 6 tears were in the red-white zone and only one tear in the white zone. Six patients underwent concomitant anterior cruciate ligament (ACL) reconstruction with meniscal repair while the remaining cases were isolated meniscal repair. The average postoperative follow-up time was 53 months (range 26-140). Postoperative knee MRI scans were only performed for patients experiencing persistent or new knee symptoms to assess and rule out potential failure of the meniscal repair.

Table 1 Demographics and meniscal tear characteristics in the study population.

Surgical demographic
Age at time of surgery
Mean (SD)	14 (2.4)
Range	6-16
Gender, n (%)
Male	37 (67)
Female	22 (33)
Operative side, n (%)
Right	37 (56)
Left	29 (44)
Meniscal side, n (%)
Medial	32 (48)
Lateral	34 (52)
Tear type, n (%)
Longitudinal	41 (62)
Bucket handle	14 (21)
Horizontal	6 (9)
Complex	5 (8)
Tear location, n (%)
Red-red	59 (89)
Red-white	6 (9)
White-white	1 (2)

Surgical technique

Standard knee arthroscopy was performed with an anterolateral and an anteromedial portals. A thigh tourniquet was utilised in all cases. The meniscal tear was assessed intraoperatively to determine its suitability for meniscal repair, depending on the meniscal tear pattern and location. All meniscal tears underwent preparation including reduction of tear, freshening of tear edges and rasping with meniscal rasp to stimulate bleeding. Depending on the type of tear, a vertical or horizontal mattress suturing pattern was used to approximate the torn edges till meniscal stability was achieved. The stability of the meniscal repair was assessed using a meniscal probe to ensure satisfactory repair. All meniscal tears were repaired using all inside FasT-Fix devices (Smith & Nephew). The number of meniscal sutures was dependent on the tear pattern with a minimum gap of 5 mm between sutures.

Rehabilitation

The rehabilitation protocol following meniscal repair involved utilizing crutches for protected weightbearing and restricting the range of motion to below 90° for a period of 4-6 week postoperatively depending on the type of tear. Gradual increments in activity levels were implemented, with explicit avoidance of squatting or pivoting for a duration of 3 months. Clearance for sports participation was granted between 4 to 6 months post-surgery, subject to favourable clinical advancements.

Outcomes

The primary outcome measure for this study was to assess the re-operation rate following meniscal repair. Re-operation was defined as any further surgery on the same meniscus. The secondary outcome measure was patient reported outcomes measures (PROMs) at final follow up (minimum 2 years). We collected the following PROMs for this study: Subjective International Knee Documentation Committee (IKDC)[18], the Lysholm and the Tegner activity score[19,20]. Descriptive statistics including means and range were deemed appropriate to assess the available demographic, surgical and patient-reported outcome data.

RESULTS

There were no recorded intraoperative complications. The re-operation rate was 16.6% (11 cases). Six out of the 11 cases were meniscal repairs for bucket handle tears (Table 2). Two out of 11 cases underwent their re-operation at local hospitals while the rest of patient underwent surgery at our centre. At final postoperative follow up, the mean IKDC score was 88 (44-100), Tegner score was 7(2-10) and Lysholm score was 94 (57-100). Table 3 describes the PROMs scores at final follow up in patients who had successful meniscal repair compared to patients who had failure of the meniscal repair.

Table 2 Characteristics of failed meniscal repair cases.

	Age/gender	Side	Medial/lateral	Tear type	Tear location	Meniscal zone	Associated ACL reconstruction	Further surgery
1	14/F	Left	Medial	Longitudinal	Posterior horn	Red-White	No	Partial meniscectomy
2	11/M	Left	Lateral	Longitudinal	Posterior horn	Red	Yes	Meniscal repair
3	15/F	Left	Medial	Longitudinal	Posterior	Red	No	Meniscal repair
4	15/M	Right	Lateral	Bucket handle	Posterior to anterior	Red-White	No	Partial meniscectomy
5	15/M	Left	Lateral	Longitudinal	Body	Red	No	Partial meniscectomy
6	15/M	Right	Medial	Longitudinal	Posterior	Red	No	Partial meniscectomy
7	13/M	Right	Medial	Bucket handle	Posterior to anterior	Red-White	No	Partial meniscectomy
8	6/F	Right	Lateral	Bucket handle	Posterior to anterior	Red	No	Partial meniscectomy
9	14/M	Left	Lateral	Bucket handle	Posterior to anterior	Red	No	Partial meniscectomy
10	14/M	Right	Lateral	Bucket handle	Posterior to anterior	Red	No	Partial meniscectomy
11	13/F	Left	Medial	Bucket handle	Posterior to anterior	Red	No	Partial meniscectomy

ACL: Anterior cruciate ligament.

Table 3 Patient reported outcome measures in patients with success meniscal repair compared to patients with failure of the meniscal repair.

PROMs at final follow up (mean)	Successful meniscal repair group (55 cases)	Failed meniscal repair group (11 cases)
Tegner (range)	7 (2-10)	6 (2-9)
Lysholm (range)	94 (66-100)	88 (57-96)
IKDC (range)	90 (46-100)	86 (44-100)

PROMs: Patient Reported Outcome Measures; IKDC: International Knee Documentation Committee.

DISCUSSION

This study reports good to excellent outcomes for meniscal repair in children and adolescence. The re-operation rate following primary meniscal repair was 16.6%. Bucket handle tears were associated with higher failure rate compared to other types of meniscal tear. Krych et al[21] reviewed 99 patients under the age of 18 who underwent arthroscopic meniscal repair with concomitant ACL reconstruction. They reported an overall success rate of 74% at 8 years postoperatively with a mean IKDC and Tegner score of 90.3 and 6.2 respectively. Similar to the results of our study, subgroup analysis showed a lower success rate of 59% for bucket handle tears. Moreover, the authors compared their results with a previously published data by the same group for isolated meniscal tears[22]. They concluded that higher success rate was noted when complex type meniscal tears were repaired in association with ACL reconstruction compared to meniscal repair in isolation.

Several studies have reported favourable outcomes for meniscal repairs when associated with ACL reconstruction compared to isolated meniscal repair in adult population[23-25]. This could potentially be attributed to the stability provided by the ACL reconstruction and the favourable healing environment fostered by the haemarthrosis and release of bone marrow elements during femoral and tibial tunnel drilling[25-27]. Wasserstein et al. reviewed 1332 patients who underwent meniscal repair and ACL reconstruction, among whom 1239 (93%) were matched with patients who underwent isolated meniscal repair[25]. The rate of meniscal reoperation was notably lower in the group that underwent meniscal repair alongside ACL reconstruction (9.7%) compared to the group that underwent isolated meniscal repair (16.7%). Their conclusion was that a meniscal repair performed alongside ACL reconstruction entails a 7% absolute and 42% relative risk reduction of re-operation after 2 years compared to isolated meniscal repair. This implies that surgeons should be inclined to perform a meniscal repair when encountering a potentially repairable meniscal tear during ACL reconstruction, as there is a greater likelihood of meniscal healing.

The prevalence of meniscal tears in paediatric patients has not been clearly determined. Nevertheless, Stanitski et al[28] observed that 47% of paediatric individuals with knee injuries accompanied by haemarthrosis exhibited the presence of meniscal tears. Jackson et al[29] studied a large case series of 880 paediatric patients with meniscal injuries that underwent subsequent arthroscopic surgery. They observed that 63% of patients were male. Peripheral tears were most likely to heal by the time of intervention, and vertical tears were most likely to propagate to bucket-handle tears. Although meniscectomy was historically the first line treatment for meniscal tears, there is currently plethora of literature demonstrating the association between meniscectomy and increased intra-articular contact stresses with progression of osteoarthritis in the knee[30-33]. Pengas et al[32] investigated the outcomes of open total meniscectomy in adolescents. The authors illustrated significant alterations in the tibiofemoral angle indicating malalignment, as well as radiographic changes suggestive of osteoarthritis at the 40-year follow-up. Therefore, meniscal preservation is of paramount importance when managing paediatric meniscal tears. Except for extensively remodelled complex tears that are deemed irreparable through arthroscopic assessment and palpation, it is advisable to consider repair for all childhood meniscal lesions[34].

Historically, meniscal tears involving the white-white zone were believed to have poor clinical outcomes[35,36]. Considering this, treatment recommendations have revolved around nonoperative approaches vs meniscectomy in such cases. However, recent studies have demonstrated favourable outcomes following the repair of meniscal tears located in the avascular zone. Vanderhave et al[37] investigated 49 meniscal repair in paediatric patients and observed that nine were categorized as fully recovered two years following meniscal repair for tears in avascular zones. Similarly, Rubman et al[38] assessed the outcomes of 198 tears in the avascular zone, revealing that 80% of patients were asymptomatic at two years postoperative follow up. The available data endorse the arthroscopic repair of meniscal tears in the avascular zone, especially given the greater abundance of blood supply to the menisci in children compared to adults[39]. We have not observed significant difference in outcome of meniscal tears in different vascular zones of the meniscus. However, our cohort was limited to only one meniscal tear in the white-white zone.

In our study, the re-operation rate and PROMs were comparable to other published case series. Schmitt et al[40] conducted a study assessing the mean 6-year survival among 19 patients with a mean age of 14.8 years, of whom 11 had an associated ACL tear. The study revealed a survival rate of 89.5%. Similarly, Shieh et al[41] examined the outcomes of 129 adolescent and paediatric patients who underwent meniscal repair and reported a failure rate of 18%. Utilising a multivariate analysis, the authors demonstrated that children with an open physis and a bucket-handle tear had the highest re-tear rate of 46% (P = 0.039). However, variables such as age, sex, body mass index, extremity side, laterality (medial-lateral), time to repair, tear location, and associated ligament reconstruction were found to have no significant relationship with the need for revision meniscal surgery. In a recent systematic review, Liechti et al[17] analysed the outcomes of 301 meniscal repairs in paediatric patients. The authors reported a re-operation rate of 17.3% at a mean time of 16.6 month from index surgery. At a mean follow up 51.6 months (range, 22.3-96 months), the average postoperative Lysholm scores ranged from 85.4 to 96.3 while the average postoperative Tegner activity scores ranged from 6.2 to 8.

Limitations

Our study has several limitations that need to be acknowledged. The primary limitation of this study was its retrospective design, which confined the analysis to the data accessible within our medical record database. While this represents a relatively large case series for paediatric meniscal repair, the restricted number of included patients aligns with the relatively rare incidence of traumatic meniscal lesions in the paediatric population. We did not perform knee MRI scan or second-look arthroscopy for asymptomatic patients to identify clinically silent failures. This means that the reported failure rate may potentially be underestimated. Previous studies have indicated that as many as half of asymptomatic patients may exhibit failed repairs when assessed during second-look arthroscopy[41]. Additionally, this study lacks a control group for comparative analysis, preventing the assessment of results in patients who underwent nonsurgical treatment or partial meniscectomy as the primary intervention. There was no objective assessment performed for these patients. A significant portion of these patients, who were initially children at the time of surgery, has undergone relocations, including moves to different cities or even changes in countries. As a result, clinical examinations were not feasible for all patients.

CONCLUSION

Our findings indicate that arthroscopic repair of meniscal tears in the paediatric population is an effective treatment option characterized by a low failure rate and favourable postoperative clinical outcomes with the advantage of preserving meniscal tissues. All inside meniscal repair has yielded good to excellent outcomes in our cohort with low complication rate. Future long-term studies should undertake an analysis of factors associated with meniscal repair survival and outcomes in the paediatric population.