Meniscal Repair in Pediatric Populations: A Systematic Review of Outcomes

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

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.

Revision and Conversion to Arthroplasty Are Low Among Adolescents Undergoing Meniscal Allograft Transplantation Using the Bridge-In-Slot Technique at Midterm Follow-Up

PURPOSE

To report midterm outcomes after primary medial and lateral meniscal allograft transplantation (MAT) with fresh-frozen allografts implanted with the bridge-in-slot technique in the adolescent patient population.

METHODS

Adolescent patients less than 18 years old at the time of primary MAT from 1999 to 2016 were retrospectively identified. International Knee Documentation Committee (IKDC) subjective form, Lysholm, and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales scores were collected before surgery and at 1-year, 2-year, and a minimum 5-year follow-up. Thresholds for achieving clinically significant outcomes were calculated, and the proportion of patients achieving minimal clinically important difference (MCID), patient-acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) was determined. Meniscus reoperation (partial, subtotal, or total meniscectomy, repair, or failure) and failure (revision MAT or conversion to arthroplasty) rates were determined.

RESULTS

Forty-four (female n = 33; male n = 11) of 62 identified patients met inclusion criteria and were followed for a mean of 9.5 ± 3.8 years (range, 5.0-17.7). Lateral MAT was performed in most patients (n = 35/44 [80%]). Isolated MAT was performed in 27 (61%) patients. Common concomitant procedures included osteochondral allograft transplantation (32%), autologous chondrocyte implantation (18%), and anterior cruciate ligament reconstruction (14%). MCID, PASS, and SCB were achieved by patients at a minimum 5-year follow-up for IKDC (62%; 76%; 31%), Lysholm (62%; 79%; 23%), and KOOS questionnaires (Pain [65%; 81%; 41%], Symptoms [58%; 81%; 47%], Activities of Daily Living [53%; 77%; 35%], Sport [86%; 75%; 50%], and Quality of Life [59%; 81%; 59%]), respectively. Fourteen patients (32%) underwent reoperation at an average of 5.0 ± 4.3 years (range, 0.8-14.0) after MAT. Three (7%) patients met criteria for failure, requiring revision MAT an average of 3.8 ± 1.1 years (range, 2.8-4.9) after transplantation. No patients underwent arthroplasty. Overall survival free from failure at 1, 2, 5, and 10 years was 100%, 100%, 93%, and 93%, respectively. At the time of final follow-up, 80% of patients reported satisfaction with their current physical status.

CONCLUSIONS

Primary MAT in adolescent patients resulted in significant and durable functional improvements at mid- to long-term follow-up. At an average of 9.5 years after surgery, meniscal reoperation rate was 32% whereas graft survival free of revision MAT was 93%. Adolescents undergoing MAT demonstrated similar functional outcomes and graft survivability when compared to available adult MAT literature.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Surgical Management of Traumatic Meniscus Injuries

The menisci increase the contact area of load bearing in the knee and thus disperse the mechanical stress via their circumferential tensile fibers. Traumatic meniscus injuries cause mechanical symptoms in the knee, and are more prevalent amongst younger, more active patients, compared to degenerative tears amongst the elderly population. Traumatic meniscus tears typically result from the load-and-shear mechanism in the knee joint. The treatment depends on the size, location, and pattern of the tear. For non-repairable tears, partial or total meniscal resection decreases its tensile stress and increases joint contact stress, thus potentiating the risk of arthritis. A longitudinal vertical tear pattern at the peripheral third red-red zone leads to higher healing potential after repair. The postoperative rehabilitation protocols after repair range from immediate weight-bearing with no range of motion restrictions to non-weight bearing and delayed mobilization for weeks. Pediatric and adolescent patients may require special considerations due to their activity levels, or distinct pathologies such as a discoid meniscus. Further biomechanical and biologic evidence is needed to guide surgical management, postoperative rehabilitation protocols, and future technology applications for traumatic meniscus injuries.

Meniscal injuries in skeletally immature children with tibial eminence fractures. Systematic review of literature

PURPOSE

Although the mechanisms of injury are similar to ACL rupture in adults, publications dealing with meniscal lesions resulting from fractures of the intercondylar eminence in children are much rarer. The main objective was to measure the frequency of meniscal lesions associated with tibial eminence fractures in children. The second question was to determine whether there is any available evidence on association between meniscal tears diagnostic method, and frequencies of total lesions, total meniscal lesions, and total entrapments.

METHODS

A comprehensive literature search was performed using PubMed and Scopus. Articles were eligible for inclusion if they reported data on intercondylar tibial fracture, or tibial spine fracture, or tibial eminence fracture, or intercondylar eminence fracture. Article selection was performed in accordance with the PRISMA guidelines.

RESULTS

In total, 789 studies were identified by the literature search. At the end of the process, 26 studies were included in the final review. This systematic review identified 18.1% rate of meniscal tears and 20.1% rate of meniscal or IML entrapments during intercondylar eminence fractures. Proportion of total entrapments was significantly different between groups (17.8% in the arthroscopy group vs. 6.2% in the MRI group; p < .0001). Also, we found 20.9% of total associated lesions in the arthroscopy group vs. 26.1% in the MRI group (p = .06).

CONCLUSION

Although incidence of meniscal injuries in children tibial eminence fractures is lower than that in adults ACL rupture, pediatric meniscal tears and entrapments need to be systematically searched. MRI does not appear to provide additional information about the entrapment risk if arthroscopy treatment is performed. However, pretreatment MRI provides important informations about concomitant injuries, such as meniscal tears, and should be mandatory if orthopaedic treatment is retained. MRI modalities have yet to be specified to improve the diagnosis of soft tissues entrapments.

STUDY DESIGN

Systematic review of the literature REGISTRATION: PROSPERO N° CRD42021258384.

Pediatric meniscus morphology varies with age: a cadaveric study

PURPOSE

In adolescent patients, meniscal tear injury can occur either in isolation (e.g., discoid lateral meniscus tears) or in association with other traumatic injuries including tibial eminence fracture or ACL tear. Damage to meniscal integrity has been shown to increase contact pressure in articular cartilage, increasing risk of early onset osteoarthritis. In symptomatic patients failing conservative management, surgical intervention via meniscus repair or meniscus transplant is indicated. The purpose of this study was to evaluate the radial dimensions of pediatric menisci throughout development. The hypothesis was that the average radial meniscus dimensions will increase as specimen age increases, and mean medial and lateral region measurements will increase at a linear rate.

METHODS

Seventy-eight skeletally immature knee cadaver specimens under age 12 years were included in this study. The meniscal specimens were photographed in the axial view with ruler in the plane of the tibial plateau and analyzed using computer-aided design (CAD) software (Autodesk Fusion 360). Measurements were taken from inner to outer meniscus rims at five 45 degree intervals using the clockface as a reference (12:00, 1:30, 3:00, 4:30, 6:00), and total area of meniscus and tibial plateau was recorded. Generalized linear models were used to evaluate the associations of radial width measurements with age, tibial coverage, and lateral vs. medial meniscus widths.

RESULTS

All radial width measurements increased significantly with specimen age (p ≤ 0.002), and all lateral-medial meniscal widths increased (p < 0.001). The anterior zones of the meniscus were found to increase at the slowest rate compared to other regions. Tibial plateau coverage was found to not significantly vary with age.

CONCLUSIONS

Meniscus radial width and lateral-medial meniscus width are related to age. The anterior width of the meniscus varied least with age. Improved anatomic understanding may help surgeons more effectively plan for meniscus repair, discoid resection/saucerization/repair, and also support appropriate selection of meniscus allograft for transplantation.

Pediatric meniscal injuries: Current concepts

Meniscal pathology is widely prevalent in the adult population, secondary to acute trauma and chronic degeneration. It is less commonly seen in children, although its incidence is rising. The true prevalence in children remains unknown, as pathologies such as discoid menisci often go undiagnosed, or are found only incidentally. The rising incidence can be attributed to increased participation in sports at younger ages, both in intensity and frequency, with potentially year-round competition. Meniscal tears lead to pain and mechanical symptoms in the short to medium term, but more significantly, have been shown to lead to compartmental chondral degeneration and early arthritis in the long term. With advancing arthroscopic techniques, and children's propensity for better healing, osteoarthritis secondary to meniscal pathology is a potentially preventable problem. This article discusses meniscal injuries in children and adolescents and their management.

Age, Sex, and BMI Differences Related to Repairable Meniscal Tears in Pediatric and Adolescent Patients

BACKGROUND

The incidence of meniscus tears and ACL tears in pediatric patients continues to rise, bringing to question the risk factors associated with these injuries. As meniscus tears are commonly repaired in pediatric populations, the epidemiology of repairable meniscus tears is an important for consideration for surgeons evaluating treatment options.

PURPOSE

To describe meniscal tear patterns in pediatric and adolescent patients who underwent meniscal repair across multiple institutions and surgeons, as well as to evaluate the relationship between age, sex, and body mass index (BMI) and their effect on the prevalence, type, and displacement of repaired pediatric meniscal tears.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data within a prospective multicenter cohort registry for quality improvement, Sport Cohort Outcome Registry (SCORE), were reviewed to describe repaired meniscal tear patterns. All consecutive arthroscopic meniscal repairs from participating surgeons in patients aged <19 years were analyzed. Tear pattern, location, and displacement were evaluated by patient age, sex, and BMI. A subanalysis was also performed to investigate whether meniscal tear patterns differed between those occurring in isolation or those occurring with a concomitant anterior cruciate ligament (ACL) injury. Analysis of variance was used to generate a multivariate analysis of specified variables. Sex, age, and BMI results were compared across the cohort.

RESULTS

There were 1185 total meniscal repairs evaluated in as many patients, which included 656 (55.4%) male and 529 (44.6%) female patients. Patients underwent surgery at a mean age of 15.3 years (range, 5-19 years), with a mean BMI of 24.9 (range, 12.3-46.42). Of the 1185 patients, 816 (68.9%) had ACL + meniscal repair and 369 (31.1%) had isolated meniscal repair. The male patients underwent more lateral tear repairs than the female patients (54.3% to 40.9%; P < .001) and had a lower incidence of medial tear repair (32.1% vs 41.4%; P < .001). Patients with repaired lateral tears had a mean age of 15.0 years, compared with a mean age of 15.4 years for patients with repaired medial or bilateral tears (P = .001). Higher BMI was associated with "complex" and "radial" tear repairs of the lateral meniscus (P < .001) but was variable with regard to medial tear repairs.

CONCLUSION

In pediatric and adolescent populations, the data suggest that the surgical team treating knees with potential meniscal injury should be prepared to encounter more complex meniscal tears, commonly indicated in those with higher BMI, while higher rates of lateral meniscal tears were seen in male and younger patients. Future studies should analyze correlates for meniscal repair survival and outcomes in this pediatric cohort undergoing knee surgery.

Magnetic Resonance Imaging of Lateral Meniscus Root Tears in the Pediatric and Adolescent Knee: Is the Diagnosis Missed, Mentioned, or Made?

Background:

Failure to address meniscus root tears may place undue loads on anterior cruciate ligament (ACL) reconstructive surgery in the adult population. Because the intraoperative management of lateral meniscus posterior root tears (LMPRTs) may diverge from standard meniscal work and requires specialty items, preoperative diagnosis may be advantageous.

Purpose:

To evaluate the reliability of radiologist interpretations of preoperative knee magnetic resonance imaging (MRI) scans of lateral meniscus root pathology in a mixed pediatric and adolescent population.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

A retrospective review of medical records was performed to identify patients younger than 18 years with an arthroscopically confirmed LMPRT who underwent knee arthroscopy between March 1, 2010, and April 1, 2020. Arthroscopic findings were compared with the reading radiologist’s preoperative MRI interpretations, and patients were stratified into 2 groups: (1) LMPRT diagnosis made preoperatively or (2) diagnosis missed or only mentioned to describe pathology nonspecific to the root. Variables such as body mass index (BMI), open physes, time from injury to MRI, time from MRI to surgery, MRI magnet field strength, musculoskeletal radiologist designation, insurance type, and tear grade were assessed between groups.

Results:

Overall, 1116 knee arthroscopies were performed, with 49 LMPRTs found; all 49 LMRPTs were found concomitantly with ACL tears (49/535; 9.2%). The average patient age was 15.97 years (range, 11.52-17.97 years). There were 50 MRI scans for 49 patients. An LMPRT was diagnosed based on preoperative MRI scans in 12 of these 50 scans (24%) and mentioned or missed in 38 of the 50 scans (76%). No significant difference was seen between the diagnosis-made versus diagnosis-mentioned/missed groups in BMI, skeletal maturity, time from injury to MRI, time from MRI to surgery, MRI magnet strength, fellowship training of the reading radiologist, tear grade, or insurance type.

Conclusion:

In 76% of patients, a definitive diagnosis of LMPRT was not made on preoperative MRI scans. Notably, all LMPRTs found intraoperatively were found concomitantly with ACL tears.

Treatment Trends in Meniscal Pathology in the Setting of Concomitant ACL Injuries in Pediatric and Young Adult Patients: An Insurance Database Study

BACKGROUND

Meniscal pathology is commonly encountered in the setting of anterior cruciate ligament (ACL) rupture and is increasingly common in the pediatric and adolescent population. Studies have shown that over half of individuals presenting with ACL rupture will have concurrent meniscal pathology.

PURPOSE

To define trends in the utilization of meniscal procedures (ie, meniscus repair vs partial meniscectomy) and short-term complications in pediatric and young adult patients with meniscal pathology in the setting of a concurrent ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The IBM MarketScan Commercial Database was utilized to identify ACL reconstruction procedures performed between 2006 and 2018 for individuals aged 5 to 30 years. Annual proportions of meniscectomy and meniscal repair were analyzed, and short-term complications were compared between pediatric/adolescent patients (aged 5-17 years) and young adults (aged 18-30 years).

RESULTS

An overall 40,736 records of individuals <18 years old with ACL tears were included. The pediatric/adolescent population had a significantly lower proportion of concomitant meniscal procedures (56.8%; 23,149/40,736) than the young adult population (59.7%; 33,764/56,515; P < .01). From 2006 to 2018, utilization of meniscal repair in the setting of ACL reconstruction steadily increased (20.1% to 35.1% [+15 percentage points], P < .01), while the proportion with meniscectomy decreased (34.4% to 21.3% [-13.1 percentage points], P < .01). There was no difference in rate of reoperation for repeat meniscal repair or meniscectomy in the pediatric/adolescent population for those undergoing meniscal repair versus meniscectomy within 180 days of primary surgery (1.7% [188/10,766] vs 1.5% [186/12,383]; P = .14).

CONCLUSION

From 2006 to 2018, the proportion of patients receiving ACL reconstruction with concomitant meniscal repair increased (20.1% to 35.1%) while the proportion with meniscectomy decreased (34.4% to 21.3%) in the pediatric/adolescent population. Meniscal repair was not associated with a higher 180-day rate of reoperation for repeat meniscal repair or meniscectomy than meniscectomy in the setting of ACL reconstruction.

What Is the Failure Rate After Arthroscopic Repair of Bucket-Handle Meniscal Tears? A Systematic Review and Meta-analysis

BACKGROUND

Meniscal repair has become the treatment of choice for meniscal tears, especially in the subset of bucket-handle meniscal tears (BHMTs). However, a comprehensive estimate of the corresponding failure rate is not available, thus maintaining doubts about the healing potential of these tears. Furthermore, a wide range of factors to predict high failure rates have been reported but with conflicting evidence.

PURPOSE

To determine the failure rate after arthroscopic repair of BHMTs as reported in the literature, compare this with the failure rate of simple meniscal tears extracted from the same studies, and analyze the influence of factors previously reported to be predictive of meniscal repair failure.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A systematic search was conducted by 2 independent reviewers using principal bibliographic databases (PubMed, Scopus, Cochrane Library, and EMBASE). After a stepwise exclusion process, 38 articles met the inclusion criteria. Failure rate data were analyzed with a random-effects proportional meta-analysis (weighted for individual study size), and forest plots were constructed to determine any statistically significant differences between BHMTs versus simple tears (longitudinal, radial, or horizontal), medial versus lateral BHMTs, isolated procedures versus repairs with concomitant anterior cruciate ligament reconstruction, and tears in red-red versus red-white zones. Moreover, a meta-regression analysis was conducted to evaluate the effect of patient age and sex, suture technique (in-out or all-inside), time from injury to surgery, mean number of stitches, and length of follow-up on failure rates.

RESULTS

The pooled failure rate was 14.8% (95% CI, 11.3%-18.3%; I² = 77.2%). A total of 17 studies provided failure rates of both BHMT repairs (46/311 repairs) and simple tear repairs (54/546 repairs), demonstrating a significantly higher failure rate for BHMT repairs (risk ratio [RR] = 1.50; 95% CI, 1.05-2.15; I² = 0%; P = .03). Medial BHMT repairs (RR = 1.94; 95% CI, 1.25-3.01; I² = 0%; P = .003) and isolated repairs (RR = 1.77; 95% CI, 1.15-2.72; I² = 0%; P = .009) had statistically higher risk of failure, but no statistically significant difference was found between tears in red-red versus red-white zones. Among the other factors evaluated with meta-regression, only the mean number of stitches showed a statistically significant effect on failure rates.

CONCLUSION

Based on the currently available literature, this systematic review provides a reasonably comprehensive analysis of failure rate after arthroscopic BHMT repair; failure is estimated to occur in 14.8% of cases. Medial tears and isolated repairs were the 2 major predictors of failure.

Paediatric injuries around the knee: Soft tissue injuries

We review the diagnosis, management and potential pitfalls of acute soft tissue injuries in the skeletally immature knee, including anterior cruciate ligament (ACL) injuries, meniscal injuries, patellar dislocation and patellofemoral instability (PFI). There has been an increasing incidence of such injuries in the paediatric population, and controversy remains regarding their treatment. We summarise evidence-based treatments for these injuries and discuss strategies to minimise complications as the child reaches skeletal maturity.

Changes in the avascular area of the meniscus using mesenchymal stem cells and growth plate chondrocytes in a pig model

Menisci are wedge-shaped cartilage discs that are divided into two parts: the avascular and vascular regions. They are formed by fibrocartilage tissue, which contains round cartilage-like cells and extracellular matrix. Meniscus injury in animals is a common orthopedic problem, but data on the natural healing process mainly deals with the vascular zone. The healing processes in the avascular zone of the meniscus are significantly limited. Thus, this study aimed to evaluate autologous growth plate chondrocytes' impact on the healing process of a damaged meniscus in the avascular zone based on a growing animal model. The study group consisted of 10 pigs at about three months of age. From each animal, chondrocytes from the iliac growth plate and from concentrated bone marrow were taken. Knee joints were divided into right (R) and left (L). The medial meniscus of the R knee joint was treated with a hyaluronic acid based scaffold incubated with bone marrow cells from marrow aspirates (nCHON). The medial meniscus of the L knee joint was treated with a hyaluronic acid based scaffold incubated with bone marrow cells from marrow aspirates supplemented with immature chondrocytes isolated from growth plates (wCHON). The meniscus was damaged in the avascular zone in both knee joints. Followingly, the damaged part of the meniscus was filled with a scaffold with cells from the concentrated bone marrow and from growth plate chondrocytes. In the control group, a scaffold with concentrated bone marrow cells was used. After three months the animals were euthanized and preparations (microscopic slides) were made from the meniscus' damaged part. A qualitative and quantitative analysis have been prepared. The wCHON group in comparison with the nCHON group showed a statistically significantly higher number of fusiform cells on the surface of the graft as well as better healing of the graft. In addition, the degree of vascularization was higher in specimens from the wCHON group than in the nCHON group. The results of our research on immature pig knees revealed that mesenchymal stem cell and growth plate chondrocytes could be treated as the cell source for meniscus reconstruction, and growth plate chondrocytes enhance healing processes in the avascular zone of the injured meniscus.

Epidemiology of Meniscal Allograft Transplantation at Children's Hospitals in the United States

Background:

Meniscal allograft transplantation (MAT) was developed with the goal of delaying the progression of degenerative disease in the setting of substantial meniscal deficiency. This may be especially important in children and adolescents; however, there is a paucity of literature on MAT in this population.

Purpose:

To evaluate the epidemiology of MAT at pediatric hospitals in the United States, with specific attention to regional and characteristic trends.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

The Pediatric Health Information System, a national database consisting of 49 children’s hospitals, was queried for all patients younger than 25 years who underwent MAT between 2011 and 2018. Characteristic information and surgical history were collected for each patient. The database was also queried for all patients who underwent other meniscal surgeries (including debridement, meniscectomy, and meniscal repair) during the same period (controls). Characteristic and geographic data from the control group were compared with those of the patients who underwent MAT. Univariate analysis was followed by purposeful entry multivariate regression to adjust for confounding factors.

Results:

A total of 27,168 meniscal surgeries were performed in 47 hospitals, with MAT performed 67 times in 17 hospitals. Twelve (18%) patients underwent a subsequent procedure after transplantation. In multivariate analysis, each year of increasing age resulted in 1.1 times higher odds of having undergone MAT (95% CI, 1.03-1.1; P = .002) compared with repair or meniscectomy. Patients who underwent MAT also had 2.0 times higher odds of being women (95% CI, 1.2-3.3; P = .01) and 2.0 times higher odds of being privately insured (95% CI, 1.1-3.6; P = .02). MAT was performed most frequently in the Northeast (4.9/1000 meniscal surgeries) and least often in the South (1.1/1000 meniscal surgeries) (P < .001).

Conclusion:

In the United States, pediatric and adolescent patients who underwent MAT were older and more likely to be female and have private insurance than those undergoing meniscal repair or meniscectomy. MAT was only performed in 17 of 47 children’s hospitals that perform meniscal surgery. These trends highlight the need for further research, especially regarding differences along the lines of sex and insurance status.

Return-to-Sport Rate and Activity Level Are High Following Arthroscopic All-Inside Meniscal Repair With and Without Concomitant Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To systematically review the literature of return-to-sport outcomes following all-inside meniscus repair and evaluate whether concomitant anterior cruciate ligament reconstruction (ACLR) influenced these outcomes.

METHODS

A systematic review of the MEDLINE, PubMed, Embase, and Cochrane Registry of Systematic Reviews databases was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two reviewers examined all literature pertaining to sport outcomes following all-inside meniscal repair. Studies were included if they had a 12-month minimum follow-up and reported return to sport rate, Tegner, or Knee injury and Osteoarthritis Outcome Score (KOOS) Sport outcomes. Studies with meniscal repair techniques other than the all-inside technique were excluded. Studies were not excluded if they contained patients receiving concomitant ACLR. Study quality was evaluated with the Methodological Index for Nonrandomized Studies.

RESULTS

Nineteen studies comprising 872 patients were included in this investigation. The weighted average patient age was 28.7 (range 14.1-42.1) years, and the weighted average follow-up was 56.0 (range 18.0-155.0) months. The mean Methodological Index for Nonrandomized Studies score was 14.4 ± 3.7. Ten investigations reported both preoperative (range 2.3-3.5) and postoperative (range 4.0-7.3) Tegner outcomes, with scores at final follow-up greater in each of the 10 reporting investigations. KOOS Sport outcomes were examined in 5 investigations, with scores at follow-up ranging from 63.6 to 91. Three studies reported a return to sport rate ranging from 89.6 to 90% at follow-up. Four investigations compared sport-related outcomes between isolated meniscal repair and meniscal repair with concomitant ACLR. Two such studies reported no difference between the 2 cohorts, 1 favored the isolated cohort, and 1 favored the combined cohort.

CONCLUSIONS

This systematic review found a 90% return-to-sport rate and high postoperative activity level following all-inside meniscal repair, as assessed by KOOS Sport and Tegner activity scales. Further, concurrent ACLR did not significantly affect these outcomes.

LEVEL OF EVIDENCE

IV, systematic review of level I-IV studies.

Changes in Pediatric Sports Injury Presentation During the COVID-19 Pandemic: A Multicenter Analysis

Background:

The current coronavirus 2019 (COVID-19) pandemic has prompted a multitude of public health response measures including social distancing, school cancellations, and cessation of organized sports.

Purpose:

To examine the impact of COVID-19 and corresponding public health measures on the characteristics of common pediatric musculoskeletal injuries associated with sports.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This was a multicenter retrospective cohort study comparing patients with sports injuries presenting to 3 geographically diverse level I pediatric trauma hospitals and outpatient orthopaedic surgery clinics in the United States during the COVID-19 pandemic and a prepandemic period at the same institutions. Patients were included if they presented for care between February 15 and July 15 in 2020 (pandemic cohort) or between March 15 and April 15 in 2018 and 2019 (prepandemic cohort).

Results:

Included were 1455 patients with an average age of 12.1 ± 4.5 years. When comparing patients presenting in 2018 and 2019 with those presenting in 2020, we observed a decrease in mean age during the pandemic (12.6 ± 4.0 vs 11.0 ± 5.2 years; P = .048). Additionally, a decrease in the proportion of injuries attributed to sports (48.8% vs 33.3%; P < .001) and those occurring at school (11.9% vs 4.0%; P = .001) was observed. The proportion of injuries attributable to clavicle fractures increased during the early stages of the pandemic (13.2% vs 34.7%; P < .001). There was no statistically significant delay to care in injuries presenting during the pandemic (41.5 ± 141.2 vs 19.23 ± 79.1 days; P = .175).

Conclusion:

Across 3 tertiary care institutions, patients were seen without significant delay during the pandemic. We observed a significant decline in pediatric musculoskeletal injuries associated with sports during the COVID-19 pandemic. This decrease has been accompanied by a shift in both injury type and mechanism.

Pediatric Simple Knee Value: a simple patient-reported outcome measure for the knee

PURPOSE

The pediatric Simple Knee Value (pedi-SKV) is an outcome score in which paediatric patients are asked 'How would you rate your knee today as a percentage of normal (0% to 100% scale with 100% being normal)?'. The primary aim of this study was to validate the pedi-SKV by measuring its correlation with validated knee function scores used most often in paediatric orthopaedics.

METHODS

This prospective study was conducted at a teaching hospital to evaluate the pedi-SKV's validity. A total of 44 paediatric patients (ten to 15 years old), were enrolled prior to anterior cruciate ligament reconstruction as well as 17 healthy controls. A survey form consisting of the Lysholm, International Knee Documentation Committee Pediatric Form (Pedi-IKDC) and pedi-SKV was given to subjects twice (enrolment and six months postoperatively). The criterion validity of the pedi-SKV was determined by correlating it to existing knee functional scores. Responsiveness to change was evaluated by comparing the pedi-SKV scores before and after surgery (enrolment visit and six-month postoperative visit). Discriminative ability was evaluated by comparing the pedi-SKV distribution in patients versus controls.

RESULTS

There was a strong and significant correlation between the pedi-SKV and the Lysholm and Pedi-IKDC (p < 0.0001). The pedi-SKV had a good responsiveness to change (p < 0.0001 for the pedi-SKV before versus six months postoperatively). Like the other knee-specific functional sores (p < 0.0001), the pedi-SKV was able to distinguish between patients and controls (p < 0.0001).

CONCLUSION

The pedi-SKV is a valid outcome measure that is strongly correlated with the Lysholm and Pedi-IKDC. This is a novel simple score that can be used by physicians in their daily practice.

LEVEL OF EVIDENCE

II.

Meniscal pathology in children and adolescents

The menisci play a key role in knee biomechanics and long-term cartilage protection. Preserving the meniscus is thus a major functional consideration in children and adolescents. In normal menisci, lesions are traumatic in origin. They are often vertical, in the posterior segment, associated with anterior cruciate ligament tear. In abnormal menisci, lesions are much more specific to children, occurring atraumatically, mainly in discoid menisci. Clinical signs of traumatic meniscal lesion are minimal, and associated ligament involvement should be systematically screened for. In contrast, clinical findings are rich and specific in discoid malformative pathology, sometimes showing the typical "clunk" sign highly suggestive of a detachment. The complementary examination of choice is MRI. In children more than in adults, lesions need screening for in apparently normal menisci. This particularly concerns ramp lesions of the medial meniscus. It is important also to be aware of false signs, and notably linear hypersignal of vascular origin in the posterior segment of the medial meniscus. MRI is essential in determining type of tear and guiding surgery in discoid meniscal pathology. Indications for meniscal repair in children are maximal, even in lesions extending into the white zone, and the risk of failure needs to be assumed. All meniscal suture techniques - all-inside, in-out and out-in - need to be acquired. Meniscectomy, even partial, should be exceptional. Treatment of symptomatic discoid meniscus usually involves minimal central meniscoplasty and suture of the discovered lesion. Results of meniscal repair in children are generally very satisfactory, whatever the type or site of lesion. Vertical suture is to be preferred; suture failure is often only partial. In all, optimal treatment of meniscal pathology in children and adolescents requires perfect knowledge of pediatric specificities and above all mastery of repair techniques to restore meniscal tissue as fully as possible so as to conserve future knee function.

Changes in Matrix Components in the Developing Human Meniscus

BACKGROUND

Treatment of meniscal tears is necessary to maintain the long-term health of the knee joint. Morphological elements, particularly vascularity, that play an important role in meniscal healing are known to change during skeletal development.

PURPOSE

To quantitatively evaluate meniscal vascularity, cellularity, collagen, and proteoglycan content by age and location during skeletal development.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Medial and lateral menisci from 14 male and 7 female cadavers aged 1 month to 11 years were collected and evaluated. For each meniscus, histologic and immunohistologic techniques were used to establish the ratio of the area of proteoglycan (safranin O) positivity to the total area (proteoglycan ratio), collagen type I and type II immunostaining positivity, number of blood vessels, and cell density. These features were evaluated over the entire meniscus and also separately in 5 circumferential segments: anterior root, anterior horn, body, posterior horn, and posterior root. Additionally, cell density and number of blood vessels were examined in 3 radial regions: inner, middle, and periphery.

RESULTS

Age was associated with a decrease in meniscal vessel count and cell density, while the proteoglycan ratio increased with skeletal maturity. Differences in vessel counts, cellular density, and proteoglycan ratio in different anatomic segments as well as in the inner, middle, and peripheral regions of the developing menisci were also observed. Collagen immunostaining results were inconsistent and not analyzed.

CONCLUSION

The cellularity and vascularity of the developing meniscus decrease with age and the proteoglycan content increases with age. All of these parameters are influenced by location within the meniscus.

CLINICAL RELEVANCE

Age and location differences in meniscal morphology, particularly in the number of blood vessels, are expected to influence meniscal healing.

Isolated lateral meniscus tear masquerading as a potential septic arthritis in a 7 year old

A 7-year-old boy presented with a 1-week history of a limp, low grade temperature and mildly elevated inflammatory markers. He sustained a fall 2 weeks ago but was relatively symptom free for a week. The inital physical exam demonstrated a knee effusion clinically, radiographs did not demonstrate any overt pathology and biochemical testing demonstrated an elevated C reactive protein of 8 mg/L. An arthroscopy was conducted, with a plan for synovial biopsies to investigate for infective versus inflammatory arthritis as a cause for the effusion. An isolated lateral meniscal tear was discovered. This was repaired using all inside technique with Smith and Nephew's FastFix 360 (R) suture anchors. It is quite uncommon to find isolated lateral meniscus tears in this population, but the learning point demonstrates it is important to arthroscopically examine the whole knee, even while performing synovial biopsies as there may be unexpected findings.

An Up-to-Date Review of the Meniscus Literature: A Systematic Summary of Systematic Reviews and Meta-analyses

Background:

A large number of systematic reviews and meta-analyses regarding the meniscus have been published.

Purpose:

To provide a qualitative summary of the published systematic reviews and meta-analyses regarding the meniscus.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic search of all meta-analyses and systematic reviews regarding the meniscus and published between July 2009 and July 2019 was performed with PubMed, CINAHL, EMBASE, and the Cochrane database. Published abstracts, narrative reviews, articles not written in English, commentaries, study protocols, and topics that were not focused on the meniscus were excluded. The most pertinent results were extracted and summarized from each study.

Results:

A total of 332 articles were found, of which 142 were included. Included articles were summarized and divided into 16 topics: epidemiology, diagnosis, histology, biomechanics, comorbid pathology, animal models, arthroscopic partial meniscectomy (APM), meniscal repair, meniscal root repairs, meniscal allograft transplantation (MAT), meniscal implants and scaffolds, mesenchymal stem cells and growth factors, postoperative rehabilitation, postoperative imaging assessment, patient-reported outcome measures, and cost-effectiveness. The majority of articles focused on APM (20%), MAT (18%), and meniscal repair (17%).

Conclusion:

This summary of systematic reviews and meta-analyses delivers surgeons a single source of the current evidence regarding the meniscus.

Patient Outcomes After Horizontal Cleavage Tear Repair: A Systematic Review

PURPOSE

To analyze the clinical outcomes and survivorship of meniscal horizontal cleavage tear (HCT) repairs with hopes of guiding future treatment decisions.

METHODS

Standard systematic review methodology was used. A comprehensive search of PubMed was conducted on June 1, 2019. The inclusion criteria were articles that were published in English, involved human subjects, and reported on at least 1 outcome after repair of HCTs. The exclusion criteria included technique guides and reviews, studies without full text available, and studies with HCT outcomes not separated from other repair groups. Effect heterogeneity was determined using the I² measure. Forest plots were created in addition to a random-effects model to show the results.

RESULTS

The systematic review yielded 19 studies evaluating 289 knees in a total of 273 patients. At most recent follow-up, there was a high probability of return to sport (93.1% [67 of 72]). Overall, 74% of patients (67 of 90) were symptom free at last follow-up, and 80% expressed satisfaction with their overall result (80 of 100). The most frequently reported subjective outcome was the Lysholm score, which improved from a preoperative study range of 48 to 79 (I² = 20.7%, P = .283) to a postoperative study range of 56 to 99 (I² = 49%, P = .081). The next most commonly reported was the International Knee Documentation Committee subjective score, which improved from a preoperative study range of 16 to 49 (I² = 47.7%, P = .125) to a postoperative study range of 72 to 95 (I² = 0%, P = .660). An overall 11.7% reported risk of reoperation was found, with most cases involving revision meniscectomy. Rates of complications beyond fixation failure were overall very low, with infrequent reports of septic arthritis and transitory dysesthesia.

CONCLUSIONS

The short- to intermediate-term results of repair of HCTs are comparable to prior studies. Survivorship is comparable to repairs of other types of meniscal tears with high rates of return to sport and low complication rates.

LEVEL OF EVIDENCE

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