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

Trends in utilization of meniscal allograft transplantation between 2010 and 2019

OBJECTIVES

The aim of this study was to observe the trends in (1) utilization of meniscus allograft transplantation (MAT), (2) demographics and comorbidities of patients undergoing transplants and (3) reimbursements for this procedure between the years of 2010 and 2019.

METHODS

Using a national database, patients who underwent MAT were observed. Incidence of MAT, percentage of female patients, average age, and average Charlson comorbidity index (CCI) were analyzed between 2010 and 2019. Average reimbursement during the index and postoperative 90-day bundle period were also calculated from 2010 to 2019. Compound annual growth rate (CAGR) of change in incidence, demographic and reimbursement was calculated, and linear regressionwas conducted for each trends analysis.

RESULTS

In total, 744 patients underwent a MAT between the years of 2010 and 2019. The incidence of MAT increased from 0.12 per 100,000 to 0.15 per 100,000 during this period but was not statistically significant (p=0.345). There was no significant difference in age (p=0.462) and gender (p=0.831) among the patients, but the average CCI significantly increased from 2010 to 2019 (CAGR: +15.30; p=0.001). The total reimbursement in the index (p=0.451) and 90-day bundle period (p=0.191) did not significantly change from 2010 to 2019.

CONCLUSIONS

Although MAT has been shown to be a safe and reliable surgery for the treatment of meniscus deficient knees, the incidence of MAT as well as the population undergoing MAT has minimally increased from 2010 to 2019. Future studies should seek to identify why the utilization of this efficacious surgery has not increased.

LEVEL OF EVIDENCE

IV; Descriptive Epidemiology Study.

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.

Increased rate of out-of-network surgeon selection for hip arthroscopy compared to more common orthopedic sports procedures

Background

Demand for hip arthroscopy (HA) has increased, but shortfalls in HA training may create disparities in care access. This analysis aimed to (1) compare out-of-network (OON) surgeon utilization for HA with that of more common orthopedics sports procedures, including rotator cuff repair (RCR), partial meniscectomy (PM), and anterior cruciate ligament reconstruction (ACLR), (2) compare the HA OON surgeon rate with another less commonly performed procedure, meniscus allograft transplant (MAT), and (3) analyze trends and predictors of OON surgeon utilization.

Methods

The 2013-2017 IBM MarketScan database identified patients under 65 who underwent HA, RCR, PM, ACLR, or MAT. Demographic differences were determined using standardized differences. Cochran-Armitage tests analyzed trends in OON surgeon utilization. Multivariable logistic regression identified predictors of OON surgeon utilization. Statistical significance was set to p < 0.05 and significant standardized differences were >0.1.

Results

410,487 patients were identified, of which 12,636 patients underwent HA, 87,607 RCR, 233,241 PM, 76,700 ACLR, and 303 MAT. OON surgeon utilization increased for HA, rising from 7.98 % in 2013 to 9.37 % in 2017 (p = 0.026). Compared to RCR, PM, and ACLR, HA was associated with higher likelihood of OON surgeon utilization. Usage of ambulatory surgery centers (ASCs) was predictive of higher OON surgeon rates along with procedure year, insurance plan type, and geographic region. HA performed in an ASC was 13 % less likely to have an OON surgeon (p = 0.047).

Conclusion

OON surgeon utilization generally declined but increased for HA. HA was a predictor of OON surgeon status, possibly because HA is a technically complicated procedure with fewer trained in-network providers. Other predictors of OON surgeon status included ASC usage, PPO/EPO plan type, and Northeast geographic region. There is a need to improve access to experienced HA providers-perhaps with prioritization of HA training in residency and fellowship programs-in order to address rising OON surgeon utilization.

Midterm Clinical and Radiological Outcomes of Revision Lateral Meniscal Allograft Transplantation

Background

It is unknown whether the outcomes achieved in the early period after revision lateral meniscal allograft transplantation (RLMAT) are maintained through the midterm period.

Purpose

To evaluate the midterm clinical and radiological results of patients who underwent RLMAT.

Study Design

Case series; Level of evidence, 4.

Methods

We reviewed the outcomes of 19 RLMATs in 18 patients with at least 5 years of follow-up data. The mean follow-up period was 6 ± 1.1 years (range, 5-8.5 years). Clinical outcomes were assessed using the modified Lysholm score, the International Knee Documentation Committee (IKDC) subjective score, and the Tegner activity level. Radiographic progression of arthritis was measured by the absolute and relative joint space widths on 45° of knee flexion posteroanterior radiographs preoperatively, 1 year postoperatively, and at the latest follow-up.Failure was defined as meniscocapsular separation, removal, or tear of more than half of the meniscal allograft on postoperative magnetic resonance imaging (MRI) or conversion to total knee arthroplasty. Of the 18 patients, 3 underwent ≥2 RLMATs. The survival rate was evaluated according to the number of revision surgeries.

Results

For knees with an intact meniscus transplant at the final follow-up, the modified Lysholm and IKDC scores were significantly improved compared with preoperatively, but the Tegner activity level was unchanged. No significant differences were found in the absolute and relative joint space widths postoperatively. There were 6 failures within 3 years after RLMAT; the overall 5-year survival rate was 68.4% (13/19 knees). All failed knees showed bucket-handle tear patterns on MRI due to meniscocapsular healing failure. The survival rate decreased as the number of RLMATs increased-73.3% for a first RLMAT (n = 15 knees), 66.7% for a second RLMAT (n = 3 knees), and 0% for a third RLMAT (n = 1 knee). Midterm MRIs of 8 well-healed RLMATs showed evidence of meniscal degeneration; nonetheless, this did not affect clinical outcomes.

Conclusion

The midterm results of RLMATs demonstrated a 5-year survival rate of 68.4% and positive clinical and radiological outcomes for failed MATs despite unimproved activity levels. Inadequate meniscocapsular healing was the leading cause of failure, and it needs to be carefully considered when performing RLMATs.

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.

Meniscal Allograft Transplants in Skeletally Immature Patients: A Systematic Review of Indications and Outcomes

Meniscal lesions in skeletally immature patients can lead to joint degradation and knee instability. Meniscal allograft transplant (MAT) surgery is a solution to maintain knee stability. There is a lack of consensus on MAT surgery outcomes in pediatric patients. A systematic review was conducted according to the PRISMA guidelines. PubMed, Scopus and EMBASE databases were searched from 1965 to June 2022. Studies were evaluated using the Newcastle-Ottawa Scale (NOS). Three studies were selected, and 58 patients were included (mean age 15.9 years) in total. The lateral meniscus was involved in 82.8% of all MAT surgeries. Post-meniscectomy syndrome and discoid meniscus were the main indications for MAT surgery. All studies reported improved subjective clinical scores and levels of sport after the surgery. The complication rate was 27.5%. Partial meniscectomy, meniscus knot removal, chondral defect treatment and lysis of adhesions were the most frequent procedures performed during reoperation. MAT surgery can improve clinical outcomes in pediatric patients with strictly selected indications. MAT surgery is safe when there are no limb asymmetries or malalignments, but it remains a challenging procedure with a high complication rate. Long-term follow-up is needed for definitive statements on the use of MAT in skeletally immature patients.