Paper 15: Survivorship of 157 Arthroscopic Meniscal Allograft Transplants Using Bone Fixation at Mean 7 Years and Prognostic Factors Analysis
Authors: Krych Aaron , Husen Martin , Wang Allen , Pan Xuankang , Levy Bruce , Saris Daniel , Stuart Michael 
Published: August 2024

Objectives:

Meniscal allograft transplantation (MAT) is an accepted and effective treatment option in the context of unsalvageable menisci, particularly in young and active patients. It has been shown to reduce pain and improve knee function in previously symptomatic patients. However, there is still limited knowledge about the long-term survival rates of allografts, the durability of clinical results, and the influence of patient-specific parameters, such as leg alignment, tibial slope, and preoperative International Cartilage Regeneration & Joint Preservation Society (ICRS) grade. The purpose of this study was to determine (1) the long-term clinical success rate after MAT with bony fixation in a large, single-center cohort of consecutive patients, and (2) if patient-specific and procedural variables influence the clinical, anatomic, and subjective outcomes and risk of failure.

Methods:

Data on 185 consecutive knees undergoing MAT in a single institution were prospectively collected and screened for inclusion in this study. The minimum follow-up time was 2 years. Radiographic variables (International Cartilage Regeneration & Joint Preservation Society [ICRS] grade and Kellgren and Lawrence grade) were assessed preoperatively and at follow-up. Subjective patient-reported outcome measures (PROMs), Lysholm score, Knee Disability and Osteoarthritis Outcome Score (KOOS) including subscores, International Knee Documentation Committee (IKDC) score, and visual analog score (VAS) were collected preoperatively and at follow-up. Clinical failure was defined as revision surgery due to graft failure or conversion to total knee arthroplasty (TKA). Anatomic failure was considered a tear covering >20% of the allograft, any peripheral tear, and unstable peripheral fixation leading to dislocation of the graft. Subjective failure was defined as Lysholm score ≤65. Preoperative tibial slope and leg alignment were assessed. Survival analyses were performed utilizing the Kaplan-Meier estimate. Univariate and multivariate analyses were performed to determine risk factors for clinical and anatomic failure.

Results:

A total of 157 knees met inclusion criteria (Table 1). After a mean follow-up time of 7 ± 3.5 years, 127 (80.9%) knees were free of clinical, anatomic, and subjective failure. Fourteen (8.9%) knees experienced clinical failure, 26 (16.6%) knees were identified as anatomic failure, and 13 patients (8.3%) suffered from subjective failure with a reported Lysholm score of ≤65 at a mean follow-up of 7 years. Concurrent osteochondral allograft transplantation was identified as a predictor of both clinical (HR 4.55; 95% CI 1.46-14.17; p=0.009) and anatomic failure (HR 3.05; 95% CI 1.34-6.92; p=0.008). Cartilage damage of ICRS grade 3 or 4 of the index compartment conveyed an increased risk for clinical (HR 3.41; 95% CI 1.05-11.01; p=0.04) and anatomic failure (HR 3.04; 95% CI 1.31-7.11; p=0.01) (Table 2). There were no differences in outcomes between medial and lateral MAT. High-grade cartilage damage (defined as ICRS grades 3 and 4) preoperatively (HR 10.67; 95% CI 1.037-109.768; p=0.046), patients age over 25 (HR 5.44; 95% CI 0.120-246.070; p=0.384), and a body mass index >30 (HR 2.24; 95% CI 0.748-6.705; p=0.149) were associated with subjective failure. Considering the entire study population, PROMs including KOOS and IKDC were significantly improved at final follow-up compared to preoperative scores across all measurements (p<0.005).

Conclusions:

MAT showed good-to-excellent clinical results at a mean follow-up of 7 years. Low ICRS lesion grade was associated with a higher clinical and anatomic survival rate. Patients with concurrent osteochondral allograft transplantation are at higher risk of clinical and anatomic failure, but still report significantly improved PROMs. These results suggest MAT has a lasting beneficial effect both as in isolation and in complex cases with one or more concurrent procedures.