Summary

Based on single centre comparative assessment following lateral meniscal transplantation there is no difference in failure rate, re-operation rate or PROMS outcome between bone bridge and soft tissue fixation techniques for lateral MAT; it is a successful procedure based on objective patient reported outcomes irrespective of the fixation technique.

Abstract

Introduction

Meniscal Allograft Transplantation (MAT) has established clinical effectiveness for symptomatic meniscal deficiency. Optimal fixation, however, for lateral MAT is unclear, with bone bridge techniques technically harder but allowing maintenance of root attachments while soft tissue techniques are potentially more challenging for healing. Size matching for the bone bridge is more exacting whereas soft tissue fixation can be adjusted.

Aim

to compare the clinical results of the bone bridge and soft tissue techniques for lateral MAT in terms of failure, re-operation rate, complications and patient reported outcomes.

Methods

Retrospective analysis of prospectively collected data for patients undergoing lateral MAT since January 2017 with minimum 12 months follow up. Patients undergoing transplantation with the Bone Bridge (BB) technique, introduced in march 2018, were compared to historical control patients implanted using the Soft Tissue (ST) technique. Patients having a revision procedure were excluded. Outcome was assessed by failure rate, defined as removal or revision of the meniscus transplant, re-operation rates, other adverse events and Patient Reported Outcome Measures (PROMs) including Lysholm, IKDC, Tegner and KOOS. For the PROMs, the 2 year scores were analysed. Kaplan Meir analysis was performed to compare survivorship. The PROMs data (non-parametric and dependent) was analysed using the Wilcoxon signed rank test and the CHI squared test was used to evaluate the re-operation rates.

Results

112 patients following lateral meniscal transplants were included, 31 in the BB group and 81 in the ST historical control group. Median age was 27 years for both groups (age range: BB – 13-54; ST - 13-50). 48.5% patients in the BB group and 40.8% in the ST group underwent additional concomitant procedures. There were no significant differences in the demographic data between the groups. Median follow-up for the BB group was 18 (12-43) months compared to 46 (15-62) months for the ST group.

The failure rate was 9.6% in the BB group v 2.4% in the ST group (p=0.08) with mean time to failure of 9 months in both groups. The re-operation rate in the BB group was 29.03% v 29.62% in the ST group (p=0.3). There was 1 posterior root tear in the BB group v 3 (2 anterior and 1 posterior) in the ST group (3.2% v 3.7%; p = 0.9). 5 patients (BB group) and 6 patients (ST group) had graft tears requiring fixation (16.1% v 7.4%, p=0.2). There was significant improvement (p<0.0001) in all PROMs (Tegner, IKDC, KOOS and Lysholm) between baseline and 2 years’ follow-up for both groups but no between-group differences.

Conclusions

Lateral MAT has a high success rate for symptomatic meniscal deficiency with significant objective benefits irrespective of the fixation technique. There appears to be no advantage in performing the more technically demanding BB technique over ST fixation. Surgeons can choose their preferred technique based on their experience and results. MRI based data on meniscal extrusion and further long term follow-up is required for further analysis.