The biomechanical and functional outcomes of fresh osteochondral allograft for the knee: A systematic review

TL;DR

This review examines how well fresh osteochondral allografts improve knee function and biomechanics, finding that they may offer results similar to another treatment called ACI.

Contribution

The study provides a systematic review of biomechanical outcomes of fresh osteochondral allografts for knee lesions.

Findings

Post-operative knee range of motion generally exceeded 120° across studies.

No correlation was found between final range of motion and follow-up time.

FOCA outcomes were comparable to those of autologous chondrocyte implantation in terms of range of motion.

Abstract

Fresh osteochondral allograft (FOCA) is a treatment option for osteochondral lesions of the knee which cause pain, locking, and joint instability. While FOCA aims to eliminate these mechanical symptoms, the biomechanical outcomes of the procedure remain poorly understood. This systematic review aimed to collate and interpret the available literature on the biomechanical outcomes of FOCA.

Systematic searches were performed in three databases using the terms ‘(Knee OR knee joint) AND (FOCA OR fresh osteochondral allograft OR fresh OCA)’. Eligible studies contained objective biomechanical or functional outcomes, such as knee range of motion, strength, or parameters of gait. The National Institute of Health Quality Assessment Tool assessed study quality. Extracted data were synthesised in a spreadsheet and then a linear regression analysis was performed on the available range of motion data (p = 0.05). Data from a prior systematic review on the biomechanical outcomes of autologous chondrocyte implantation (ACI) were also included in this analysis to facilitate interpretation of the results. PROSPERO ID: CRD42024531998.

Eight studies with 54 participants met the inclusion criteria. On average, studies included 10 participants with a follow up range of 9–108 months.

Knee range of motion was reported to improve post-operatively in each study, and the post-operative range of motion was generally reported to be > 120°. A linear regression analysis showed no correlation between final range of motion and follow-up time (p value – 0.860; R2 - 0.019). These results did not differ statistically from the range of motion data reported in a prior review on ACI outcomes (F = 0.003; p = 0.874).

One study also reported an improvement in knee strength following FOCA, while two others commented on improvements to gait, although little numerical data was provided.

The limited reporting of improvements to knee range of motion suggest that FOCA has the potential to improve patient quality of life through improved knee function. Linear regression analyses of data presented in this study and obtained from a prior report on the biomechanical outcomes of ACI suggest that the knee ranges of motion following both procedures are comparable. However, further research with larger patient cohorts and consistent methodologies are required to corroborate existing data. This knowledge is important for optimising outcomes via evidence-based rehabilitation programmes.

Figures