Summary

Autologous chondrocyte implantation (ACI) and conventional microfracture was the most common cartilage restoration technique for the patellofemoral joint, and most reported improvements in patient reported outcomes with low complication rates.

Abstract

Objective

The purpose of this study was to systematically assess the trends in surgical techniques, outcomes, and complications of cartilage restoration of the patellofemoral (PF) joint.
Design: The electronic databases PubMed, MEDLINE and EMBASE were searched from 2007 to April 2018. The Methodological Index for Non-Randomized Studies (MINORS) was used to assess study quality. A two-proportion z-test was used to determine whether the differences between the proportions of cartilage restoration techniques used from 2007-2012 and 2013-2018 were statistically significant.

Results

Overall, 28 studies were identified, including 708 patients (824 knees) with a mean age of 39.5 ± 10.5 years and a mean follow-up of 39.1 ± 16.0 months. Majority of patients were treated with autologous chondrocyte implantation (ACI) (45.5%) and conventional microfracture (MFx) (29.6%). A significant increase in the use of third generation ACI occurred with a simultaneous decreased usage of conventional MFx over the last five years (p < 0.001). All techniques had significant (p < 0.05) improvements in clinical outcomes. The overall complication rate was 9.2%, of which graft hypertrophy (2.7%) was the most prevalent.

Conclusions

ACI was the most common restoration technique. The use of third generation ACI has increased with a concurrent decline in the use of conventional MFx over the latter half of the past decade (p < 0.001). Overall, the various cartilage restoration techniques reported improvements in patient reported outcomes with low complication rates. Definitive conclusions on the optimal treatment remains elusive due to a lack of high quality comparative studies.