Summary

Current surgical cartilage procedures seem to be effective in treating patellofemoral cartilage lesions; however, further comparative studies are required to assess which is the best technique.

Abstract

Introduction

Osteochondral lesions of the patellofemoral joint are challenging to manage due to complex joint biomechanics and the substantial load transmitted through this joint during weight-bearing activities. The first-line choice is often the conservative treatment (muscular strengthening and weight loss, nonsteroidal anti-inflammatory drugs and corticosteroids or hyaluronic acid intra-articular injections) aiming the inflammation relief, decrease of pain and reestablish the functional capacities. However, if not successful after 3 months, surgical management should be considered. Patellofemoral cartilage surgical repair has surged as a viable option for patellofemoral cartilage defects after conservative treatment has failed. Hence, this systematic review aims to analyze the postoperative outcomes following patellofemoral cartilage surgery.

Methods

A systematic review of databases Pubmed and Cochrane Library was performed in order to search for relevant studies reporting surgical outcomes of patellofemoral cartilage injuries. The search collected all available studies up to the 31th of December of 2017, and was designed by combining the following keywords: patella*, patellofemoral, femoropatellar, trochlea*, cartilag*, articul*, chondral, mosaicplasty, OATS, "osteochondral autograft transfer", ACI, MACI, "autologous chondrocyte implantation", "matrix-induced autologous chondrocytes implantation", "cartilage transplantation", microfracture, drilling, allograft, chondroplasty; with resource to the Boolean operators (AND) and (OR) and the command [Ti/Ab].

Results

A total of 18 studies comprising 721 patients (33.1 ± 4.5 years, 26.1 ± 1.7 kg/cm2, 53% males) with patellofemoral cartilage injuries were included. The mean cartilage defect size was 4.4 ± 1.5 cm2 and were mostly located at the patella (n=480, 67%) and trochlea (n=135, 19%). Additionally, 70 bipolar lesions and 33 multiple cartilage injuries including the patella and/or trochlea were also included. Surgical treatment included autologous chondrocyte implantation (10 studies), matrix-induced autologous chondrocyte implantation (5 studies), particulated juvenile transplantation (2 studies), osteochondral allograft transplantation (2 studies) and microfracture (1 study). Associated procedures included tibial tubercle medialization in 272 patients (38%), lateral release in 78 patients (11%), trochleoplasty in 22 (3%) and medial patellofemoral ligament reconstruction/repair in 8 patients (1%). All surgical techniques provided significant improvement in knee symptoms and function, with high rates of patient-reported satisfactory results. As there were only two comparative studies, meta-analysis could not be performed.

Conclusion

Current surgical cartilage procedures seem to be effective in treating patellofemoral cartilage lesions, being the autologous chondrocyte implantation and matrix-induced autologous chondrocyte implantation the treatment of choice in most studies. However, further comparative studies are required to assess which is the best technique for treating patellofemoral cartilage injuries.