Patellofemoral Cartilage Restoration: A Systematic Review and Meta-analysis of Clinical Outcomes

Betina B. Hinckel, William Beaumont Hospital
Eli L. Pratte, University of Missouri
Charles A. Baumann, University of Missouri
Anirudh K. Gowd, Wake Forest Baptist Medical Center
Jack Farr, Indiana University-Purdue University Indianapolis
Joseph N. Liu, Loma Linda University Medical Center
Adam B. Yanke, Rush University Medical Center
Jorge Chahla, Rush University Medical Center
Seth L. Sherman, Stanford University


© 2020 The Author(s). Background: Many surgical options for treating patellofemoral (PF) cartilage lesions are available but with limited evidence comparing their results. Purpose: To determine and compare outcomes of PF cartilage restoration techniques. Study Design: Systematic review and meta-analysis. Methods: PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines were followed by utilizing the PubMed, EMBASE, and Cochrane Library databases. Inclusion criteria were clinical studies in the English language, patient-reported outcomes after PF cartilage restoration surgery, and >12 months’ follow-up. Quality assessment was performed with the Coleman Methodology Score. Techniques were grouped as osteochondral allograft transplantation (OCA), osteochondral autograft transfer (OAT), chondrocyte cell–based therapy, bone marrow–based therapy, and scaffolds. Results: A total of 59 articles were included. The mean Coleman Methodology Score was 71.8. There were 1937 lesions (1077 patellar, 390 trochlear, and 172 bipolar; 298 unspecified). The frequency of the procedures was as follows, in descending order: chondrocyte cell–based therapy (65.7%), bone marrow–based therapy (17.2%), OAT (8%), OCA (6.6%), and scaffolds (2.2%). When compared with the overall pooled lesion size (3.9 cm2; 95% CI, 3.5-4.3 cm2), scaffold (2.2 cm2; 95% CI, 1.8-2.5 cm2) and OAT (1.5 cm2; 95% CI, 1.1-1.9 cm2) lesions were smaller (P <.001), while chondrocyte cell–based therapy lesions were larger (4.7 cm2; 95% CI, 4.1-5.3 cm2; P =.039). Overall, the instability pool was 11.9%, and the anatomic risk factors pool was 32.1%. Statistically significant improvement was observed on at least 1 patient-reported outcome in chondrocyte cell–based therapy (83%), OAT (78%), OCA (71%), bone marrow–based therapy (64%), and scaffolds (50%). There were no significant differences between any group and the overall pooled change in International Knee Documentation Committee score (30.2; 95% CI, 27.4-32.9) and Lysholm score (25.2; 95% CI, 16.9-33.5). There were no significant differences between any group and the overall pooled rate in minor complication rate (7.6%; 95% CI, 4.7%-11.9%) and major complication rate (8.3%; 95% CI, 5.7%-12.0%); however, OCA had a significantly greater failure rate (22.7%; 95% CI, 14.6%-33.4%) as compared with the overall rate (6.8%; 95% CI, 4.7%-9.5%). Conclusion: PF cartilage restoration leads to improved clinical outcomes, with low rates of minor and major complications. There was no difference among techniques; however, failures were higher with OCA.