Cartilage defects in the patellofemoral joint (PFJ) can be caused by either traumatic or non-traumatic/degenerative events to the PFJ. Yet, no previous study has evaluated the effect of cartilage defect etiology on clinical outcomes after autologous chondrocyte implantation (ACI) to the PFJ. The purpose of this study was therefore to determine the relationship between cartilage lesion etiology and clinical outcomes after ACI in the PFJ.
A retrospective review of all patients that underwent ACI in the PFJ by a single surgeon was performed. Patient factors, cartilage lesion etiology and morphology, and pre- and postoperative patient-reported outcomes measures (PROMs) were collected. Patients were stratified into three groups based on the etiology of PFJ cartilage lesions: patellar instability (group 1); non-traumatic lesions including chondromalacia, osteochondritis dissecans and degenerative defects (group 2); and post-traumatic lesions excluding patellar dislocations (group 3). A clinical comparison was established between groups based on PROMs and failure rates.
Eighty patients that underwent ACI in the PFJ with a mean follow-up of 3.9 ±2.1 yearswere enrolled in this study. Patient’s mean age was 30.4 ± 9.4 years. Patients in group 1 were significantly younger (n = 26; 25.2 ±7.7 years) than group 2 (n = 31; 32.9 ±10.5 years) (p = 0.005) and group 3 (n = 23; 32.6 ± 7.6 years) (p = 0.008). Body mass index averaged 26.42 ± 4.5 kg/m2, with a significant difference between group 1 (24.7 ± 3.7 kg/m2) and group 3 (28.8 ± 4.3 kg/m2) (p = 0.006). Neither pre- or post-operative PROMs differed between the groups (p > 0.05). No difference was seen in success rates between the groups (96.2% vs. 83.9% vs. 91.3%, p = 0.301).
Cartilage lesion etiology does not influence clinical outcomes after ACI in the PFJ.