The influence of trochlear dysplasia on the clinical outcomes of autologous chondrocyte implantation (ACI) to the patellofemoral joint (PFJ) has not been studied yet. The purpose of this study was to evaluate the influence of trochlear dysplasia on clinical outcomes after ACI for the treatment of large cartilage lesions in the PFJ with a follow-up range of 2 to 5.6 years.
A retrospective review of prospectively collected data of all patients that underwent ACI for focal cartilage defect repair in the PFJby a single surgeon was performed.Patient factors, lesion morphology, and pre- and postoperative patient-reported outcomes measures (PROMs) were collected, including the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner and International Knee Documentation Committee (IKDC). Two independent observers assessed preoperative imaging to determine the presence and grade of trochlear dysplasia according to Dejour and Lippacher classifications. Patients were stratified into two groups based on the presence or absence of trochlear dysplasia, and patients without trochlear dysplasia served as controls. Patients were matched 1:1 for sex, age, BMI, lesion size and location.
Forty-six patients that underwent ACI in the PFJ with a mean follow-up of 3.7 ±1.9 yearswere enrolled in this study. Patient’s mean age was 30.1 ±8.8 years. Interobserver reliability (k) was 0.774 for the Dejour and 0.924 for the Lippacher classification (p < 0.001). PROMs at final follow-up did not differ between both groups (p > 0.05). No difference was seen regarding success rates between both groups (95.7% vs. 95.7%, p > 0.999). No difference in clinical outcome was seen between patients with high-grade dysplasia and patients without dysplasia (p > 0.05).
ACI in the PFJ provides favorable outcomes in patients with trochlear dysplasia, which are in fact comparable to those of matched patients with normal trochlear anatomy.