Lateral patellar compression syndrome vs. tibiofemoral osteoarthritis: a comparative study on meniscal and cartilage...

Knee joint pain is very common in clinical practice, with a complex etiology in which osteoarthritis is the most frequent cause. Among the various types of osteoarthritis, tibiofemoral osteoarthritis (TFOA) is the most prevalent. Patients with lateral patellar compression syndrome (LPCS) also present with knee joint pain. This study aims to compare meniscal and articular cartilage injuries in patients with LPCS and those with TFOA. This study could provide insights into the clinical characteristics and radiological features that distinguish these two conditions.

This study recruited 206 eligible patients from the Department of Sports Medicine at a hospital from March 2018 to February 2023. Patients were divided into two groups of 103: LPCS and TFOA. Magnetic resonance imaging was conducted using standardized protocols. Image analyses were undertaken by experienced radiologists to assess meniscal and cartilage injuries.

The mean age was 58.0±10.9 years in the LPCS group and 54.3±10.3 years in the TFOA group, with a significant difference between groups (P=0.01). Patients with LPCS exhibited a higher proportion of meniscal injuries (55.34% vs. 39.81%, P=0.03) and a significantly higher prevalence of posterior root tears of the medial meniscus (34.95% vs. 3.88%, P<0.001) compared with patients with TFOA. Significant differences in the grading of cartilage injuries were observed, particularly in the medial tibiofemoral compartment, where patients in LPCS group had higher grades of injury compared with TFOA patients (P<0.001). Specifically, in the medial compartment, grade 4 cartilage injuries were more frequent in the LPCS group (34.95% vs. 24.27%), while grade 1 injuries were more frequent in the TFOA group (53.40% vs. 29.13%). Among LPCS patients aged ≤50 years, 55% (11/20) had higher-grade cartilage injuries in the lateral compartment than in the medial compartment, suggesting more rapid cartilage damage progression in younger patients with LPCS.

This study underscores the significant differences in meniscal and articular cartilage injuries between patients suffering from LPCS and patients with TFOA. The results highlight the importance of radiological features for accurate clinical differentiation and the need for 'tailored' treatment strategies.