Epidemiology of Knee Articular Cartilage Injuries in Patients Undergoing Arthroscopy: Insights From 25,293 Procedures...

There is a paucity of large-scale epidemiological evidence on cartilage injuries among the Chinese population. This cross-sectional study was designed to delineate the prevalence, distribution, and determinants of knee cartilage injuries in patients undergoing primary knee arthroscopy.

We retrospectively reviewed patients who underwent primary knee arthroscopy from 2017 to 2023. Intraoperative findings were used to document the location, severity, and size of cartilage defects. Mixed-effects logistic regression models were employed to identify independent factors, accounting for bilateral procedures. Analysis of covariance was conducted to assess differences in preoperative Patient-Reported Outcome Measures (PROMs).

Among 25,293 arthroscopies, the overall prevalence of cartilage injury was 66.2%, and severe lesions (Outerbridge Grade III-IV) were present in 26.6%. Patellar cartilage exhibited the highest overall prevalence (39.4%), whereas the trochlea showed the highest prevalence of severe lesions (12.0%). Patella-related disorders revealed the highest prevalence of concomitant cartilage injuries of 86.08% (severe injuries of 51.42%). Positive associations were found between overall cartilage injuries with professional athletic status (adjusted OR = 2.18, 95% CI: 1.47, 3.22, p < 0.001), higher BMI (adjusted OR = 1.05, 95% CI: 1.04, 1.06, p < 0.001), longer injury duration (adjusted OR = 1.00, 95% CI: 1.00, 1.00, p < 0.001), patella-related disorders (adjusted OR = 3.73 vs. meniscal tear, 95% CI: 3.18, 4.37, p < 0.001), and prior musculoskeletal injury (adjusted OR = 1.31, 95% CI: 1.17, 1.47, p < 0.001). Negative associations were observed for pre-injury regular sports participation (adjusted OR = 0.74, 95% CI: 0.65, 0.85, p < 0.001), ACL rupture (adjusted OR = 0.47 vs. meniscal tear, 95% CI: 0.43, 0.52, p < 0.001). A significant sex-age interaction was noted. In males, older age was associated with higher prevalence of cartilage injuries, while females exhibited an even more significant increase after 50 years. For patients with isolated cartilage injuries, patient-reported outcomes and limitations on daily activity were significantly worse than those with other intra-articular disorders (all with p < 0.001).

Knee cartilage injury was highly prevalent in patients undergoing primary arthroscopy. Patellar and trochlear cartilage were the most frequently and most severely affected, respectively. Patella-related disorders carried the greatest risk of concomitant cartilage damage. Several potentially modifiable factors, including regular sports participation, were associated with injury occurrence, underscoring opportunities for prevention and early intervention.