[Risk factors for the postoperative effect of symptomatic discoid lateral meniscus after arthroscopy]

To explore the influencing factors of the postoperative effect of arthroscopic treatment of symptomatic discoid lateral meniscus (DLM).

From September 2008 to September 2015, patients with symptomatic DLM treated by arthroscopic surgery were retrospectively analyzed. The knee function was evaluated by Lysholm scoring system. According to the scoring results, it was divided into excellent (≥90 points), good (80 to 89 points), fair (70 to 79 points) and poor (<70 points). Sixteen research factors were collected, namely gender, operation age, body mass index, work intensity, symptom duration, history of knee injury, involved knee side, DLM classification, DLM injury type, DLM injury site, medial meniscus injury, knee cartilage injury site and degree, Kellgren-Lawrence (K-L) classification, operation method, and latest follow-up time. According to the data type, Kruskall-Wallis rank sum test or χ² test was used for univariate analysis, and ordinal Logistic regression model was used for multivariate analysis. Univariate analysis showed that the statistically significant factors were included in the multivariate analysis model, and the independent risk factors influencing the curative effect of symptomatic DLM were obtained.

According to the inclusion and exclusion criteria, 502 patients were included. Lysholm functional grade at the latest follow-up was higher than that before operation (P<0.001). Univariate analysis showed that there were significant differences in gender, body mass index, work intensity, history of knee injury, age of operation, duration of symptoms, medial meniscus injury, K-L grade, operation method, location and degree of knee cartilage injury among Lysholm functional grades(P<0.05). Ordinal logistic regression analysis showed that female was an independent risk factor for postoperative efficacy (P=0.002, OR=0.370);body mass index (P=0.007, OR=0.894), work intensity(P=0.004, OR=0.525), age of operation(P<0.001, OR=0.953), duration of symptoms(P<0.001, OR=0.989), degree of cartilage damage (P=0.016, OR=0.631) were negatively correlated with Lysholm knee function classification.

Arthroscopy is a safe and effective method for the treatment of symptomatic DLM. The gender, body mass index, work intensity, age of operation, duration of symptoms and degree of knee cartilage injury are independent influencing factors for the postoperative efficacy of symptomatic DLM.