Long-term follow-up and survival analysis of patients undergoingpartial meniscectomy for discoid meniscus

Discoid lateral meniscus (DLM) is the most common meniscus variant. Surgical treatment is recommended in symptomatic DLM cases that occur as a mechanical result of structural changes, meniscus tears and instability. The main purpose of this study is to reveal the mid- and long-term results of the DLM patients who underwent arthroscopic saucerization. The hypothesis of the study is that successful results can be achieved by avoiding excessive resection while reshaping the DLM to an extent that prevents mechanical symptoms. The study included 57 knees of 53 patients who underwent arthroscopic treatment for discoid meniscus between 2000 and 2018 at Hacettepe University Department of Orthopedics and Traumatology, and had at least 5 years of follow-up after surgery. The average follow-up period is 12.1 (5-23.1) years. 31 knees were treated in the pediatric group and 26 knees in the adult group. Kellgren-Lawrence stages differ between pediatric and adult groups. When the pre- and post-treatment stages were compared, no change was observed in the pediatric group (p=0.125), while osteoarthritis was shown to progress in the adult group (p<0.001). Although there was no difference in the femorotibial angle between the pediatric and adult groups (p=0.316), a weak negative correlation was detected when correlated with age (r=-0.299; p=0.03). Clinical scores were found to be higher in the pediatric group than in adults (p<0.05). Return to the operating room was needed in a total of 4 knees. 10-year survival was found to be 90.6%. The study showed that the surgical technique and goals were successful. Valgus alignment and its complications, which can occur after reshaping, were avoided. It has been shown that the outcomes of patients treated in the adult age group are worse. Treatment of symptomatic DLM should not be delayed. During treatment, it should be taken into consideration that DLM has different mechanical properties than the normal meniscus structure and excessive resection should be avoided.