Abstract
BACKGROUND: The discoid lateral meniscus (DLM) is a common congenital abnormality of the meniscus. Tears are common, and initial treatment is often not definitive, leading to a spectrum of complications, including persistent symptoms, meniscal insufficiency, osteochondral defects, and recurrent tears potentially requiring reoperation. PURPOSE: To determine demographic, injury, and perioperative risk factors that increase the likelihood of complications and reoperation after treatment in patients with DLM. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients surgically treated for DLM from 9 institutions between 2000 and 2020 were reviewed. Data on demographics, presenting symptoms and signs, surgical findings and treatments, complications, and reoperations were collected and analyzed using a 2-level generalized linear mixed model. The conditional probability of complications was predicted using logistic regressions. Odds ratios were calculated to identify findings associated with an increased likelihood of postoperative complications and reoperations. RESULTS: In total, 867 knees in 784 patients were surgically treated for DLM. There were 175 complications in 139 knees (16%); reoperations were performed in 110 knees (13%). Complication rates varied among institutions, ranging from 0% to 29%. The most common complication was retear of the meniscus (12%). Female patients were more likely to have complications and reoperations than male patients. Patients with a meniscus tear were 74% less likely to have a complication than those without tears, although patients with a complex meniscal tear were 3.4 times more likely to have a complication and 4.4 times more likely to have a reoperation than those without. Horizontal tears, as well as the open repair technique, had an increased risk of reoperation. Other tear types, tear locations, repair techniques, the presence of rim instability, age, and preoperative symptoms were not significantly associated with complications. CONCLUSION: Of the patients, 17% (16% of knees) had postoperative complications after DLM treatment, of whom 17% had more than 1 complication. Additionally, 13% underwent reoperation. Complications were less likely in those treated for their DLM who had a meniscus tear and more likely in female patients and those with complex meniscus tears. Reoperation was more likely in female patients, those with a horizontal or complex tear, and those who had an open meniscus repair.