The Influence of Physeal Status on Rate of Reoperation After Arthroscopic Screw Fixation for Symptomatic Osteochondritis Dissecans of the Knee.

Abstract

To determine if physeal status or other preoperative or intraoperative variables influence the failure rate after arthroscopic reduction and internal fixation of osteochondritis dissecans (OCD) lesions in the knee. Consecutive patients undergoing screw fixation of osteochondral fragments from OCD by a single surgeon from 2005 to 2015 with a minimum 2-year follow-up were included. Demographic, preoperative imaging, and intraoperative data were analyzed to determine risk factors associated with failure, which was defined as the need for a revision reoperation or arthroplasty after initial OCD fixation. A total of 45 knees met the inclusion criteria, including 26 skeletally mature patients and 19 patients with incompletely closed physes on preoperative imaging. The mean ages of the skeletally mature and immature groups were 18.3 ± 2.5 years and 14.9 ± 2.2 years, respectively (P < .001), and the mean body mass index values were 24.3 ± 3.6 and 23.2 ± 4.0, respectively (P = .432). We excluded 10 patients from the survivorship analysis because they had less than 2 years' follow-up. No statistically significant difference in failure rates was found between skeletally mature and immature individuals (30% and 40%, respectively; P = .721). The only factor significantly associated with fixation failure was undergoing a prior surgical procedure to address the OCD lesion (P = .038). Kaplan-Meier analysis showed rates of overall survivorship from revision reoperations of 88.6% at 1 year and 68.8% at 5 years. Outcomes after internal fixation of OCD fragments are guarded, with a fragment survival rate of 65.7% at a mean of 4.1 years' follow-up. No difference in fragment survival was noted in skeletally mature versus immature patients. The only independent risk factor identified for fixation failure was the number of previous operations. LEVEL OF EVIDENCE: Level IV, case series with subgroup analysis.