Internal Fixation of Osteochondritis Dissecans of the Knee Leads to Good Long-Term Outcomes and High Degree of Healing without Differences between Fixation Devices.

The aim of the present study is to describe results at long-term follow-up of internal fixation of unstable Osteochondritis Dissecans (OCD) achieved with three different fixation devices in skeletally mature knees. A retrospective cohort study was performed at 5 to 19 years follow-up. Patient-reported questionnaires were collected at the final follow-up. Postoperative X-rays and MRIs were evaluated for healing of the lesion and articular degeneration. An arthroscopic second look was performed in 74.3% of the cases. Failures were reported as reintervention to address the osteochondral lesion or poor functional outcomes at the last follow-up. A total of 39 subjects with a median follow-up of 10.7 years were included. Herbert screws were used in 51.2% of the cases, bioabsorbable nails in 25.7% of the cases and cannulated screws in 23.1% of the cases. No differences were observed in terms of the clinical score (International Knee Documentation Committee (IKDC) p = 0.211; Lysholm p = 0.197), radiographic union (p = 0.102) or radiographic degeneration (p = 0.238) between the three different fixation devices. Arthroscopic second look found complete stability of the lesions in all 29 cases evaluated. The mean postoperative Lysholm score was 83 (range = 33-100) and IKDC score was 79 (range = 39-100). Radiographic union was seen in 74% of the cases. Lack of radiographic union was correlated with worst functional scores. A failure rate of 20.5% was found: four reinterventions were performed, and four patients had poor scores at last follow up. This study shows that internal fixation of condylar OCD in skeletally mature patients provides good long-term clinical results and a high degree of healing regardless of the dimensions of the lesion and type of fixation.