Osteochondral Autologous Transplantation Was More Effective Than Microfracture for Osteochondritis Dissecans in Children Younger than Eighteen Years

Abstract

Question: In children with osteochondritis dissecans (OCD) injuries ofthe knee, is osteochondral autologous transplantation (OAT) more effective than microfracture? Design: Randomized (allocation concealment unclear), blinded (assessor of magnetic resonance imaging [MRI] findings) controlled trial with 4-year follow-up. Setting: A university hospital in Kaunas, Lithuania. Patients: 50 children < 18 years of age (mean age, 14.3 y; 56% boys) with a single International Cartilage Repair Society (ICRS) grade 3 to 4 OCD lesion between 2 and 4 cm 2 in a stable knee were included. All patients had not improved after 6 months of conservative treatment. 47 patients (94%) completed follow-up. Intervention: Patients were allocated to OAT (n = 25) or microfracture (n = 25). For all patients, residual fibrotic tissue of subchondral bone was removed from the defect. For the OAT procedure, the donor transplant was harvested with a larger (0.1-mm) cylinder and the lesion was carved out with a smaller cylinder. 5 and 6-mm plugs from the lateral or medial margin of the femoral trochlea were placed at the same level as the healthy cartilage, as close together as possible. The joint trough was moved through a full range of movement to check for stable and correct placement of the plugs. For the microfracture procedure, an arthroscopic awl made multiple holes (2 to 4 mm wide) in the exposed subchondral bone plate, as close together as possible. Patients in both groups received prophylactic antibiotics at the time of surgery and at 6 and 12 hours after surgery and followed an identical rehabilitation program with the goal of full weight-bearing by 6 weeks. Main outcome measures: The outcomes of interest were ICRS repair grade score (score range: 1 = excellent, 2 = good, 3 = fair, and 4 = poor), return to preinjury activity level, and MRI evaluation. Main results: Both the OAT and microfracture groups improved in ICRS scores from baseline. More patients in the OAT group maintained excellent or good results than did patients in the microfracture group, but the differences were not significant (Table). More patients in the OAT group achieved the preinjury activity level than did patients in the microfracture group (Table). At 18.2 months after surgery, MRI showed excellent or good repairs in more patients who received OAT than in patients who received microfracture (Table). Conclusion: In children with OCD injuries of the knee, OAT was superior to microfracture repair.