Osteochondral allografts in the treatment of osteonecrosis of the knee.

In summary, patients with spontaneous osteonecrosis of the knee requiring surgery were elderly and generally had late stage IV disease. They seemed to do better with osteotomy and debridement than with osteochondral allograft replacement because they could not tolerate restricted weight bearing. Patients with steroid-induced osteonecrosis did well initially after allograft replacement (6 to 18 months), especially in experiencing pain relief. However, because of the continuous use of high doses of steroids, revascularization of the allografts was poor, resulting in graft subsidence. Patients have better long-term results following osteotomy and debridement. Patients with traumatic osteonecrosis and osteochondritis dissecans had the best results following osteochondral allograft replacements. In conclusion, based on our series and others, our current surgical approach in the management of osteonecrosis of the knee is as follows: 1. In patients with spontaneous osteonecrosis with asymptomatic small lesions, nonsurgical treatment is recommended. For an asymptomatic or symptomatic large lesion with associated angular deformity, the active patient should have a tibial osteotomy for stages I and II and tibial osteotomy and debridement for stages III and IV. Less active patients with symptomatic stage III or IV disease should have unicompartmental or total knee prosthetic arthroplasty. 2. For steroid-induced osteonecrosis, osteochondral allografts are not recommended. If the patient's systemic disease has a limited prognosis, or if the patient has multijoint involvement, total knee or unicompartmental arthroplasty is warranted. If the patient has a good prognosis and is active, debridement with or without realignment should be performed. 3. For traumatic osteonecrosis in the younger patient or for osteochondritis dissecans, fresh osteochondral allograft replacement is recommended. High tibial osteotomy in combination with allograft replacement should also be done if there is associated malalignment. The realignment should be done prior to or simultaneously with the allograft (providing the osteotomy is done on the side of the joint opposite the allograft).