Osteonecrosis of the tibial plateau.

The clinical, radiographic and scintigraphic findings in 12 patients diagnosed with osteonecrosis of the tibial plateau (10 of the medial and two of the lateral plateau) were analysed. The disease presented suddenly in most of the patients, as acute pain in the lateral side of the knee, with no major traumatic antecedents. X-ray findings were varied and non-specific, and hence of little value for initial diagnosis. On the other hand, scintigraphic findings were very useful for diagnostic purposes in all cases. All the patients were over 55 years of age and 11 out of 12 were women. The most frequent location of the disease was the medial tibial plateau; however, two cases involved the lateral plateau and two involved both plateaux. Seven patients were subjected to full knee arthroplasty, four to valgising osteotomy and one to grafting. The patients' diagnoses were considerably delayed (by more than 6 months), which affected their treatment and prognosis.