Osteonecrosis lesion size predicts THA in survivors of pediatric leukemia, lymphoma

Most hips with lesions occupying more than 30% of the femoral head collapse within 2 years of diagnosis.

The size of an osteonecrotic lesion at diagnosis can be used to predict the risk of femoral head collapse and need for total hip arthroplasty in patients who survived certain childhood hematologic malignancies, according to a study by researchers in Tennessee.

Evguenia Jane Karimova, MD, and colleagues at St. Jude Children's Research Hospital and at the University of Tennessee School of Medicine, Memphis, reviewed medical records and MRIs for 80 patients diagnosed with osteonecrosis of the capital femoral epiphysis. All patients had survived either leukemia or lymphoma as children, according to the study, published in the Journal of Clinical Oncology.

Patients were diagnosed with hip osteonecrosis at an average of 1.7 years after their primary diagnosis. Surgeons performed 36 total hip arthroplasties (THAs) in 23 patients (29%) a mean of 1.3 years after they were diagnosed with hip osteonecrosis. These 23 patients averaged 20.1 years of age at the time of their first THA, with ages ranging from 15.1 to 35.4 years, according to the study.

"Joint outcomes of osteonecrosis [were] predicted solely by lesion size at diagnosis of osteonecrosis," the study authors wrote. "The worst prognosis was associated with lesions occupying more than 30% of the femoral head volume; 80% of hips with these lesions collapsed within 2 years of diagnosis and 50% required arthroplasty."

The study is important because intensive use of corticosteroids, which has been implicated in the development of osteonecrosis, is a major component of chemotherapy for pediatric leukemia and lymphoma, according to a press release from St. Jude's announcing the study findings.

"Being able to predict which children are likely to experience serious bone deterioration in the future will help investigators identify and monitor survivors who are at particularly high risk for developing this problem," said Sue Kaste, DO, a member of the Radiological Sciences department at St. Jude, and senior author of the study, in the release.

"Osteonecrosis has become one of the most important side effects of therapy that affects the quality of life of these long-term survivors," Kaste said. "We want the survivors to have the best quality of life possible. Therefore, we analyzed the extensive amount of data on such patients accumulated at St. Jude over the years to determine which factors cause joint collapse and make it likely that the patient will need arthroplasty."

For more information:
Karimova EJ, Rai SN, Hioward SC, et al. Femoral head osteonecrosis in pediatric and young adult patients with leukemia or lymphoma. J Clin Oncol. 2007;25:1525-1531.