Femoral resurfacing in young patients with hematologic cancer and osteonecrosis.

UNLABELLED: Resurfacing hemiarthroplasties were performed to treat advanced osteonecrosis of 20 femoral heads in 14 patients (median age, 19.8 years; range, 15.1-27.4 years), treated for hematologic cancer in childhood or adolescence. Seven hips in five patients were revised to total hip arthroplasties (THA) because of pain; three of these showed radiographic loosening of the femoral head resurfacing component. The median time from resurfacing to revision was 2.4 years (range, 0.9-4.8 years). Marginal Cox-regression analysis, adjusting for correlations owing to bilateral involvement, showed positive association of revision-free survival of the prosthesis with patient's age; time from resurfacing to the end of anticancer therapy, end of glucocorticosteroid therapy; percentage of joint space at the last radiograph; and size of the lesion has a negative association with revision-free survival. Because of this study's exploratory nature, p values were not adjusted for the number of statistical comparisons. Among 14 patients, the probability of not requiring resurfacing prosthesis revision was 66% (SE, +/-15%; 95% CI, 44%-100%) at 3 years. Osteonecrosis of the femoral head in young patients treated for hematologic cancer in childhood or adolescence poses a serious challenge to the orthopaedic surgeon. The data of this preliminary study suggest that in selected patients resurfacing hemiarthroplasty may delay the need for THA for 3-7 years. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Femoral head osteonecrosis in pediatric and young adult patients with leukemia or lymphoma.

PURPOSE: Osteonecrosis of the capital femoral epiphysis is a significant late toxicity of treatment for childhood leukemia and lymphoma. We determined clinical and imaging risk factors predicting clinical joint outcomes of femoral head osteonecrosis in pediatric patients with leukemia or lymphoma. PATIENTS AND METHODS: We reviewed retrospectively medical records and magnetic resonance imaging scans of 80 patients with osteonecrosis of the capital femoral epiphysis. Logistic regression was used to examine relationships between risk factors and outcomes of joint surface collapse and arthroplasty. We used Kaplan-Meier survival curves to display the time to joint surface collapse and arthroplasty based on selected predictors. RESULTS: Median time between primary diagnosis and diagnosis of osteonecrosis of the hip was 1.7 years (range, 0.1 to 17.5 years). Twenty-three patients (29%) underwent arthroplasty in 36 hips at a mean of 1.3 years (range, 0.5 to 8.6 years) after diagnosis of osteonecrosis. Median age at time of first arthroplasty was 20.1 years (range, 15.1 to 35.4 years). Joint outcome of osteonecrosis was predicted solely by lesion size at diagnosis of osteonecrosis. 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. CONCLUSION: Lesion size of osteonecrosis is the best predictor of clinical joint outcome of hip osteonecrosis in survivors of pediatric hematologic malignancy. Lesions occupying more than 30% of the femoral head have high likelihood of joint deterioration necessitating arthroplasty at a young age.

Childhood cancer survivors: an at-risk cohort for ankle osteonecrosis.

UNLABELLED: We aimed to determine if the ankle is at risk for corticosteroid-induced osteonecrosis as a cause of pain in a cohort of childhood cancer survivors. We retrospectively reviewed magnetic resonance imaging scans of the ankle in patients treated at our institution between 1993 and 2003. Among the 15 patients who met study criteria, 20 of 30 (67%) ankles were involved. Older children had the highest incidence of the disease. The tibial metaphysis, epiphysis, and talus were the most frequent sites of osteonecrotic lesions. Ten patients were symptomatic with extended weightbearing activity. Surgery was required in four with continued amelioration of pain at last followup (17-44 months). As early detection and intervention lead to prevention of ankle morbidity, childhood cancer survivors would benefit from a prospective multi-institutional study that would provide understanding of ankle osteonecrosis and development of effective interventions. LEVEL OF EVIDENCE: Prognostic study, Level II-1 (retrospective study).

Use of a smooth press-fit stem preserves physeal growth after tumor resection.

We conducted this study to determine whether the small-diameter, press-fit stem of a novel, noninvasive expandable endoprosthetic device implanted in the limbs of 6 pediatric patients with Stage IIB osteosarcoma affected the growth of the physis through which the stem was inserted. Local control of the tumor necessitated resection of the involved growth plate, and implantation of the device required penetration of the adjacent uninvolved bone, through the growth plate, by the stem of the device. We measured longitudinal growth and the rate of growth of the adjacent uninvolved bone in the salvaged limb and of the equivalent bone in the unoperated contralateral limb. In all cases but one (in which the patient's growth in the contralateral limb appeared complete), longitudinal growth continued in the limb into which the device was implanted: the adjacent uninvolved bone in the salvaged limb grew by an average of 2.4 cm, and the equivalent bone in the unoperated contralateral limb grew by an average of 2.3 cm. We conclude that implantation of a smooth, press-fit stem through the central portion of the uninvolved adjacent physis does not result in growth retardation or arrest.

The effect of a mediastinal mass on the initial positioning of a peripherally inserted central venous catheter.

The purpose of this project was to assess if the presence of a mediastinal mass adversely influences peripherally inserted central catheter (PICC) positioning. A retrospective review of all PICC placements over an 18-month period in a pediatric oncology hospital was conducted in which patients were categorized by the presence or absence of a mediastinal mass. A much higher proportion of patients with a mediastinal mass (8 of 13) had a malpositioned catheter than those without a mass (3 of 38; P = .0002). A significant proportion of the malpositioned catheters in patients with a mediastinal mass terminated in the right heart chambers. These findings show that clinicians must be vigilant about checking for PICC malpositioning in this patient population.