Incidence of Severe Osteonecrosis Requiring Total Joint Arthroplasty in Children and Young Adults Treated for Leukemia or Lymphoma: A Nationwide, Register-Based Study in Finland and Denmark.

Purpose: The population-based incidence of severe osteonecrosis (ON) necessitating total joint arthroplasty (TJA) in patients with hematological cancer is unknown. This study assessed the incidence of ON requiring primary TJA in children and young adults treated for leukemia or lymphoma.

Methods

Patients diagnosed with leukemia or lymphoma before 31 years of age were identified from the Finnish and Danish Cancer Registries. These data were combined with those from the National Hospital Discharge and the Finnish Arthroplasty Registers. Data on the orthopedic procedures performed and the appropriate diagnosis codes given before the age of 40 were also retrieved.

Results

The estimated cumulative incidence of TJA was 4.5% at 20 years for patients treated for chronic myeloid leukemia, followed by 2.1% for patients treated for acute myeloid leukemia. It was considerably lower in patients with acute lymphoblastic leukemia (ALL; 0.4%). Multivariate analysis revealed that allogeneic stem cell transplantation (allo-SCT) increased the risk of TJA (hazard ratio [HR]=9.4; 95% CI: 5.3-16.9). The risk of TJA was higher in patients diagnosed with cancer at 10-19 and 20-30 years of age than in those diagnosed before the age of 10 (HR=24; 95% CI: 3.1-176 and HR=26; 95% CI: 3.6-192 respectively).

Conclusion

The incidence of ON requiring TJA was highest among patients with myeloid leukemias and lowest in patients treated for ALL. Allo-SCT and age ≥10 years at diagnosis were the most important risk factors for ON requiring TJA in hematological malignancies.