[MRI of aseptic osteonecrosis in children and adolescents with acute lymphoblastic leukemia].

PURPOSE: To evaluate the incidence, localisation, and course of symptomatic aseptic osteonecrosis (AON) in children undergoing treatment for acute lymphoblastic leukemia (ALL).

METHODS

72 MRI examinations obtained from 26 children with bone pain selected from a group of 121 children with ALL were evaluated retrospectively. The area of the AON was determined by computer assisted planimetry. Follow-up examinations after 2-5 years were considered.

RESULTS

10/121 (8.3%) of the children had symptomatic AON, the number of lesions varied between 1 and 24 per child. 62/66 lesions were localized within the lower extremities. 58% of the AON were positioned in the epiphysis and 42% in the meta- and diaphysis. The mean area of AON was 7.6 cm2 with a range of 0.5 to 50 cm2. Follow-up examinations revealed a regression in 19 AON, no change in 43 and a progression in 4 lesions. AON within the epiphysis with joint involvement or lesions greater than 9 cm2 more frequently showed a progression of AON with final joint destruction. An elevated risk for AON was seen in children older than 10 years and in children with intensified chemotherapy due to high-risk ALL.

CONCLUSION

AON is a common complication in ALL-children under chemotherapy. Most frequently, the course is benign but large AON with joint involvement have an elevated risk for progression of AON with final joint destruction.