Background Children receiving chemotherapy for acute lymphoblastic leukaemia (ALL) may be susceptible to skeletal morbidity.

Aim To determine the incidence and risk factors for skeletal morbidity in ALL children.

Patients and methods The medical records of all (n=186, boys=110) children presenting to a single centre with ALL between 1997 and 2007 and treated on UKALL97, UKALL97/01 or UKALL2003 were studied. Skeletal morbidity included musculoskeletal pain, fractures and osteonecrosis (ON). Musculoskeletal pain was classified as any event of limb pain, muscle pain, joint symptoms or back pain that required radiological examination. Fractures and ON were confirmed by x-rays and MRI, respectively.

Results Skeletal morbidity, presenting as musculoskeletal pain, fractures or ON were reported in 88 (47%) children of whom 56 (63%) were boys. Of 88 children, 49 (55%), 27 (30%) and 18 (20%) had musculoskeletal pain, fracture(s) or ON, respectively. 6 (7%) had fractures and ON. The median (10th, 90th centiles) age at diagnosis of ALL in those children without skeletal morbidity was 3.9 (1.4–12) years which was lower than in those with skeletal morbidity at 8.2 (2.2–14.3) years (p<0.00001, 95% CI 1.7 to 4.4). Children with ALL diagnosed over 8 years of age were at increased risk of developing fracture(s) (p=0.01, OR=2.9, 95% CI 1.3 to 6.5) whereas the risk of ON was higher in those who were diagnosed after 9 years of age (p<0.0001, OR=15, 95% CI 4.1 to 54.4). There was no sex difference in the incidence of skeletal complications. Children who received Dexamethasone had a higher incidence of skeletal morbidity than those who were treated with Prednisolone (p=0.027, OR=2.6, 95% CI 1.1 to 5.9).

Conclusion The occurrence of skeletal morbidity in ALL children may be influenced by age and the type of glucocorticoids. These findings may facilitate the development of effective bone protective intervention.