Bone age in unilateral spastic cerebral palsy: is there a correlation with hand function and limb length?

BACKGROUND: The purpose of this study was to analyze the bone age and the upper extremity segmental lengths between the affected and the unaffected side and to reveal the correlation between the difference of bone age and the upper limb length discrepancy in the unilateral spastic cerebral palsy (CP). We also evaluated the relationship between difference of bone age and hand function.

METHODS: Seventy-eight patients participated in this study. The bone ages of hand-wrists of the patients were determined by the Greulich and Pyle atlas. Upper extremity segmental lengths were measured by radiograph. The side-to side length discrepancy was calculated as a percentage. Hand function was classified according to the Manual Ability Classification System (MACS).

RESULTS: There was significant difference in the bone age between the affected and unaffected side (p<0.001). Segmental lengths of the upper extremities showed significant differences between the affected and unaffected side (p<0.001). The hand function of 56 patients was evaluated by MACS and the MACS level showed correlation with difference of side-to-side bone age (r=0.29, p=0.03) and all segmental upper limb length discrepancies (p<0.05). The hand function in the bone-age-delayed group was significantly better than the hand function in the bone-age-symmetrical group (p<0.01).

CONCLUSIONS: The bone age of the affected side compared to the unaffected side is delayed and the hand function of the affected side is correlated with the difference of side-to-side bone age and the upper limb length discrepancy. Hand function might be helpful for predicting potential limb shortness and delayed bone age.