Progressive valgus deformity after curettage of benign lesions of the proximal tibia.

Background: Progressive valgus deformity after proximal tibial metaphyseal fractures in pediatric patients has been well described, although the pathophysiology is not clear. We performed a retrospective study to evaluate the occurrence of progressive tibia valga after curettage of benign bone lesions of the tibia.

Methods: During a 6-year period, we performed curettage and bone grafting of benign bone lesions of the tibia in 20 patients aged 16 years and younger. Radiographs and clinical notes were reviewed. The diagnosis, age, sex, location of lesion, surgical approach, physeal arrest, limb-length discrepancy, deformity, and treatment were documented.

Results: Four patients subsequently developed progressive tibia valga (mean, 12 degrees; range, 7-21 degrees). Progressive valgus deformity occurred in 4 of 5 patients younger than 10 years old who had curettage of lesions of the proximal tibial metaphysis. Deformity did not occur in any of the 13 patients older than 10 years (range, 13-16 years) or in any of the 8 patients who had curettage of the distal tibia (age range, 6-14 years). In patients who developed tibia valga, the deformity progressed during the first 6 to 17 months postoperatively and then stabilized. One patient required corrective osteotomy at age 12 years for a symptomatic 21-degree deformity 3 years after curettage. The other 3 patients with tibia valga remained asymptomatic and demonstrated partial correction of their deformities, currently ranging from 3 to 7 degrees with a mean follow-up of 31 months (range, 19-47 months).

Conclusions: Progressive tibia valga seem to be relatively common in patients younger than 10 years who have had curettage of the proximal tibial metaphysis. This potential sequela should be discussed thoroughly with the patient's parents before proceeding with surgery, and patients should be followed and evaluated for this postoperatively.