Deformity correction of knee and leg lengthening by Ilizarov method in hypophosphatemic rickets: outcomes and significance of serum phosphate level.

The authors evaluated 14 patients with hypophosphatemic rickets who underwent correction of a knee deformity along with a leg lengthening by the Ilizarov method. Deformity correction alone was performed in 8 femora and 4 tibiae-fibulae, and concomitant deformity correction and limb lengthening (>1.0 cm) in 9 femora and 19 tibiae-fibulae. The healing index correlated with the biochemical parameters. Knee deformities were satisfactorily corrected in all patients except one. There was a statistically significant negative correlation between the healing index and the serum phosphate level: those who had a serum phosphate level higher than 2.5 mg/dL showed a relatively rapid regenerate bone healing compared with those with less than 2.5 mg/dL. The authors conclude that a serum phosphate level of 2.5 mg/dL as a cut-off point should be considered in deciding whether deformity correction alone or with a concomitant leg lengthening should be undertaken.