Bow leg deformity correction and lengthening with TSF system in an adolescent with hereditary hypophosphatemic rickets

Abstract

Background: X-linked hereditary hypophosphatemic rickets (XHPR) is the dominant form of hereditary rickets characterized by alteration of phosphate metabolism and defective mineralization of the growth cartilage and the newly formed bone collagen. Case report: We report a case of a 12-year-old girl with disproportionately short stature and bowed legs, diagnosed with X-linked hereditary hypophosphatemic rickets at the age of 2 years. Despite adequate medical treatment, her growth response was unsatisfactory. The Taylor spatial frame (TSF) was chosen as the most appropriate technique, which would ensure this dual objective of increasing the stature of the body and correcting the deformity of the lower limbs. This process was completed within a total period of 14 months. A total increase of 13 ​cm in the stature of the patient was achieved. In the final follow-up, five years postoperatively, a normal alignment of the lower extremities was maintained. Conclusion: This Hexapod frame system can lengthen the legs by distraction histogenesis, and at the same time, correct all the constituents of the deformity. Besides, TSF assisted by a web-relied software program, allows the execution, at any time throughout the correction process, of all appropriate modifications of the prescription needed to correct the deformity.

Keywords

• Bowed legs
• Short stature
• X-linked rickets
• Hexapod external fixator