Tibial lengthening for unilateral Crowe type-IV developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is associated with chronic pain and limping which especially has a negative impact on the patients' daily activities, body image, and self-esteem. Although total hip arthroplasty remains the first choice for treatment of DDH in adults, minimally invasive alternative approaches are being increasingly favored both by the surgeon and the patients with severe DDH. This study aimed to evaluate the outcome of these patients treated with a mono-lateral external fixator-based tibial lengthening procedure.

During the period of month between June 1999 and January 2006, 13 (mean ages 20.8 years) adult patients with unilateral Crowe type-IV DDH were treated by tibial lengthening using a mono-lateral external fixator over an intramedullary nail. Bone healing, infection, gait correction and improvement in body image were assessed during postoperative followup. Patients' overall health status at the end of followup was assessed using the short form-36 (SF-36) health survey.

Patients were followed up for an average of 7.3 years. Successful bone healing was observed in all 13 patients and no further surgeries were indicated. A mean external fixation index of 12.4 days/cm was achieved. Bone formation fell in good to excellent categories with a mean consolidation index of 50.1 days/cm. Pin-tract infections were observed in two patients. The degree of limping was reduced from severe or moderate preoperatively to mild postoperatively. Neither equinus deformity nor painful degenerative osteoarthritis and hip dysfunction were observed in any of the patients studied. The SF-36 questionnaire survey showed that all patients were satisfied with their outcomes.

Tibial lengthening may effectively correct gait and satisfactorily improve body image in young patients with unilateral Crowe type-IV DDH. Mono-lateral external fixator allows for accelerated postoperative rehabilitation and optimal preservation of ankle movements. Lengthening along with intramedullary nails may significantly reduce the external fixation time and the risk of fixator-related complications.