Background
Hip fusion restricts most of daily-living activities, and patients request takedown of their fusion hoping to improve gait and function and relieve pain from adjacent joints.
Patients and methods
We retrospectively reviewed 27 fused hips (22 patients) converted to total hip arthroplasty between 2001 and 2013. A total of 19 male and three female patients had hip fusion for an average of 17 years (range: 6–32), with mean age at conversion of 34 years (range: 22–55). The etiology of fusion was surgical arthrodesis in seven, ankylosing spondylitis in 12, post-traumatic in four, dysplasia in two, and idiopathic in two hips. Posterolateral approach was used in all patients with intraoperative imaging to guide in-situ neck osteotomy and ensure correct positioning of the cup. A total of 18 hips were uncemented, with ceramic-on-ceramic bearing used in 11.
Results
Patients were followed for a mean of 96 months (range: 36–168). Center of rotation was restored to within 0.5 cm in 24 hips. Limb-length discrepancy averaging 1 cm (range: 0.5–2 cm) was noted in six patients. Harris hip score improved significantly from 46 (range: 20–56) to 78 (range: 42–97) at the last follow-up with a mean flexion range of 85° (65–120°). Abductor lurch with positive Trendelenburg sign was present in eight hips. All but two patients were satisfied with the result. One cup was aseptically loose, making for 96% implant survival. Complications also included two cases of heterotypic ossification, one partial sciatic nerve palsy that later recovered, and one hematoma formation. No dislocations or wound infections were reported.
Conclusion
Successful takedown of hip fusion is possible with improved function and gait and low complication rate.