Titanium wire mesh and impact bone allograft in treating acetabular bone defects in revision total hip arthroplasty

Abstract

Objective To investigate the method and efficacy in treating acetabular bone defects by the use of titanium wire mesh and impact bone allograft in revision total hip arthroplasty. Methods Twenty-two patients (22 hips) with acetabular bone defects in revision total hip arthroplasty were treated with wire mesh and impact bone allograft from January 2008 to December 2013. There were 7 males and 15 females in the present study. The average age of the patients at the surgery was 64.8 (37-78) years. According to Paprosky classification, there were 9 cases of type IIA, 4 cases of IIB, 7 cases of IIC and 2 cases of IIIB. Twenty cases with aseptic loosen and 2 with periprosthetic infection were underwent revision surgery. Deep frozen cancellous bone allograft was sterilized and morselized to particles with the size of 7 to 10 mm. After removal of loosed acetabular component, the bone grafts were impacted into the acetabular defects area to restore the bone quantity. Titanium wire mesh with appropriate diameter was chosen to fix on impacted bone graft and fixed acetabulum with screws. Polyethylene cup was cemented in the mesh wire with proper position. Harris hip score system was used to evaluate the hip joint function. The AP pelvis X-ray was taken at 1 week, 3 months, 12 months and annually thereafter postoperatively to evaluate the rotation center, fusion of the bone graft and loosening of cup. Results All patients were followed up with the average period 5.1 years (3-7 years). The average Harris hip score before revision was 43.75±13.45, while the score was 85.33±7.84 at last follow-up (t=7.930, P=0.000). The average height of hip rotation center of surgical side was 3.49±0.77 cm before surgery, while its height at last follow-up was 2.22±0.22 cm (t=4.390, P=0.005). The distance between hip rotation center and the base of acetabulum was 3.54±0.45 cm before surgery, while its value was 3.52± 0.76 cm at last follow-up. All the bone grafts came to infusion with the average time 12 months (9-15 months). There was no case with cup migration more than 4 mm or rotation greater than 5° at last follow-up. One patient had the symptom of sciatic nerve injury. No case was with infection or dislocation. Conclusion In the treatment of acetabular bone defects, wire mesh and impact bone allograft with cemented cup in revision total hip arthroplasty can reconstruct hip rotation center and the acetabular bone quantity effectively. Satisfied early-midterm curative effects could be acquired by using this method. Key words: Arthroplasty, replacement, hip; Reoperation; Acetabulum; Bone transplantation; Transplantation, homologous; Surgical mesh