Comparison of the range of motion of the femoral head at two different diameters during primary total hip arthroplasty / 中国组织工程研究

ABSTRACT

BACKGROUND:Dislocation is a common short-term complication after total hip arthroplasty. Many factors can induce dislocation. Among controlable factors, the diameter of the femoral head may be one of factors affecting the incidence of dislocation. Generaly, large prosthesis meets the biomechanical feature of hip joint, and can increase the joint stability. OBJECTIVE:To observe the effects of different diameters of the femoral head on range of motion of the hip joint during primary total hip arthroplasty so as to provide evidence for selecting the prosthesis with an ideal diameter. METHODS: We colected data of 77 cases (87 hips), who underwent primary total hip arthroplasty with the femora head of 28 mm and 32 mm diameter in the Department of Orthopedics, Inner Mongolia Autonomous Region Wulanchabu Central Hospital from August 2009 to August 2012. Hip prosthesis was provided by ZIMMER Company. The hip motion interface was made from polyethylene on metal. The femoral head prosthesis was used as folows 28 mm diameter in 51 hips, and 32 mm diameter in 36 hips. Posterior approach was utilized. Range of motion of hip internal rotation and external rotation to dislocation was measured at hip flexion 90° during the operation, and compared between different diameter groups. RESULTS AND CONCLUSION:The method of surgery was not changed during operation in al patients. No significant difference in the sum of degree at dislocation was detected between two different diameter groups (P > 0.05). No significant difference in the intraoperative range of motion during total hip arthroplasty was visible in patients with femoral neck fracture between the two different diameter groups (P > 0.05). No significant difference in the intraoperative range of motion during total hip arthroplasty was visible in patients with avascular necrosis of the femoral head between the two different diameter groups (P > 0.05). These data suggested that compared with the femoral head of 28 mm diameter, the femoral head of 32 mm diameter did not increase the range of motion during total hip arthroplasty. After operation, two kinds of femoral head did not affect the dislocation after total hip arthroplasty in 2-year folow-up.