初次全髋关节置换中两种直径股骨头活动度的对比

背景：人工全髋关节置换后脱位是置换后最常见的近期并发症，引起脱位的因素很多。在术者的可控制的因素中，股骨头直径可能是影响脱位发生率的因素之一。一般认为较大的假体头更符合髋关节生物力学特点，能够增加关节稳定性。目的：观察初次全髋关节置换术中不同股骨头直径对髋关节活动度的影响，以期为临床选择理想直径的股骨头假体提供依据。方法：收集乌兰察布市中心医院骨科自2009年8月至2012年8月采用28 mm及32 mm直径的股骨头假体行初次全髋置换77例(87髋)患者的病历资料。全部髋关节假体由ZIMMER公司提供，髋关节活动界面为聚乙烯对金属。股骨头假体采用28 mm直径51髋，32 mm直径36髋。手术入路均为后侧入路。术中测髋关节屈髋90°时髋关节内、外旋至脱位的活动度，并在不同直径股骨头假体组间进行对比分析。结果与结论：全部患者术中未更改术式。将两种直径股骨头组间脱位时度数总和进行统计学分析，发现差异无显著性意义(P > 0.05)。其中股骨颈骨折患者行人工全髋关节置换术中，两种不同直径人工股骨头假体的术中活动度差异无显著性意义(P > 0.05)；股骨头缺血性坏死患者行人工全髋关节置换术中，两种不同直径人工股骨头假体的术中活动度差异无显著性意义(P > 0.05)。提示与28 mm股骨头相比，32 mm股骨头未能增加全髋关节置换术中活动度，置换后随访2年两种直径的人工股骨头对于全髋关节置换后脱位无影响。中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程 

Comparison of the range of motion of the femoral head at two different diameters during primary total hip arthroplasty

BACKGROUND:Dislocation is a common short-term complication after total hip arthroplasty. Many factors can induce dislocation. Among controllable factors, the diameter of the femoral head may be one of factors affecting the incidence of dislocation. Generally, 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 collected 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 follows: 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 all 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 follow-up.