混合型金属对金属人工全髋表面置换术18例:2年随访

背景:金属对金属人工髋关节提高了髋关节假体的耐磨性能,具有符合正常生物学应力传递的特点.目的:观察混合型金属对金属人工全髋表面置换患者髋关节功能的远期状况.设计:病例随访.单位:武装警察部队江苏省总队医院骨科和南通大学附属医院骨科.对象:选择2004-09/2005-07在武装警察部队江苏省总队医院骨科和南通大学附属医院骨科接受人工全髋表面置换术治疗的髋关节病变18例(23髋)患者.男11 例,女7例,年龄28～54岁.按病因学分类:股骨头坏死13例(16髋)、骨性关节炎3例(4髋)、先天性髋关节发育不良1例(2髋)和创伤后骨性关节炎1例(1髋).混合型金属对金属人工全髋表面关节假体由Wright公司提供,髋臼杯型号:38～56 mm (内径)/44～62 mm (外径);股骨头假体型号:38～56 mm (外径);髋臼杯压配深度1～2 mm.术前患者签署手术知情同意书,该术式的临床应用经过医院伦理委员会批准许可.方法:①硬腰联合麻醉后,暴露髋臼,选择大小合适的具有羟基磷灰石涂层的金属髋臼帽按解剖位置安放冲紧、压配固定.安装股骨头假体,用调制好的骨水泥涂摸在预制好的股骨头及股骨假体内表面,将金属杯套于准备好的股骨头上,用加压器压紧,使金属杯与骨质紧密相贴,并使金属杯的短柄与股骨颈的轴线保持一致.②术后2 d允许患者进行不负重的关节活动、被动关节活动及股四头肌主动等长舒缩功能锻炼,2 周后允许下床扶拐不负重行走,术后6周可逐渐过渡至完全脱拐行走.术后对所有患者予以患肢 "T"字横板鞋外展位固定.③术后1,2年行X 射线分析全髋表面置换效果及与宿主的生物相容性;术前及术后1,2年进行患髋Harris评分并观察患者髋关节情况.主要观察指标:①全髋表面置换效果.②生物相容性.③患髋Harris得分.④术后髋关节疼痛情况.结果:纳入患者18例均进入结果分析.①全髋表面置换效果:1例患者1个股骨假体内翻成10°角,未出现假体松动和股骨颈骨折的并发症, 其余表面置换假体位置满意.2例患者分别于术后1年和2年发现髋臼假体边缘1、2区有X线透亮线, 而在股骨短柄周围1、2和3区未发现有X线透亮线.②生物相容性:所有病例均无明显肾毒性、热原性及排斥反应,未发现有髋关节脱位、异位骨化、股骨颈狭窄、股骨头坏死及假体固定失败等并发症.③患髋Harris得分:术前患者平均46分,术后1年为85分,术后2年为93分,其中15个为优, 6个为良, 2个为中.④术后疼痛情况:2例患者术后轻微疼痛, 1例中度疼痛, 无严重疼痛者.结论:应用混合型金属对金属人工全髋表面假体置换髋关节疾病患者后远期疗效满意.

Hybrid metal-on-metal hip surface arthroplasty in 18 cases: 2 -year follow-up study

BACKGROUND: Metal-on-metal hip surface arthroplasty has improved the abradability for hip joint prosthesis and has the characteristics of normal biological stress transfer.OBJECTIVE: To observe the long-term state of hip-joint function of patients who underwent metal-on-metal hip surface arthroplasty.DESIGN: Follow-up study for cases.SETTING: Department of Orthopaedics, Jiangsu Provincial Corps Hospital of the Chinese People's Armed Police Force; Department of Orthopaedics, Affiliated Hospital of Nantong University.PARTICIPANTS: Eighteen cases (23 hips) who underwent a metal-on-metal hip surface arthroplasty procedure in the Department of Orthopaedics, Jiangsu Provincial Corps Hospital of the Chinese People's Armed Police Force, and Department of Orthopaedics, Affiliated Hospital of Nantong University between September 2004 and July 2005 were recruited in this study. All cases, aged 28 to 54 years, include 11 males and 7 females. According to the classification of etiology, there were 13 cases of osteonecrosis(16 hips),3 cases of osteoarthritis( 4 hips ),1 case of congenital hip dysplasia (2 hips) and 1 case of posterior trauma arthritis(1 hip ). All cases applied the Conserve Plus resurfacing prosthesis (manufactured by Wright Medical Technology, USA), of which the pattern number of acetabular cup (press-fit depth: 1-2 mm) ranged from 38 mm to 56 mm in the inner diameter and from 44 mm to 62 mm in the outer diameter and that of femoral head cup ranged from 38 mm to 56 mm in the outer diameter. Preoperatively all patients signed the informed consent for the surgery, and the application of this technique also gave the approval of the Ethics Committee of the hospital.METHODS: ①After the epidural and lumbar combination anesthesia was satisfactory, the coxacava was exposed at first and the suitable size acetabular cup coated by hydroxyapatite ceramic was selected to be implanted, to be tightened and to be fixed by press-fit referring to the anatomical position. Subsequently to install the femoral head prosthesis, femoral cup was laid on the ready caput femoris and impacted by the presser to make the metal cup paste close-up with sclerotin when the concocted bone cement was overlaid on the prefabricated caput femoris surface and internal surface of prosthesis. Further, short-term of femoral cup should be kept the conformity with axial ray of the femoral neck. ②Patients were allowed to make the function exercise such as initiative stretch and contract of quadriceps muscle of thigh, passive motion of the knee joint and initiative motion of the knee joint under the non-weight loading on bed. Then they were encouraged to walk with two walking sticks two weeks after operation, progressing to get out of the two walking sticks six weeks postoperatively. All affected extremities were fixated with T-shaped tabula shoes in the abduction position after operation. ③All patients were reviewed with taking the anteroposterior radiographs of pelvis, evaluation of the clinically curative effect on the procedure of metal-on-metal hip surface arthroplasty and biocompatibility between the prosthesis and the host one year and two years after operation. Moreover, Harris score was assessed for all affected hips preoperatively, one year and two years postoperatively.MAIN OUTCOME MEASURES: ①The clinically curative effect on metal on metal hip surface arthroplasty; ②Biocompatibility;③The Harris score for the affected hips; ④The pain status of hip after operation.RESULTS: Eighteen cases were all brought into the outcome analysis at last.①The curative effect on the metal-on-metal hip surface arthroplasty: The femoral component of one case had a varus deformation of 10°six weeks after operation, but such complications as component loosening and femoral neck fractures, etc. Did not occur during the coming follow-up. The locations of rest prosthesis were satisfactory. Substantial radiolucencies were found at the rim of acetabular component (1 and 2 zone) in two hips, respectively one and two years after operation. But there was no evidence of radiolucencies around the short-stem of femoral component.②Biocompatibility: No patients were found to have obvious reactions including renal toxicity, pyretogen and rejection. No radiograph showed signs of loosening, dislocation, heterotopic bone formation, femoral neck narrowing, femoral head necrosis and prosthesis fixation failure, etc.③Harris score for the affected hips: The Harris score of all disease hips was improved from the mean 46 preoperatively to 85 one year after operation to 93 two years postoperatively. Of these,15 hips were excellent(> 90),6 hips good (80-89), and 2 hips fair(70–79).④The pain status of hip after operation: Two patients complained of slight pain, one patient of moderate pain, and no cases of severe pain happened.CONCLUSION: The long-term outcome for hip disease patients who undergo metal-on-metal hip surface arthroplasty is satisfactory.