Department of Orthopedics, Martini Hospital, Van Swietenplein 1, 9728 NT Groningen, The Netherlands.
J Bone Joint Surg Am. 2013 Sep 4;95(17):1554-60. doi: 10.2106/JBJS.L.00716.
Recently, concern has emerged about pseudotumors (lesions that are neither malignant nor infective in the soft tissues surrounding total hip arthroplasty components) after hip arthroplasties with metal-on-metal bearings. Patients treated in our hospital for degenerative arthritis of the hip with a Birmingham Hip Resurfacing (BHR) prosthesis were invited to return for follow-up evaluation. The prevalence and clinical relevance of pseudotumors were investigated. Risk factors for pseudotumor formation were sought.
A single-center cross-sectional prospective cohort study was conducted and included all patients who received a BHR from 2005 to 2010 in Martini Hospital, Groningen, The Netherlands. Data were collected on patient and surgical characteristics, clinical hip outcome scores (Harris hip score and Oxford score), serum metal ion levels (cobalt and chromium), and radiographs. A computed tomographic scan (without metal suppression) was made. In patients who had a revision, tissue samples were histologically examined.
Originally, there were 129 patients with 149 BHRs. Four patients (six hips; 4%) were lost to follow-up. Our final cohort consisted of 125 patients (143 hips). From this final cohort, eleven patients (twelve hips) had a revision, and three of them (three hips) had the revision before the present study was conducted. Seven patients (eight hips; 5.6%) had a revision because of a symptomatic pseudotumor. Survival analysis showed an implant survival rate of 87.5% at five years (failure was defined as a revision for any reason). A pseudotumor was found on computed tomography in thirty-nine patients (forty hips; 28%). Of those patients, ten (eleven hips; 28%) had complaints involving groin pain and discomfort, a noticeable mass, or paresthesia. Symptomatic pseudotumors were significantly larger than asymptomatic pseudotumors (a mean volume of 53.3 cm3 compared with 16.3 cm3; p = 0.05). A serum cobalt level of >85 nmol/L was a predictor for pseudotumor formation (odds ratio, 4.9).
Pseudotumor formation occurred in 28% of hips after an average follow-up of forty-one months. Most pseudotumors (72.5%) were asymptomatic. Larger pseudotumors were associated with more complaints. Survival analysis showed an implant survival of 87.5% at five years. Failure occurred in 5.6% (eight) of 143 hips because of a symptomatic pseudotumor.
最近，在使用金属对金属关节轴承的髋关节置换术后，出现了所谓的假性肿瘤（即髋关节置换术后假体周围软组织中既非恶性也非感染性的病变），这引起了人们的关注。我们医院对患有髋关节退行性关节炎的患者采用 Birmingham Hip Resurfacing（BHR）假体进行治疗，邀请这些患者回来进行随访评估。本研究旨在调查假性肿瘤的发生率和临床相关性，并探讨其形成的危险因素。
本研究为单中心、前瞻性队列研究，纳入了 2005 年至 2010 年在荷兰格罗宁根 Martini 医院接受 BHR 治疗的所有患者。收集了患者和手术特征、临床髋关节评分（Harris 髋关节评分和牛津评分）、血清金属离子水平（钴和铬）和影像学资料。所有患者均行 CT 扫描（不进行金属抑制）。对接受翻修手术的患者，行组织学检查。
最初，共有 129 例患者的 149 个 BHR 纳入研究。4 例（6 髋）患者失访。我们的最终队列包括 125 例患者（143 髋）。在这最终队列中，11 例（12 髋）患者接受了翻修手术，其中 3 例（3 髋）在本研究进行之前已接受了翻修手术。7 例（8 髋）因有症状的假性肿瘤而行翻修手术。生存分析显示，5 年时的假体生存率为 87.5%（定义为任何原因的翻修）。39 例（40 髋）患者在 CT 上发现假性肿瘤，其中 10 例（11 髋）患者出现腹股沟疼痛和不适、可触及肿块或感觉异常等症状。有症状的假性肿瘤明显大于无症状的假性肿瘤（平均体积分别为 53.3cm3和 16.3cm3；p=0.05）。血清钴水平>85nmol/L 是假性肿瘤形成的预测因素（比值比，4.9）。
平均随访 41 个月后，有 28%的髋关节出现了假性肿瘤。大多数假性肿瘤（72.5%）为无症状。较大的假性肿瘤与更多的症状相关。生存分析显示，5 年时的假体生存率为 87.5%。8 髋（5.6%）因有症状的假性肿瘤而行翻修手术。
