Lombardi Adolph V, Berend Keith R, Morris Michael J, Adams Joanne B, Sneller Michael A
Joint Implant Surgeons, Inc, 7277 Smith's Mill Road, Suite 200, New Albany, OH, 43054, USA,
Clin Orthop Relat Res. 2015 Feb;473(2):509-20. doi: 10.1007/s11999-014-3976-0. Epub 2014 Nov 4.
Use of large-diameter metal-on-metal (MoM) articulations in THA increased, at least in part, because of the possibility of achieving improved joint stability and excellent wear characteristics in vitro. However, there have been subsequent concerning reports with adverse reactions to metal debris (ARMD), pseudotumors, and systemic complications related to metal ions.
QUESTIONS/PURPOSES: The purpose of this study was to determine at a minimum of 2 years' followup (1) the proportion of patients who experienced a dislocation; (2) the short-term survivorship obtained with these implants; (3) the causes of failure and the proportion of patients who developed ARMD; and (4) whether there were any identifiable risk factors for revision.
We reviewed the results of 1235 patients who underwent 1440 large-diameter MoM primary THAs at our institution using two acetabular devices from a single manufacturer with minimum 2-year followup. Large-diameter MoM devices were used in 48% (1695 of 3567) of primary THAs during the study period. We generally used these implants in younger, more active, higher-demand patients, in patients considered at higher risk of instability, and in patients with adequate bone stock to achieve stable fixation without use of screws. Clinical records and radiographs were reviewed to determine the incidence and etiology of revision. Patients whose hips were revised were compared with those not revised to identify risk factors; Kaplan-Meier survivorship analysis was performed as was multivariate analysis to account for potential confounding variables when evaluating risk factors. Minimum followup was 2 years (average, 7 years; range, 2-12 years); complete followup was available in 85% of hips (1440 of 1695).
Dislocation occurred in one hip overall (<1%; one of 1440). Kaplan-Meier analysis revealed survival free of component revision was 87% at 12 years (95% confidence interval, 84%-90%). The two most common indications for revision were ARMD (48%; 47 of 108 hips revised) and loosening or failure of ingrowth (31%; 34 of 108). Risk factors for component revision were younger age at surgery (relative risk [RR] 0.98 per each increased year; p=0.02), higher cup angle of inclination (RR 1.03 per each increased degree; p=0.04), and female sex (RR 1.67; p=0.03).
Large-diameter MoM THAs are associated with a very low dislocation rate, but failure secondary to ARMD and loosening or lack of ingrowth occur frequently. Patients with MoM THA should be encouraged to return for clinical and radiographic followup, and clinicians should maintain a low threshold to perform a systematic evaluation. Early diagnosis and appropriate treatment are recommended to prevent the damaging effects of advanced ARMD.
Level IV, Therapeutic study.
在全髋关节置换术（THA）中，大直径金属对金属（MoM）关节的使用有所增加，至少部分原因是其在体外有可能实现更好的关节稳定性和出色的磨损特性。然而，随后有令人担忧的报告称出现了与金属碎屑相关的不良反应（ARMD）、假肿瘤以及与金属离子有关的全身并发症。
问题/目的：本研究的目的是在至少2年的随访期内确定：（1）发生脱位的患者比例；（2）这些植入物的短期生存率；（3）失败原因以及发生ARMD的患者比例；（4）是否存在任何可识别的翻修风险因素。
我们回顾了在我们机构接受1440例大直径MoM初次THA的1235例患者的结果，使用的是来自单一制造商的两种髋臼装置，随访期至少为2年。在研究期间，3567例初次THA中有48%（1695例）使用了大直径MoM装置。我们通常将这些植入物用于更年轻、活动更多、需求更高的患者，以及被认为不稳定风险更高的患者，还有骨量充足无需使用螺钉即可实现稳定固定的患者。回顾临床记录和X线片以确定翻修的发生率和病因。将接受髋关节翻修的患者与未翻修的患者进行比较以识别风险因素；进行了Kaplan-Meier生存率分析以及多变量分析，以便在评估风险因素时考虑潜在的混杂变量。最短随访期为2年（平均7年；范围2 - 12年）；85%的髋关节（1695例中的1440例）有完整的随访资料。
总体上有1例髋关节发生脱位（<1%；1440例中的1例）。Kaplan-Meier分析显示，12年时无部件翻修的生存率为87%（95%置信区间，84% - 90%）。翻修的两个最常见原因是ARMD（48%；108例翻修髋关节中的47例）和植入物松动或骨长入失败（31%；108例中的34例）。部件翻修的风险因素包括手术时年龄较小（每增加一岁相对风险[RR]为0.98；p = 0.02）、髋臼倾斜角度较大（每增加一度RR为1.03；p = 0.04）以及女性（RR为1.67；p = 0.03）。
大直径MoM THA的脱位率非常低，但因ARMD以及松动或骨长入不足导致的失败情况频繁发生。应鼓励接受MoM THA的患者返回进行临床和X线随访，临床医生应保持较低的阈值进行系统评估。建议早期诊断并进行适当治疗以防止晚期ARMD的破坏性影响。
IV级，治疗性研究。
