Department of Orthopaedic Surgery, OrthoCarolina, Charlotte, NC.
Department of Orthopaedic Surgery, Vanderbilt University, Nashville, TN.
Surg Technol Int. 2023 Sep 15;42:280-284. doi: 10.52198/23.STI.42.OS1638.
As implant technology has continued to improve over the past decade, there has been an increase in the utilization of highly porous metal substrate acetabular components for primary total hip arthroplasty (THA). These implants have several theoretical benefits including a lower modulus of elasticity, which may result in a reduction in stress shielding, a higher coefficient of friction, which may enable better initial implant fixation, as well as higher porosity that may facilitate improved biological fixation. Although these components are implanted frequently, there are some studies that have posed concerns regarding radiographic evidence of loosening. Therefore, the purpose of this study was to assess: 1) The quality of fixation of porous metal acetabular components based on radiographs; 2) clinical outcomes; and 3) revision rates.
A total of 159 patients (169 hips) who had undergone a primary THA utilizing a porous metal primary acetabular cup with minimum two-year follow up were assessed. The study cohort consisted of 51% women, had a mean age of 65 years (range, 30 to 92 years), a mean body mass index (BMI) of 29kg/m2 (range, 15 to 54), and a mean follow up of approximately four years (range, three to six years). Acetabular revision for component failure was documented. Radiographic assessments were independently performed by two fellowship-trained arthroplasty surgeons to determine implant stability and radiolucencies. Clinical evaluations were made by assessing the hip disability and osteoarthritis outcome score (HOOS-Jr) survey scores. Failure was defined as the need to revise the acetabular component, for either septic or aseptic pathology.
At final follow up, one patient had definitive loosening, one had probable loosening, and three patients had possible loosening. Only 3.0% had radiolucencies or radiosclerotic lesions in at least one zone. Of these patients, three developed progressive radiolucencies. All patients achieved excellent postoperative HOOS-Jr scores, and no significant differences were noted between patients who did not have loosening compared to patients who had possible or probable loosening. Only two patients underwent revision for aseptic loosening of the cup (success rate for this implant was 98.8% [2/169]).
There is a paucity of studies focused on the results of this porous metal substrate acetabular component, with some of the current literature reporting conflicting outcomes. Our study reported a low acetabular revision rate of only 1.2% at an approximate mean follow up of four years. The incidence of radiolucencies and progressive radiolucencies were lower (3.0%) than has been found in some studies. Overall, the results of this study support the utilization of this acetabular component in appropriately indicated patients.
These data show a low rate of acetabular revision at mean four-year follow up.
在过去十年中，随着植入物技术不断改进，初次全髋关节置换术（THA）中使用高多孔金属基底髋臼组件的情况有所增加。这些植入物具有几个理论优势，包括较低的弹性模量，这可能导致应力屏蔽减少，较高的摩擦系数，这可能使初始植入物固定更好，以及更高的孔隙率，这可能促进更好的生物固定。尽管这些组件经常被植入，但有些研究对松动的放射学证据提出了担忧。因此，本研究的目的是评估：1）多孔金属髋臼组件的固定质量；2）临床结果；和 3）翻修率。
评估了 159 例（169 髋）接受初次 THA 且至少有两年随访的患者，这些患者使用了多孔金属初级髋臼杯。研究队列包括 51%的女性，平均年龄 65 岁（范围 30 至 92 岁），平均体重指数（BMI）为 29kg/m2（范围 15 至 54），平均随访时间约为四年（范围 3 至 6 年）。记录了髋臼组件的翻修情况。两名经过 fellowship培训的关节置换外科医生独立进行放射学评估，以确定植入物的稳定性和放射性透亮区。临床评估通过评估髋关节残疾和骨关节炎结果评分（HOOS-Jr）调查评分来进行。失败定义为需要翻修髋臼组件，无论是感染性还是无菌性病变。
最终随访时，1 例患者有明确的松动，1 例有疑似松动，3 例有可疑松动。只有 3.0%的患者至少在一个区域有放射性透亮区或放射性硬化病变。这些患者中有 3 例出现进行性放射性透亮区。所有患者术后 HOOS-Jr 评分均极佳，无松动的患者与可疑或可能松动的患者之间无显著差异。只有 2 例患者因髋臼杯无菌性松动而接受翻修（该植入物的成功率为 98.8%[169 例中的 2 例]）。
目前针对这种多孔金属基底髋臼组件的研究结果很少，部分现有文献报告的结果相互矛盾。我们的研究报告了较低的髋臼翻修率，仅为 1.2%，平均随访时间约为四年。放射性透亮区和进行性放射性透亮区的发生率（3.0%）低于一些研究。总的来说，这项研究的结果支持在适当的患者中使用这种髋臼组件。
这些数据显示，在平均四年的随访中，髋臼翻修率较低。
