Wilkinson J Mark, Gordon Andrew, Stockley Ian
Lower Limb Arthroplasty Unit, Department of Orthopaedics, Northern General Hospital, Sheffield, United Kingdom.
Int Orthop. 2003;27 Suppl 1:S16-9.
Whilst advances in cementing technique have led to improvement in the survival of cemented femoral stems in total hip arthroplasty (THA), cup failure due to aseptic loosening remains a major clinical problem. These observations have led to a move away from cemented cup designs, particularly in young patients, towards uncemented implants. The Plasmacup is a hemispherical, press-fit, cementless, titanium-shelled, acetabular component with a polyethylene liner. In this article we review our experience of its pattern of early migration, wear, bone remodelling, and mid-term survival. In 18 cups followed for 2 years in subjects with a mean age at operation of 58 years, the mean total vectorial cup migration was 0.75 mm, and cup orientation remained stable (EBRA method). The mean polyethylene linear wear rate over this period was 0.21 mm/year. In 27 cups followed for 6 months using dual-energy X-ray absorptiometry (DXA), average bone loss was -5%, and the pelvic bone-remodelling pattern was consistent with the rim-loading principle of the cup design. In a clinical review of the outcome of 128 cups in 104 patients with a mean age at operation of 51 years and follow-up of 59 months, we found that 82% of patients had a good or very good Merle D'Aubigne score, and cup survival rate was 98% (Kaplan-Meier). Four cups had small radiographic areas of focal osteolysis and three had been revised (two for recurrent dislocation and one for deep sepsis; none were revised for aseptic loosening). The mean linear wear rate in this series was 0.14 mm/year. In conclusion, the Plasmacup shows satisfactory early stability, a wear rate similar to other uncemented cups, and favourable mid-term clinical function and survival rates.
虽然骨水泥技术的进步已使全髋关节置换术（THA）中骨水泥固定股骨柄的生存率有所提高，但无菌性松动导致的髋臼杯失败仍是一个主要的临床问题。这些观察结果促使人们，尤其是在年轻患者中，从骨水泥固定髋臼杯设计转向非骨水泥植入物。Plasmacup是一种半球形、压配式、无骨水泥、钛壳、带聚乙烯内衬的髋臼部件。在本文中，我们回顾了其早期移位、磨损、骨重塑模式及中期生存率方面的经验。在平均手术年龄为58岁的受试者中，对18个髋臼杯进行了2年的随访，髋臼杯平均总矢量移位为0.75毫米，髋臼杯方向保持稳定（EBRA方法）。在此期间，聚乙烯平均线性磨损率为每年0.21毫米。在使用双能X线吸收法（DXA）对27个髋臼杯进行6个月的随访中，平均骨质流失为-5%，骨盆骨重塑模式与髋臼杯设计的边缘加载原则一致。在对104例平均手术年龄为51岁、随访59个月的患者中128个髋臼杯的临床结果进行的回顾中，我们发现82%的患者Merle D'Aubigne评分良好或非常好，髋臼杯生存率为98%（Kaplan-Meier法）。4个髋臼杯有小面积的影像学局灶性骨溶解，3个进行了翻修（2个因复发性脱位，1个因深部感染；均非因无菌性松动而翻修）。该系列的平均线性磨损率为每年0.14毫米。总之，Plasmacup显示出令人满意的早期稳定性，磨损率与其他非骨水泥髋臼杯相似，中期临床功能和生存率良好。
