Bader Rainer, Mittelmeier Wolfram, Zeiler Guenther, Tokar Isabella, Steinhauser Erwin, Schuh Alexander
Orthopaedische Klinik und Poliklinik, Universitaet Rostock, Ulmenstr 44/45, 18057 Rostock, Germany.
Arch Orthop Trauma Surg. 2005 Oct;125(8):558-63. doi: 10.1007/s00402-005-0051-z. Epub 2005 Oct 22.
For the reconstruction of acetabular bone defects different types of acetabular reinforcement rings are being used. In clinical practice, these implants showed to some extent good long-term results. In the present work pitfalls and complications after the implantation of acetabular reinforcement rings as well as possible solutions are being discussed.
In the first case recurrent dislocation was caused by the malposition of the acetabular component with an impingement of the protruding bone cement and the anterior edge of the acetabular ring as well as muscle insufficiency as a result of the shortening of the leg length. The second case revealed an impingement of the iliopsoas tendon due to a protruding acetabular reinforcement ring. During revision, bone cement was used to smoothen the protruding anterior edge of the acetabular reconstruction ring in order to obtain a relieved sliding of the tendon. Furthermore, we report on the case of a delayed neuropathy of the sciatic nerve after reconstruction of the acetabulum with an acetabular reinforcement ring.
Intraoperatively an impingement of the sciatic nerve at the protruding dorsal edge of the acetabular reinforcement ring and the surrounding scar tissue was found. In a further case an aseptic loosening of an acetabular reinforcement ring caused the formation of an excessive granuloma with a large intrapelvic portion. The granuloma led to persisting senso-motoric deficits of the femoral nerve. In summary, based on these clinical cases possible pitfalls, associated with the use of acetabular reinforcement rings, are shown. The mal-positioning and the intra-operative re-shaping of the implant by the surgeon are pointed out as the substantial factors for the occurrence of an impingement phenomenon and total hip instability. Furthermore, in case of an adequate orientation of the cemented polyethylene insert an improper position of the acetabular ring which results in protruding edges has to be considered as a cause of a prosthetic impingement.
The cases presented emphasize the necessity of prevention of such pitfalls intra-operatively as well as accurate analysis of implant failures. Furthermore, they suggest explicit preoperative planning before deciding on the strategy of revision surgery of acetabular reinforcement rings.
为重建髋臼骨缺损，人们使用了不同类型的髋臼加强环。在临床实践中，这些植入物在一定程度上显示出良好的长期效果。在本研究中，我们将讨论髋臼加强环植入后的陷阱和并发症以及可能的解决方案。
在第一个病例中，髋臼组件位置不当，突出的骨水泥与髋臼环前缘相互碰撞，以及腿长缩短导致肌肉功能不足，从而引起反复脱位。第二个病例显示，由于髋臼加强环突出，髂腰肌肌腱受到撞击。在翻修手术中，使用骨水泥将髋臼重建环突出的前缘磨平，以使肌腱滑动顺畅。此外，我们还报告了一例使用髋臼加强环重建髋臼后坐骨神经迟发性神经病变的病例。
术中发现坐骨神经在髋臼加强环突出的背侧边缘及周围瘢痕组织处受到撞击。在另一病例中，髋臼加强环无菌性松动导致形成巨大的盆腔内肉芽肿。该肉芽肿导致股神经持续存在感觉运动功能障碍。总之，基于这些临床病例，展示了使用髋臼加强环可能存在的陷阱。植入物的位置不当和外科医生在术中的重新塑形被指出是撞击现象和全髋关节不稳定发生的主要因素。此外，如果骨水泥固定的聚乙烯内衬方向合适，髋臼环位置不当导致边缘突出也应被视为假体撞击的一个原因。
所展示的病例强调了术中预防此类陷阱以及准确分析植入物失败的必要性。此外，它们还建议在决定髋臼加强环翻修手术策略之前进行明确的术前规划。
