Lachiewicz Paul F, Kelley Scott S
Department of Orthopaedics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
J Am Acad Orthop Surg. 2002 Jul-Aug;10(4):233-8. doi: 10.5435/00124635-200207000-00001.
The use of a constrained component may be appropriate for the surgical treatment of recurrent dislocation due to soft-tissue insufficiency following a total hip arthroplasty. Constrained components usually include a locking mechanism incorporated into the polyethylene acetabular liner to keep the prosthetic femoral head in place. Two different prosthetic designs are available and have been approved by the U.S. Food and Drug Administration. The S-ROM constrained component uses additional polyethylene in the rim, which deforms to more fully capture the femoral head and then is held in place by a metal locking ring. The Howmedica Osteonics constrained component is a tripolar device; its bipolar component articulates with another polyethylene liner. These constrained components transfer hip forces that would otherwise lead to dislocation to the locking mechanism, the liner-shell interface, or the bone-prosthesis interface. These forces may eventually contribute to failure of the component due to loosening, dissociation, breakage, or recurrent dislocation. Studies of these components show a failure rate of 4% to 29% at relatively short-term follow-up.
对于全髋关节置换术后因软组织不足导致的复发性脱位，使用受限型假体组件可能适用于手术治疗。受限型假体组件通常包括一个集成在聚乙烯髋臼内衬中的锁定机制，以将人工股骨头固定在位。有两种不同的假体设计可供使用，并已获得美国食品药品监督管理局的批准。S-ROM受限型假体组件在边缘使用了额外的聚乙烯，其会变形以更完全地固定股骨头，然后由金属锁定环固定在位。豪美德奥施康（Howmedica Osteonics）受限型假体组件是一种三极装置；其二极组件与另一个聚乙烯内衬相铰接。这些受限型假体组件将原本会导致脱位的髋关节力传递至锁定机制、内衬-外壳界面或骨-假体界面。这些力最终可能由于松动、分离、破损或复发性脱位而导致假体组件失效。对这些组件的研究表明，在相对短期的随访中，失败率为4%至29%。
