Vendittoli Pascal-André, Ganapathi Muthu, Nuño Natalia, Plamondon Dominic, Lavigne Martin
Department of Surgery, Montreal University, Maisonneuve-Rosemont Hospital, Montreal, Quebec, Canada H1T 2M4.
Clin Biomech (Bristol). 2007 Nov;22(9):1004-12. doi: 10.1016/j.clinbiomech.2007.07.007. Epub 2007 Sep 17.
Surface replacement arthroplasty aims to re-create normal hip biomechanics; however the pathoanathomy of the hip, prosthetic component design, surgical technique and other factors may have a significant impact on the range of motion restoration attained following surface replacement arthroplasty. However, there is paucity of information on the effect of such factors.
A computerized three-dimensional hip model was created from preoperative computerized tomography images of a patient who was scheduled for a surface replacement arthroplasty. The effects of the femoral component size, translation and orientation on the range of motion were analysed as was the effect of increasing the seating depth and modification of the version of the acetabular component.
Increasing the femoral component size led to global improvement in range of motion while translation increased range of motion in one direction but reduced it in the opposite direction. Change in the femoral component orientation had minimal effects on range of motion in comparison to the effect of changes in the version of the acetabular component. Increasing the seating depth of the acetabulum only caused reduced range of motion in internal rotation in 90 degrees flexion.
To restore hip range of motion, surgeons performing surface replacement arthroplasty should aim to reproduce the natural femoral head-neck offset. Although increasing the femoral component size may achieve this, more acetabular bone will be resected. Knowing the specific zones of impingement of each arc of movement, selective translation of the femoral component or femoral neck osteoplasty can restore femoral neck offset in more critical areas without affecting acetabular bone stock. Over deepening of the acetabulum or leaving rim osteophytes should also be avoided to prevent impingement.
表面置换关节成形术旨在重建正常的髋关节生物力学；然而，髋关节的病理解剖、假体部件设计、手术技术及其他因素可能对表面置换关节成形术后实现的活动度恢复范围产生重大影响。然而，关于这些因素的影响，相关信息匮乏。
从一名计划接受表面置换关节成形术患者的术前计算机断层扫描图像创建了一个计算机化三维髋关节模型。分析了股骨部件尺寸、平移和方向对活动度的影响，以及增加髋臼部件的座深和改变髋臼部件版本的影响。
增加股骨部件尺寸可使活动度整体改善，而平移在一个方向增加活动度，但在相反方向降低活动度。与髋臼部件版本变化的影响相比，股骨部件方向的改变对活动度的影响最小。增加髋臼的座深仅在90度屈曲时导致内旋活动度降低。
为恢复髋关节活动度，进行表面置换关节成形术的外科医生应旨在重现天然股骨头-颈偏心距。虽然增加股骨部件尺寸可能实现这一点，但会切除更多髋臼骨。了解每个运动弧的特定撞击区域，股骨部件的选择性平移或股骨颈截骨术可在更关键区域恢复股骨颈偏心距而不影响髋臼骨量。还应避免髋臼过度加深或保留边缘骨赘以防止撞击。
