Malo Michel, Vince Kelly G
Department of Orthopaedic Surgery, Hôpital du Sacré-Coeur de Montréal, University of Montreal, Montreal, Quebec, Canada.
J Am Acad Orthop Surg. 2003 Sep-Oct;11(5):364-71. doi: 10.5435/00124635-200309000-00009.
In total knee arthroplasty, most complications related to the extensor mechanism are caused by patellar maltracking or instability. Patellar maltracking may result from component malpositioning and limb malalignment, prosthetic design, improper patellar preparation, or soft-tissue imbalance. Patellofemoral instability likely results most frequently from internal malrotation of the femoral or tibial components. Although a patellofemoral radiograph may display the lateral subluxation of the patella, only computed tomography can quantify rotational malalignment of the femoral or tibial component. Nonsurgical treatment is generally unsuccessful; major malposition of components is best managed by implant revision. In the absence of component malposition, proximal realignments (lateral patellar retinacular release with lateral advancement of the vastus medialis obliquus muscle) or tibial tubercle transfers have been used. Surgical procedures on the patellar tendon itself may risk rupture of the extensor mechanism.
在全膝关节置换术中，大多数与伸肌机制相关的并发症是由髌骨轨迹不良或不稳定引起的。髌骨轨迹不良可能由假体组件位置不当、肢体对线不良、假体设计、髌骨准备不当或软组织失衡导致。髌股关节不稳定最常见的原因可能是股骨或胫骨组件的内旋。尽管髌股关节X线片可能显示髌骨的外侧半脱位，但只有计算机断层扫描才能量化股骨或胫骨组件的旋转对线不良。非手术治疗通常不成功；组件的严重位置不当最好通过植入物翻修来处理。在没有组件位置不当的情况下，已采用近端重新对线（外侧髌旁支持带松解并斜向内收肌外侧推进）或胫骨结节转移术。对髌腱本身进行手术可能会有伸肌机制断裂的风险。
