Cho K J, Erasmus P J, Müller J H
Department of Mechanical and Mechatronic Engineering, Stellenbosch University, Private Bag X1, Matieland 7600, South Africa.
Department of Orthopaedics, Stellenbosch University, Private Bag X1, Matieland 7600, South Africa.
Knee. 2016 Oct;23(5):895-9. doi: 10.1016/j.knee.2016.04.006. Epub 2016 May 16.
Patellofemoral arthroplasty (PFA) has a small but definite place in replacement surgery of the knee, especially in young patients. The main surgical considerations in PFA are the patient's anatomy, the type of prosthesis and the surgical technique. The surgical technique and PFA success rely heavily on the anterior resection. In this study we investigate the effect of axial rotation of the anterior resection plane.
We tested the outcome of PFA fit based on resection footprint measurements, axial and coronal groove angles, and lateral trochlear inclination (LTI) angle in a virtual PFA model. The range of anterior resection plane axial rotations was from five degree internal to five degree external with an increment of one degree.
Axial rotation of anterior resection plane changes the resection footprint dimension, which leads to coronal rotation of the femoral component. External rotation of the resection plane results in valgus rotation of the trochlear groove and decreased LTI after PFA and the opposite was observed for internal rotation.
Our study showed that by changing the axial rotation of the anterior cut, the coronal groove of the prosthesis can be altered to lie more closely with the native groove line without compromising the prosthesis-cartilage transition.
髌股关节置换术（PFA）在膝关节置换手术中虽占比小但地位明确，尤其对于年轻患者。PFA手术的主要考量因素包括患者解剖结构、假体类型及手术技术。手术技术及PFA的成功很大程度上依赖于前方切除。在本研究中，我们探究前方切除平面轴向旋转的影响。
我们在虚拟PFA模型中，基于切除足迹测量、轴向和冠状沟角度以及外侧滑车倾斜（LTI）角测试PFA拟合结果。前方切除平面轴向旋转范围为内旋5度至外旋5度，增量为1度。
前方切除平面的轴向旋转改变了切除足迹尺寸，进而导致股骨部件的冠状面旋转。切除平面外旋导致PFA术后滑车沟外翻旋转且LTI减小，内旋时情况相反。
我们的研究表明，通过改变前方截骨的轴向旋转，可改变假体的冠状沟，使其更贴近天然沟线，同时不影响假体与软骨交界处。
