Johnson A L, Probst C W, Decamp C E, Rosenstein D S, Hauptman J G, Weaver B T, Kern T L
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
Vet Surg. 2001 Mar-Apr;30(2):140-50. doi: 10.1053/jvet.2001.21391.
To compare trochlear block recession (TBR) to trochlear wedge recession (TWR) with regards to patellar depth (percentage of patellar volume under the trochlear ridges), patellar articular contact, percentage of recessed trochlear surface area, and resistance to patellar luxation.
In vitro computed tomography (CT) and biomechanical evaluation using a cadaver model.
Twelve normal, large-breed canine cadavers.
Bilateral pelvic limb specimens with intact stifle joints were mounted on a positioning device. The femoral trochlear ridges were reduced to provide a standard shallow trochlea. TBR or TWR was performed to a standard depth randomly on paired specimens. CT and biomechanical evaluations were performed pre- and postoperatively in both an extended (148 degrees ) and flexed (113 degrees ) stifle position. CT images were digitized and measurements made using an image-analysis software program. Biomechanical testing consisted of applying 40 degrees of internal tibial rotation and documenting patellar luxation.
The change in trochlear depth (depth of recession) was not significantly different between groups. In the extended stifle position (patella in the proximal trochlea), patellar depth and patellar articular contact with the recessed trochlea were significantly greater after TBR compared with TWR. The percentage of recessed trochlear surface area was significantly greater after TBR compared with TWR. In the extended position, a smaller percentage of the patellae luxated within 40 degrees of internal tibial rotation after TBR compared with TWR.
TBR increases proximal patellar depth, increases patellar articular contact with the recessed proximal trochlea, recesses a larger percentage of trochlear surface area, and results in a greater resistance to patellar luxation in an extended position as compared with TWR.
TBR may help limit the development of stifle DJD in dogs treated for canine patellar luxation.
比较滑车阻滞性后移（TBR）与滑车楔形后移（TWR）在髌骨深度（滑车嵴下髌骨体积的百分比）、髌骨关节面接触、滑车后移表面积百分比以及髌骨脱位阻力方面的差异。
使用尸体模型进行体外计算机断层扫描（CT）和生物力学评估。
12具正常的大型犬尸体。
将具有完整膝关节的双侧后肢标本安装在定位装置上。降低股骨滑车嵴以形成标准的浅滑车。在配对标本上随机将TBR或TWR进行到标准深度。在膝关节伸展（148度）和屈曲（113度）位置术前和术后进行CT和生物力学评估。CT图像数字化，并使用图像分析软件程序进行测量。生物力学测试包括施加40度的胫骨内旋并记录髌骨脱位情况。
两组之间滑车深度（后移深度）的变化无显著差异。在膝关节伸展位置（髌骨位于滑车近端），与TWR相比，TBR后髌骨深度和髌骨关节面与后移滑车的接触明显更大。与TWR相比，TBR后滑车后移表面积百分比明显更大。在伸展位置，与TWR相比，TBR后在40度胫骨内旋范围内脱位的髌骨百分比更小。
与TWR相比，TBR增加了髌骨近端深度，增加了髌骨关节面与后移近端滑车的接触，使更大百分比的滑车表面积后移，并在伸展位置对髌骨脱位产生更大的阻力。
TBR可能有助于限制接受犬髌骨脱位治疗的犬膝关节退行性关节病的发展。
