Amongst the interesting selection of articles in this issue of the journal, three concern the patella. Notable as being the largest sesamoid bone of the body, this humble sesamoid bone is a frequent contributor to stifle joint pathology in dogs and cats. Located in the tendon of insertion of the quadriceps femoris muscle, it acts as a fulcrum, gliding in the femoral trochlea during stifle joint extension. Interestingly, many marsupials such as the kangaroo and the koala and some possums lack an osseous patella. Instead, they have a patellar-shaped pad of fibrocartilage in this location. One explanation for this species difference is that a non-osseous ‘patella’ is more resistant to fatigue fracture with repeated loading, as may occur in cats.

Patellar luxation, and to a lesser extent patellar fracture, are common; they may cause hindlimb lameness or exist as undiagnosed abnormalities. There is a growing body of literature on the surgical correction of patellar luxation, providing us with multiple effective procedures for correcting this disorder. Malalignment of the combined patella-quadriceps complex no doubt contributes to medial or lateral patellar luxation, but the role of patella alta and patella baja is not so clear.

Two of the studies in this issue of the journal concern the proximo-distal position of the patella relative to the canine stifle. The third computed tomography study on the feline stifle found that block recession trochlear plasty alone is not effective in maintaining the patella, and that ostectomy of the medial and lateral margins of the patella was necessary. Ongoing research is required to elucidate the complex pathogenesis of patellar disorders in dogs and cats.

在本期杂志的有趣文章中，有3篇涉及the骨。作为人体最大的芝麻骨，这种不起眼的芝麻骨经常导致窒息猫和狗的关节病变。它位于股四头肌插入肌腱中，充当支点，在窒息关节伸展时滑入股骨滑车。有趣的是，许多有袋动物，例如袋鼠和考拉，以及一些负鼠都没有骨骨。相反，它们在此位置具有a骨状的纤维软骨垫。对于这种物种差异的一种解释是，非骨质“ pat骨”在猫反复出现的情况下，在反复加载时更能抵抗疲劳断裂。

ella骨脱位和and骨骨折较轻是常见的。它们可能导致后肢la行或以无法诊断的异常状态存在。关于pa骨脱位的手术矫正的文献越来越多，为我们提供了多种有效的方法来矫正这种疾病。combined骨-股四头肌综合体的错位无疑会导致内侧或外侧pa骨脱位，但of骨和and骨的作用尚不清楚。

本期杂志中的两项研究涉及the骨相对于犬窒息的近距位置。对猫的窒息进行的第三次计算机断层扫描研究发现，仅阻塞性后退性滑车成形术不能有效地维持pat骨，并且必须对骨的内侧和外侧切缘进行植骨切除术。需要正在进行的研究来阐明猫和狗的pa骨疾病的复杂发病机理。