The lateral meniscus is less frequently injured than the medial meniscus and is often more challenging to evaluate with ultrasonography or arthroscopy. This report describes two horses with lateral meniscal rupture identified ultrasonographically and confirmed on post-mortem examination. Both horses were evaluated for severe unilateral hindlimb lameness. Ultrasonography revealed absence of lateral meniscal tissue in the mid-body region with marked distortion cranial and caudal to the rupture. Radiographic evidence of uniaxial degenerative change heightened the suspicion for lateral femorotibial injury in one horse with chronic lameness but otherwise underestimated the degree of injury. Arthroscopy was not performed due to the severity of ultrasonographic findings but was considered unlikely to have been able to visualise the rupture given its mid-body location. Meniscal rupture appears to be an unusual but significant injury, with only one similar case identified. The involvement of the lateral meniscus underscores the importance of detailed evaluation of both menisci in horses with stifle lameness.

中文翻译：

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两匹严重跛行马外侧半月板破裂的超声诊断

与内侧半月板相比，外侧半月板受伤的频率较低，并且通过超声检查或关节镜检查进行评估通常更具挑战性。这份报告描述了两匹马的侧面半月板破裂，经超声检查发现并经尸检证实。两匹马都接受了严重的单侧后肢跛行评估。超声检查显示在身体中部区域没有外侧半月板组织，破裂的头颅和尾端有明显的扭曲。单轴退行性改变的放射学证据增加了对一匹慢性跛行马的股胫外侧损伤的怀疑，但在其他方面低估了损伤程度。由于超声检查结果的严重性，没有进行关节镜检查，但鉴于其位于身体中部，被认为不太可能能够看到破裂。半月板破裂似乎是一种不寻常但意义重大的损伤，仅发现了一个类似病例。外侧半月板的参与强调了对膝关节跛行马的两个半月板进行详细评估的重要性。