Diagnostic stifle joint arthroscopy using a needle arthroscope in standing horses

OBJECTIVE: To assess use of an 18 g arthroscope for diagnostic stifle joint examination in the standing horse. STUDY DESIGN: Phase 1 used cadaver limbs and simultaneous ultrasonographic assessment. Phase 2 used 6 normal horses where stifles were assessed in both a standing and flexed position. Phase 3 used horses with suspected stifle injury or disease. ANIMALS: Normal horses (n = 6) to assess ability to perform diagnostic procedure (phase 2) and 3 clinical cases (phase 3). METHODS: Five cadaver limbs were used in phase 1 to assess all stifle joints. Phase 2 used standing sedated and locally anesthetized horses. Routine arthroscopic approaches were used in both weight bearing and flexed nonweight bearing positions. In both phase 1 and 2 simultaneous ultrasonographic and arthroscopic examinations were used to confirm extent of diagnostic examination. The methods developed in phase 2 were used to examine the stifle in 3 horses with suspected stifle disease. RESULTS: In cadaveric limbs and horses, all intra articular structures that constitute a complete arthroscopic examination were identified; no intra -or postoperative morbidity occurred. In phase 3, the needle arthroscope was used in accurate identification of pathologic change and in 1 horse, an osteochondral fragment not detected by ultrasonography and radiography was identified. CONCLUSIONS: This preliminary work indicates that an 18 g arthroscope can be used for diagnostic examination of the equine stifle in standing horses.