Arthroscopic Removal of Large Extensor Process Fragments in 18 Friesian Horses: Long-Term Clinical Outcome and Radiological Follow-Up of the Distal Interphalangeal Joint.

OBJECTIVE: Report long-term clinical and radiological follow-up in horses after removal of large extensor process fragments occupying >25% of the joint surface of the distal interphalangeal joint (DIJ). STUDY DESIGN: Retrospective case series. ANIMALS: Friesian horses (n=18) that underwent arthroscopic removal of a large extensor process fragment. METHODS: Arthroscopic examination of the DIJ was performed in dorsal recumbency with the affected foot in extension using routine portals. Visualization of the fragment was improved using motorized synovial resectors. A dissection plane between the common digital extensor tendon and the extensor process fragment was created using sharp lever instruments, in some cases aided by motorized burrs and radiofrequency ligament dissection. The fragment was removed piecemeal using Ferris-Smith rongeurs. Medical records, preoperative and postoperative radiographs, and owner surveys were reviewed for case details and outcome. RESULTS: The technique described allowed removal of the large fragment in all 18 horses. Of the 17 horses where long-term clinical follow-up was available, 14 were used as intended and 3 kept some degree of lameness. The angle between the remodeled extensor process and the dorsal surface of the distal phalanx was increased and subchondral bone remodeling at the fragment bed was noted on postoperative lateromedial radiographs. CONCLUSION: Arthroscopic removal is a good treatment option for horses with large extensor process fragmentation with a good long-term outcome. Remodeling of the remaining extensor process and the subchondral new bone formation in the fragment bed can occur with functional recovery.

An Alternative, Direct Approach for Arthroscopic Removal of Osteochondral Fragments in the Dorsal Pouch of the Proximal Intertarsal Joint of Horses.

OBJECTIVE: To describe an alternative technique and resulting outcomes for arthroscopic removal of osteochondral (OC) fragments from the proximal intertarsal joint (PIJ) using a direct approach without resection of the membrane between the tarsocrural joint (TCJ) and the PIJ. STUDY DESIGN: Retrospective case series. ANIMALS: Client owned horses (n = 11) with Category 1 OC fragments in the PIJ. METHODS: Arthroscopic examination of the dorsal pouch of the TCJ was performed with horses positioned in dorsal recumbency using routine portals. A hook probe placed through one of the standard portals was used to lift the edge of the communication between TCJ and PIJ to help pass the arthroscope into the PIJ from the opposite standard portal. A third direct portal into the PIJ was created under arthroscopic visualization, and loose OC fragments (Category 1) were removed using the direct portal. Medical records, race records, and owner surveys were reviewed for case details and outcome. RESULTS: The described technique allowed removal of all fragments in all 11 cases. No complications associated with the procedure were observed. Of the 9 horses with long term follow-up available, 7 were used as intended (4/4 riding horses, 3/5 racehorses). Two horses did not enter an athletic career because of reasons unrelated to fragment removal. CONCLUSION: A direct approach for arthroscopic removal of OC fragments of the PIJ using a third portal into this joint, without resection of the membrane between the TCJ and PIJ is a good alternative for removal of fragments at this site.