Digital sheath synovial ganglion cysts in horses.
Authors: Crawford Andrew, O'Donnell Matthew, Crowe Oliver, Eliashar Ehud, Smith Roger K
Journal: Veterinary surgery : VS
Summary
# Digital Sheath Synovial Ganglion Cysts in Horses: Clinical Recognition and Surgical Management Fluid-filled masses arising from the digital flexor tendon sheath (DFTS) represent an under-recognised source of lameness in horses, yet their clinical presentation and optimal management have been poorly characterised until recently. Crawford and colleagues reviewed ten cases of DFTS-associated ganglion cysts, using diagnostic anaesthesia blocks, ultrasonography, and histopathological analysis to establish diagnostic criteria and treatment outcomes. Eight of the ten horses presented with lameness, which was localised to the lesion in six cases via intrathecal DFTS anesthesia; surgical resection of the mass resolved lameness in seven horses, with histology confirming the characteristic fibrous-walled, non-synovial-lined structure of true ganglion cysts. The consistent ultrasonographic finding of communication between the DFTS and the cyst in all cases, combined with the fibrous rather than synovial histology, suggests these lesions originate from traumatic disruption of the sheath wall rather than aberrant synovial outpouching. For practitioners, this work provides a diagnostic framework—combining lameness localisation with ultrasound imaging to identify sheath communication—that enables earlier surgical intervention, which appears to offer reliable resolution of associated lameness in the majority of affected horses.
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Practical Takeaways
- •Digital flexor tendon sheath ganglion cysts cause lameness in horses; if ultrasonography shows a fluid-filled mass communicating with the DFTS, consider intrathecal anesthesia or perineural blocks proximal to the lesion to confirm it as the lameness source before pursuing surgical intervention
- •Surgical resection of confirmed ganglion cysts is effective, resolving lameness in most cases; ensure histopathology is performed to confirm diagnosis
- •Ganglion cysts likely result from traumatic injury to the sheath wall, so address any concurrent DFTS pathology or predisposing biomechanical factors in your management and rehabilitation plan
Key Findings
- •Ganglion cysts of the digital flexor tendon sheath were identified in 10 horses, with 8 presenting with lameness and 7/7 hind limb and 3/3 front limb cases showing unilateral presentation
- •Ultrasound confirmed communication between DFTS and the cystic mass in all 10 horses
- •Surgical resection resolved lameness in 7 horses; diagnostic anesthesia (intrathecal DFTS or perineural proximal to cyst) confirmed cyst as lameness source in 8/10 cases
- •Histopathology (5 specimens) revealed fibrous outer layer without synovial lining, consistent with ganglion cyst origin from sheath wall trauma