Scapulohumeral arthrodesis in miniature horses.

This research highlights the study of surgical procedure in mini horses called ‘scapulohumeral arthrodesis’, investigating its effectiveness in reducing suffering linked to serious shoulder dysfunction. Despite complications and an altered gait, it was found to be effective, leading to improved mobility and early weight-bearing return, specifically benefiting miniature horses with severe scapulohumeral joint osteoarthrosis, suggesting its potential consideration for debilitating shoulder conditions in mini horses.

Research Methodology

• Four miniature horses were subjected to this retrospective study.
• The medical histories and radiographs of the horses were scrutinised, focusing on the lameness evaluation, radiographic evaluation, surgical techniques, and the postoperative complications and outcomes.
• The surgical technique involved the application of a 10 or 11-hole, 4.5-mm narrow dynamic compression plate and 4.5-mm cortical screws to the cranial surface of the scapula and cranial surface of the humerus, following osteotomy of the intermediate tubercle.
• Most horses had 1 or 2 screws inserted across the joint (in lag fashion), via holes in the plate.

Results and Observations

• All horses were suffering from grade 3 or 4 lameness prior to the operation, which improved by 1 to 2 grades post-surgery, suggesting the method reduced lameness severity.
• Radiographs illustrated scapulohumeral osteoarthritis in all four horses, with three also showing signs of concurrent shoulder luxation or subluxation.
• Despite complications like implant failure (2 cases), infection (2 cases), scapular fracture (1 case), and shoulder muscle atrophy (1 case); all horses experienced reduced morbidity post-function arthrodesis.
• Post surgery, despite functional gait abnormality, the horses were competent ambulators.

Conclusions

• The study concludes that scapulohumeral arthrodesis facilitates an early return to weight bearing, benefitting miniature horses with severe scapulohumeral joint osteoarthrosis.
• In spite of a somewhat altered gait, the surgery provided a significantly improved quality of life for the horses, specifically those used for breeding or that are primarily pasture animals.
• The research suggests the consideration of scapulohumeral arthrodesis for miniature horses suffering from debilitating shoulder conditions.