Sliding Humeral Osteotomy (SHO)

Introduction
Elbow dysplasia is an important cause of thoracic limb lameness in dogs. Most frequent pathological changes are associated with the medial aspect of the coronoid process of the ulna and medial aspect of the humeral condyle. Cartilage erosion in the region defined by the medial aspect of the coronoid process and medial aspect of the humeral condyle has been referred to as medial compartment disease (MCD).

In light of the typically unicompartmental nature of elbow dysplasia, force redistribution within a joint from an area with profound cartilage and subchondral pathology to a more normal area may have benefit in the treatment of dogs with elbow dysplasia. Sliding humeral osteotomy (SHO) involves a mid-diaphyseal humeral osteotomy and stabilization with a custom, locking, stepped plate to the medial aspect of the humerus, medially translating the distal segment relative to the proximal segment. Our purpose is to document ongoing clinical experiences and outcomes with the SHO procedure and report on various modifications of technique from our previous case series. Mid-term complication rates and clinical outcomes were compared with or without focal treatment (FT) of the coronoid process.

Materials and Methods
Medical records of dogs that underwent SHO between February 2009 and October 2011 were evaluated. Signalment, lameness, pain score and preoperative radiographic findings were recorded and modified Outerbridge score and fissure/fragmentation were recorded arthroscopically. SHO was performed with technical modifications and outcome measures included lameness score, elbow pain score, owner function assessment and force-plate preoperatively, at 6 and 12 weeks and 6-25 months. Major complications were defined as those that needed subsequent surgical intervention including major infections, whereas minor complications implied no further surgical treatment.  [...]