Surgical management of medial humeral epicondylitis, cubital synovial osteochondromatosis and humeroradial subluxation in a cat

Abstract

Case summaryA 13-year-old domestic shorthair cat presented for evaluation of pain and difficulty ambulating. Orthopedic examination and CT facilitated a diagnosis of bilateral elbow synovial osteochondromatosis with medial humeral epicondylitis and concurrent osteoarthritis. Right humeroradial subluxation was evident on CT images, but no instability was evident preoperatively. Surgical treatment was elected, including external neurolysis of the ulnar nerve, removal of the areas of mineralization within the flexor carpi ulnaris muscle and medial arthrotomy to remove intra-articular mineralized bodies. Following closure, instability of the right elbow was noted with humeroradial subluxation necessitating placement of circumferential suture prostheses to provide satisfactory stability. Reassessment was performed 2, 6, 12, 24 and 40 weeks postoperatively and revealed maintenance of elbow stability and substantial improvement in mobility and comfort.Relevance and novel informationWhile humeroradial subluxation has been reported in association with medial humeral epicondylitis on post-mortem examination, associated clinically significant instability has not been documented previously. Surgeons should be aware of the potential for this complication and check elbow stability following surgery. Despite this complication, a favorable medium-term outcome was achieved for this cat.

Structure and Pathologies of Articular Cartilage

“…It may affect one or a number of joints at a time -usually knees and elbows. It is most often diagnosed in cats and tends to be accompanied by epicondylitis (49). In dogs, osteochondral hyperplasia tends to be located in the region of the epiphyseal plate and is related to endochondral ossification.…”

“…This causes pain, lameness, reduced joint mobility, and secondary degenerative disease. As the disease progresses, numerous fibrochondromas which cause deformation of and pressure on periarticular structures such as ligaments and nerves, which in turn leads to joint destabilisation, secondary sprains and limb paralysis (Figure 3) (49,50). Pressure and irritation may result in local erosion of healthy cartilage (so-called "kissing lesions") ( 45) and development of secondary degenerative joint disease (48).…”