Incidence and risk factors of surgical site infection and septic arthritis after elective arthroscopy in horses.

OBJECTIVE: To determine the incidence of infection and associated risk factors, after elective arthroscopy. STUDY DESIGN: Retrospective case study. ANIMALS: Horses (n=1079) undergoing elective arthroscopy. METHODS: Medical records of all horses that underwent elective arthroscopy between 2006 and 2013 were reviewed. Age, gender, breed, surgeon, number of joints operated, total anesthetic time, perioperative antimicrobial administration, and the presence and size of osteochondral fragments/subchondral lesions were recorded. For each operated joint, the development of postoperative infection (surgical site infection [SSI] and/or septic arthritis) and long-term outcome (>6 months) were recorded. Multivariate logistic regression was used to test for association between the independent variables and the dependent outcomes. RESULTS: A total of 1741 joints in 1079 horses underwent arthroscopy. SSI without septic arthritis occurred in 1 fetlock joint (0.14%), 1 tibiotarsal joint (0.19%), and 6 femoropatellar joints (1.67%). Thirteen joints (0.75%) were diagnosed with septic arthritis, including 1 fetlock joint (0.14%), 4 tibiotarsal joints (0.74%), and 8 femoropatellar joints (2.23%). The probability of postoperative SSI was higher when large lesions (>40 mm long) were treated, compared to medium (20-40 mm, P = .005) and small (<20 mm, P < .001) lesions. SSI was a significant risk factor for the development of septic arthritis (P < .001). Although age did not affect the incidence of SSI, increasing age was associated with a lower rate of septic arthritis rate (P = .028). CONCLUSION: Septic arthritis after elective arthroscopy was more likely in the presence of SSI and younger age. Horses with large lesions were at risk for SSI, which translated into a higher incidence of postoperative septic arthritis after femoropatellar arthroscopy.

Equine Antebrachial Compartment Syndrome Secondary to Flexor Muscle Myopathy With Subsequent Muscle Atrophy And Tendonitis: A Case Report.

This case report describes a 16-year-old jumping stallion that had a marked swelling over the left antebrachial area along with substantial lameness after a fall. The horse was weight bearing but lame (4/5; AAEP scale) at the walk with marked enlargement in the caudal aspect of the antebrachial region. After a static musculoskeletal examination, radiography and ultrasonography the horse was diagnosed with flexor muscle myopathy and presumptive extremity compartment syndrome. Following medical treatment, the horse improved clinically over several days. Six-months post injury the horse showed flexor muscle atrophy but was sound at the walk and trot. The horse was presented again 3 months later with an enlargement of the palmar left metacarpus that was diagnosed as a superficial digital flexor tendonitis. This report describes the episodes from the onset of extremity compartment syndrome until the superficial digital flexor tendonitis, discusses anatomical features of the region, physiopathology of compartment syndrome and the possible biomechanics behind the flexor muscle atrophy and the tendonitis.