Radiographic analysis of trochlear notch sclerosis in the diagnosis of osteoarthritis secondary to medial coronoid disease

Trochlear notch sclerosis (TNS) as assessed by radiography has been shown to be increased in elbow dysplasia (ED) associated medial coronoid process disease (M(D). The aims of this study were to investigate whether two defined radiographic tests evaluating INS would increase the sensitivity of detecting osteoarthritis secondary to MCD, and to assess whether there was a of relation between increasing TNS with severity of MCD. Sixty-one dogs with MCD (121 elbows) were selected from the imaging database. The controls were nine cadavers (18 disease-free elbows). Standard International Elbow Working Group radiographs and CI scans were taken of each elbow, Plain radiographs were analysed using various assessments: osteophyte grade (0-3), coronoid grade (0-3), INS descriptive grade (0-3) and INS ratio, The INS ratio was calculated from the depth of ulnar sclerosis at the level of the disto-cranial margin of the humeral condyles divided by the cranio-caudal ulna depth. The INS descriptive assessment and ratio both increased the overall sensitivity of diagnosing osteoarthritis secondary to MCD above the other radiographic tests. The sensitivity of the TNS ratio or < 0.3 mm was 91%-96% and the INS descriptive assessment was 77%-96%. Radiographic INS significantly increased with increasing severity of coronoid disease grade as evaluated by CT p < 0.01. The finding that INS increases the sensitivity of diagnosing osteoarthritis secondary to MCD is valuable to those that have neither a CT scanner nor arthroscopy readily available. The assessments described in this study are easy to apply and do not require any sophisticated technology in order to detect sclerosi