Seyrek-Intas D, Michele U, Tacke S, Kramer M, Gerwing M. Department of Veterinary Clinical Sciences, Clinic for Small Animals-Surgery, Justus-Liebig University, 35392 Giessen, Germany. JAVMA 2009 Feb 15 234 4 480-485 Objective-To determine the accuracy of ultrasonography in detecting fragmentation of the medial coronoid process (FMCP) in dogs. Design-Cross-sectional study. Animals-102 dogs (112 elbow joints) suspected to have FMCP. Procedures-Elbows were examined ultrasonographically prior to surgery for evidence of fragmentation, fissuring, or deformation of the medial coronoid process; thickening of the joint capsule; joint effusion; and secondary new bone formation. Results were compared with intraoperative findings. Results-At surgery, 51 (46%) joints had free fragments, 55 (49%) had nondisplaced fragments, and 6 (5%) did not have any fragments or fissures. Fragments were not seen ultrasonographically in 23 of the 51 (45%) joints in which a free fragment was found during surgery or in 50 of the 55 (91%) joints in which a nondisplaced fragment was found during surgery. Accuracy of using ultrasonographic evidence of any medial coronoid process abnormality (ie, a medial coronoid process fragment, deformation of the medial coronoid process, or both) for diagnosis of medial coronoid process fragmentation was 77%. The kappa coefficient for the level of agreement between ultrasonographic (ie, any medial coro-noid process abnormality) and surgical findings was -0.014, indicating that there was no agreement. Conclusions and Clinical Relevance-Results suggested that ultrasonography was of limited diagnostic value in detecting FMCP in dogs.