Computed tomographic arthrography is a useful adjunct to survey computed tomography and arthroscopic evaluation of the canine shoulder joint.

The aim of this retrospective, methods comparison study was to assess the diagnostic utility of computed tomographic arthrography in the assessment of various intraarticular shoulder pathologies in dogs in comparison with survey computed tomography (CT), using arthroscopic examination as the reference standard. Computed tomography, computed tomographic arthrography, and arthroscopic findings of 46 scapulohumeral joints of dogs with forelimb lameness were reviewed retrospectively. Predefined sites were assessed for the presence or absence of disease. If a lesion was present, a prespecified pathology was designated. Computed tomographic arthrography was found to be a safe technique which provided a superior diagnostic efficacy relative to survey CT for the assessment of the biceps tendon and biceps tendon sheath (sensitivity 71%, specificity 75%, positive likelihood ratio 2.9, negative likelihood ratio 0.38) and humeral head cartilage (sensitivity 65%, specificity 97%, positive likelihood ratio 19, negative likelihood ratio 0.37). Computed tomography and computed tomographic arthrography provided additional diagnostic information to arthroscopy in regard to osteophytosis, subchondral defects, and joint mice. Computed tomographic arthrography alone was of limited diagnostic value for assessment of the medial and lateral glenohumeral ligaments (sensitivity 13% and 0%, specificity 1% and 78%, positive likelihood ratios unmeasurable and 0, negative likelihood ratios 0.88 and 1.29, respectively) and the subscapularis tendon (sensitivity 14%, specificity 98%, positive likelihood ratio 5.7, negative likelihood ratio 0.88). Computed tomographic arthrography is therefore a useful adjunct to survey CT and arthroscopic evaluation of the canine shoulder joint, however, is not a replacement for these techniques.

Surgical management of pivot-shift phenomenon in a dog.

CASE DESCRIPTION A 6.8-year-old neutered male Labrador Retriever-Poodle mix was evaluated because of continued left pelvic limb lameness unresponsive to conservative management 1 year after undergoing tibial plateau leveling osteotomy (TPLO). CLINICAL FINDINGS A jerking lateral movement of the left stifle joint was detected during walking. Orthopedic examination revealed a pivot-shift phenomenon (PSP). Palpation elicited no signs of discomfort over the TPLO plate or caudomedial aspect of the stifle joint. Radiography revealed complete bone fusion at the osteotomy site and only mild joint effusion. TREATMENT AND OUTCOME Arthrotomy was performed at the medial aspect of the stifle joint, revealing no meniscal tears. The previously applied plate was removed, and an extracapsular, synthetic, ligament-like biomaterial was placed to counteract internal tibial rotation, thereby eliminating the PSP. Six weeks later, lameness had improved considerably with no evidence of PSP; 8 weeks after surgery, the dog was assessed for sudden-onset lameness in the right pelvic limb. Cranial cruciate ligament rupture was suspected, and TPLO was performed. The PSP was identified intraoperatively, so an extracapsular implant was placed. Six weeks later, the dog had only mild lameness and no evidence of PSP in either pelvic limb. In a follow-up telephone conversation 1 year later, the owner reported no obvious lameness or gait abnormalities. CLINICAL RELEVANCE Use of an extracapsular implant effectively eliminated the PSP following TPLO in the dog of this report and can be considered as an intra- or postoperative option for dogs with PSP that responds poorly to conservative management.