Anaesthetic arthrography of the shoulder joint in dogs.

OBJECTIVE

To evaluate the use of intra-articular anaesthesia combined with positive contrast arthrography (collectively called 'anaesthetic arthrography' [AA]) in the shoulder in order to identify and confirm the source of pain in lame dogs.

METHODS

Anaesthetic arthrography was performed in 30 dogs with shoulder joint lameness with a mixture of contrast medium (iohexol: 240 mg I/ml) and a local anaesthetic (mepivacaine 2%: 20 mg/ml). The effect of intra-articular anaesthesia was evaluated by an objectified visual scoring system and the arthrograms were evaluated for their diagnostic value.

RESULTS

This study showed that AA was positive in 28 out of 30 dogs. Dilution of the contrast medium with a local anaesthetic produced an arthrogram of good quality for each shoulder joint. In 16 out of 18 cases of osteochondritis dissecans, a cartilage flap could be identified following arthrography. In all cases the flap was not identified from plain radiographs. Biceps brachii tendon pathology was diagnosed on arthrography in seven dogs but was missed in two dogs. Calcification at the caudal rim of the glenoid cavity was diagnosed in three dogs, but was of clinical importance in only two dogs. In addition one infection was diagnosed during synovial aspiration.

CONCLUSIONS

Anaesthetic arthrography of the shoulder is a simple, safe, and reliable diagnostic test to confirm shoulder joint pain and simultaneously identify a lesion. This procedure may be of particular importance in cases of occult shoulder joint lameness when clinical findings and plain radiographs are inconclusive.