Humero-anconeal elbow incongruity in spaniel breed dogs with humeral intracondylar fissure: Arthroscopic findings.

Objective: To report arthroscopic findings in dogs with humeral intracondylar fissure (HIF) and compare these findings in joints of dogs not affected by HIF on preoperative CT images.

Study Design: Controlled clinical study.

Animals: Dogs with HIF (14 dogs, 21 elbows) and dogs without HIF (20 dogs, 31 elbows).

Methods: A caudo-medial arthroscope portal was used to inspect all elbow joints. Arthroscopic features of 21 joints of dogs with HIF were compared with 31 control elbows of HIF- negative dogs.

Results: All elbows with HIF showed a focal cartilage lesion on the caudal aspect of the humeral condyle. The lesions ranged from a simple indentation into the articular surface to a full thickness cartilage erosion. Humero-anconeal incongruity was identified in all elbows with HIF as absence of joint space at the point of contact between the tip of the anconeal process and the cartilage lesion, with a wider joint space distally within the ulnar trochlear notch. None of the elbows without HIF showed the cartilage lesion or evidence of humero-anconeal incongruity.

Conclusion: Use of a novel arthroscope portal allowed description of a previously unreported cartilage lesion on the caudal humeral condyle of dogs with HIF. The lesion was found in all dogs with HIF but in no dogs without HIF.

Clinical Significance: Humero-anconeal incongruity and an associated cartilage lesion appear to be present in dogs with HIF. We propose that this lesion may be associated with humero-anconeal incongruity. This may be considered as a possible future therapeutic target for HIF.