Comparison of a dorsolateral approach and a dorsomedial approach to access the medial malleolus of the distal tibia in horses.

Objective: To determine the utility of a dorsolateral arthroscopic approach to the tarsocrural joint (TCJ) to examine and surgically access the medial malleolus (MM) and compare this to the standard dorsomedial approach to the MM.

Study design: Experimental cadaver study.

Animals: Six pelvic limbs from four adult horses.

Methods: Arthroscopic examination of the dorsal aspect of the TCJ was performed followed by the dorsomedial and dorsolateral surgical approaches to the MM, in randomized order on cadaver limbs (n = 6). The dorsomedial approach involved placing the arthroscope and instrument in the dorsomedial pouch. The dorsolateral approach involved placing the arthroscope dorsolaterally and the instrument dorsomedially. Identification and surgical access grades for the MM were assessed and recorded.

Results: Using the dorsomedial approach, identification grades were excellent for the MM and surgical access to the MM was excellent or good in all limbs. Using the dorsolateral approach, identification and surgical access grades for the MM were excellent in all limbs. Interference between the arthroscope and instrument only occurred during the dorsomedial approach. The view of the axial aspect of the MM was improved with the dorsolateral approach.

Conclusion: The dorsolateral approach allowed identification and surgical access to the MM and provided an improved view of the axial aspect of the MM. No interference between the instrument and arthroscope was encountered.

Clinical significance: The dorsolateral arthroscopic approach to the TCJ can be used for debridement of MM OCD lesions.