Resection of Grade III cranial horn tears of the equine medial meniscus alter the contact forces on medial tibial condyle at full extension: an in-vitro cadaveric study.

OBJECTIVE

To evaluate the magnitude and distribution of joint contact pressure on the medial tibial condyle after grade III cranial horn tears of the medial meniscus.

STUDY DESIGN

Experimental study.

ANIMALS

Cadaveric equine stifles (n = 6).

METHODS

Cadaveric stifles were mounted in a materials testing system and electronic pressure sensors were placed between the medial tibial condyle and medial meniscus. Specimens were loaded parallel to the longitudinal axis of the tibia to 1800 N at 130°, 140°, 150°, and 160° stifle angle. Peak pressure and contact area were recorded from the contact maps. Testing was repeated after surgical creation of a grade III cranial horn tear of the medial meniscus, and after resection of the simulated tear.

RESULTS

In the intact specimens, a significantly smaller contact area was observed at 160° compared with the other angles (P < .05). Creation of a grade III cranial horn tear in the medial meniscus did not significantly alter the pressure or contact area measurements at any stifle angle compared with intact specimens (P > .05). Resection of the tear resulted in significantly higher peak pressures in the central region of the medial tibial condyle at a stifle angle of 160° relative to the intact (P = .026) and torn (P = .012) specimens.

CONCLUSIONS

Resection of grade III cranial horn tears in the medial meniscus resulted in a central focal region of increased pressure on the medial tibial condyle at 160° stifle angle.