Thieman KM, Pozzi A, Ling HY, Lewis DD, Horodyski M. Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida Veterinary Medical Center, 2015 S.W. 16th Avenue, Gainesville, FL 32610, USA. Vet Surg 2009 Oct 38 7 803-10 OBJECTIVE: To evaluate the biomechanical effects of 5 types of meniscal lesions on contact mechanics in the canine stifle. STUDY DESIGN: Experimental study. ANIMALS: Cadaveric canine stifles (n=12 pair). METHODS: Medial meniscal lesions (radial, vertical longitudinal, nonreducible bucket handle, flap, and complex tears) were simulated in cadaveric stifles. A contact map was recorded from each tear type and contact area (CA) and peak contact pressure (PCP) from each tear type were compared. RESULTS: A significant difference in PCP was detected between control and nonreducible bucket handle, flap, and complex tears. PCP increased by >45% in nonreducible bucket handle, flap, and complex meniscal tears when compared with control. No significant difference was found in PCP between control and radial and vertical longitudinal tears. No significant difference was found in CA between any of the meniscal conditions. CONCLUSIONS: Nonreducible bucket handle, flap, and complex tears cause a significant increase in PCP. Radial and vertical longitudinal tears had a minimal impact on the contact pressures of the medial compartment of the stifle. CLINICAL RELEVANCE: Based on this ex vivo model, we support the clinical recommendation of debriding nonreducible bucket handle, flap, and complex tears because the injured portion of the meniscus no longer contributes significantly to the function of the meniscus. Radial and vertical longitudinal tears do not cause a change in contact mechanics allowing consideration of nonsurgical treatment and meniscal repair, respectively. Future experimental and clinical studies should aim to refine the treatment of specific meniscal injuries.