gms | German Medical Science

The primary roles of the menisci are to act as load distributors and shock absorbers within the knee. While tibiofemoral contact mechanics within the human knee has been measured several times less is known about the biomechanical effect of meniscectomy in relatively smaller animals. Aim of the study was thus to quantify the effect of chronic meniscectomy in an ovine model.

Twelve sheep were divided into two groups (n=6): - group A was the sham group; in group B a medial meniscectomy was performed. After six months the animals were sacrificed. The lower limb specimen were placed in a material testing machine in 30°, 60° and 90° of flexion and loaded through the femoral axis to 500N. For determining contact area and pressure a thin pressure transducer (Tekscan^®) was positioned underneath the meniscus. Statistical analysis was performed using Mann-Whitney test.

Contact area and peak contact pressure showed significant differences between the meniscectomized knees and the knees with the intact meniscus (p<0.05). Reductions of 53.2 %, 56.9% and 53.5% in contact area of meniscectomized knees were observed relative to the sham control group at 30°, 60° and 90° of flexion. Peak contact pressure showed an average increase of 260.4% for the meniscectomized compared to the intact knees.

Measurement of the tibiofemoral contact mechanics is possible with electronic pressure measuring sensors even in relatively smaller animals. The values fit into the range of the biomechanical studies with human cadaveric knees.