Meniscus Hoop Tensioning Function of the Meniscofemoral Ligament: An Experimental Study Using the Knee Joint of the Pig

ABSTRACT

PURPOSE: To prove experimentally if the posterior meniscofemoral ligament (PML) has hoop tensioning function for the lateral meniscus using the knee joint of the pig. MATERIALS AND METHODS: Amputated stumps with the knee joint of the pig (Yorkshire) were used. The experiment was performed under 6 conditions; 1) intact PML with intact lateral meniscus (LM), 2) intact PML with radial tear of posterior horn of LM, 3) intact PML with total lateral meniscectomy, 4) cut PML with intact LM, 5) cut PML with radial tear of posterior horn of LM, and 6) cut PML with total lateral meniscectomy. The pressure-sensitive film (Prescale,Fuji) was inserted under the lateral femoral condyle and axial loads was transmitted to the knee joint with universal testing machine (Instron, model No.4469, USA). The pressed area, maximum pressure and average pressure were measured by the Prescale imaging analysis system FDP-901E series. RESULTS: With the intact PML, there was little difference in pressed area and maximum and average pressures between the conditions of intact meniscus and radial tear of posterior horn of LM. With the cut PML, regardless of the states of the LM, pressure concentration (much decreased pressed area, and increased maximum and average pressures) occurred, which had similar results to the condition of total lateral meniscectomy with intact PML. CONCLUSION: The PML of the pig had hoop tensioning function for the LM under axial loads.