ORIGINAL ARTICLES   

Gazzetta Medica Italiana Archivio per le Scienze Mediche 2013 July-August;172(7-8):595-601

Copyright © 2013 EDIZIONI MINERVA MEDICA

language: English

Do the soft tissues located outside tibiofemoral joint have a role in bearing the compressive loads of the joint? - An in-vitro study on sheep stifle joints

Hakkak F. ¹, Rostami M. ¹, Parnianpour M. ², Jabalameli M. ³

¹ Biomechanics Division, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran; ² Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran; ³ Orthopedics Division, Tehran University of Medical Sciences and Health Services, Tehran, Iran

Aim: The compressive loads on the tibiofemoral joint are normally assumed to be borne solely via contact and pressing of the cartilage surfaces of tibia and femur. However, recent findings suggest that non-contact load-bearing mechanisms are active in the joint as well. In this context, a non-contact load-bearing mechanism involving soft tissue connections outside the tibiofemoral joint has been hypothesized as well. This paper addresses the validity of this hypothesis and the possible involvement of several soft tissue connections outside the joint.
Methods: Sheep stifle (knee) joints were studied in vitro. The specimens were loaded in fixed displacement. Various soft tissues outside the joint were cut during the loading, and their effect on the force-time curve was studied. The cuts were applied on the medial collateral ligament, quadriceps conntection to the patella, patellar tendon, and soft tissues 5-7 cm distal and proximal to the tibiofemoral joint. Two cameras were used to observe possible motion in the joint tissues during the fixed-displacement loading.
Results: The cuts had no or very small effect on the force-time curve. The cameras did not detect motion in the joint during the fixed displacement loadings.
Conclusion: The soft tissues outside the tibiofemoral joint have no or probably very small role in bearing compressive loads of the joint. Moreover, the hypothesized load-bearing mechanism introduced in this paper does not exist. Considering the differences in living and non-living bodies, in-vivo experiments are required to confirm applicability of these findings to living joints.