Knee Joint Stabilisation Antero-posterior Stability
Antero-posterior Stability
Antero-posterior stability of the knee is provided by static and dynamic stabilisers and lateral and medial compartment structures. The anterior cruciate ligament provides the majority of the resistance to anterior tibial translation and likewise the posterior cruciate ligament provides the major resisting factor to posterior tibial translation.
The extensor retinaculum which is composed of fibres from the quadriceps femoris, fuses with fibres of the joint capsule to provide critical dynamic support for the antero-medial, antero-lateral aspects of the knee. The medial and lateral heads of the gastrocnemius reinforce the medial and lateral aspects of the posterior capsule. The popliteus is considered to be a particularly important postero-lateral stabiliser complimenting the function of the PCL.
The ACL and the hamstrings work in a complimentary manner to resist forces that are attempting to displace the tibia anteriorily or sheer the femur posteriorily. Such forces are exemplified by the pull of the quadriceps and by the effect of the ground reaction force on the tibia when the heel hits the ground.
The role of the patella itself can not be ignored when assessing antero-posterior stability of the knee. The patella prevents the femur from sliding forward off the tibia actually serving as an extension of the tibia, connected by an elastic tendon. This combination of patella and tibia creates a cradling effect on the femur.
