Knee Orthoses:

  • Knee orthoses control ligament deficiencies around the knee and are often custom made. For example, a knee orthosis for a patient with an injured anterior cruciate ligament resists abnormal forward translation of the tibia (large lower leg bone) on the femur (thigh bone). This is most often achieved through a control system that prevents hyperextension (extreme/excessive extension) of the knee.
  • For osteoarthritis of the knee, similar orthoses are used, but they work on a different biomechanical principle. In osteoarthritis, the joint space between the femur and tibia is reduced due to degeneration and inflammation, resulting in chronic pain in the knee.
  • Osteoarthritis of the knee occurs more often in the medial (inner aspect) compartment than in the lateral (outer aspect) compartment. During normal walking, the knee joint is subjected to a varus (inward bending) force, which shifts the joint load to the medial compartment.
  • To reduce this load in the patient with osteoarthritis, the orthosis applies a valgus (outward bending) correction using three-point pressure, which ultimately shifts the load to the lateral compartment of the knee.