Greeshma Prabhu, BPT, M.S.
The knee is the most important joint of the leg, providing stability and locomotion. This joint is formed by the articulation of the long bones of the leg called the femur (above the knee) and the tibia (below), along with a triangular bone, the patella (or kneecap), in between. Ligaments serving the knee joint are the anterior and posterior cruciate and the medial and lateral collateral ligaments.
Approximately 60 degrees of knee bending (flexion) is required for normal human locomotion. This range is limited in cases of arthritis, swelling and inflammation in soft tissue injuries, and in post-surgical stiffness due to immobilization. Knee evaluation should be performed carefully, and along with the knee, the hip, ankle and lower back must also be evaluated to rule out their possible impairments .The most common cause of knee pain in the elderly population is arthritis. This is diagnosed radiographically by narrowing of inner joint space, and presence of small outgrowths on the joint surface called osteophytes. In the athletic population, the most common knee affection is soft tissue injury, usually to the anterior cruciate ligament (ACL), the medial cruciate ligament (MCL), and the medial menisci. This can be detected by tests that examine the laxity or looseness of the knee joint. For example, since the ACL restrains excessive forward movement of the lower leg bone, a torn ACL permits the tibia to be moved forward more than normal. Sometimes habitual positions such as prolonged kneeling may cause increased friction of the patella, which in turn leads to inflammation of the lining of the joint. This is termed as patellar bursitis.
The non-surgical treatment for ligament injuries involves providing rest and a brace for support. The surgical treatment for ligament tears is called a reconstruction surgery in which the torn ligament is reconstructed by using a graft from another tendon or ligament.
A study by Petersen et al evaluated the efficacy of early and late reconstruction surgery both followed by brace treatment and an accelerated rehabilitation protocol respectively, and found that late reconstruction had better outcomes in combined ACL and MCL injuries.
Rehabilitation protocols mainly differ according to the nature of injury, occupation of the patient, and the clinician’s experience. After an ACL injury, swelling around the knee is reduced by using cold packs. Once the pain and swelling is reduced, gentle static quadriceps and hamstring muscle exercises (involving slight contraction and relaxation) are initiated. Mobility exercises involve sliding the leg on the bed to bend the knee. Emphasis is placed on passive knee extension to avoid scarring and joint contracture. Passive knee extension can be defined as extension of the knee due to an external force. For example, sit in a chair with the foot propped up on another chair and add an external weight on the knee to allow a deep stretch in the hamstring. The individual is given crutches and is taught to walk with only partial weight bearing on the affected leg. Once the quadriceps muscle gains enough strength, and knee range is more than 60 degree with complete extension, full weight bearing is initiated.
- Petersen W, Laprell H. Combined injuries of the medial collateral ligament and the anterior cruciate ligament. Early ACL reconstruction versus late ACL reconstruction. Arch Orthop Trauma Surg. 1999;119:258-262. http://www.ncbi.nlm.nih.gov/pubmed/10447618
- Conservative Management of Sports Injuries – Thomas Hyde and Marianne Gengenbach,2nd Ed.,2007. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2732261/
- Kisner C, Colby LA. The knee. Therapeutic exercise: Foundations and techniques, 4th ed. Philadelphia: F.A. Davis Company; 2002. http://faculty.ksu.edu.sa/sfs/medical%20books/Therapeutic%20Exercise%204th%20ED.pdf