Total Knee Replacement
The knee joint is a hinge joint with several compartments that are lined with cartilage. Each of these compartments is susceptible to degenerative changes caused by age-related wear and tear, previous trauma, or inflammatory conditions. A total knee replacement addresses the inner (medial) and outer (lateral) compartments, and may also address the patellofemoral compartment (in the front of the knee) The eroded joint surfaces are cut away and metal components are inserted, separated by a plastic liner.
*an illustration of an arthritic knee would be useful here*
Partial Knee Replacement
Knee arthritis is sometimes localized to just one compartment on the inner or outer part of the knee. Implants have been designed to address isolated arthritic compartments, where the damaged joint surfaces of the inner or outer knee are removed and replaced with metal implants, separated by a plastic liner.
References
- Migliorini F, Tingart M, Niewiera M, Rath B, Eschweiler J. Unicompartmental versus total knee arthroplasty for knee osteoarthritis. Eur J Orthop Surg Traumatol. 2019;29(4):947-955. doi:10.1007/s00590-018-2358-9
- Niinimäki T, Eskelinen A, Mäkelä K, Ohtonen P, Puhto AP, Remes V. Unicompartmental knee arthroplasty survivorship is lower than TKA survivorship: a 27-year Finnish registry study. Clin Orthop Relat Res. 2014;472(5):1496-1501. doi:10.1007/s11999-013-3347-2
Knee Arthroscopy
The knee is a hinge joint formed by the femur and tibia. The patella (knee cap) glides against the front of the femur to improve the strength and range of motion of the knee. The knee is stabilized not only by the muscles that cross the joint, but also by many ligaments. Some ligaments do not heal once torn and lead to chronic instability and may eventually lead to premature arthritis. Ligaments such as the anterior and posterior cruciate ligaments, ACL and PCL respectively, can be reconstructed if torn.
The knee is cushioned by the cartilage lining throughout the joint, as well as by the menisci. These are two semicircular structures of cartilage that are on the inside and outside aspects of the knee. The menisci may be damaged through wear and tear related to age or they may be torn acutely from physical activity or other trauma. Small tears can be treated by cutting away the small loose portion (a partial meniscectomy), and other tears can be repaired using sutures.
ACL reconstruction
The anterior cruciate ligament (ACL) is important for the stability of the knee. This ligament may be torn during a sports injury or other traumatic event. Because the ligament is located within the knee and does not have a good blood supply, complete tears cannot heal on their own. The ACL may need to be reconstructed in order to restore stability to the knee. The procedure is performed arthroscopically through several small incisions. The torn portion of the ligament is removed and is replaced with a graft from the hamstring, quadriceps tendon, or patellar tendon. In some individuals, an allograft from a donor may be used. The graft is secured into place with a combination of sutures, screws and/or staples.
Recovery from ACL reconstruction takes approximately 9-12 months as the graft needs to integrate into the bone. It is important to follow a rigorous physiotherapy program prior to returning to sports.