The most common form of arthritis of the knee is osteoarthritis which is a progressive loss of the bearing surface of the knee (joint cartilage). Typically the inner part of the knee usually bears most of the weight and predictably this becomes the most worn and damaged part of the knee joint. Eventually the joint cartilage wears away leaving the underlying bones wearing against each other “bone on bone”. As the bearing surface of the knee deteriorates, pain and stiffness usually occur. The knee joint may become deformed and result in a bowed leg deformity. Traditionally the surgical options included a complete knee replacement or re-alignment procedure (osteotomy) when non-operative means of treatment fail to provide adequate symptom relief.
It is now possible to replace only the worn inside part of the knee that spares the remainder of the knee. Partial knee replacement is the re-lining of the damaged part of the joint surface with artificial bearings made of metal and plastic. The damaged joint cartilage of the knee is removed and replaced with the artificial bearing.
All bearing surfaces, including artificial knee replacement bearings “wear out”, therefore age and demands upon the knee influence the decision to replace the worn out knee or consider other options such as re-alignment procedures. Partial knee replacement surgery is feasible only when the majority of the knee is not excessively worn and the cruciate ligaments (internal ligaments of the knee) are normal. It is only possible to correct deformity (such as bowed legs) without requiring extensive ligament releases. Your orthopaedic surgeon (specialist of bone and joint surgery) will examine the knee to determine its suitability for a variety of treatment options. Specialised x-rays of the knee may be required, and if you are considered a candidate for partial knee replacement, special x-rays to stress the knee may be performed. The final decision to proceed with a partial knee replacement or a full knee replacement may be made at the time of surgery when the knee is examined with a camera (arthroscope) or opened for a visual inspection.
Download our information sheet to learn more about Partial Knee Replacements and treatment options.