Articular cartilage is a thin layer of highly specialised tissue that provides a smooth, lubricated surface for joint movement and transmits forces to the underlying bone. Articular cartilage, however, has a limited capacity for healing and repair, which means that once the joint surface is damaged, the subsequent repair is limited. The resultant repair is often with a different type of cartilage – fibrocartilage, which lacks the same biochemical structure as normal articular cartilage and has been shown to break down more rapidly. The injured joint is therefore unlikely to return to its original structure and function, predisposing the patient to premature osteoarthritis.
Articular cartilage damage in the younger population is a far more challenging dilemma with no currently accepted and effective treatment. This can lead to pain, loss of function and an inability to participate in everyday activities. This damage can also lead to further breakdown of the joint resulting in early osteoarthritis. Joint replacement in active, younger patients often gives inferior outcomes and will result in premature implant failure due to the higher demands being placed upon the implant.
The first stage is a telescopic examination of the knee to take a small piece of normal cartilage which is sent to the cell culture laboratory. This cartilage is then cultured for 4 to 6 weeks to increase the number of cartilage cells. These cells are then transplanted back into the damaged area of the knee by an open operation to develop a new cartilage surface in the joint.
More recently the surgeons on the Cartilage Transplantation Unit have begun using an exciting and novel single-stage procedure involving the patients’ own stem cells. Stem cells are initially harvested from the patient’s bone marrow in the pelvis using a small needle and are then centrifuged in a specialised machine in the operating room. This provides a concentrated volume of stem cells which, when transplanted and secured back into the knee joint, will give rise to new cartilage cells and repair the damaged part of the joint.
This method has proved very valuable in relieving pain and restoring activity in younger patients.
Only one operation and hospital stay are required for the patient and rehabilitation is accelerated.
The Cartilage Transplantation Unit has over the last fifteen years pioneered the technique of two-stage cartilage transplant in the United Kingdom. Over 1500 cases have been performed with high success rates, producing healing of the joint, relief of pain and restoration of function. The onset of osteoarthritis, which affects 25% of people over 50, is also delayed, preventing the need for joint replacement.
The single stage procedure team have performed over 75 procedures with promising short to medium term results.