New and Future Techniques in Knee and Shoulder Surgery

Biologic Tissue Engineering is continuing to bring exciting new approaches from the lab to the practical application of medicine and surgery.

It may be possible to use cells from the bone marrow or the lining of the bone (periosteum) that have multiple potential capabilities and transform them into joint surface cartilage.

More research is being done on stem cells. These cells are called pluri-potential which means they can influenced to grow in a certain manner. Based on environment and other factors, the same cells can produce cartilage or bone. PRP (platelet rich plasma) which is peripheral blood that has been concentrated to enhance its growth factors has become very popular especially by some athletes. But, the literature is still confusing and has not come to any conclusions about its true effectiveness. It is being used for tendons that are not healing well. It has also been tried to treat arthritis in the knee joint. On the other hand, BMAC, (Bone Marrow Aspirate Concentrate) seems to have more of an opportunity to be effective. Here, blood taken from the skeleton, usually the pelvis which is where blood is made, is concentrated and formed into a patch to help heal defects in a joint. BMAC seems to have higher levels of growth factors and seems to have been shown more effective. Both of these techniques are currently available in the USA. Both need to have longer track records.

New techniques and tissues are also being developed to help with tissue reinforcement. Several tissues in our bodies become weaker as a result of poorer blood supplies as we all get older. As a result of they are more prone to tearing or rupture. Common tissues include the Achilles tendon, patella tendon and the rotator cuff. Repair of these tissues occasionally requires reinforcement. Xenografts, tissues from other species such as a pig have been developed, as these tissues are biologically compatible with the human and offer no rejection. One of these the Restore Biologic Patch by Depuy has had a good reputation since 1999. BioGuide and ChondroGuide the USA and British equivalents respectively are also based in porcine (pig) tissue and have long histories in orthopedics and dentistry. There are grafts that are also made of human tissue. Some of these are from skin where in the cells have been removed. There are others. One of the newer tissue reinforcements is a man-made device made by ArtImplant in Sweden called Artelon. This product has the advantage of not being made of either another species or from a human. It retains its strength longer and deteriorates chemically which makes it an advantageous choice.

Hopefully to be marketed in the USA in 2015 is the MACI procedure. This is the newer adaptation of the Carticel procedure. MACI (Matrix Autologous Chondrocyte Implantation) is a two stage procedure where cultured chondrocytes are placed on a matrix (scaffold) which is then used to patch articular cartilage defects in the knee of all sizes. This procedure has the potential based on current studies to create cartilage closer to true normal and natural articular cartilage than any other procedure currently being developed.