Joint replacement of the hand has continuously advanced as better implant materials have been developed. Metal hinge joints were initially developed, but were wrought with complications. Joint replacement today has two main categories: silicone and PyroCarbon implants.
Silicone implants are a single rubber piece that bridges the joint after removing the destroyed cartilage ends of the bone that is able to bend. This is beneficial because it has intrinsic stability because it is a single piece. However, risks are associated with increased stability such as implant fracture or loosening from too much force occurring on the implant-bone interface. This has long been the standard of care. Another more recent type of joint replacement is PyroCarbon implants.
PyroCarbon is a graphite-derived substance that has been shown to have excellent durability and compatibility within the human body. Additionally, it has similar strength characteristics to the bone, which helps in preventing abnormal forces between the bone-PyroCarbon interface. This results in improved longevity of the implants.
Studies have also shown that PyroCarbon that articulates with PyroCarbon has essentially no wear effect, even after 10 million cycles less than 1000th of an inch of wear was measured in the prosthesis. These implants, however, are not connected and rely on the body’s natural soft tissues to provide stability after replacement.
Joint fusion was the mainstay of treatment for hand arthritis for many years. In the early 1900s, however, surgeons started perform surgery to place tissue between the bone ends to prevent direct contact within the arthritic joint. This resulted in pain relief with preservation of joint motion with modest success.
More recently joint replacement has been developed. Joint replacement is the process of removing the diseased and damaged bone ends around a joint and replacing them with artificial prosthetics that can move. The keys to successful joint replacement include preserving motion and stability to the joint.
Arthritis of the hand affects millions of people, particularly in older populations. Arthritis can result from wear-and-tear, also called primary osteoarthritis, or from certain disease processes such as rheumatoid arthritis.
Often this presents as a progressive pain with the use of the hands, and at first, can be treated with anti- inflammatory medications alone. In a small number of people however, it can continue to worsen until it severely affects their daily lives.
All joints of the hand can be affected to include the wrist, the knuckle (called the metacarpophalangeal joint or MCPJ), to the small joints of the fingers. When the symptoms are too severe, surgery becomes an option. Surgical intervention can be the fusion of the joint, preventing all movement and thereby relieving pain, or joint replacement
Integra Ascension MCP Joint Replacement™ is a PyroCarbon based joint replacement that takes advantage of exceptional wear characteristics and bio- compatibility of PyroCarbon for the replacement of the MCPJ. The system uses two articulating implants with high-congruence and the body’s natural ligaments and joint capsules to recreate the MCPJ.
This can be done through an S-shaped or straight longitudinal incision over the knuckle. This implant allows for maintenance of more natural motion at the joint and often significant pain relief to restore function to a painful hand.