OSSEOINTEGRATION
The typical prosthetic for a leg amputation is often thought of as a socket that fits tightly over the amputation stump connected to some sort of prosthetic leg. These types of devices were used as far as 2500 years ago and at that time they were made of leather and bronze and wood. It was in the 1600s that prosthetics became more advanced and hinges were added to replace the knee joint. At that time surgical procedures were also invented to create a more functional amputation. This consisted of rerouting muscles and tendons and varying the incision as well to areas that would not rub against the prosthetic socket.
The American Civil War in 1861 led to a significant amount of innovation in terms of prosthetics since the new weaponry used on the battlefield required amputations more often due to the severity of the injuries caused. And in the early 1900s different materials were then used for the prosthetic devices including aluminum and steel and other new lightweight plastic materials called bakelite.
There were many known issues with socket type prostheses these included the difficulty of fitting a socket well which led to pain blistering and even ulcerations to the stump. Excessive sweating was also a problem which was very frustrating to the prosthetic user. And also the problem of proper fitment really depended on the length of the amputation stump which in some cases was difficult to control depending on the cause of the amputation.
In the mid 1960s a technique was developed Dr. Ingvar Branemark in Sweden of implanting a metallic dental device into the jawbone. This new implant was designed to allow bone to grow into it and fuse to the patients skeleton. This method became known as osseointegration and some of these dental implants and techniques are still used today. In the 1990s Dr. Rikard Branemark, The son of the original surgeon begin the development of osseointegration implants for use in amputees. This consisted of an implant screwed into a long bone at the amputation site. A portion of the implant would protrude through the skin and would allow the attachment of a prosthetic directly to the patient's bone through this implant. This was quickly found to have significant benefits no more need for a socket, no more need for specific amputation stump architecture and gave the patient the ability to have more range of motion because the prosthetic was tightly attached to the bone.
Since then there have been significant innovations in this field and more recently the procedures and implants were allowed by the FDA to be used in the United states. The prosthetics themselves have become very advanced, computerized biofeedback devices control artificial joints and feet are complex shock absorbing devices.
The bone has a hollow center that the implant is made to fit into!
How the surgery works:
Generally patient need a CT scan and a proper examination. The Cat Scan is necessary because the osseointegration implants are custom made in all cases so measurement of the bone to be implanted must be done. If the amputation stump is normal it is a relatively simple procedure done through a minimal incision. In other cases more complex stump reconstruction must be performed.
These surgeries are one step. The limb is prepared, and the device is inserted into the canal of the bone. Once it is healed ,about two months later in most cases the prosthetic is affixed to the osseointegration implant and gradual and progressive weight bearing is started.
