Osseointegration

After an amputation the residual limb (stump) is molded for fitting of a prosthesis. Amputation through the tibia bone is referred to as Below Knee (BK) and those through the femur are referred to as Above Knee (AK). Amputation at the level of the knee joint is referred to as through knee (TK). Amputation at the level of the humerus is referred to as Above Elbow (AE) and those through the forearm bones as Below Elbow (BE). While the component parts of the prosthetic joints, feet, hands are much more sophisticated than they were years ago the connection to the residual limb is through a custom molded socket. Despite casting or digital scanning in preparation for a perfectly fitted socket the stump often shrinks or expands resulting in the socket being too tight or too loose. in many instances, it is the source and the cause of skin rash, breakdown or infection. Prosthetic devices are heavy and the shorter the residual limb and the longer the prosthesis the greater the stresses are on the stump. This is especially true for AK and residual limbs and prosthetics. Furthermore, these large sockets which transfer load to the surface of the residual limb, also shield it from receiving sensation from weightbearing (proprioception).

A solution to the socket issues and the lack of proprioception was developed in 1995. It is referred to as ‘osteointegration’ or OI. OI involves insertion of a metal prosthetic into the central marrow cavity of the bone (medullary canal) with the end of this prosthetic sticking out the end of the stump. The prosthetic limb is then attached directly to to the internal metal prosthesis. There is no further need for a socket. When weight is placed the weight goes directly to the bone and the patient feels the ground. This gives the patient improved balance and responsiveness of the limb during walking. (Dental implants are the same concept. A metal peg is inserted into the bone of the mandible or maxilla and a prosthetic tooth is then mounted to this peg).

Osteointegration offers many advantages over conventional socket prosthetics especially for AK and AE but also for BK amputees and some BE amputees. There are two different methods to do OI. One is called the OPRA system, Swedish or Branemark method. The other is referred to as the Australian method of Dr. Munjed Almuderis. The Paley Institute is the only center trained in both of these methods and offering both methods of OI. There are pros and cons of each method. The OPRA system is a two surgery method compared to only one surgery method for the Australian system. For this reason alone it is preferred by most patients and by The Paley Orthopedic & Spine Institute, The surgery is performed by Drs. Paley and Quinnan at St. Mary’s Medical Center. After a short two to three day hospital stay patients start rehabilitation under the supervision of Dr. Craig Lichtblau, physiatrist and director of rehabilitation for the Paley Institute OI program. Prosthetic fitting is carried out by our Paley Prosthetics prosthetist Paula Gomez.

Taking on and off the prosthesis is very easy and takes less than 10 seconds. Due to the solid fixture to the bone, it accurately connects in the exact spot each and every time you attach the prosthesis. This device can be used with all types of prosthetic componentry. With this new technology, the days of fiddling around with time consuming and cumbersome suction socks and liners is over. Using this titanium bone implant allows for natural loading of the hip joint and the femur, which encourages bone growth, and creates a more natural gait and requires less physical exertion. Osteoporosis of the residual limb is reversed and prevented by direct bone loading through OI. Any weight gain, muscle hypertrophy or atrophy or fluid variations of the residual limb all of which cause change in shape and diameter of the stump have no effect on the security of attachment to the prosthetic limb. Eliminating the bulky socket also provides a much more natural streamlined look in clothes.

OI allows for full freedom of movement from walking to cycling and recreational activities. Muscular strength is developed freely, which minimizes muscle wasting of the distal stump. Movement of the effected extremity is not restricted by the protruding edges of the socket allowing for greater ease and comfort sitting, standing, and walking. The direct connection between the femoral bone implant and the knee enables free natural pivoting movements. Patients can also allow the prosthetic connection to rotate which permits crossing one leg over the other for AK amputees.

Because the titanium implant attaches directly to the bone, the patient regains the ability to feel the ground and can differentiate between different surfaces such as carpet, grass, tile and uneven ground, reducing the risk of falling even in dim light.

Osseointegration can be performed on most skeletally mature extremity amputees. The Paley Orthopedic & Spine Institute is one of less than a handful of centers experienced in the use of OI technology. The goal of the osseointegration procedure and process at the Paley Orthopedic & Spine Institute is to turn disability to ability, illness to health and hopelessness to hope. Most patients that receive osseointegration will experience a significant decrease in pain and suffering, increase in ability to participate in activities of daily living, and improvement in quality of life.

OI with stump revision is frequently combined with surgery to treat chronic nerve related pain and phantom pain. This is done by shuting down neuroma related pain. Neuromas are hypersensitive endings of previously cut nerves. If such neuroma related pain is present, the offending nerve is sutured to an unused motor nerve e.g. sciatic nerve to one of the innervating branches of the hamstring muscles. The mixed sensory and motor nerve will grow into the muscle and shut down all sensory function which stops the pain nerves from firing and causing pain. This technique is called Targeted Muscle Reinervation (TMR). Both Dr. Paley and Dr. Quinnan perform TMR either in conjunction with OI or separate to it.