Osseointegration for limbs involves inserting a metal rod into an arm or leg bone. The bone then fuses with the rod in a manner similar to fracture healing. The resulting implant is strong, stable, and intimately connected with the patient. It also provides a good connector for a prosthesis, with less discomfort, increased use, and an overall improvement in quality of life.
Traditional Prosthetic Attachments
Traditional prostheses use a fitted socket, often combined with a harness or other type of suspension system.
Modern materials, casting, and fitting methods have allowed for an increased use of fitted sockets solely on their own. This applies both to cosmetic and bionic limbs.
Unfortunately, even modern sockets still cause skin abrasion, lesions, sweating, etc., which discourages their use.
A traditional prosthesis can also tire the user because it is essentially a dead weight.
Osseointegration provides an alternative mechanism for attachment, eliminating the need for external sockets altogether.
Prosthetic Attachments With Osseointegration
As mentioned in the introductory paragraph, osseointegration involves inserting a metal rod into an arm or leg bone. Part of the rod protrudes from the residual limb. This abutment is then connected to a prosthesis as shown in these two diagrams of the OPRA™ Implant System from Integrum.
The main advantages of this approach include:
The main disadvantages include:
This video provides a good description of the benefits and disadvantages of oesseointegration:
Osseoperception refers to the transfer of vibrations from the osseointegrated rod to the attached bone.
A recent study by the DeTop Consortium proved that vibrations travelling through the bone can be perceived by the ear. This helps the wearer distinguish between different stimuli.
For example, this young man can feel when he’s touching his partner’s arm vs the bowl vs the counter top:
A person with an osseointegrated leg prosthesis can identify the type of surface he or she is walking on. This improves safety, especially when the surface suddenly changes.
The advantages of osseoperception go beyond function. Amputees who have undergone osseintegration feel more connected to their surroundings. In a world where those with limb differences often feel isolated, this increased connectedness improves their sense of well-being.
Scientists are trying to take this a step further by adding touch to bionic prostheses through a electronic sensors, targeted muscle reinnervation, and/or brain control interfaces.
Osseointegration With Bionic Arm / Hand
Combining osseointegration with a bionic arm gives amputees the best of both worlds. They have full shoulder motion plus fine control over joints and fingers:
For more information, see Understanding Bionic Arms & Hands.
Osseointegration With Bionic Leg / Foot
The increased strength and stability of osseointegrated implants makes them ideal for lower limb amputees. When combined with the advanced capabilities of a bionic prosthesis like Ottobock’s C-Leg, the results can be transformative.
Jerry Monteiro lost his right leg to bone cancer at the age of 15. He hadn’t walked without crutches for 35 years. Yet, here here is, only 1 year after surgery, out for a walk. Note the ability of the bionic knee to automatically adjust on stairs.
To learn more, see Understanding Bionic Legs & Feet.