What is Joint Replacement Surgery?
Every year more than 700,000 Americans undergo joint replacements, usually performed on the hips and knees. Diseases like arthritis, trauma and sports injuries can cause a lot of pain and limitation in movement of the joints, especially those involving the knees and hips which are weight-bearing joints. When medications and physical rehabilitation do not correct the defect, joint replacement with a prosthetic device is recommended.
Knee replacement and hip replacement may be done either under general or regional anesthesia. The prosthesis may be made of metal, plastic or both. It may or may not be cemented in place, depending on the age of the patient. The procedure may take a couple of hours, after which the patient is allowed to recover in a post anesthesia care unit.
Possible complications are bleeding, pain, blood clots, dislocation and loosening of the joint, and injury to the nerves or blood vessels.
Why Computerized Joint Replacement Surgery?
Replacing or repairing a joint may be done under computer guidance or computer navigation. Unlike open surgery with mechanical guides, which can be traumatic in terms of incision size and potential blood loss, computerized joint replacement surgery is minimally invasive. The small incision and minimal blood loss result in faster recovery and fewer complications. Scarring is also limited.
Advances in science and computer engineering have allowed orthopedic surgeons to perform surgeries under computerized guidance systems that are composed of tracking devices and cameras that feed information to a computer. Three dimensional images of the model of the patient’s bones and joint are seen on a monitor in the operating room. This enables the surgeon to ascertain correct measurement, alignment and positioning of the new joint that will be set to replace the damaged ones. The precision of computer-guided surgery permits adjustments in a fraction of a degree which results in successful joint replacement.
Joint prostheses are designed to replicate the patient’s own joint, and they have to be carefully positioned to ensure proper movement and avoid pain.
With these advantages in precision, dislocations and malalignments are avoided so that there are fewer chances for the need for revision surgery. Whereas in the past, as much as 20 percent of hip surgeries resulted in malpositioning of implants, computerized joint replacement has reduced this incidence to 5 percent. For knee replacement, precision in positioning with mechanical guides is estimated at 80 percent, but this has been increased to 95 percent with computer guidance. Correct positioning also results in decreasing the possibility of wear in the materials implanted.
It must be taken into account, however, that the success of computer navigation technology is also dependent on the orthopedic surgeon’s skill and experience. The stability and greater range of motion in the replaced joint together with post-operative pain management and rehabilitation make the procedure a success, and a happy restored patient recovers in a shorter time with fewer complications.
Stryker, “Computer Assisted Surgery" accessed 1/12/11
The Jewish Hospital, “Minimally Invasive Surgery" accessed 1/12/11
“Computer Navigation for Hip Replacement Surgery" accessed 1/12/11