After receiving osseointegrated percutaneous implants, transfemoral amputees experienced high cumulative survival rate at 2 years, enhanced prosthetic use and mobility, fewer problems and improved quality life, according to a study published in The Bone & Joint Journal.
Between 1999 and 2007, researchers enrolled 51 patients with 55 transfemoral amputations in a prospective, single-center non-randomized study and used a two-stage surgical procedure to introduce a percutaneous implant and attach an external amputation prosthesis. Researchers followed patients for 2 years and compared preoperative and postoperative data regarding the osseointegrated prostheses. To assess the functional and health-related quality of life, researchers used the Questionnaire for Persons with Transfemoral Amputation (Q-TFA) and the Short-Form 36 Health Survey. Primary outcomes included the Q-TFA prosthetic use score; secondary outcomes included the remaining scores and the single overall questions from the Q-TFA, and all scores on the SF-36.
Overall, 48 of 51 patients were followed, with a cumulative survival of 92%. A total of 101 complications were reported with 49 complications reported as serious. The most common complication was superficial infections, which occurred 41 times in 28 patients and treated effectively with oral antibiotics for 10 days. According to study results, two patients with pain on weight-bearing had loose implants and five patients described episodic pain during rehabilitation, but without evidence of loosening of the implant. Four patients sustained five fractures, including three ipsilateral fractures of the hip, one below-elbow fracture and one vertebral compression.
Researchers found 89% of patients reported daily prosthesis use at 24 months vs. 51% of patients before the implant was inserted. According to study results, the mean prosthetic use score improved from 47 before the first stage procedure to 79 2 years after the second stage procedure, whereas all Q-TFA scores improved, demonstrating improved prosthetic mobility and fewer problems. SF-36 physical function scores also showed general quality of life improved.
Rickard Brånemark, MD, PhD, orthopedic surgeon and association professor at Sahlgrenska University Hospital, told O&P Business News the researchers found somewhat better implant survival than expected and fewer skin infections. However, additional prospective studies and longer follow-up are still needed.
“In the future, it is hoped that these novel percutaneous devices will not only allow improved fixation of prostheses, but may also help deliver information between the artificial components and other systems within the body,” the researchers wrote.
Osseointegration vs. the socket
This is the first prospective study for the treatment of patients with transfemoral amputation, Brånemark said.
“There are a large number of lower limb amputees worldwide; many are young, and TFA prostheses traditionally have used suspended sockets,” the researchers wrote. “However, problems with the socket are common because of poor suspension and fit, local pain, skin ulceration and general discomfort.”
Patients with a short residual limb or inadequate soft tissues may choose not to use their prosthesis due to discomfort caused by the socket, according to the researchers. Sockets have also been shown to hinder the movements of the hip and may promote a risk of infection. However, a study published by Jonatan Tillander, MD, and colleagues in Clinical Orthopaedics and Related Research in 2010 showed 39 amputees treated with osseointegrated percutaneous implants lived with the implants for a mean of 56 months and had a frequency of implant infection of 5% at inclusion and 18% at follow-up. The infections that occurred had low infectious activity and prosthetic use was not affected in five of the seven patients with infections.
“Osseointegrated implants are a novel addition to the growing number of mucosa- and skin-penetrating implants,” Brånemark and colleagues concluded. “These devices not only allow for fixation of the components to bone, they also create new opportunities for the exchange of information between the prosthesis and the rest of the body, using vibration, epimysial electrodes and nerve cuff electrodes.” — by Casey Tingle
Disclosure: Brånemark owns stock in Integrum, the manufacturer of the implant system used in the study.