A study in the June issue of the Journal of Bone and Joint Surgery concluded there is minimal risk for severe infection with osseointegrated implants for prosthetic attachment in patients with transfemoral amputations.
The researchers specifically reported on the safety of press-fit osseointegrated implants currently used in Australia and the Netherlands. They prospectively recorded all adverse events in 86 patients (91 implants) who received the implant between 2009 and 2013. Adverse events were categorized according to type (infection or other) and severity. Infections were classified according to four grades of severity based on clinical and radiographic findings: low-grade soft-tissue infection, high-grade soft-tissue infection, bone infection, and septic implant failure-the infection classification system was developed by the Osseointegrated Group of Australia, with which the lead study author, Munjed Al Muderis, MB ChB, FRACS, FAOrthA, is associated.
For each patient, the procedure was performed in two stages: first, a porous-coated implant was placed in the femur bone, and second, a stoma, or opening, was created to attach the prosthesis. The patients ranged in age from 25 to 81, and were followed for a median of 31 months.
According to the study abstract, 31 patients had an uneventful course with no complications; 29 developed a grade 1 or 2 infection; and 26 had no infection but developed other complications, including stoma hypergranulation (17 patients); soft-tissue redundancy (14); proximal femoral fracture (three); inadequate osseointegration leading to implant replacement (one); implant breakage (two); and breakage of the pin used as a fail-safe mechanism (25). No patients had a grade 3 or 4 infection.
These results led the researchers to conclude that mild infection and irritation of the soft tissue in the skin-penetration were common in this study cohort, and that these complications were successfully managed with simple measures. Further, severe infections resulting in septic implant loosening are rare.
Editor’s note: This story was adapted from materials provided by the Journal of Bone and Joint Surgery and the American Academy of Orthopaedic Surgeons.