Article

Rehabilitation of patients with transfemoral amputations
is particularly difficult due to problems in using standard socket prostheses. We
wanted to assess long-term fixation of the osseointegrated implant system (OPRA)
using radiostereometric analysis (RSA) and periprosthetic bone remodeling.
METHODS: 51 patients with transfemoral amputations (55 implants) were enrolled in
an RSA study. RSA and plain radiographs were scheduled at 6 months and at 1, 2,
5, 7, and 10 years after surgery. RSA films were analyzed using UmRSA software.
Plain radiographs were graded for bone resorption, cancellization, cortical
thinning, and trabecular streaming or buttressing in specifically defined zones
around the implant. RESULTS: At 5 years, the median (SE) migration of the implant
was -0.02 (0.06) mm distally. The rotational movement was 0.42 (0.32) degrees
around the longitudinal axis. There was no statistically significant difference
in median rotation or migration at any follow-up time. Cancellization of the
cortex (plain radiographic grading) appeared in at least 1 zone in over half of
the patients at 2 years. However, the prevalence of cancellization had decreased
by the 5-year follow-up. INTERPRETATION: The RSA analysis for the OPRA system
indicated stable fixation of the implant. The periprosthetic bone remodeling
showed similarities with changes seen around uncemented hip stems. The OPRA
system is a new and promising approach for addressing the challenges faced by
patients with transfemoral amputations.

Langue : ANGLAIS