The PFMR® proximal femoral modular reconstruction implant (Protek, Sulzer Orthopedics, Switzerland) is a straight modular stem in sanded titanium with press-fit anchorage, intended to achieve spontaneous bone reconstruction following Wagner's principle. The aim of the present study was to analyze long-term clinical and radiological outcome.
Material and method
A single-center retrospective study included 48 PFMR stems implanted in 47 patients between 1998 and 2002. Results in this series were previously reported at 7 years’ follow-up.
Clinical assessment used PMA and Harris scores. Radiologic assessment focused on stem stability and osseointegration, and bone stock following Le Béguec.
Twenty-three patients were seen at a mean 14.5 years’ follow-up (13 deceased, 11 lost to follow-up), including 1 with bilateral implants, i.e., 24 stems. PMA and Harris scores, stem stability and osseointegration and bone stock were stable with respect to the 7-year findings. Radiology found 7 stem fractures in the Morse taper, i.e., in 29% of implants. Two of these cases required femoral implant replacement; 5 were asymptomatic.
Discussion and conclusion
Long-term outcome for PFMR stems was clinically and radiologically satisfactory for the 16 patients free of mechanical complications. The Morse taper fracture rate was high, and higher than reported elsewhere. The usual risk factors for implant fracture were not found in the present series. The modular design of the press-fit revision implant is its weak point; monoblock implants should be used in patients with good life-expectancy.
Level of evidence
IV (retrospective study).Le texte complet de cet article est disponible en PDF.
Keywords : Revision, Modular, Femoral stem, Fracture, Survival, PFMR