The Müller self-locking cemented total hip prosthesis with polyethylene liner: After twenty years, what did they become?
The M.E. Müller (MEM) prosthesis is a self-locking straight stem. Although this prosthesis is widely used, few outcomes have been published thus far.



We examined long-term outcomes with the MEM cemented self-locking total hip arthroplasty (THA) with a polyethylene liner and 28-mm head. Between 1993 and 1994, 167 patients (173 hips) underwent primary THA implantation and were invited for clinical and radiological review a mean of 20.6 (20.1 - 21.7) years later; 111 patients had a metal and 62 a ceramic head. Hip function was assessed using the Postel Merle d'Aubigné Score.



Overall, 121 patients died and six were lost to follow-up. Forty patients (41 hips) were reviewed. Five patients required revision, of whom two were due to acetabular loosening, one to premature haematoma, one to recurrent dislocation and one to femoral fracture. Wear levels were significantly lower with ceramic than metal heads. The majority of radiological or clinical failures were acetabular (7.3 % versus 2.4 % femoral). At the femoral level, osteolysis was observed in seven patients (17 %). Twenty-year survival was 88.67 ± 6.61 % using an endpoint of all-cause revision and 97.9 ± 2.1 % using femoral failure as the endpoint.



Our retrospective analysis confirms the good results seen with the MEM stem in the literature and support the "French paradox" concept. Failures of these prostheses with a cemented polyethylene cup are largely on the acetabular side and, as such, the cup is the weak link. Improvements in survival will require optimisation of cup fixation and the use of a ceramic head to reduce wear in patients with a long life expectancy.
Service de Chirurgie Orthopédique et Traumatologique, Hôpital Gabriel Montpied, CHU de Clermont Ferrand BP 69, 63003, Clermont Ferrand Cedex 01, France. rerivan@chu-clermontferrand.fr.|Equipe C-Biosenss, 4éme R2, Faculté de Médecine, Place Henri Dunand, 63000, Clermont Ferrand, France. rerivan@chu-clermontferrand.fr.
Roger
R
Erivan
Service de Chirurgie Orthopédique et Traumatologique, Hôpital Gabriel Montpied, CHU de Clermont Ferrand BP 69, 63003, Clermont Ferrand Cedex 01, France.|Equipe C-Biosenss, 4éme R2, Faculté de Médecine, Place Henri Dunand, 63000, Clermont Ferrand, France.
Guillaume
G
Villatte
Service de Chirurgie Orthopédique et Traumatologique, Centre Hospitalier Sens, 1 Avenue Pierre de Coubertin, 89100, Sens, France.
Youcef Reda
YR
Khelif
Biostatistics Unit, Délégation à la recherche clinique et à l'innovation, Clermont-Ferrand University Hospital, 63000, Clermont-Ferrand, France.
Bruno
B
Pereira
Attachée de Recherche Clinique, Service d'Orthopédie, CHU Clermont-ferrand, 58 rue Montalembert - B.P. 69, 63003, Clermont Ferrand Cedex 1, France.
Myriam
M
Galvin
Service de Chirurgie Orthopédique et Traumatologique, Hôpital Gabriel Montpied, CHU de Clermont Ferrand BP 69, 63003, Clermont Ferrand Cedex 01, France.|Equipe C-Biosenss, 4éme R2, Faculté de Médecine, Place Henri Dunand, 63000, Clermont Ferrand, France.
Stéphane
S
Descamps
Service de Chirurgie Orthopédique et Traumatologique, Hôpital Gabriel Montpied, CHU de Clermont Ferrand BP 69, 63003, Clermont Ferrand Cedex 01, France.
Stéphane
S
Boisgard
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D001843:Bone Cements / Q000009:adverse effects*; D005260:Female; D006621:Hip Joint / Q000601:surgery*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
D001843:Bone Cements; D020959:Polyethylene
Cemented straight stem; Femoral loosening; Femoral stem survival; Hip arthroplasty; Primary hip replacement