Brief Article
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World J Orthop. Oct 18, 2013; 4(4): 303-308
Published online Oct 18, 2013. doi: 10.5312/wjo.v4.i4.303
Cemented Müller straight stem total hip replacement: 18 year survival, clinical and radiological outcomes
Vasileios S Nikolaou, Demetrios Korres, Stergios Lallos, Andreas Mavrogenis, Ioannis Lazarettos, Ioannis Sourlas, Nicolas Efstathopoulos
Vasileios S Nikolaou, Stergios Lallos, Ioannis Lazarettos, Ioannis Sourlas, Nicolas Efstathopoulos, 2nd Orthopaedic Department, Athens University, 15124 Athens, Greece
Demetrios Korres, 3rd Orthopaedic Department, Athens University, 15124 Athens, Greece
Andreas Mavrogenis, 1st Orthopaedic Department, Athens University, 15124 Athens, Greece
Author contributions: Nikolaou VS collected the data and analyzed the results; Lallos S, Mavrogenis A, Lazarettos I and Sourlas I contributed to the manuscript preparation and writing; Korres D and Efstathopoulos N performed the operations and did the final checking of the manuscript.
Correspondence to: Vasileios S Nikolaou MD, PhD, Orthopaedic Surgeon, Lecturer of Orthopaedics, 2nd Orthopaedic Department, Athens University, 21 Dimitriou Ralli Str, Maroussi, 15124 Athens, Greece. vassilios.nikolaou@gmail.com
Telephone: +30-6932-543400 Fax: +30-210-8022142
Received: February 22, 2013
Revised: July 11, 2013
Accepted: July 17, 2013
Published online: October 18, 2013
Abstract

AIM: To present the 18 year survival and the clinical and radiological outcomes of the Müller straight stem, cemented, total hip arthroplasty (THA).

METHODS: Between 1989 and 2007, 176 primary total hip arthroplasties in 164 consecutive patients were performed in our institution by the senior author. All patients received a Müller cemented straight stem and a cemented polyethylene liner. The mean age of the patients was 62 years (45-78). The diagnosis was primary osteoarthritis in 151 hips, dysplasia of the hip in 12 and subcapital fracture of the femur in 13. Following discharge, serial follow-up consisted of clinical evaluation based on the Harris Hip Score and radiological assessment. The survival of the prosthesis using revision for any reason as an end-point was calculated by Kaplan-Meier analysis.

RESULTS: Twenty-four (15%) patients died during the follow-up study, 6 (4%) patients were lost, while the remaining 134 patients (141 hips) were followed-up for a mean of 10 years (3-18 years). HSS score at the latest follow-up revealed that 84 hips (59.5%) had excellent results, 30 (22.2%) good, 11 (7.8%) fair and 9 (6.3%) poor. There were 3 acetabular revisions due to aseptic loosening. Six (4.2%) stems were diagnosed as having radiographic definitive loosening; however, only 1 was revised. 30% of the surviving stems showed no radiological changes of radiolucency, while 70% showed some changes. Survival of the prosthesis for any reason was 96% at 10 years and 81% at 18 years.

CONCLUSION: The 18 year survival of the Müller straight stem, cemented THA is comparable to those of other successful cemented systems.

Keywords: Total hip, Replacement, Muller, Straight stem, Cemented, Survivorship

Core tip: There are few cemented implants that have made history and are still used today. The original Müller straight stem prosthesis falls into this category. In this study, 176 primary cemented total hip replacements in 164 consecutive patients were followed-up for a mean of 10 years (3-18) years. Survival of the prosthesis, as calculated by Kaplan-Meier analysis, was 96% at 10 years and 81% at 18 years. The 18 year survivorship of the Müller straight stem, cemented total hip arthroplasty is comparable with that of other successful cemented or uncemented systems.