Abstract
Introduction
Hip resurfacing arthroplasty (HRA) is an alternative to traditional total hip arthroplasty (THA) in young active patients. While comparative implant survival rates are well documented, there is a paucity of studies reporting the patient mortality rates associated with these procedures. The purpose of this study was to evaluate the mortality rates in patients age 55 years and younger who underwent HRA versus THA and to assess whether the type of operation was independently associated with mortality.
Patients and Methods
The database of a single high-volume surgeon was reviewed for all consecutive patients age 55 years and younger who underwent hip arthroplasty between 2002 and 2010. HRA became available in the United States in 2006. This yielded 504 patients who had undergone HRA from 2006 to 2010 and 124 patients who had undergone a THA. Patient characteristics were collected from the electronic medical record including age, gender, body mass index, Charleston comorbidity index, smoking status, and primary diagnosis. Mortality was determined through a combination of electronic chart reviews, patient phone calls, and online obituary searches. Univariate analysis was performed to identify a survival difference between the two cohorts. Multivariable Cox-Regression analyses were used to determine whether the type of operation was independently associated with mortality.
Results
The mean follow up for consecutive patients was 7 years (up to 11 years) in the HRA group and 8 years (up to 16 years) in the THA group. A total of 467 HRA patients (92%) and 105 THA patients (85%) were followed for a minimum of 5-years. 92% of the THA procedures were performed prior to the availability of HRA. There were 8 mortalities (1.6%) in the HRA cohort and 11 (8.9%) in the THA cohort, a statistically significant difference (p<0.001) on univariate analysis. Low mortality rates produced underpowered multivariate models.
Conclusion
We have demonstrated that patients under age 55 who undergo HRA have a significantly lower mortality rate than those undergoing THA at mid-term follow-up. This is consistent with previously published large database studies. Such studies typically analyze large heterogeneous populations of patients and surgeons. Our study uniquely examined only patients age 55 or younger from a single high-volume surgeon, and we primarily reviewed THA performed prior to the availability of HRA as a surgical option. Thus, surgeon selection bias was largely eliminated. To our knowledge, this is the first single surgeon study comparing HRA and THA in terms of mortality.
