Long-term Mortality After Revision THA

Abstract

Background: Long-term mortality after primary THA is lower than in the general population, but it is unknown whether this is also true after revision THA.

Questions/purposes: We examined (1) long-term mortality according to reasons for revision after revision THA, and (2) relative mortality trends by age at surgery, years since surgery, and calendar year of surgery.

Methods: This retrospective study included 5417 revision THAs performed in 4532 patients at a tertiary center between 1969 and 2011. Revision THAs were grouped by surgical indication in three categories: periprosthetic joint infections (938; 17%); fractures (646; 12%); and loosening, bearing wear, or dislocation (3833; 71%). Patients were followed up until death or December 31, 2016. The observed number of deaths in the revision THA cohort was compared with the expected number of deaths using standardized mortality ratios (SMRs) and Poisson regression models. The expected number of deaths was calculated assuming that the study cohort had the same calendar year, age, and sex-specific mortality rates as the United States general population.

Results: The overall age- and sex-adjusted mortality was slightly higher than the general population mortality (SMR, 1.09; 95% CI, 1.05-1.13; p < 0.001). There were significant differences across the three surgical indication subgroups. Compared with the general population mortality, patients who underwent revision THA for infection (SMR, 1.35; 95% CI, 1.24-1.48; p < 0.001) and fractures (SMR, 1.23; 95% CI, 1.11-1.37; p < 0.001) had significantly increased risk of death. Patients who underwent revision THA for aseptic loosening, wear, or dislocation had a mortality risk similar to that of the general population (SMR, 1.01; 95% CI, 0.96-1.06; p = 0.647). The relative mortality risk was highest in younger patients and declined with increasing age at surgery. Although the relative mortality risk among patients with aseptic indications was lower than that of the general population during the first year of surgery, the risk increased with time and got worse than that of the general population after approximately 8 to 10 years after surgery. Relative mortality risk improved with time after revision THA for aseptic loosening, wear, or dislocation.

Conclusions: Shifting mortality patterns several years after surgery and the excess mortality after revision THA for periprosthetic joint infections and fractures reinforce the need for long-term followup, not only for implant survival but overall health of patients having THA.

Level of evidence: Level III, therapeutic study.

Fig. 1

The revision THA cohort is separated by surgical indication in aseptic loosening and/or wear, fracture, and infection. Each surgical indication group is represented by a line. The dotted horizontal line at a relative mortality rate of 1 represents a relative mortality rate equivocal to that of the general population as matched by age and sex. Relative mortality above the dotted line at 1 indicates that risk of mortality is higher than that of the general population. Relative mortality below the dotted line at 1 indicates that the risk of mortality is lower than that of the general population.

Fig. 2

The revision THA cohort is separated by surgical indication in aseptic loosening and/or wear, fracture, and infection. Each surgical indication group is represented by a line. The dotted horizontal line at a relative mortality rate of 1 represents a relative mortality rate equivocal to that of the general population as matched by age and sex. Relative mortality above the dotted line at 1 indicates that risk of mortality is higher than that of the general population. Relative mortality below the dotted line at 1 indicates that the risk of mortality is lower than that of the general population.

Fig. 3

The revision THA cohort is separated by surgical indication in aseptic loosening and/or wear, fracture, and infection. Each surgical indication group is represented by a line. The dotted horizontal line at a relative mortality rate of 1 represents a relative mortality rate equivocal to that of the general population as matched by age and sex. Relative mortality above the dotted line at 1 indicates that risk of mortality is higher than that of the general population. Relative mortality below the dotted line at 1 indicates that the risk of mortality is lower than that of the general population.