Tags

Type your tag names separated by a space and hit enter

Body Mass Index Is Associated With All-cause Mortality After THA and TKA.
Clin Orthop Relat Res. 2018 06; 476(6):1139-1148.CO

Abstract

BACKGROUND

Both obesity and underweight are associated with a higher risk of mortality in adulthood, but the association between mortality after arthroplasty and extreme ranges of body mass index (BMI) have not been evaluated beyond the first year.

QUESTIONS/PURPOSES

The purpose of this study was to investigate the association between BMI and all-cause mortality after TKA and THA.

METHODS

Data from two arthroplasty registries, the St Vincent's Melbourne Arthroplasty (SMART) Registry from Australia and the Kaiser Permanente Total Joint Replacement Registry (KPTJRR) from the United States, were used to identify patients aged ≥ 18 years undergoing elective TKAs and THAs between January 1, 2002, and December 31, 2013. Same-day bilateral THA and hemiarthroplasties were excluded. All-cause mortality was recorded from the day of surgery to the end of the study (December 31, 2013). Data capture was complete for the SMART Registry. No patients were lost to followup in the KPTJRR cohort and 2959 (5%) THAs and 5251 (5%) TKAs had missing data. Cox proportional hazard regression was used to estimate the all-cause mortality associated with six BMI categories: underweight (< 18.5 kg/m), normal weight (18.5-24.9 kg/m), overweight (25.0-29.9 kg/m), obese class I (30.0-34.9 kg/m), obese class II (35.0-39.9 kg/m), and obese class III (> 40 kg/m). For TKA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years). For THA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years).

RESULTS

In both the Australian and US cohorts, being underweight (Australia: hazard ratio [HR], 3.72; 95% confidence interval [CI], 1.94-7.08; p < 0.001 and United States: HR, 1.88; 95% CI, 1.33-2.64; p < 0.001) was associated with higher all-cause mortality after TKA, whereas obese class I (Australia: HR, 0.66; 95% CI, 0.47-0.92; p = 0.015; United States: HR, 0.71; 95% CI, 0.66-0.78; p < 0.001) or obese class II (Australia: HR, 0.54; 95% CI, 0.35-0.82; p = 0.004; United States: HR, 0.73; 95% CI, 0.66-0.81; p < 0.001) was associated with lower mortality when compared with normal-weight patients. In the US cohort, being overweight was also associated with a lower risk of mortality (HR, 0.76; 95% CI, 0.71-0.82; p < 0.001). In the US cohort, being underweight had a higher risk of mortality after THA (HR, 2.09; 95% CI, 1.65-2.64; p < 0.001), whereas those overweight (HR, 0.73; 95% CI, 0.67-0.80; p < 0.001), obese class I (HR, 0.68; 95% CI, 0.62-0.75; p < 0.001), or obese class II (HR, 0.71; 95% CI, 0.62-0.81; p < 0.001) were at a lower risk of mortality after THA when compared with normal-weight patients. In patients undergoing THA in the Australian cohort, we observed no association between BMI and risk of death.

CONCLUSIONS

We found that even severe obesity is not associated with a higher risk of death after arthroplasty. Patients should be informed of this when considering surgery. Clinicians should be cautious when considering total joint arthroplasty in underweight patients without first considering their nutritional status.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Authors+Show Affiliations

M. M. Dowsey, P. F. M. Choong, T. Spelman, The University of Melbourne Department of Surgery, St Vincent's Hospital Melbourne, Victoria, Australia E. W. Paxton, M. C. S. Inacio, Surgical Outcomes and Analysis, Kaiser Permanente, San Diego, CA, USA R. S. Namba, Southern California Permanente Medical Group, Orange County, CA, USA M. C. S. Inacio, Healthy Ageing Research Consortium, ROSA Registry, South Australian Health and Medical Institute, Adelaide, South Australia.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Evaluation Study
Journal Article

Language

eng

PubMed ID

29775187

Citation

Dowsey, Michelle M., et al. "Body Mass Index Is Associated With All-cause Mortality After THA and TKA." Clinical Orthopaedics and Related Research, vol. 476, no. 6, 2018, pp. 1139-1148.
Dowsey MM, Choong PFM, Paxton EW, et al. Body Mass Index Is Associated With All-cause Mortality After THA and TKA. Clin Orthop Relat Res. 2018;476(6):1139-1148.
Dowsey, M. M., Choong, P. F. M., Paxton, E. W., Spelman, T., Namba, R. S., & Inacio, M. C. S. (2018). Body Mass Index Is Associated With All-cause Mortality After THA and TKA. Clinical Orthopaedics and Related Research, 476(6), 1139-1148. https://doi.org/10.1007/s11999.0000000000000108
Dowsey MM, et al. Body Mass Index Is Associated With All-cause Mortality After THA and TKA. Clin Orthop Relat Res. 2018;476(6):1139-1148. PubMed PMID: 29775187.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Body Mass Index Is Associated With All-cause Mortality After THA and TKA. AU - Dowsey,Michelle M, AU - Choong,Peter F M, AU - Paxton,Elizabeth W, AU - Spelman,Tim, AU - Namba,Robert S, AU - Inacio,Maria C S, PY - 2018/5/19/entrez PY - 2018/5/19/pubmed PY - 2019/7/2/medline SP - 1139 EP - 1148 JF - Clinical orthopaedics and related research JO - Clin Orthop Relat Res VL - 476 IS - 6 N2 - BACKGROUND: Both obesity and underweight are associated with a higher risk of mortality in adulthood, but the association between mortality after arthroplasty and extreme ranges of body mass index (BMI) have not been evaluated beyond the first year. QUESTIONS/PURPOSES: The purpose of this study was to investigate the association between BMI and all-cause mortality after TKA and THA. METHODS: Data from two arthroplasty registries, the St Vincent's Melbourne Arthroplasty (SMART) Registry from Australia and the Kaiser Permanente Total Joint Replacement Registry (KPTJRR) from the United States, were used to identify patients aged ≥ 18 years undergoing elective TKAs and THAs between January 1, 2002, and December 31, 2013. Same-day bilateral THA and hemiarthroplasties were excluded. All-cause mortality was recorded from the day of surgery to the end of the study (December 31, 2013). Data capture was complete for the SMART Registry. No patients were lost to followup in the KPTJRR cohort and 2959 (5%) THAs and 5251 (5%) TKAs had missing data. Cox proportional hazard regression was used to estimate the all-cause mortality associated with six BMI categories: underweight (< 18.5 kg/m), normal weight (18.5-24.9 kg/m), overweight (25.0-29.9 kg/m), obese class I (30.0-34.9 kg/m), obese class II (35.0-39.9 kg/m), and obese class III (> 40 kg/m). For TKA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years). For THA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years). RESULTS: In both the Australian and US cohorts, being underweight (Australia: hazard ratio [HR], 3.72; 95% confidence interval [CI], 1.94-7.08; p < 0.001 and United States: HR, 1.88; 95% CI, 1.33-2.64; p < 0.001) was associated with higher all-cause mortality after TKA, whereas obese class I (Australia: HR, 0.66; 95% CI, 0.47-0.92; p = 0.015; United States: HR, 0.71; 95% CI, 0.66-0.78; p < 0.001) or obese class II (Australia: HR, 0.54; 95% CI, 0.35-0.82; p = 0.004; United States: HR, 0.73; 95% CI, 0.66-0.81; p < 0.001) was associated with lower mortality when compared with normal-weight patients. In the US cohort, being overweight was also associated with a lower risk of mortality (HR, 0.76; 95% CI, 0.71-0.82; p < 0.001). In the US cohort, being underweight had a higher risk of mortality after THA (HR, 2.09; 95% CI, 1.65-2.64; p < 0.001), whereas those overweight (HR, 0.73; 95% CI, 0.67-0.80; p < 0.001), obese class I (HR, 0.68; 95% CI, 0.62-0.75; p < 0.001), or obese class II (HR, 0.71; 95% CI, 0.62-0.81; p < 0.001) were at a lower risk of mortality after THA when compared with normal-weight patients. In patients undergoing THA in the Australian cohort, we observed no association between BMI and risk of death. CONCLUSIONS: We found that even severe obesity is not associated with a higher risk of death after arthroplasty. Patients should be informed of this when considering surgery. Clinicians should be cautious when considering total joint arthroplasty in underweight patients without first considering their nutritional status. LEVEL OF EVIDENCE: Level III, therapeutic study. SN - 1528-1132 UR - https://www.unboundmedicine.com/medline/citation/29775187/Body_Mass_Index_Is_Associated_With_All_cause_Mortality_After_THA_and_TKA_ L2 - https://Insights.ovid.com/pubmed?pmid=29775187 DB - PRIME DP - Unbound Medicine ER -