Revision Rates and Functional Outcome Scores for Severely, Morbidly, and Super-Obese Patients Undergoing Primary Total Hip Arthroplasty

Abstract

Background: We performed a systematic review and meta-analysis of the literature to quantify the impact of patients with severe obesity (body mass index [BMI] . 35 kg/m 2 ), those with morbid obesity (BMI . 40 kg/m 2 ), and those with super-obesity (BMI . 50 kg/m 2 ) on revision rates and outcome scores after primary total hip arthroplasty compared with non-obese patients (BMI , 25 kg/m 2 ).Methods: Four electronic databases were reviewed (AMED, Embase, Ovid Healthstar, and MEDLINE) from their inception to August 2016. The search strategy used combined and/or truncated keywords, including hip replacement or arthroplasty and obesity, BMI, or any synonym of the latter in the title, abstract, or manuscript text. Abstracts and full text were reviewed by 3 pairs of reviewers to identify those assessing outcomes following primary total hip arthroplasty for different BMI categories. Outcomes evaluated were revisions (total, aseptic, and septic) and change in outcome scores (preoperative to postoperative). Results:The literature search identified 1,692 abstracts; 448 were included for the full-text review, and 33 were included in the meta-analysis. The morbidly obese and super-obese groups were at an increased risk for revision, especially for septic revisions, compared with the non-obese group. The severely obese group had risk ratios of 1.40 (95% confidence interval [CI], 0.97 to 2.02) for revision, 0.70 (95% CI, 0.45 to 1.10) for aseptic revision, and 3.17 (95% CI, 2.25 to 4.47) for septic revision. Morbidly obese patients had risk ratios of 2.01 (95% CI, 1.81 to 2.23) for revision, 1.40 (95% CI, 0.84 to 2.32) for aseptic revision, and 9.75 (95% CI, 3.58 to 26.59) for septic revision. Super-obese patients had risk ratios of 2.62 (95% CI, 1.68 to 4.07) for revision, 1.98 (95% CI, 0.80 to 4.94) for aseptic revision, and 7.22 (95% CI, 1.51 to 34.60) for septic revision. However, there was no significant difference (p . 0.05) in the standardized mean difference of functional outcome scores between the severely obese cohort (0.04 [95% CI, 20.02 to 0.10]), the morbidly obese cohort (0.19 [95% CI, 20.08 to 0.46]), and the super-obese cohort (20.12 [95% CI, 20.57 to 0.33]).Conclusions: Severely obese patients, morbidly obese patients, and superobese patients undergoing total hip arthroplasty should be counseled that, although they have comparable outcome score improvements compared Disclosure: There was no source of external funding for this study. On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one or more of the authors checked "yes" to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work (http://links.lww.com/JBJSREV/A440).

Greater risks of complications, infections, and revisions in the obese versus non-obese total hip arthroplasty population of 2,190,824 patients: a meta-analysis and systematic review

“…This increases the external validity of the results presented and improves its applicability to the general population 74 . Furthermore, the most recent analysis by Ponnusamy 75 was performed with articles until August 2016. Since then, there are several high statistical powered articles that have been published and included in this updated analysis.…”

“…Our analysis has overcome this by including a subgroup analysis of morbidly obese patients and showed even greater risks of complications in the latter group. Whilst recent analysis by Ponnusamy 75 did perform subgroup analysis for BMI exceeding 35, 40, and 45 patient groups, statistical analysis was focused mainly on infection and revision rates only. However, it is our opinion that complications such as dislocations, readmissions, and unplanned reoperations are also imperative to consider as they have huge financial, social, and emotional consequences for the individual patients, their families, and the health system.…”

Outcomes of outpatient total hip arthroplasty: a systematic review

“…32 In addition, studies have shown that obesity is a risk factor for revision THA. [33][34][35] Ponnusamy et al 35 found that THA patients with a body mass index (BMI) > 35 kg/m 2 were at greater risk for a revision, particularly septic revisions. The findings in this systematic review coincide with the New Zealand registry, revealing favorable outcomes for patients with ASA ⩽ 2.…”

EFORT recommendations for off-label use, mix & match and mismatch in hip and knee arthroplasty

“…It is well recognized and well recorded that obesity is influencing the rate of peri- and postoperative complications in THA and TKA arthroplasty. There are several meta-analyses, including those by Kunutsor et al 18 and reviews by Liu et al, 19 – 21 Ponnusamy et al, 22 Boyce et al, 23 Chaudhry et al, 24 and Sun and Li. 25 They all reported that obesity results in increased rates of infections and revisions secondary to deep infection besides an increase in overall complications.…”