Total knee replacement in the morbidly obese: a literature review

135

Background Surgical site infection (SSI) after total joint arthroplasty (TJA) is a major cause of morbidity. Multiple patient comorbidities have been identified as SSI risk factors including obesity, tobacco use, diabetes, immunosuppression, malnutrition, and coagulopathy. However, the independent effect of multiple individual patient factors on risk of subsequent periprosthetic infection is unclear. Questions/purposes The purposes of this study are (1) to collect data on several preestablished infection risk factors in addition to SSI-related data on a large TJA cohort; and (2) to use multivariate modeling on previously established patient risk factors to determine independent preoperative predictors of SSI.Methods We reviewed records of patients undergoing TJA from January 1, 2010, to July 30, 2012. Confirmation of SSI followed published guidelines for superficial, deep, and periprosthetic. A total of 29 culture-positive SSIs (1.5% total) and 1846 controls were identified. The prevalence of known patient-specific infection risk factors was determined for both infected cases and healthy control subjects followed by multiple regression analysis to determine independent risk. Results Isolated organisms consisted of methicillinresistant Staphylococcus aureus (MRSA; 34.5%) followed by gram-negative rods (31.0%). After adjusting for anatomic site, independent risk factors for infection include: revision surgery (odds ratio [OR]

Section: Discussionsupporting

confidence: 82%

Medical Comorbidities Are Independent Preoperative Risk Factors for Surgical Infection After Total Joint Arthroplasty

Everhart

Altneu

Calhoun

2013

135

“…Some studies show patients' weight and/or BMI after surgery continues to be elevated, despite successful recovery from surgery, regain of biomechanical strength, increase in functional status [11,12,31], relief of pain [11,12], and an increase in overall quality of life [12]. Other studies suggest a proportion of patients either do not change or lose some of their excess weight [1,2,11,12,18,22,34,37].…”

Section: Introductionmentioning

confidence: 99%

Do Patients Lose Weight After Joint Arthroplasty Surgery? A Systematic Review

Inacio

Kritz‐Silverstein

Paxton

et al. 2013

Background The ability of patients with a total joint arthroplasty (TJA) to lose weight after surgery has been investigated in a few studies with inconsistent results. Questions/Purposes We asked: (1) What is the quality of evidence of current published literature on postoperative weight trends for patients who have had a TJA? (2) Do patients lose any weight after TJA? (3) Do patients lose a clinically meaningful amount of weight after TJA?Methods We conducted a systematic review of PubMed and the Cochrane Library. Studies were summarized according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement. Studies were reviewed for quality of evidence and limitations according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. Twelve studies were identified, one case-cohort study and 11 case series. Most studies were from single-surgeon or single-hospital series. Five studies included THAs and TKAs, four only THAs, and three only TKAs. We determined study type, level of evidence, inclusion criteria, procedures, proportion of patients who changed weight, body composition assessment, time of composition assessment, statistical analysis performed, and subgroup analysis conducted. Results Owing to the observational nature of the studies and the serious limitations identified, all were considered very low quality according to GRADE criteria. Studies reported 14% to 49% of patients had some weight loss at least 1 year postoperatively. Conclusions We found no conclusive evidence that weight or body composition increases, decreases, or remains the same after TJA.

“…Apart from operative time, other surgeon-related factors associated with PJI after TKA include surgeon case volume [14] and use of antibioticimpregnated cement [20]. Reported patient factors include male sex [13], preoperative comorbidities [13], diabetes mellitus [17], obesity [10,15,28], rheumatoid arthritis [26], and previous fractures about the knee [9]. Previously, the 75 th percentile of duration of the operation has been used to delineate between operations of short and long duration [4].…”

Section: Introductionmentioning

confidence: 99%

Does Operative Time Affect Infection Rate in Primary Total Knee Arthroplasty?

Naranje

Lendway

Mehle

et al. 2015

103

Background Prolonged operative time may increase the risk of infection after total knee arthroplasty (TKA). Both surgeon-related and patient-related factors can contribute to increased operative times. Questions/purposes The purpose of this study was to determine (1) whether increased operative time is an independent risk factor for revision resulting from infection after TKA; (2) whether increasing body mass index (BMI) increased operative time; and (3) whether increasing experience substantially decreased operative time. Methods We retrospectively evaluated primary TKAs from our joint registry between March 2000 and August 2012. Cox proportional hazard models were used to assess the relationship between operative time and revision resulting from infection after accounting for age, sex, BMI, and Agency for Healthcare Research and Quality comorbidity score. Of 9973 instances of primary TKA, 73 underwent revision surgery for infection (0.73%). Results After accounting for the confounders of age and sex, operative time was not found to have a significant effect; a 15-minute increase in operative time increased the hazard of revision resulting from infection by only 15.6% (p = 0.053; 95% confidence interval, 0.0%-34.0%). In addition, a five-unit increase in BMI was found to increase mean operative time by 1.9 minutes, on average, regardless of sex (p \ 0.0001). Operative time decreases with increasing experience but appears to plateau at approximately 300 surgeries. Conclusions Operative time is only one of many factors that may increase infection risk and may be influenced by numerous confounders. Increasing BMI increased operative time but the effect was modest. The effect of increasing experience on operative duration of this common procedure was surprisingly limited among our surgeons. Level of Evidence Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.