The Effects of Obesity and Morbid Obesity on Outcomes in TKA

Background Patients with morbid obesity, defined as a BMI greater than 40 kg/m 2 , and super obesity, defined as a BMI greater than 50 kg/m 2 , increasingly present for total hip replacement. There is disagreement in the literature whether these individuals have greater surgical risks and costs for the episode of care, and the magnitude of those risks and costs. There also is no established threshold for obesity as defined by BMI in identifying increased complications, risks, and costs of care. Until recently, analysis of higher BMI data was limited to small cohorts from hospital-based data banks, based on BMI or height and weight only, often as part of a multivariate analysis. On October 1, 2010 the Centers for Medicare & Medicaid Services added a fifth digit to the BMI data, V85.xx, in the Medicare data bank, which allowed data mining of cases of patients with higher BMI. To our knowledge, our study is the first large retrospective Medicare data mining study, which allows us to examine BMI levels greater than 40 and 50 kg/m 2 to delineate risks, complications, and costs for these patients. Questions/purposes We sought to quantify (1) the surgical risk, and (2) the costs associated with complications after THA in patients who were morbidly obesity (BMI C 40 kg/m 2 ) or super obese (BMI C 50 kg/m 2 ). Methods This is a retrospective study of patients, using Medicare hospital claims data, who underwent THA. The ICD-9 Clinical Modification (CM) diagnosis code V85.4x was used to identify patients with morbid obesity and with super obesity from October 1, 2010 through December 31, 2014. Patients without any BMI-related diagnosis codes were used as the control group. Twelve complications occurring during the 90 days after THA were analyzed using multivariate Cox models adjusting for patient demographic, comorbidities, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through the subsequent 90 days.Each author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board members are on file with the publication and can be viewed on request. Each author certifies that his or her institution approved or waived approval for the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research. This study was performed via electronic collaboration at the authors' institutions. (HR, 3.91; 95% CI, 3.14-4.86; p \ 0.001). In addition, patients with morbid obesity had increased risk of deep vein thrombosis (HR, 1.43; 95% CI, 1.14-1.79; p \ 0.002), pulmonary embolism (HR, 1.57; 95% CI, 1.25-1.99; p \ 0.001), implant failure (HR, 1.48; 95% CI, 1.3-1.68; p \ 0.001), acute ...

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Surgical Risks and Costs of Care are Greater in Patients Who Are Super Obese and Undergoing THA

Meller¹,

Toossi

Gonzalez

et al. 2016

“…In our series, pain at the proximal aspect (defined as the area between the joint line and the 5 cm above) of the tibia was analyzed postoperatively. Pain has been evaluated after TKA in patients with obesity but to our knowledge, the proximal tibial pain that we evaluated has not been studied by others [4,12,[15][16][17]23]. In a previous report, obesity was not associated with a higher risk of moderate to severe pain in patients undergoing primary TKA at 2-or 5-year followup [4].…”

Section: Discussionmentioning

confidence: 95%

“…Previously published papers regarding BMI and pain after TKA reported controversial results [6,14,[17][18][19]24]. Most previous studies have examined the association of BMI with summary scores (not pain) [4,12,[15][16][17]23], mostly using the KSS total and objective/subjective scores and most reporting lack of an association, whereas few were positive. In one study, however, analyzing the results of 67 patients undergoing TKA for an association of obesity with pain outcomes [17], BMI of 35 to 40 kg/m 2 was associated with higher pain scores in multivariable-adjusted models that included age, gender, and comorbidities.…”

Section: Discussionmentioning

confidence: 99%

Do Stemmed Tibial Components in Total Knee Arthroplasty Improve Outcomes in Patients With Obesity?

Parratte

Ollivier

Lunebourg

et al. 2017

Background Recent clinical studies have reported that patients with higher body mass index (BMI) are more likely to experience premature failure of total knee arthroplasty (TKA), lower knee scores, and perhaps more pain in the prosthetic joint. However, it is not known whether certain implant design features such as tibial stems might be associated with differences in the frequency of tibial pain in patients with higher BMIs.

“…The potential advantage is to identify an organism not identified through preoperative aspiration. The disadvantage is that patients are deprived of the benefit of antimicrobial prophylaxis before skin incision, a benefit that has been called the greatest single contribution to minimizing infection in total joint arthroplasties [13,14], especially in revisions where infection rates can range from 5% to 10%, and has been documented as much as 40% in different studies [12,15,21]. This risk discrepancy is likely multifactorial, but withholding antimicrobial prophylaxis until after cultures are obtained intraoperatively may contribute to the higher rates of PJIs observed in patients undergoing revision arthroplasties.…”

Section: Discussionmentioning

confidence: 99%

Does Preoperative Antimicrobial Prophylaxis Influence the Diagnostic Potential of Periprosthetic Tissues in Hip or Knee Infections?

Bedenčič

Kavčič

Faganeli

et al. 2016

Background Undiagnosed low-grade prosthetic joint infections (PJI) are recognized as an important reason for early failure of presumably aseptic revisions. Preoperatively administered antimicrobial prophylaxis reduces the incidence of PJI but it may reduce the sensitivity of microbiologic periprosthetic tissue cultures and consequently increase the incidence of undiagnosed septic prosthetic joint failures, which can lead to catastrophic serial revisions. Questions/purposes We wished to determine whether administration of preoperative antibiotics decreases the likelihood of diagnosing PJI in patients undergoing revision hip or knee arthroplasty in whom infection is suspected. Methods We prospectively enrolled and evaluated 40 patients (29 with THAs and 11 with TKAs) who met the following inclusion criteria: older than 18 years, with suspected PJI of unknown cause, undergoing surgical revision. After arthrotomy, three tissue samples were obtained for microbiologic analysis and diagnosis, and antimicrobial prophylaxis (cefazolin 2 g intravenously) then was administered. Later during the procedure, but before débridement and irrigation, the second set of three tissue samples was obtained from the same surgical area and was cultured. Tissue concentration of prophylactic antibiotic was verified with the second set of samples. A positive culture result was defined as one or more positive cultures (growth on agar at or before 14 days). We then compared the yield on the microbiologic cultures obtained before administration of antibiotics with the yield on the cultures obtained after antibiotics were administered. An a Each author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board members are on file with the publication and can be viewed on request. Clinical Orthopaedics and Related Research 1 neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use. Each author certifies that his or her institution approved the human protocol for this investigation, and that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. This work was performed at the Valdoltra Orthopaedic Hospital, Ankaran, Slovenia. priori analysis was performed; with the numbers available, we had 98% power to detect a difference in diagnostic sensitivity of 33%. Results With the numbers available, we found no difference in the likelihood that an infection would be diagnosed between the samples obtained before and after administration of antimicrobial prophylaxis...