Patients with uncontrolled components of metabolic syndrome have increased risk of complications following total joint arthroplasty

The Predictive Potential of Nutritional and Metabolic Burden: Development of a Novel Validated Metric Predicting Increased Postoperative Complications in Adult Spinal Deformity Surgery

STUDY DESIGN

A retrospective cohort review.

OBJECTIVE

To develop a scoring system for predicting increased risk of postoperative complications in adult spinal deformity (ASD) surgery based on baseline nutritional and metabolic factors.

BACKGROUND

Endocrine and metabolic conditions have been shown to adversely influence patient outcomes and may increase the likelihood of postoperative complications. The impact of these conditions has not been effectively evaluated in patients undergoing ASD surgery.

MATERIALS AND METHODS

ASD patients 18 years or above with baseline and two-year data were included. An internally cross-validated weighted equation using preoperative laboratory and comorbidity data correlating to increased perioperative complications was developed via Poisson regression. Body mass index (BMI) categorization (normal, over/underweight, and obese) and diabetes classification (normal, prediabetic, and diabetic) were used per the Centers for Disease Control and Prevention and the American Diabetes Associates parameters. A novel ASD-specific nutritional and metabolic burden score (ASD-NMBS) was calculated via Beta-Sullivan adjustment, and Conditional Inference Tree determined the score threshold for experiencing ≥1 complication. Cohorts were stratified into low-risk and high-risk groups for comparison. Logistic regression assessed correlations between increasing burden score and complications.

RESULTS

Two hundred one ASD patients were included (mean age: 58.60±15.4, sex: 48% female, BMI: 29.95±14.31, Charlson Comorbidity Index: 3.75±2.40). Significant factors were determined to be age (+1/yr), hypertension (+18), peripheral vascular disease (+37), smoking status (+21), anemia (+1), VitD hydroxyl (+1/ng/mL), BMI (+13/cat), and diabetes (+4/cat) (model: P <0.001, area under the curve: 92.9%). Conditional Inference Tree determined scores above 175 correlated with ≥1 post-op complication ( P <0.001). Furthermore, HIGH patients reported higher rates of postoperative cardiac complications ( P =0.045) and were more likely to require reoperation ( P =0.024) compared with low patients.

CONCLUSIONS

The development of a validated novel nutritional and metabolic burden score (ASD-NMBS) demonstrated that patients with higher scores are at greater risk of increased postoperative complications and course. As such, surgeons should consider the reduction of nutritional and metabolic burden preoperatively to enhance outcomes and reduce complications in ASD patients.

Dyslipidaemia is associated with Cutibacterium acnes hip and knee prosthetic joint infection

PURPOSE

Optimization of medical factors including diabetes and obesity is a cornerstone in the prevention of prosthetic joint infection (PJI). Dyslipidaemia is another component of metabolic syndrome which has not been thoroughly investigated as an individual, modifiable risk factor. This study examined the association of dyslipidaemia with PJI caused by the lipophilic microbe Cutibacterium acnes (C. acnes).

METHODS

A retrospective chart review examined patients with positive C. acnes culture at hip or knee arthroplasty explantation. A control group with methicillin-sensitive Staphylococcus aureus (MSSA) positive cultures at explantation was matched for age, sex, and surgical site, as well as a second control group with no infection. A total of 80 patients were included, 16 with C. acnes, 32 with MSSA, and 32 with no infection. All patients had a lipid panel performed within one year of surgery. Lipid values and categories were compared using multinomial logistic regressions.

RESULTS

High or borderline triglycerides (TG) (relative risk ratio (RRR) = 0.13; P = 0.013) and low high-density lipoprotein (HDL) (RRR = 0.13; P = 0.025) were significantly associated with C. acnes PJI compared to MSSA-PJI. High or borderline TG (RRR = 0.21; P = 0.041) and low HDL (RRR = 0.17; P = 0.043) were also associated with a greater probability of C. acnes infection compared to no infection.

CONCLUSIONS

The presence of elevated TG and low HDL were both associated at a statistically significant level with C. acnes hip or knee PJI compared to controls with either MSSA PJI or no infection. This may represent a specific risk factor for C. acnes PJI that is modifiable.

Components of metabolic syndrome as significant risk factors for postoperative complications following total shoulder arthroplasty: hypertension, diabetes, and obesity

Background

Metabolic syndrome (MetS) is a known risk factor for adverse postoperative outcomes. However, the literature surrounding the effects of MetS on orthopedic surgery outcomes following total shoulder arthroplasty (TSA) remains understudied. The purpose of this study is to investigate the effect of MetS on postoperative 30-day adverse outcomes following TSA.

Methods

The American College of Surgeons National Surgical Quality Improvement Program database was queried for all patients who underwent TSA between 2015 and 2020. After exclusion criteria, patients were divided into MetS and no MetS cohorts. MetS patients were defined as presence of hypertension, diabetes, and body mass index > 30 kg/m2. Bivariate logistic regression was used to compare patient demographics, comorbidities, and complications. Multivariate logistic regression, adjusted for all significant patient demographics and comorbidities, was used to identify the complications independently associated with MetS.

Results

A total of 26,613 patients remained after exclusion criteria, with 23,717 (89.1%) in the no MetS cohort and 2896 (10.9%) in the MetS cohort. On multivariate analysis, MetS was found to be an independent predictor of postoperative pneumonia (odds ratio [OR] 1.61, 95% confidence interval [CI] 1.02-2.55; P = .042), renal insufficiency (OR 4.09, 95% CI 1.67-10.00; P = .002), acute renal failure (OR 4.17, 95% CI 1.13-15.31; P = .032), myocardial infarction (OR 2.11, 95% CI 1.21-3.69; P = .009), nonhome discharge (OR 1.41, 95% CI 1.24-1.60; P < .001), and prolonged hospital stay > 3 days (OR 1.44, 95% CI 1.25-1.66; P < .001).

Conclusion

MetS was identified as an independent risk factor for postoperative pneumonia, renal insufficiency, acute renal failure, myocardial infarction, nonhome discharge, and prolonged hospital stay following TSA. These findings encourage physicians to medically optimize MetS patients prior to surgery to limit adverse outcomes.

Does Metabolic Syndrome Impact the Risk of Reoperation, Revision, or Complication After Primary Total Knee Arthroplasty?

BACKGROUND

Metabolic syndrome (MetS) is an increasingly frequent condition characterized by insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study evaluated implant survivorship, complications, and clinical outcomes of primary TKAs performed in patients who have MetS.

METHODS

Utilizing our institutional total joint registry, 2,063 primary TKAs were performed in patients with a diagnosis of MetS according to the World Health Organization criteria. MetS patients were matched 1:1 based on age, sex, and surgical year to those who did not have the condition. The World Health Organization's body mass index (BMI) classification was utilized to evaluate the effect of obesity within MetS patients. Kaplan-Meier methods were utilized to determine implant survivorship. Clinical outcomes were assessed with Knee Society scores. The mean follow-up was 5 years.

RESULTS

MetS and non-MetS patients did not have significant differences in 5-year implant survivorship free from any reoperation (P = .7), any revision (P = .2), and reoperation for periprosthetic joint infection (PJI; P = .2). When stratifying, patients with MetS and BMI >40 had significantly decreased 5-year survivorship free from any revision (95 versus 98%, respectively; hazard ratio = 2.1, P = .005) and reoperation for PJI (97 versus 99%, respectively; hazard ratio = 2.2, P = .02). Both MetS and non-MetS groups experienced significant improvements in Knee Society Scores (77 versus 78, respectively; P < .001) that were not significantly different (P = .3).

CONCLUSION

MetS did not significantly increase the risk of any reoperation after TKA; however, MetS patients with BMI >40 had a two-fold risk of any revision and reoperation for PJI. These results suggest that obesity is an important condition within MetS criteria and remains an independent risk factor.

LEVEL OF EVIDENCE

Level 3, Case-control study.

[Postoperative outcomes and survival rates after aseptic revision total hip arthroplasty : What can patients expect from revision surgery?]

BACKGROUND

In 2020, more than 14,000 aseptic revision procedures for total hip arthroplasty (THA) were registered in Germany. Patient expectations of revision hip arthroplasty are not substantially different from expectations of primary hip replacement.

OUTCOME

However, revision surgery is associated with increased complication rates and a higher proportion of dissatisfied patients. In particular, poorer postoperative function and mobility as well as increased pain levels following revision THA have been described compared to the outcome after primary THA. Quality of life and return-to-work can also be impaired.

SURVIVAL RATE

Implant survival is influenced by age, BMI, and comorbidities of the patients, but also by the size and complexity of bone defects, the extent of periprosthetic soft tissue compromise and the choice of revision implant(s). In addition, the number of previous revision surgeries inversely correlates with the survival rates. Previous revisions have been shown to be associated with increased risks of aseptic loosening, instability and periprosthetic infection.

The Impact of Metabolic Syndrome on Reoperations and Complications After Primary Total Hip Arthroplasty

BACKGROUND

Metabolic syndrome (MetS) represents a constellation of interrelated conditions including insulin resistance, abdominal obesity, hypertension, and dyslipidemia. The goals of this study are to determine the impact of MetS on implant survivorship, complications, and clinical outcomes after primary total hip arthroplasty (THA).

METHODS

Utilizing our institutional total joint registry, 1,268 patients undergoing primary THA were identified with MetS based on the World Health Organization definition and matched 1:1 to those without MetS based on age, gender, and surgical year. MetS patients were further stratified according to the World Health Organization body mass index (BMI) classification to contextualize obesity. Kaplan-Meier analyses were utilized to compare survivorship free of any reoperation, revision, and complications. Clinical outcomes were assessed with Harris hip scores. Mean follow-up after THA was 5 years.

RESULTS

MetS patients had significantly worse 5-year survivorship free from any reoperation compared to those without MetS (93.5% vs 96.1%, respectively; hazard ratio [HR] 1.4, P = .04). When stratifying MetS and BMI classification, the BMI >40 kg/m² had significantly decreased 5-year implant survivorship free from any reoperation (85.9% vs 96.1%, HR 3.4, P < .001), any revision (91.7% vs 97.3%, HR 2.7, P < .001), and reoperation for periprosthetic joint infection (95% vs 99%, HR 5.1, P < .001). Both groups experienced significant and similar improvement in final Harris hip scores (P < .001).

CONCLUSION

Patients with MetS had a 1.4-fold increased risk of reoperation after primary THA compared to a matched cohort without the condition. MetS patients with a BMI >40 kg/m² had the highest risk of reoperation, and had a significantly higher revision and periprosthetic joint infection rates, suggesting that morbid obesity remains a critical, independent risk factor beyond MetS.

LEVEL OF EVIDENCE

Level 3, Case-control study.

Decreasing Trend in Complications for Patients With Obesity and Metabolic Syndrome Undergoing Total Knee Arthroplasty From 2006 to 2017

BACKGROUND

To describe longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing total knee arthroplasty (TKA) and the impact on complications.

METHODS

We identified primary TKA patients between 2006 and 2017 within the National Surgical Quality Improvement Program database. We recorded patient demographics and 30-day complications. We labeled those with an obese Body Mass Index (BMI ≥30), hypertension, and diabetes as having MetS. We used regression to evaluate trends in BMI and complications over time and variables associated with the odds of complication.

RESULTS

We identified 270,846 TKA patients, 63.71% of which were obese (n = 172,333), 15.21% morbidly obese (n = 41,130), and 12.37% met the criteria for MetS (n = 33,470). Mean BMI increased by 0.03 per year (0.02-0.05). Despite this, the odds of adverse events in obese patients decreased: major complications by 0.94 (0.93-0.96) and minor complications by 0.94 (0.93-0.95). The proportion of patients with MetS remained stable; however, we found improvements in major (0.94 [0.91-0.97]) and minor complications (0.97 [0.94-1.00]) over time. MetS components (hypertension, diabetes, and BMI ≥40) were associated with major and minor complications in obese patients, while neuraxial anesthesia lowered the odds of major complications in obese patients (0.87 [0.81-0.92]).

CONCLUSION

Mean BMI in primary TKA patients increased from 2006 to 2017. MetS components diabetes and hypertension elevated the odds of complications in obese patients. Rates of complications in patients with obesity and MetS exhibited a longitudinal decline. These findings may reflect increased awareness and improved management of these patients.

Age-adjusted Charlson comorbidity index as a novel guideline for patient selection between unilateral versus bilateral simultaneous total knee arthroplasty

PURPOSE

The aim of this study was to validate the age-adjusted Charlson comorbidity index as a clinical practice guideline for patient selection between unilateral total knee arthroplasty (UTKA) and bilateral simultaneous total knee arthroplasty (BSTKA).

METHODS

A consecutive series of 1016 patients undergoing UTKA (402 patients) or BSTKA (614 patients) was analysed. The age-adjusted Charlson comorbidity index (ACCI) was measured for all the patients and graded as low (0-2 score), moderate (3-4 score) and high risk (≥ 5 score). The complications occurring within 3 months of surgery were compared between UTKA and BSTKA recipients.

RESULTS

Following surgery, the complication rate was comparable between both the groups. However, among high-risk patients, there was significant difference in the complication rates between UTKA and BSTKA groups (12% versus 30.76%, minor; 8% versus 23.07%, major complication). The high-risk patients who had bilateral surgery were at more than three times greater risk of developing major and minor complications than those who had unilateral surgery.

CONCLUSION

The BSTKA procedure is associated with significantly higher risk of post-operative complications than UTKA procedure in patients with ≥ 5 ACCI scores.

"Uncontrolled" Hypertension Is Not an Independent Risk Factor for Adverse Short-Term Outcomes Following Total Joint Arthroplasty

BACKGROUND

Uncontrolled hypertension (HTN) is a risk factor for mortality following elective surgery and poor hemodynamic control during total joint arthroplasty (TJA). However, the relationship between uncontrolled HTN and TJA outcomes remains poorly understood. The purpose of this study is to better define HTN parameters that are predictive of adverse arthroplasty outcomes.

METHODS

This is a retrospective cohort analysis on patients who underwent primary TJA for osteoarthritis between 2017 and 2021 at a large orthopedic practice. Uncontrolled HTN was defined as a systolic blood pressure (SBP) > 140 mm Hg, or diastolic blood pressure (DBP) > 90 mm Hg. Spearman's rank correlations were used to evaluate relationships among uncontrolled HTN and operative duration, hemoglobin drop, allogenic transfusions, length of stay, intraoperative/postoperative complications, and readmissions.

RESULTS

Four thousand three hundred forty-five patients met the selection criteria, of which 55.1% (N = 2394) presented with uncontrolled HTN. In total, 17.1% (N = 745) and 3.2% (N = 138) of patients had an SBP ≥ 160 and 180 mm Hg, respectively. In addition, 1.9% of patients (N = 84) presented with SBP ≥ 200 mm Hg (N = 13) and/or DBP ≥ 100 mm Hg (N = 71). Eight-four percent (N = 626) of patients who presented with SBP > 160 mm Hg had been preoperatively prescribed HTN control medications. Receiver operator curve analysis demonstrated poor predictive value of blood pressure for all aforementioned outcome variables.

CONCLUSION

Our findings suggest that as defined, uncontrolled HTN is not an appropriate individual predictor of TJA outcomes and should not be used as a "hard stop" when determining eligibility for elective surgery. Further research utilizing a larger cohort is needed to define the relationship between HTN and TJA outcomes.

Metabolic syndrome as a predictor of perioperative outcomes in primary bariatric surgery, a MBSAQIP survey

BACKGROUND

Among bariatric surgery patients, body mass index (BMI) does not fully capture the severity of obesity and it may be complicated to stratify patients at higher risk of peri-operative complications. In our study, we surveyed the MBSAQIP database to determine whether bariatric patients with metabolic syndrome (MetS) are at higher risk for peri-operative complications.

METHODS

MBSAQIP database was used to investigate the correlation between MetS and perioperative outcomes. All patients between 2015 and 2018, ≥ 18 years old, who underwent primary bariatric surgery were included. Patients were excluded if they underwent natural orifice transluminal endoscopic surgery or had surgery performed by gastroenterologist or interventional radiologist. We modified the International Diabetes Federation definition of MetS for our study to select patients with BMI > 30 in addition to two or more of the following comorbidities: hypertension, hyperlipidemia, or diabetes. The primary outcome was perioperative mortality. Secondary outcomes included post-operative surgical site infections (SSI), perioperative MI, stroke, acute renal failure, transfusion requirement, readmission, conversion to open and reoperation.

RESULTS

Between 2015 and 2018, 760,076 bariatric operations were performed. 670,935 met criteria for analysis. 190,239 patients were identified to have MetS. Patients with MetS were found to have higher odds of death (OR 2.32; 95% CI 1.97-2.72), SSI (OR 1.39; 95% CI 1.31-1.48), perioperative MI (OR 4.70; 95% CI 3.42-6.45), stroke (OR 3.30; 95% CI 2.08-5.24), acute renal failure (OR 3.04; 95% CI 2.48-3.72), and transfusion requirement (OR 1.30; 95% CI 1.33-1.39).

CONCLUSION

Patients with metabolic syndrome are at increased odds of peri-operative complications after bariatric surgery.

Postoperative Morbidity and Mortality in Diabetic Patients After Fast-Track Hip and Knee Arthroplasty: A Prospective Follow-up Cohort of 36,762 Procedures

BACKGROUND

Diabetes increases the risk of adverse outcomes in surgical procedures, including total hip and knee arthroplasty (THA/TKA), and the prevalence of diabetic patients undergoing these procedures is high, ranging from approximately 8% to 20%. However, there is still a need to clarify the role of diabetes and antihyperglycemic treatment in a fast-track THA/TKA setting, which otherwise may decrease morbidity. Consequently, we investigated the association between diabetes and antihyperglycemic treatment on length of stay (LOS) and complications following fast-track THA/TKA within a multicenter fast-track collaboration.

METHODS

We used an observational study design on data from a prospective multicenter fast-track collaboration on unselected elective primary THA/TKA from 2010 to 2017. Complete follow-up (>99%) was achieved through The Danish National Patient Registry, antihyperglycemic treatment established through the Danish National Database of Reimbursed Prescriptions and types of complications leading to LOS >4 days, 90-day readmission or mortality obtained by scrutinizing health records and discharge summaries. Patients were categorized as nondiabetic and if diabetic into insulin-, orally, and dietary-treated diabetic patients.

RESULTS

A total of 36,762 procedures were included, of which 837 (2.3%) had insulin-treated diabetes, 2615 (7.1%) orally treated diabetes, and 566 (1.5%) dietary-treated diabetes. Overall median LOS was 2 (interquartile range [IQR]: 1-3) days, and mean LOS was 2.4 (standard deviation [SD], 2.5) days. The proportion of patients with LOS >4 days was 6.0% for nondiabetic patients, 14.7% for insulin-treated, 9.4% for orally treated, and 9.5% for dietary-treated diabetic patients. Pharmacologically treated diabetes (versus nondiabetes) was independently associated with increased odds of LOS >4 days (insulin-treated: odds ratio [OR], 2.2 [99.6% confidence interval {CI}, 1.3-3.7], P < .001; orally treated: OR, 1.5 [99.6% CI, 1.0-2.1]; P = .002). Insulin-treated diabetes was independently associated with increased odds of "diabetes-related" morbidity (OR, 2.3 [99.6% CI, 1.2-4.2]; P < .001). Diabetic patients had increased renal complications regardless of antihyperglycemic treatment, but only insulin-treated patients suffered significantly more cardiac complications than nondiabetic patients. There was no increase in periprosthetic joint infections or mortality associated with diabetes.

CONCLUSIONS

Patients with pharmacologically treated diabetes undergoing fast-track THA/TKA were at increased odds of LOS >4 days. Although complication rates were low, patients with insulin-treated diabetes were at increased odds of postoperative complications compared to nondiabetic patients and to their orally treated counterparts. Further investigation into the pathogenesis of postoperative complications differentiated by antihyperglycemic treatment is needed.

Multidisciplinary Intervention Before Joint Replacement Surgery May Improve Outcomes for People with Osteoarthritis and Metabolic Syndrome: A Cohort Study

Background: Metabolic syndrome has been associated with poorer outcomes in the immediate postoperative period following joint replacement surgery for osteoarthritis. The aim of this study was to determine whether a multidisciplinary, preoperative intervention would minimize postoperative differences between people with and without metabolic syndrome who underwent joint replacement surgery for osteoarthritis. Method: A retrospective cohort study of older adults with multiple comorbidities (n = 230) attending a preoperative intervention service before lower limb joint replacement surgery. The intervention aimed to optimize the patient's health and functional reserve before surgery through weight loss, physical activity and medical management. Patient outcomes were adverse events, discharge destination and function. Health service outcomes were length of stay, hospital readmissions and emergency department presentations over a 2-year follow-up. Results: Two-thirds of participants (n = 151) had metabolic syndrome. There were no significant differences between those with and without metabolic syndrome in terms of discharge destination or adverse events during the acute hospital admission. There were no differences in function during rehabilitation but people with metabolic syndrome had significantly more adverse events (P = 0.037) during rehabilitation. In the 2 years following surgery, there were no differences in hospital readmission rates but people with metabolic syndrome had a higher observed frequency of potentially avoidable emergency department presentations (P = 0.066). Conclusions: Providing a preoperative intervention may help minimize differences between people with and without metabolic syndrome in the immediate postoperative period. However, having a diagnosis of metabolic syndrome may still adversely affect some long-term health service outcomes following joint replacement surgery.

Is obesity associated with short-term revision after total knee arthroplasty? An analysis of 121,819 primary procedures from the Dutch Arthroplasty Register

BACKGROUND

The prevalence of obesity is increasing. The association with knee osteoarthritis is well documented, resulting in the population requesting total knee arthroplasty (TKA) for invalidating symptoms to be heavier in nature. The purpose of the current analysis was to assess the association between preoperative body mass index (BMI) and short-term revision rate after TKA. The secondary aim was to investigate the influence of implant fixation method on the association between BMI and survivorship.

METHODS

This is a retrospective analysis of prospectively collected registry data (Dutch Arthroplasty Register; LROI). All primary TKA procedures in patients >18 years of age with registered BMI were selected (n = 121,819). Non-obese patients (BMI 18-25) were compared with overweight (BMI 25-30) and class I-III obese (BMI >30, >35, >40) patients. Crude all-cause revision rates were calculated using competing risk analysis. Adjusted hazard ratios (HRs) were determined with Cox multivariable regression analyses for all-cause, septic and aseptic revision and secondary patellar resurfacing.

RESULTS

Revision rates were 3.3% for non-obese patients, 3.5% for overweight patients, 3.7% for class I obese patients, 3.6% for class II obese patients and 3.7% for class III obese patients. Class III obese patients had a significant higher risk for septic revision compared with non-obese patients (HR 1.53, 95% confidence interval (CI) 1.06-2.22). Class I obese patients had a higher risk for secondary patellar resurfacing (HR 1.52, 95% CI 1.12-2.08). All-cause and aseptic revision rates were similar between BMI groups.

CONCLUSIONS

Obesity appeared to be associated with some short-term revision risks after TKA, but was not associated with an overall increase in revision rate.

Association between metabolic syndrome and venous thromboembolism after total joint arthroplasty: a meta-analysis of cohort studies

Objective

Metabolic syndrome (MetS) has been associated with hypercoagulative status. However, previous studies evaluating the association between MetS and incidence of venous thromboembolism (VTE) after total joint arthroplasty (TJA) showed inconsistent results. We performed a meta-analysis to evaluate the influence of MetS on the risk of VTE following TJA.

Methods

Cohort studies were identified by the search of PubMed, Embase, and the Cochrane’s Library databases. A random-effect model was used if considerable heterogeneity was detected; otherwise, a fixed-effect model was used. Subgroup analyses according to the category of VTE, definition of MetS, category of procedure, and follow-up durations were performed.

Results

Seven cohort studies with 1,341,457 patients that underwent TJA were included, with 118,060 MetS patients (8.8%) at baseline. With a follow-up duration up to 3 months after surgery, 9788 patients had VTE. Pooled results with a random-effect model showed that MetS was not associated with increased overall VTE after TJA (adjusted risk ratio [RR] = 1.24, 95% confidence interval [CI] 0.89 ~ 1.72, p = 0.20; I² = 69%). The results were not significantly affected by the diagnostic criteria of MetS, category of the procedure, and follow-up durations. Subgroup analyses showed that MetS was not associated with an increased the risk of pulmonary embolism ([PE], RR 1.06, 95% CI 0.37 ~ 3.02, p = 0.91), but an increased risk of deep vein thrombosis (DVT) after TJA (RR 3.38, 95% CI 1.83 ~ 6.24, p < 0.001).

Conclusions

Current evidence from observational studies suggests MetS might be associated with an increased risk of DVT but not PE after TJA.

Patients with metabolic syndrome have a greater rate of complications after arthroplasty: A systematic review and meta-analysis

Aims

Patients with metabolic syndrome (MetS) are known to be at increased risk of postoperative complications, but it is unclear whether MetS is also associated with complications after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Here, we perform a systematic review and meta-analysis linking MetS to postoperative complications in THA and TKA.

Methods

The PubMed, OVID, and ScienceDirect databases were comprehensively searched and studies were selected and analyzed according to the guidelines of the Meta-analysis of Observational Studies in Epidemiology (MOOSE). We assessed the methodological quality of each study using the Newcastle-Ottawa Scale (NOS), and we evaluated the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Data were extracted and meta-analyzed or qualitatively synthesized for several outcomes.

Results

Ten cohort studies involving 1,352,685 patients were included. Qualitative analysis suggested that MetS was associated with a higher incidence of cardiovascular events, and meta-analysis showed that MetS increased the risk of all-cause complications (risk ratio (RR) 1.55, 95% confidence interval (CI) 1.28 to 1.89), surgical site infection (SSI; RR 2.99, 95% CI 1.30 to 6.90), urinary tract infection (UTI; RR 2.58, 95% CI 1.03 to 6.43), and 30-day readmission (RR 1.45, 95% CI 1.33 to 1.59). There was insufficient evidence for assessing an association between MetS and venous thromboembolism events, pulmonary or gastrointestinal complications, or mortality.

Conclusion

Patients with MetS undergoing THA and TKA are at increased risk of all-cause complications, cardiovascular complications, SSI, UTI, and 30-day readmission. Surgeons should be aware of the increased risk of these complications in MetS, and presurgical protocols for these complications should give special consideration to MetS patients.

Cite this article:Bone Joint Res. 2020;9(3):120–129.

Metabolic syndrome - Evidence-based strategies for patient optimization

With the increasing prevalence of obesity worldwide, it is inevitable that anesthesiologists will encounter patients with metabolic syndrome. Metabolic syndrome encompasses multiple diseases, which include central obesity, hypertension, dyslipidemia, and hyperglycemia. Given the involvement of multiple diseases, metabolic syndrome involves numerous complex pathophysiological processes that negatively impact several organ systems. Some of the organ systems that have been well-documented to be adversely affected include the cardiovascular, pulmonary, and endocrine systems. Metabolic syndrome also leads to prolonged hospital stays, increased rates of infections, a greater need for care after discharge, and overall increased healthcare costs. Several interventions have been suggested to mitigate these negative outcomes ranging from lifestyle modifications to surgeries. Therefore, anesthesiologists should understand metabolic syndrome and formulate management strategies that may modify perianesthetic and surgical risks.

Supplementation of enteral nutritional powder decreases surgical site infection, prosthetic joint infection, and readmission after hip arthroplasty in geriatric femoral neck fracture with hypoalbuminemia

BACKGROUND

Nearly half of elderly patients with hip fracture were malnourished, indicated with a serum marker of hypoalbuminemia. Malnutrition was a risk factor for poor outcomes in geriatrics after hip replacement. The purpose of this study was to investigate if oral nutritional supplementation after the procedure in geriatrics with hypoalbuminemia was beneficial for outcomes.

METHODS

A retrospective cohort study of older (≥ 65 years old) patients suffering femoral neck fracture and undergoing hip replacement with hypoalbuminemia was conducted. Outcomes were compared between patients with and without postoperative nutritional supplementation.

RESULTS

There were 306 geriatric patients met the criteria. Following adjustment for baseline characteristics, patients with nutritional supplementation showed a lower grade of wound effusion with adjusted OR 0.57 (95% confidence interval (CI), 0.36 to 0.91, P < 0.05). And also a lower rate of surgical site infection (5.5% compared with 13.0% [adjusted OR 0.40, 95% CI, 0.17 to 0.91, P < 0.05]), periprosthetic joint infection (2.8% compared with 9.9% [adjusted OR 0.26, 95% CI, 0.08 to 0.79, P < 0.05]), and 30 days readmission (2.1% compared with 8.7% [adjusted OR 0.22, 95% CI, 0.06 to 0.79, P < 0.05]). The average total hospital stay was longer in patients without nutritional supplementation (10.7 ± 2.0 compared with 9.2 ± 1.8 days, P < 0.05).

CONCLUSIONS

The data suggest that postoperative nutritional supplementation is a protective factor for surgical site infection, periprosthetic joint infection, and 30-days readmission in geriatric with hypoalbuminemia undergoing a hip replacement. Postoperative nutritional supplementation for these patients should be recommended.

Number of Metabolic Syndrome Components Is the Central Predictor of the Impact of Metabolic Syndrome on Outcome of Percutaneous Nephrolithotomy in Staghorn Nephrolithiasis

Introduction: How to quantify the impact of metabolic syndrome (MetS) on percutaneous nephrolithotomy (PCNL) is unclear. We aimed to evaluate the quantified effect of the number of MetS components on the outcome of PCNL.

Materials and Methods: In this retrospective cohort study, consecutive 606 patients with idiopathic staghorn renal stones undergoing PCNL were included. The participants were divided into two groups: MetS(+) and MetS(−). The number of MetS components were calculated as 0 to 5. Primary outcomes were stone-free rate (SFR) and overall complication rate.

Results: MetS, obesity, hypertension, increased triglycerides (TG), decreased high-density lipoprotein cholesterol (HDL), and diabetes mellitus were found in 24.1%, 38.1%, 70.0%, 29.9%, 34.5%, and 26.4% of the patients, respectively. SFR values were comparable between groups. MetS resulted in a higher rate of overall complication (p < 0.001, odds ratio [OR] = 2.4, 95% confidence interval [CI] 1.67–3.69), blood transfusion, urosepsis, larger hemoglobin deficiency, and length of hospital stay. Multivariable analysis confirmed that fasting plasma glucose (FPG) (p = 0.033, OR = 1.164, 95% CI 10.22–1.348) and number of MetS components (p = 0.001, OR = 1.496, 95% CI 1.184–1.890) were independent risk factors, whereas HDL (p = 0.014, OR = 0.428, 95% CI 0.217–0.837) played an independent protective role. Compared with 0, having 3, 4, and 5 MetS components was associated with stepwise increase in complication rate (19.5% vs 34.2%, 41.5%, 62.5%, p = 0.027, 0.006, <0.001; OR = 2.1, 2.9, 6.9). Subgroup analysis showed that MetS(+) patients without complications were associated with lower systolic blood pressure, TG, and FPG (p = 0.010, 0.031, 0.002, respectively).

Conclusions: The number of MetS components is the central predictor in assessing both inner severity of MetS and outer risk for PCNL. The number of MetS components is recommended to be calculated on a scale of 0 to 5. Three, four, and five MetS components increase risk for PCNL in a stepwise manner regardless of the presence or absence of obesity. MetS components should be controlled preoperatively.

A multifaceted intervention to improve the quality of care for patients undergoing total joint arthroplasty

Knee and hip arthroplasties vary in cost, quality and outcomes. We developed a Lean quality improvement intervention for knee and hip arthroplasty patients encompassing the recognition, readiness, restoration and recovery phases of care. The intervention included standardised, evidence-based pathways, shared decision making, patient and family member engagement, and transdisciplinary rounding, implemented successively through a series of rapid process improvement workshops. We evaluated the intervention through run charts and time series analysis for 2005-2014. Outcomes included length of stay (LOS), 30-day readmission, discharge disposition, postsurgical complications and patient satisfaction. Included were 4253 total joint arthroplasty procedures, 1659 hip and 2594 knee. LOS decreased from 3.2 to 2.4 days postintervention for both hip and knee patients (p<0.001). The 30-day hospital readmission rate for hip patients decreased from 3.1% (18/576) to 1.1% (5/446, p=0.032) with knee patients unchanged. Discharge to home (vs rehabilitation facility or skilled nursing facility) increased from 72% (415/576) to 91% (405/446) (p<0.001) for hip patients, and from 70% (599/860) to 87% (578/663) for knee patients (p<0.001). Our standardised multifaceted Lean quality improvement programme was associated with reduced LOS, decreased readmission rates and improved discharge disposition in total knee and hip arthroplasty patients.

The prevention of infection: 12 modifiable risk factors

AIMS

Prosthetic joint infection (PJI) remains a serious complication that is associated with high morbidity and costs. The aim of this study was to prepare a systematic review to examine patient-related and perioperative risk factors that can be modified in an attempt to reduce the rate of PJI.

MATERIALS AND METHODS

A search of PubMed and MEDLINE was conducted for articles published between January 1990 and February 2018 with a combination of search terms to identify studies that dealt with modifiable risk factors for reducing the rate of PJI. An evidence-based review was performed on 12 specific risk factors: glycaemic control, obesity, malnutrition, smoking, vitamin D levels, preoperative Staphylococcus aureus screening, the management of anti-rheumatic medication, perioperative antibiotic prophylaxis, presurgical skin preparation, the operating room environment, irrigant options, and anticoagulation.

RESULTS

Poor glycaemic control, obesity, malnutrition, and smoking are all associated with increased rates of PJI. Vitamin D replacement has been shown in preliminary animal studies to decrease rates of PJI. Preoperative Staphylococcus aureus screening and appropriate treatment results in decreased rates of PJI. Perioperative variables, such as timely and appropriate dosage of prophylactic antibiotics, skin preparation with chlorohexidine-based solution, and irrigation with dilute betadine at the conclusion of the operation, have all been associated with reduced rates of PJI. Similarly, aggressive anticoagulation and increased operating room traffic should be avoided to help minimize risk of PJI.

CONCLUSION

PJI remains a serious complication of arthroplasty. Surgeons should be vigilant of the modifiable risk factors that can be addressed in an attempt to reduce the risk of PJI.

Body mass index and in-hospital postoperative complications following primary total hip arthroplasty

BACKGROUND

The influence of obesity measured in terms of body mass index (BMI) on the complication rates following total hip arthroplasty (THA) is a matter of debate.

METHODS

This retrospective study conducted at a tertiary referral centre at Brisbane, Australia, examines the association between BMI and in-hospital postoperative complications, length of operating time and duration of hospital stay in 964 patients, who underwent THA from 2006 to 2010.

RESULTS

Amongst patients undergoing primary THA, when compared to the normal weight patients, those with BMI between 25 kg/m² and 29.9 kg/m² (overweight) and those with BMI between 35 kg/m² and 39.9 kg/m² (obese class II) had lower odds of perioperative complications (odds ratio [OR]: 0.62 (95% confidence intervals [CI], 0.43-0.92, p = 0.016) and OR: 0.60 (95% CI, 0.36- 0.99, p = 0.047 respectively). Patients with BMI less than or equal to 40 kg/m² were also associated with significantly lower odds of cardiac complications ( p = 0.02). With unadjusted regression analysis, it was noted that those with BMI ≥40 kg/m² had the highest odds of developing infectious complications (OR 2.68, 95% CI, 1.08-6.65, p < 0.05). As the BMI increased, there was a statistically significant increase in length of operating time ( p < 0.001).

CONCLUSION

There is a significant impact of BMI on the occurrence of perioperative complications following THA. Compared to normal weight category, the overweight and obese class II patients had a lower likelihood of developing overall, especially cardiac complications. Length of operating time increases along with an increase in BMI.

Perioperative and Modifiable Risk Factors for Periprosthetic Joint Infections (PJI) and Recommended Guidelines

PURPOSE OF REVIEW

Periprosthetic joint infection (PJI) remains a complication that is associated with high morbidity as well as high healthcare expenses. The purpose of this review is to examine patient and perioperative modifiable risk factors that can be altered to help improve rates of PJI.

RECENT FINDINGS

Evidence-based review of literature shows that improved control of post-operative glycemia, appropriate management of obesity, malnutrition, metabolic syndrome, preoperative anemia, and smoking cessation can help minimize risk of PJI. Additionally, use of Staphylococcus aureus screening, preoperative evaluation of vitamin D levels, screening for urinary tract infection, and examination of dental hygiene can help with improving rates of PJI; similarly, appropriate management of perioperative variables such as limiting operating room traffic, appropriate timing, and selection of prophylactic antibiotics and surgical site preparation can help to decrease rates of PJI. In summary, PJI is a morbid complication of total joint arthroplasty. Surgeons should be vigilant of modifiable risk factors that can be improved upon to help minimize the risk of PJI.

Surgical site infection in overweight and obese Total Knee Arthroplasty patients

Purpose

This aim of this study was to evaluate the rate of surgical site infection (SSI) in patients undergoing Total Knee Arthroplasty (TKA), to improve our understanding of the associations between infection rate and obesity.

Methods

Data was reviewed for 839 primary TKA procedures performed at a National Arthroplasty Centre over one year (April 2007-March 2008). SSI data was collected at 30 days and one year post-operatively. Patients were grouped guided by the WHO classifications of obesity; normal (BMI < 25.0), overweight (BMI 25.00-29.99), obese class I (BMI 30.00-34.99), obese class II (BMI 35.00-39.99), obese class III (BMI ≥ 40.00). Statistical significance was assessed by Fisher's Exact Test.

Results

When grouped by BMI, 30.9% of patients were obese class I, 19.0% obese class II and 8.7% obese class III. Of the total cohort, 22 patients (2.6%) had superficial SSI and 13 (1.5%) had deep SSI. When comparing the obese class III cohort to all other cohorts (non-obese class III), the odds ratios for superficial SSI was 4.20 (95% CI [1.59, 11.09]; p = 0.009) and deep SSI was 6.97 (95% CI [2.22, 21.89]; p = 0.003). In the obese class III cohort, superficial SSI rate was higher in females (8.9%) than males (5.9%), yet deep SSI demonstrated the opposite, with a higher occurrence in males (11.8%) compared to females (5.4%).

Conclusion

This study suggests that obese class III TKA patients are at increased odds of superficial and deep SSI compared to other BMI cohorts. Interestingly, male obese class III patients demonstrated a higher rate of deep infection compared to their female counterparts. However, it must be noted that study findings are limited as confounders were unable to be accounted for in this retrospective study design.

Morbid Obesity in Total Knee Arthroplasty: Joint-Specific Variance in Outcomes for Operative Time, Length of Stay, and Readmission

BACKGROUND

It is increasingly apparent that the effect of obesity in arthroplasty is joint-specific. This study evaluates the effects of morbid obesity on primary total knee arthroplasty by comparing short-term outcomes between a morbidly obese (body mass index ≥40 kg/m²) and a normal weight (body mass index 18.5-<25 kg/m²) cohort at our institution between January 2003 and December 2010.

METHODS

One hundred seventeen morbidly obese patients were compared with 94 normal weight patients. Operative time, length of stay, complications, 30-day readmission, and readmission length were compared.

RESULTS

Morbid obesity conveyed no significant increase in 30-day readmission. Operative time was increased at 100 minutes in the morbidly obese group, compared with 90.5 minutes (P = .026).

CONCLUSION

Morbid obesity conveyed no increased risk of length of stay or readmission in this cohort.

Does metabolic syndrome predict surgical complications? A protocol for a systematic review and meta-analysis

BACKGROUND

Metabolic syndrome (MetS) is defined by an accumulation of risk factors that include cardiovascular disease, diabetes, chronic high blood pressure, obesity, and hypercholesterolaemia which results in an increased risk of developing serious chronic diseases. MetS is widespread as it is estimated to affect up to 30% of the global population. For people with MetS who undergo surgery, an emerging body of literature points to significantly poorer postoperative outcomes compared with non-affected populations. Surgical patients with MetS are at significantly higher risk of a range of adverse outcomes including death, morbid cardiovascular events, coma, stroke, renal failure, myocardial infarction, and surgical site infections. Increased complication rates result in prolonged hospital stays, a greater need for post-hospitalisation care, and reduced effectiveness of surgical interventions.

METHODS/DESIGN

We will search the following electronic bibliographic databases: MEDLINE, EMBASE, ScienceDirect, and CINAHL, and the reference lists of included articles. We will also search for unpublished literature. Two authors will screen titles and abstract information independently and select studies according to established inclusion and exclusion criteria. Data will be extracted by the study investigators using Review Manager 5 and will include information on demographics, incidence, prevalence, and outcome variables. Subgroup analysis and sensitivity analysis will be performed to assess the heterogeneity of included studies. Meta-analysis will also be carried out if appropriate study groups are identified. A descriptive narrative for statistical data will also be provided to highlight findings of the systematic review and meta-analysis.

DISCUSSION

This study will report and summarise adverse outcomes among adult patients with MetS undergoing surgery across a range of surgical specialties. Developing insights into outcomes of this population of interest is necessary to develop guidelines towards better management of surgical patients with metabolic syndrome.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016051071.

A Bundle Protocol to Reduce the Incidence of Periprosthetic Joint Infections After Total Joint Arthroplasty: A Single-Center Experience

BACKGROUND

Periprosthetic joint infection (PJI) represents a devastating complication of total hip arthroplasty (THA) or total knee arthroplasty (TKA). Modifiable patient risk factors as well as various intraoperative and postoperative variables have been associated with risk of PJI. In 2011, our institution formulated a "bundle" to optimize patient outcomes after THA and TKA. The purpose of this report is to describe the "bundle" protocol we implemented for primary THA and TKA patients and to analyze its impact on rates of PJI and readmission.

METHODS

Our bundle protocol for primary THA and TKA patients is conceptually organized about 3 chronological periods of patient care: preoperative, intraoperative, and postoperative. The institutional total joint database and electronic medical record were reviewed to identify all primary THAs and TKAs performed in the 2 years before and following implementation of the bundle. Rates of PJI and readmission were then calculated.

RESULTS

Thirteen of 908 (1.43%) TKAs performed before the bundle became infected compared to only 1 of 890 (0.11%) TKAs performed after bundle implementation (P = .0016). Ten of 641 (1.56%) THAs performed before the bundle became infected, which was not statistically different from the 4 of 675 (0.59%) THAs performed after the bundle that became infected (P = .09).

CONCLUSION

The bundle protocol we describe significantly reduced PJIs at our institution, which we attribute to patient selection, optimization of modifiable risk factors, and our perioperative protocol. We believe the bundle concept represents a systematic way to improve patient outcomes and increase value in total joint arthroplasty.

Postoperative hyperglycaemia control reduces postoperative complications in patients subject to total knee arthroplasty

BACKGROUND

The aim of our study was the early detection and treatment of patients with unknown alterations of the hydrocarbon metabolism subject to total knee arthroplasty in order to reduce the incidence of postoperative complications.

METHODS

Patients were classified as non-diabetic patients (group 1), diabetic patients (group 2) and patients with stress hyperglycaemia (group 3). The last two groups were recommended assessment by a primary care physician (PCP). After one year follow-up the groups were compared with respect to incidence of postoperative complications. The groups were also compared regarding the decrease or increase of HbA1c levels with the incidence of complications.

RESULTS

Of the 228 patients, 116 (50%) were included in group 1, 40 (17.5%) in group 2 and 72 (31.6%) in group 3. Patients that consulted their PCP presented lower medical complication rates than those who did not (9.2% vs. 26.4%, P=0.020). Not being attended by a PCP was an independent predictive factor of medical complication (odds ratio (OR): 21.3; 95% confidence interval (95% CI): 4.6-98.5), surgical site infection (OR: 4.1; 95% CI: 1.1-15.0) and mechanical complication (OR: 5.0; 95% CI: 1.3-18.8). A decrease of HbA1c value was related to less medical systemic complications (7.3% vs. 24.2%, P=0.035).

CONCLUSIONS

Patients with hyperglycaemia during the postoperative total knee arthroplasty period, who are controlled by the PCP present lower incidence of complications. Decrease of HbA1c value during postoperative total knee arthroplasty period leads to a lower rate of medical complications.

Total Knee Arthroplasty in Obesity: In-Hospital Outcomes and National Trends

BACKGROUND

Both the prevalence of obesity and the utilization rate of total knee arthroplasty are increasing. The rate and proportion of total knee arthroplasty (TKA) performed in the setting of obesity/morbid obesity is increasing significantly over time.

METHODS

Using International Classification of Diseases-Ninth Revision codes, we searched the National Hospitals Discharge Survey national database for patients admitted for primary TKA between 2001 and 2010. We then used International Classification of Diseases-Ninth Revision codes for obesity (body mass index = 30-40 kg/m²) and morbid obesity (body mass index, ≥ 40 kg/m²) to select the obese cohorts.

RESULTS

We found 29,694 nonobese, 2645 obese, and 1150 morbidly obese patients. There was an increase in each group over time. The rate of obesity/morbid obesity was strongly correlated with time. Obese and morbidly obese patients were more likely to be younger, female, diabetic, and have Medicaid than nonobese patients. Obese and morbidly obese patients had shorter hospital stays and higher home discharge rates than nonobese patients. Obese and morbidly obese patients had lower transfusion rates, shorter hospital stays, and no increase in inpatient wound infection or venous thromboembolic complications than nonobese patients. The Midwest region saw a greater burden of obese TKA patients.

CONCLUSION

With the right measures and precautions, satisfactory inhospital outcomes are possible in the obese patient after primary TKA. A limitation of this study is short inhospital stay of the index procedure as complications may present later after discharge.

Morbid Obesity in Total Hip Arthroplasty: Redefining Outcomes for Operative Time, Length of Stay, and Readmission

BACKGROUND

The incidence of obesity among patients presenting for elective total hip arthroplasty (THA) has increased in the last decade, and the relationship between obesity and the need for joint arthroplasty has been demonstrated. This study evaluates the effects of morbid obesity on outcomes after primary THA by comparing short-term outcomes in THA between a morbidly obese (body mass index [BMI] ≥40) and a normal weight (BMI, 18.5 to <25) cohort at our institution between January 2003 and December 2010.

METHODS

Thirty-nine patients included in the morbidly obese group were compared with 186 in the normal weight group. Operative time, length of stay, complications, readmission, and length of readmission were compared.

RESULTS

Operative time was increased in the morbidly obese group at 122 minutes compared with 100 minutes (P = .002). Postoperatively, there was an increased 30-day readmission rate related to surgery of 12.8% associated with BMI ≥40 compared with 2.7% (P = .005) as well as a 5.1-fold increase in surgery-related readmitted bed days-0.32 bed days per patient for normal weight compared with 1.64 bed days per patient for the morbidly obese (P = .026).

CONCLUSION

Morbidly obese patients present a technical challenge and likely this, and the resultant complications are underestimated. More work needs to be performed to enable suitable allocation of resources.

The Interaction of Obesity and Metabolic Syndrome in Determining Risk of Complication Following Total Joint Arthroplasty

BACKGROUND

The arthroplasty population is increasingly comorbid, and current quality improvement initiatives demand accurate risk stratification. Metabolic syndrome (MetS) has been identified as a risk factor for adverse events after arthroplasty; however, its interaction with obesity in contributing to risk is unclear.

METHODS

A retrospective analysis of all Medicare patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) at a single institution from 2009 to 2013 investigated the interaction between MetS, body mass index (BMI), and risk for Centers for Medicare and Medicaid Services (CMS)-reportable complications, readmission, and discharge disposition.

RESULTS

A total of 1462 patients (942 TKA, 538 THA) were included, of which 16.2% had MetS. Regression analysis found that MetS was significantly related to risk of CMS complications (odds ratio [OR] = 1.96, 95% confidence interval [CI] 1.16-3.31, P = .012) and nonhome discharge (OR = 1.78, 95% CI 1.39-2.27, P < .001), but not readmission (OR = 1.23, 95% CI 0.7-2.18, P = .485). Within the MetS cohort, increasing BMI was not associated with increasing complications (P = .726) or readmissions (P = .206) but was associated with nonhome discharge (OR = 1.191 per unit increase in BMI, 95% CI 1.038-1.246, P = .001).

CONCLUSION

MetS increases risk for CMS-reportable complications and nonhome discharge disposition after THA and TKA regardless of BMI. Obesity is of less value than MetS in assessing overall risk for complication after THA and TKA.

Greater Wound and Renal Complications in Gout Patients Undergoing Total Joint Arthroplasty

BACKGROUND

Little is known about total joint arthroplasty (TJA) outcomes in gout patients. The purpose of this study was to compare adverse events between gout and nongout patients who underwent primary TJA.

METHODS

Using our institutional database and medical records review, a retrospective case-control study was conducted. From 2000 to 2012, a total of 482 gout TJA patients were matched with nongout TJA patients in a 1:1 ratio. Length of stay, complications, 90-day emergency room visits, and 90-day readmissions in these patients were compared.

RESULTS

Gout patients had greater wound healing problems (12.2% vs 5.0%, P = .001) and renal complications (8.9% vs 3.1%, P = .0003) compared with nongout patients. There were no significant differences between gout and nongout patients in terms of mean length of hospital stay (3.82 vs 3.17 days, P = .11) and 90-day emergency room visits (5.6% vs 3.5%, P = 1.00). Subgroup analysis showed that 90-day readmission rates were higher in gout patients who underwent total hip arthroplasty compared with those in nongout THA patients (6.8% vs 2.1%, P = .02).

CONCLUSION

Gout patients undergoing TJA have greater wound healing problems and renal complications. Surgeons should be cognizant of fluid management, renal monitoring and wound issues and should be cautious when treating TJA gout patients.

Medicare Reimbursement for Total Joint Arthroplasty: The Driving Forces

BACKGROUND

Total joint arthroplasty is a large and growing part of the U.S. Medicare budget, drawing attention to how much providers are paid for their services. The purpose of this study was to examine the variables that affect total joint arthroplasty reimbursement. Along with standard economic variables, we include unique health-care variables. Given the focus on value in the Affordable Care Act, the model examines the relationship of the quality of care to total joint arthroplasty reimbursement. We hoped to find that reimbursement patterns reward quality and reflect standard economic principles.

METHODS

Multivariable regression was performed to identify variables that correlate with Medicare reimbursement for total joint arthroplasty. Inpatient charge or reimbursement data on Medicare reimbursements were available for 2,750 hospitals with at least 10 discharges for uncomplicated total joint arthroplasty from the Centers for Medicare & Medicaid Services (CMS) for fiscal year 2011. Reimbursement variability was examined by using the Dartmouth Atlas to group institutions into hospital referral regions and hospital service areas. Independent variables were taken from the Dartmouth Atlas, CMS, the WWAMI (Washington, Wyoming, Alaska, Montana, Idaho) Rural Health Research Center, and the United States Census.

RESULTS

There were 427,207 total joint arthroplasties identified, with a weighted mean reimbursement of $14,324.84 (range, $9,103 to $38,686). Nationally, the coefficient of variation for reimbursements was 0.19. The regression model accounted for 52.5% of reimbursement variation among providers. The total joint arthroplasty provider volume (p < 0.001) and patient satisfaction (p < 0.001) were negatively correlated with reimbursement. Government ownership of a hospital (p < 0.001) and higher Medicare costs (p < 0.001) correlated positively with reimbursement.

CONCLUSIONS

Medicare reimbursements for total joint arthroplasty are highly variable. Greater reimbursement was associated with lower patient volume, lower patient satisfaction, a healthier patient population, and government ownership of a hospital. As value-based reimbursement provisions of the Affordable Care Act are implemented, there will be dramatic changes in total joint arthroplasty reimbursements. To meet these changes, providers should expect qualities such as high patient volume, willingness to care for sicker patient populations, patient satisfaction, safe outcomes, and procedural demand to correlate with their reimbursement.

CLINICAL RELEVANCE

Practicing orthopaedic surgeons and hospital administrators should be aware of discrepancies in inpatient reimbursement for total joint arthroplasty from Medicare. Furthermore, these discrepancies are not associated with typical economic factors. These findings warrant further investigation and collaboration between policymakers and providers to develop value-based reimbursement.

Metabolic Syndrome and Deep Vein Thrombosis After Total Knee and Hip Arthroplasty

BACKGROUND

Metabolic syndrome (MS), defined as obesity, hypertension, hyperglycemia, and dyslipidemia, is prevalent among patients undergoing total joint arthroplasty (TJA). MS has proven to promote a proinflammatory and prothrombotic state in patients. Venous thromboembolism is one of the major complications of TJA. The purpose of this retrospective study is to identify whether MS and its components increase the risk of deep vein thrombosis (DVT) after TJA.

METHODS

We retrospectively reviewed 1553 patients undergoing primary unilateral TJA from 2007 to 2014. MS was diagnosed based on the World Health Organization criteria. All subjects received venography after operation to screen for DVT. Symptomatic DVT events after TJA were also recorded. Univariate analysis and multivariate logistic regression analysis were used to identify the association of MS and its components with postoperative DVT.

RESULTS

The prevalence of MS in patients undergoing TJA was 5.1% (n = 79). A total of 335 patients (21.6%) were diagnosed with DVT by venography. Seventy-eight patients (5.0%) developed symptomatic DVT. In the total knee arthroplasty group, MS and obesity were related to postoperative DVT. MS alone was found to be associated with symptomatic DVT. In the total hip arthroplasty group, MS increased the risk of symptomatic DVT. However, obesity, rather than MS, was associated with total DVT after total hip arthroplasty.

CONCLUSIONS

MS was a significant risk factor for DVT after TJA. Strategies to minimize the adverse effect of MS should be considered for these patients.

A background for the management of osteoarthritic knee pain

Knee osteoarthritis (KOA) is the most common degenerative arthritis and is treated by a wide range of practitioners. Treatment planning requires knowledge of the knee joint components and the influence of systemic and environmental factors. The treatment of KOA has changed little in 50 years. We are entering a new stage where KOA is now being viewed as an organ in failure. Neurotransmission of pain is both peripheral and central. Medical treatment can influence both pathways. Current guidelines for treatment have more rigid criteria based on the literature. In the future, the use of genetic-based biomarkers, clinical patterns of response and imaging characteristics will likely create subgroups of individuals who could benefit from improved designer therapies.

Perioperative hyperglycaemia and incidence of post-operative complications in patients undergoing total knee arthroplasty

PURPOSE

The aim of this study was to assess whether hyperglycaemia in the post-operative period of total knee arthroplasty (TKA) affects post-operative complications regardless of diabetes mellitus (DM) diagnosis.

METHODS

All patients who had undergone primary TKA were included in the study. The following data were recorded: DM diagnosis, and pre- (BGL1), intra- (BGL2) and post-operative blood glucose levels (BGL3). After 1-year follow-up, medical, infectious and mechanical or surgery-related complications were recorded.

RESULTS

Of the 833 patients included, 130 (15.6 %) were diabetic. Median BGL1, BGL2 and BGL3 were 106.13, 93.49 and 134.16 mg/dl, respectively. After follow-up, 173 (20.8 %) patients presented complications, including 48 (5.76 %) medical complications and 94 (11.28 %) infections. Surgery-related complications presented in 31 (3.72 %) patients. A statistically significant association was found between BGL3 ≥ 126 mg/dl and complications (OR 1.95, p < 0.001), medical complications (OR 3.98, p < 0.001), and infections (OR 1.76, p < 0.006).

CONCLUSIONS

Hyperglycaemia during the post-operative period in diabetic and non-diabetic patients undergoing TKA increases post-operative medical and infectious complications. Glycemic control during this period must be performed in order to reduce these complications.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

[Personality and comorbidity: are there "difficult patients" in hip arthroplasty?]

BACKGROUND

Concomitant disorders at the time of surgery in addition to psychological and socioeconomic patient characteristics may influence treatment outcomes in hip arthroplasty.

OBJECTIVES

To describe the impact of these factors on perioperative complications and postoperative results in terms of function, quality of life, and patient satisfaction.

MATERIALS AND METHODS

Review of relevant clinical studies, meta-analyses, and presentation of our own results.

RESULTS

Comorbidities in general, especially in combination, increase the perioperative risk profile. Socioeconomic factors (education, professional qualifications, social deprivation) in addition to psychological variables (depression, distressed personality) can have a major impact on postoperative functional outcomes and patient satisfaction.

CONCLUSIONS

It is of crucial importance to avoid inequalities in the provision of joint replacement for patients with hip osteoarthritis and co-existing risk factors. Preventive strategies should be implemented to reduce the negative impact of comorbidities on treatment outcome. Personalized communication and education may be helpful in avoiding unrealistic patient expectations before hip replacement.

Diabetes is associated with persistent pain after hip and knee replacement

BACKGROUND AND PURPOSE

In some patients, for unknown reasons pain persists after joint replacement, especially in the knee. We determined the prevalence of persistent pain following primary hip or knee replacement and its association with disorders of glucose metabolism, metabolic syndrome (MetS), and obesity.

PATIENTS AND METHODS

The incidence of pain in the operated joint was surveyed 1-2 years after primary hip replacement (74 patients (4 bilateral)) or primary knee replacement (119 patients (19 bilateral)) in 193 osteoarthritis patients who had participated in a prospective study on perioperative hyperglycemia. Of the 155 patients who completed the survey, 21 had undergone further joint replacement surgery during the follow-up and were excluded, leaving 134 patients for analysis. Persistent pain was defined as daily pain in the operated joint that had lasted over 3 months. Factors associated with persistent pain were evaluated using binary logistic regression with adjustment for age, sex, and operated joint.

RESULTS

49 of the 134 patients (37%) had a painful joint and 18 of them (14%) had persistent pain. A greater proportion of knee patients than hip patients had a painful joint (46% vs. 24%; p = 0.01) and persistent pain (20% vs. 4%; p = 0.007). Previously diagnosed diabetes was strongly associated with persistent pain (5/19 vs. 13/115 in those without; adjusted OR = 8, 95% CI: 2-38) whereas MetS and obesity were not. However, severely obese patients (BMI ≥ 35) had a painful joint (but not persistent pain) more often than patients with BMI < 30 (14/21 vs. 18/71; adjusted OR = 5, 95% CI: 2-15).

INTERPRETATION

Previously diagnosed diabetes is a risk factor for persistent pain in the operated joint 1-2 years after primary hip or knee replacement.

Impact of metabolic syndrome on perioperative complication rates after total joint arthroplasty surgery

This study investigated the impact of metabolic syndrome (MetS) on perioperative and postoperative complication rates: the results of a cohort of 168 total hip and knee arthroplasties, 63 of normal weight, 105 with obesity without risk factors for metabolic syndrome and 39 with obesity and other factors that classify them with metabolic syndrome. Patients with metabolic syndrome were more likely to have complications than those without metabolic syndrome (P=0.0156). Perioperative and postoperative complication rates for the MetS and control groups were 35.9% and 16.3%, respectively. Elevated BMI was the element of MetS that had the largest impact on post-surgical complication rates, and this was statistically significant (P=0.0028). The presence of MetS in patients undergoing total joint arthroplasty has a significant impact on surgical complication rates. This cannot be attributed to the BMI component alone, and may help guide efforts of patient optimization prior to total joint arthroplasty.

Analysis of 35 cases of Xanthogranulomatous pyelonephritis

BACKGROUND

To retrospectively determine key demographic and clinical features of 35 patients with Xanthogranulomatous pyelonephritis (XGP) in a New Zealand setting and to compare it with the existing literature.

METHODS

A retrospective review of patients having a confirmed diagnosis of XGP on histopathology examination was performed. Key clinical and demographic features were analysed and compared with the published literature.

RESULTS

XGP was diagnosed in 35 patients over a 12-year (2001-2013) period in Auckland Public Hospital. Ninety-one percent of the patients were female. The population had significantly higher numbers of Maori and Pacific Island patients compared with the general population (74%). Staghorn calculi were the most common cause (51.4%) with obstructing ureteric calculi as the next most common (22.9%) cause. Twenty percent of cases were not thought to be XGP prior to nephrectomy (suspicious renal mass). Thirteen (38%) patients suffered serious complications post-operatively (Clavien 3-5).

CONCLUSION

XGP is a rare chronic inflammatory condition that appears to be overrepresented by Maori and Pacific islanders in our cohort when compared with the overall patient pool. Surgical treatment is associated with significant morbidity but remains the only definitive option. Obesity and other conditions associated with metabolic syndrome may coexist at the time of presentation and may be contributing factors to the development of XGP and poor outcomes associated with it.