The impact of glycemic control and diabetes mellitus on perioperative outcomes after total joint arthroplasty

Optimizing Outpatient Total Ankle Replacement from Clinic to Pain Management

Outpatient total ankle arthroplasty is a potential significant source of cost savings. The ability to institute an effective outpatient total ankle program depends on appropriate patient selection, surgeon experience with total ankle replacement, addressing preoperative patient expectations, the involvement of an experienced multidisciplinary care team including experienced anesthesiologists, nurse navigators, recovery room nursing staff and physical therapists, and most importantly, such a program requires complete institutional logistical support.

Should Depression Be Treated Before Lower Extremity Arthroplasty?

BACKGROUND

Patient optimization is becoming increasingly important before arthroplasty to ensure outcomes. It has been suggested that depression is a modifiable risk factor that should be corrected preoperatively. It remains to be determined whether psychological intervention before surgery will improve outcomes. We theorized that the use of preoperative depression scales to predict postoperative outcomes may be influenced by the pain and functional disability of arthritis. To determine whether depression is a modifiable risk factor that should be corrected preoperatively we asked the following questions: (1) What is the prevalence of depression in arthroplasty patients preoperatively? (2) Do depressive symptoms improve after surgery? (3) Is preoperative depression associated with outcome?

METHODS

Patients scheduled for surgery completed a patient health questionnaire (PHQ-9) to assess the presence and severity of depression pre-operatively and one year post-operatively.

RESULTS

Sixty-five of the 282 patients had a PHQ-9 score >10 indicating moderate depression and 57 (88%) improved to <10 postoperatively (P = .0012). Ten patients had a PHQ-9 score >20 indicating severe depression and 9 (90%) improved to <10 postoperatively (P = .10). Of the 65 patients who had a PHQ-9 score >10 preoperatively, the median postoperative Hip Disability and Osteoarthritis Outcome Score (N = 40) was 92.3, while the median postoperative Knee Injury and Osteoarthritis Outcome Score (N = 25) was 84.6. The median postoperative Hip Disability and Osteoarthritis Outcome Score and Knee Injury and Osteoarthritis Outcome Score in nondepressed patients were 96.2 and 84.6, respectively (P = .9041).

CONCLUSION

By diminishing pain and improving function through arthroplasty, depression symptoms improve significantly. Patients with depressive symptoms preoperatively had similar postoperative outcome scores compared to non-depressed patients. Patients should not be denied surgical intervention through optimization programs that include a depression scale threshold.

LEVEL OF EVIDENCE

III.

Diabetes Mellitus as a Risk Factor for Acute Postoperative Complications Following Elective Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Diabetes mellitus is a highly prevalent disease in the United States. Adult spinal deformity (ASD) surgery encompasses a wide variety of spinal disorders and is associated with a morbidity rate between 20% and 80%. Considering utilization of spinal surgery will continue to increase, this study investigates the influence of diabetes mellitus on acute postoperative outcomes following elective ASD surgery.

METHODS

The 2010-2014 American College of Surgeon's National Surgical Quality Improvement Program database was queried using Current Procedural Terminology and International Classification of Diseases (9th Revision) diagnosis codes relevant to ASD surgery. Patients were divided into cohorts based on their diabetic status. Bivariate and multivariate logistic regression analyses were employed to identify which 30-day postoperative outcomes patients are at risk for.

RESULTS

A total of 5809 patients met the inclusion criteria for the study of which 4553 (84.2%) patients were nondiabetic, 578 (10.7%) patients had non-insulin-dependent diabetes mellitus (NIDDM), and 275 (5.1%) patients had insulin-dependent diabetes mellitus (IDDM). Diabetes status was significantly associated with length of stay ≥5 days (NIDDM: odds ratio [OR] = 1.27, 95% confidence interval [CI] = 1.02-1.58, P = .034; IDDM: OR = 1.55, 95% CI = 1.15-2.09, P = .004), any complication (NIDDM: OR = 1.26, 95% CI = 1.01-1.58, P = .037), urinary tract infection (NIDDM: OR = 1.87, 95% CI = 1.14-3.05, P = .012), and cardiac complications (IDDM: OR = 4.05, 95% CI = 1.72-9.51, P = .001).

CONCLUSIONS

Given the prevalence of diabetes, surgeons will invariably encounter these patients for ASD surgery. The present study identifies the increased risk NIDDM and IDDM patients experience following ASD surgery. Quantification of this increased risk may improve the selection of appropriate surgical candidates, patient risk stratification, and patient postoperative safety.

Analysis of a large data set to identify predictors of blood transfusion in primary total hip and knee arthroplasty

BACKGROUND

The aim of this study was to identify the predictors of need for allogenic blood transfusion (ALBT) in primary lower limb total joint arthroplasty (TJA).

STUDY DESIGN AND METHODS

This study utilized a large dataset of 15,187 patients undergoing primary unilateral TJA. Risk factors and demographic information were extracted from the electronic health record. A predictive model was developed by both a random forest (RF) algorithm and logistic regression (LR). The area under the receiver operating characteristic curve (AUC-ROC) was used to compare the accuracy of the two methods.

RESULTS

The rate of ALBT was 18.9% in total. Patient-related factors associated with higher risk of an ALBT included female sex, American Society of Anesthesiologists (ASA) II, ASA III, and ASA IV. Surgery-related risk factors for ALBT were operative time, drain use, and amount of intraoperative blood loss. Higher preoperative hemoglobin and tranexamic acid use were associated with decreased risk for ALBT. The RF model had a better predictive accuracy (area under the curve [AUC] 0.84) than the LR model (AUC, 0.77; p < 0.001).

CONCLUSION

The risk factors identified in the current study can provide specific, personalized perioperative ALBT risk assessment for a patient considering lower limb TJA. Furthermore, the predictive accuracy of the RF algorithm was significantly higher than that of LR, making it a potential tool for future personalized preoperative prediction of risk for perioperative ALBT.

Postoperative Blood Glucose Levels Predict Infection After Total Joint Arthroplasty

BACKGROUND

Perioperative hyperglycemia has many etiologies, including medication, impaired glucose tolerance, uncontrolled diabetes mellitus, or stress, the latter of which is common in patients postoperatively. Our study investigated the influence of postoperative blood glucose levels on periprosthetic joint infection after elective total joint arthroplasty to determine a threshold for glycemic control for which surgeons should strive during a patient's hospital stay.

METHODS

A single-institution retrospective review was conducted on 24,857 primary total joint arthroplasties performed from 2001 to 2015. Of these, 13,196 had a minimum follow-up of 1 year (mean, 5.9 years). Postoperative day 1 morning blood glucose levels were utilized and were correlated with periprosthetic joint infection, as defined by the International Consensus Group on Periprosthetic Joint Infection. Multivariable analysis was used to determine the influence of several important covariates on infection. An alpha level of 0.05 was used to determine significance.

RESULTS

The rate of periprosthetic joint infection increased linearly from blood glucose levels of ≥115 mg/dL. Multivariable analysis revealed that blood glucose levels were significantly associated with periprosthetic joint infection (p = 0.028). The optimal blood glucose threshold to reduce the likelihood of periprosthetic joint infection was 137 mg/dL. The periprosthetic joint infection rate in the entire cohort was 1.59% (1.46% in patients without diabetes compared with 2.39% in patients with diabetes; p = 0.001). There was no significant association between blood glucose level and periprosthetic joint infection in patients with diabetes (p = 0.276), although there was a linear trend.

CONCLUSIONS

The relationship between postoperative blood glucose levels and periprosthetic joint infection increased linearly, with an optimal cutoff of 137 mg/dL. Immediate and strict postoperative glycemic control may be critical in reducing postoperative complications, as even mild hyperglycemia was significantly associated with periprosthetic joint infection.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Insulin Dependence Is Associated With Increased Risk of Complications After Upper Extremity Surgery in Diabetic Patients

Diabetes mellitus (DM) is associated with the development of carpal tunnel syndrome, Dupuytren disease, trigger digits, and limited joint mobility. Despite descriptions of poorer response to nonsurgical treatment, previous studies have not shown increased complication rates in diabetic patients after hand surgery. Few studies, however, differentiate between insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes mellitus. The purpose of this study was to evaluate the impact of insulin dependence on the postoperative risk profile of diabetic patients after hand surgery using a national database.

MATERIALS AND METHODS

The data were obtained through the National Surgical Quality Improvement Program (NSQIP) database. Patients undergoing surgery from the distal humerus to the hand, between 2005 and 2015, were identified using 297 distinct Current Procedural Terminology codes. Thirty-day postoperative complications were collected and categorized into medical complications, surgical site complications, and readmission. Surgical complications, medical complications, and readmissions were compared between patients with NIDDM or IDDM to those without DM using multivariable logistic regression, adjusting for baseline patient and operative characteristics.

RESULTS

The study cohort included 52,727 patients. Patients with IDDM had a 5.7% overall complication rate compared with 2.3% and 1.5% in NIDDM and nondiabetic patients, respectively. After controlling for differences in patient and surgical characteristics, patients with IDDM had a statistically significant increased rate of any complication, surgical site complications, superficial surgical site infections, and readmission. There was no significant difference in complication rates between patients with NIDDM and nondiabetic patients.

CONCLUSIONS

Our data demonstrate a greater risk of complications following hand and upper extremity surgery for patients with IDDM, specifically surgical site infections. The NIDDM patients did not have an increased rate of complications relative to nondiabetic patients. These findings are important for patient risk stratification and may guide further investigation to decrease complication rates in IDDM patients after upper extremity surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Outcomes following hip and knee replacement in diabetic versus nondiabetic patients and well versus poorly controlled diabetic patients: a prospective cohort study

Background and purpose - The impact of diabetes and glycemic control before joint replacement on clinical and patient-reported outcomes is unclear. We compared pain, function, complications, and length of hospital stay in diabetic and nondiabetic patients receiving primary total hip (THR) or knee replacement (TKR) and compared these outcomes in patients with poorly controlled versus well-controlled diabetes. Patients and methods - We conducted a prospective cohort study of patients undergoing primary THR (n = 300) or TKR (n = 287) for osteoarthritis. Self-reported diabetes and glycemic control (HbA1c ≤ or >7%) extracted from medical notes were used. Adjusted comparisons were performed with generalized linear models including body mass index (BMI) and comorbidities. Results - Diabetes prevalence was 11% (THR 8%; TKR 14%). Diabetic patients were more likely to have a higher BMI and greater number of comorbidities. The median length of hospital stay was 1 day longer in diabetic patients (p = 0.004), but this attenuated after adjustments for BMI and comorbidities (p = 0.3). Inpatient pain was greater for diabetic patients but attenuated following adjustment. The 12-month postoperative WOMAC subscales were similar by diabetes status following adjustment. There was little evidence of difference in outcomes according to glycemic control. Interpretation - The associations between diabetes and worse postoperative outcomes in patients undergoing THR or TKR for osteoarthritis appear to be predominantly due to associated obesity and comorbidities. In diabetic patients there is little evidence of association between postoperative outcome and preoperative glycemic control. The underlying mechanisms and causal pathways of obesity, diabetes, and multimorbidity that lead to worse outcomes after joint replacement are not well known.

Preoperative Opioid Use Is Associated with Higher Readmission and Revision Rates in Total Knee and Total Hip Arthroplasty

BACKGROUND

Prescription opioid use is epidemic in the U.S. Recently, an association was demonstrated between preoperative opioid use and increased health-care utilization following abdominal surgeries. Given that primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) are 2 of the most common surgical procedures in the U.S., we examined the association of preoperative opioid use with 30-day readmission and early revision rates.

METHODS

We reviewed 2003 to 2014 data from 2 Truven Health MarketScan databases (commercial insurance and Medicare plus commercial supplemental insurance). Subjects were included if they had a Current Procedural Terminology (CPT) code for primary TKA or THA and were continuously enrolled in the database for at least 6 months prior to the index procedure. Preoperative opioid prescriptions were identified using National Drug Codes (NDCs). Rates of 30-day readmissions and revision arthroplasty were identified and compared among patients with stratified durations of preoperative opioid use in the 6 months preceding TKA or THA.

RESULTS

The study included 324,154 patients in the 1-year follow-up group and 159,822 patients in the 3-year follow-up group. Opioid-naive TKA patients had a lower revision rate than did those with >60 days of preoperative opioid use (1-year cohort: 1.07% compared with 2.14%, p < 0.001; 3-year cohort: 2.58% compared with 5.00%, p < 0.001). A similar trend was noted among THA patients (1-year: 0.38% compared with 1.10%, p < 0.001; 3-year: 1.24% compared with 2.99%, p < 0.001). These trends persisted after adjusting for age, sex, and Charlson Comorbidity Index (CCI). The 30-day readmission rate after TKA or THA was significantly lower for patients with no preoperative opioid use compared with those with >60 days of preoperative opioid use (TKA: 4.82% compared with 6.17%, p < 0.001; THA: 3.71% compared with 5.85%, p < 0.001). Again, this association persisted after adjusting for age, sex, and CCI.

CONCLUSIONS

Preoperative opioid use was associated with significantly increased risk of early revision and significantly increased risk of 30-day readmission after TKA and THA. This study illustrates the increased risk of poor outcomes and increased postoperative health-care utilization for patients with long-term opioid use prior to THA and TKA.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Impact of comorbid conditions on outcomes of hip and knee replacement surgery: a systematic review and meta-analysis

OBJECTIVE

To systematically perform a meta-analysis of the association between different comorbid conditions on safety (short-term outcomes) and effectiveness (long-term outcomes) in patients undergoing hip and knee replacement surgery.

DESIGN

Systematic review and meta-analysis.

METHODS

Medline, Embase and CINAHL Plus were searched up to May 2017. We included all studies that reported data to allow the calculation of a pooled OR for the impact of 11 comorbid conditions on 10 outcomes (including surgical complications, readmissions, mortality, function, health-related quality of life, pain and revision surgery). The quality of included studies was assessed using a modified Newcastle-Ottawa Scale. Continuous outcomes were converted to ORs using the Hasselblad and Hedges approach. Results were combined using a random-effects meta-analysis.

OUTCOMES

The primary outcome was the adjusted OR for the impact of each 11 comorbid condition on each of the 10 outcomes compared with patients without the comorbid condition. Where the adjusted OR was not available the secondary outcome was the crude OR.

RESULTS

70 studies were included with 16 (23%) reporting on at least 100 000 patients and 9 (13%) were of high quality. We found that comorbidities increased the short-term risk of hospital readmissions (8 of 11 conditions) and mortality (8 of 11 conditions). The impact on surgical complications was inconsistent across comorbid conditions. In the long term, comorbid conditions increased the risk of revision surgery (6 of 11 conditions) and long-term mortality (7 of 11 conditions). The long-term impact on function, quality of life and pain varied across comorbid conditions.

CONCLUSIONS

This systematic review shows that comorbidities predominantly have an impact on the safety of hip and knee replacement surgery but little impact on its effectiveness. There is a need for high-quality studies also considering the severity of comorbid conditions.

Inadequate Glycemic Control Is Associated With Increased Surgical Site Infection in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

The association between inadequate glycemic control and surgical site infection (SSI) following total joint arthroplasty (TJA) remains unclear. The aim of this study is to assess the relationship between perioperative glycemic control and the risk for SSI, mainly periprosthetic joint infection.

METHODS

We searched OVID-MEDLINE, Embase, and Web of Science from inception up to June 2017. The main independent variable was glycemic control as defined by glycated hemoglobin (HbA1C) or perioperative glucose values. The main outcome was SSI. Publication year, location, study design, sample population (size, age, gender), procedure, glycemic control assessment, infection outcome, results, confounders, and limitations were assessed. Studies included in the meta-analysis had stratified glycemic control using a distinct HbA1C cut-off.

RESULTS

Seventeen studies were included in this study. Meta-analysis of 10 studies suggested that elevated HbA1C levels were associated with a higher risk of SSI after TJA (pooled odds ratio 1.49, 95% confidence interval 0.94-2.37, P = .09) with significant heterogeneity between studies (I² = 81.32%, P < .0001). In a subgroup analysis of studies considering HbA1C with a cut-off of 7% as uncontrolled, this association was no longer noticed (P = .50). All 5 studies that specifically assessed for SSI and perioperative hyperglycemia showed a significant association, which was usually attenuated after adjusting for covariates.

CONCLUSION

Inadequate glycemic control was associated with increased risk for SSI after TJA. However, the optimal HbA1C threshold remains contentious. Pooled data does not support the conventional 7% cut-off for risk stratification. Future studies should examine new markers for determining adequate glycemic control.

Preoperative Glycemic Control Predicts Perioperative Serum Glucose Levels in Patients Undergoing Total Joint Arthroplasty

BACKGROUND

Diabetic patients undergoing total joint arthroplasty (TJA) with postoperative hyperglycemia >200 mg/dL have increased the risk of prosthetic joint infection (PJI). We investigated the correlation between preoperative hemoglobin A1c (A1c) and postoperative hyperglycemia in diabetic patients undergoing TJA.

METHODS

A retrospective review of 773 diabetic patients undergoing TJA was conducted. A Youden's J computational analysis determined the A1c where postoperative glucose levels >200 mg/dL were statistically more likely. Patients were then stratified into 3 groups: A1c <7%, A1c 7.0-8.0%, and A1c >8.0%. Outcomes included the highest postoperative in-hospital serum glucose level and PJI.

RESULTS

We determined an A1c >7.45% resulted in a greater chance of postoperative hyperglycemia >200 mg/dL. Average postoperative serum glucose increased with A1c (A1c < 7 = 167 mg/dL, A1c 7.0-8.0 = 240 mg/dL, and A1c > 8 = 276 mg/dL, P < .0001). PJI did not statistically increase with A1c (2.25%, 1.99%, and 4.55%, respectively, P = .4319).

CONCLUSION

Preoperative hemoglobin A1c levels correlate with postoperative glucose levels. We recommend using an A1c cutoff of 7.45% for patients undergoing TJA and suggest that caution should be exercised in patients with elevated A1c levels undergoing TJA.

Impact of Perioperative HbA1c on Reimbursements in Diabetes Mellitus Patients Undergoing Total Hip Arthroplasty: A Nationwide Analysis

BACKGROUND

Patients who have diabetes mellitus (DM) are at an increased risk of postoperative complications following total hip arthroplasty (THA). Therefore, much interest has been paid to perioperative glycemic control. However, no prior studies have evaluated the patient variation of HbA1c levels on costs. Therefore, the purpose of this study was to evaluate the impact of obtaining preoperative HbA1c levels on (1) day of surgery (DOS) cost; (2) subsequent 89-day costs; and (3) global 90-day cost.

METHODS

A retrospective query of the Humana insurance claims database was performed from 2007 to 2015 for all DM patients undergoing THA. Only patients with HbA1c (%) levels within 3 months before or after the THA were included. Patients were stratified into 6 groups based on HbA1c starting at 5.5% and increasing by 1% increments to 11.5%; one additional group (11.5%-20%) for extreme cases was analyzed. Correlations between HbA1c level and reimbursements for DOS, subsequent 89-day, and global 90-day period were performed.

RESULTS

HbA1c level demonstrated a significant correlation to DOS (correlation coefficient = 0.664), subsequent 89-day (correlation coefficient = 0.789), and global 90-day period (correlation coefficient = 0.747) costs. DOS, 89-day, and global 90-day costs significantly increased with increasing HbA1c levels (P < .0001).

CONCLUSION

Higher perioperative HbA1c levels increase the DOS, subsequent 89-day, and global 90-day costs of THA. This was expected as these patients require multidisciplinary care, have longer LOS, and develop more complications. Further investigation into postoperative complications based on glycemic control is warranted.

All Patients Should Be Screened for Diabetes Before Total Joint Arthroplasty

BACKGROUND

Diabetes is highly prevalent in patients with osteoarthritis before total joint arthroplasty and presents a higher risk of adverse postoperative outcomes. However, the rate of diabetes in this population and optimal screening strategies remain unknown.

METHODS

We prospectively screened patients undergoing elective total joint arthroplasty for diabetes using glycated hemoglobin (HbA1c) and fasting blood glucose (FBG) levels. Screening was conducted within 2 time periods between 2012 and 2017. The prevalence of diabetes was assessed using a previous diagnosis of diabetes or, in the absence of diagnosis, by measuring if HbA1c ≥ 6.5% or FBG ≥ 126 mg/dL. Prediabetes was defined as 5.7% ≤ HbA1c ≤ 6.4% or 100 mg/dL ≤ FBG ≤ 125 mg/dL. Occurrence of a 90-day periprosthetic joint infection and wound complications was noted.

RESULTS

A total of 1461 patients were included in the study. The prevalence of diabetes was 20.6%; 178 patients (59.1%) had diagnosed diabetes, and 123 patients (40.9%) had undiagnosed diabetes. Prediabetes was identified in 559 patients (38.3%), resulting in a combined total of 860 (58.9%) patients with diabetes and prediabetes. Total diabetic rates were significantly higher in patients aged >65 years, of nonwhite ethnicity, and undergoing total knee arthroplasty. No significant differences in periprosthetic joint infection and wound complications were observed while comparing patients with diagnosed and undiagnosed diabetes.

CONCLUSION

A significant proportion of patients with undiagnosed diabetes and prediabetes were identified. Preadmission testing provides an opportunity to identify and address this condition, potentially reducing short-term arthroplasty-related complications and avoiding long-term systemic diabetic complications. We strongly recommend universal glycemic screening to all elective arthroplasty patients.

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.

Irrigation and Debridement for Early Periprosthetic Knee Infection: Is It Effective?

BACKGROUND

Irrigation and debridement (I&D) is performed for early management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Symptom reporting is a subjective measure and may miss direct management of PJI. Utilizing an objective time interval from index procedure to I&D may better inform treatment decisions.

METHODS

From 2009 to 2017, retrospective review was performed of 55 knee PJI cases at our institution. All patients underwent polyethylene liner exchange and I&D for PJI. Patients were stratified by time from index procedure to I&D (≤2 weeks, >2 weeks). Success was defined as eradication of infection and resolution of presenting symptoms. Failed cases required subsequent procedures due to infection.

RESULTS

Average follow-up time after index TKA was 2.5 years. Among patients with I&D within 2 weeks of index TXA, 14 patients (82%) were successfully treated while 3 (18%) had infection recurrence. These outcomes were significantly improved compared to patients with I&D after 2 weeks: 19 (50%) successes and 19 (50%) failures (P = .024). Staphylococcal species were the most frequent pathogen in patients treated before and after 2 weeks of index TKA (39% and 50%, respectively). Outcomes were pathogen-independent in PJIs treated before or after 2 weeks of index TKA (P = .206 and .594, respectively).

CONCLUSION

Our results demonstrate that patients with early PJI managed with I&D and liner exchange within 2 weeks of index TKA had higher rates of treatment success when compared to those with I&D beyond 2 weeks. These findings suggest that time from index TKA to I&D is an objective and reliable indicator of treatment success when considering I&D in acute onset knee PJI.

Temporal and external validation of a prediction model for adverse outcomes among inpatients with diabetes

AIM

To temporally and externally validate our previously developed prediction model, which used data from University Hospitals Birmingham to identify inpatients with diabetes at high risk of adverse outcome (mortality or excessive length of stay), in order to demonstrate its applicability to other hospital populations within the UK.

METHODS

Temporal validation was performed using data from University Hospitals Birmingham and external validation was performed using data from both the Heart of England NHS Foundation Trust and Ipswich Hospital. All adult inpatients with diabetes were included. Variables included in the model were age, gender, ethnicity, admission type, intensive therapy unit admission, insulin therapy, albumin, sodium, potassium, haemoglobin, C-reactive protein, estimated GFR and neutrophil count. Adverse outcome was defined as excessive length of stay or death.

RESULTS

Model discrimination in the temporal and external validation datasets was good. In temporal validation using data from University Hospitals Birmingham, the area under the curve was 0.797 (95% CI 0.785-0.810), sensitivity was 70% (95% CI 67-72) and specificity was 75% (95% CI 74-76). In external validation using data from Heart of England NHS Foundation Trust, the area under the curve was 0.758 (95% CI 0.747-0.768), sensitivity was 73% (95% CI 71-74) and specificity was 66% (95% CI 65-67). In external validation using data from Ipswich, the area under the curve was 0.736 (95% CI 0.711-0.761), sensitivity was 63% (95% CI 59-68) and specificity was 69% (95% CI 67-72). These results were similar to those for the internally validated model derived from University Hospitals Birmingham.

CONCLUSIONS

The prediction model to identify patients with diabetes at high risk of developing an adverse event while in hospital performed well in temporal and external validation. The externally validated prediction model is a novel tool that can be used to improve care pathways for inpatients with diabetes. Further research to assess clinical utility is needed.

Association of Perioperative Glycemic Control With Deep Postoperative Infection After Shoulder Arthroplasty in Patients With Diabetes

BACKGROUND

Although diabetes mellitus (DM) has been established as a risk factor for infection after lower extremity arthroplasty, no association has been reported with shoulder arthroplasty.

METHODS

We queried a national database for patients with DM who underwent primary shoulder arthroplasty. We identified perioperative hemoglobin A1c (HbA1c) levels and assessed the incidence of wound complications within 6 months and deep infection that required surgical intervention within 1 year for each HbA1c level. We performed a receiver operating characteristic analysis to determine a threshold value of HbA1c.

RESULTS

Patients with DM had markedly higher rates of wound complications (1.4% versus 0.9%; odds ratio, 1.22; P = 0.028) and deep infection (0.7% versus 0.4%; odds ratio, 1.47; P = 0.001). The rates of wound complications (P = 0.0008) and deep postoperative infection (P = 0.002) increased markedly as the perioperative HbA1c level increased. Receiver operating characteristic analysis demonstrated an inflection point at an HbA1c level of 8.0 mg/dL (P = 0.017; sensitivity, 50%; specificity, 75%).

CONCLUSIONS

The risk of wound complications and deep postoperative infection in patients with DM increases as the perioperative HbA1c level increases. An HbA1c level >8.0 mg/dL could serve as a threshold for a markedly increased risk of infection.

LEVEL OF EVIDENCE

Therapeutic level III, case-control study, treatment study.

Influence of diabetes on tissue healing in orthopaedic injuries

Diabetes is a group of metabolic diseases characterized by hyperglycaemia resulting from the defective action or secretion of insulin. Chronic hyperglycaemia can lead to the damage, dysfunction and failure of various organs. In the context of complications of healing and orthopaedic rehabilitation, vascular (microangiopathy) and nerve (neuropathy) disorders deserve particular attention. About 12% of the patients admitted to orthopaedic departments have diabetes. Studies indicate that there is an indisputable link between diabetes and: an increased risk of fractures, the difficult healing of injuries of bones, ligaments and musculotendinous. It appears that one of the main reasons for this is non-enzymatic glycosylation (glycation) of collagen molecules, a phenomenon observed in the elderly and diabetic populations, as it leads to the formation of advanced glycation end products (AGEs). Collagen is one of the major connective tissue components, and is therefore part of ligaments, tendons and bones. AGEs affect the weakening of its structure and biomechanical properties, and thus also affects the weakening of the structure and properties of the above-mentioned tissues. The aim of the study is to undertake an overview of the current knowledge of the impact of diabetes on the risk of some injuries and subsequent healing and rehabilitation of patients following orthopaedic injuries.

Hypothyroidism Increases 90-Day Complications and Costs Following Primary Total Knee Arthroplasty

BACKGROUND

Thyroid disease is common and often remains undetected in the US population. Thyroid hormone has an array of metabolic, immunologic, and musculoskeletal functions crucial to well-being. The influence of thyroid disease on perioperative outcomes following primary total knee arthroplasty (TKA) is poorly understood. We hypothesized that hypothyroidism was associated with a higher risk of postoperative complications and 90-day costs following primary TKA.

METHODS

The Medicare standard analytical files were queried using International Classification of Disease codes between 2005 and 2014 to identify patients undergoing primary TKA. Patients with a diagnosis of hypothyroidism were matched by age and gender on a 1:1 ratio. Ninety-day postoperative complication rates, day of surgery, and 90-day global period charges and reimbursements were compared between matched cohorts.

RESULTS

A total of 2,369,594 primary TKAs were identified between 2005 and 2014. After age and gender matching, each cohort consisted of 98,555 patients. Hypothyroidism was associated with greater odds of postoperative complications compared to matched controls (odds ratio 1.367, 95% confidence interval 1.322-1.413). The 90-day incidence of multiple postoperative medical and surgical complications, including periprosthetic joint infection, was higher among patients with hypothyroidism. Day of surgery and 90-day episode of care costs were significantly higher in the hypothyroidism cohort.

CONCLUSION

This study demonstrated an increased risk of multiple postoperative complications and higher costs among patients with hypothyroidism following primary TKA. Surgeons should counsel patients on these findings and seek preoperative optimization strategies to reduce these risks and lower costs in this patient population.

Short-Term Perioperative Complications and Mortality After Total Ankle Arthroplasty in the United States

This study sought to identify patient and operative demographics associated with 30-day perioperative complications in patients undergoing total ankle arthroplasty as recorded in the National Surgical Quality Improvement Project database. Complications were divided into local and systemic and further subcategorized as major and minor. A total of 404 patients underwent total ankle arthroplasty between 2007 and 2014 as captured in the National Surgical Quality Improvement Project database. The overall complication rate was 2.4% with 0.5% mortality and 0.2% infection rate. Length of hospital stay, both as an end point at >5 days and as a continuous variable, was associated with overall complications (odds ratio [OR] = 9.90, P = .002 and OR = 1.52, P = .006, respectively). Patient characteristics that predicted perioperative morbidity included presence of 3 or comorbidities (OR = 8.48, P = 0.038), American Society of Anesthesiologists class III, and history of previous cardiac surgery (OR = 12.22, P = .033). Correct patient selection is imperative in achieving improved outcomes and those that are at risk for complications should be counseled as such.

LEVELS OF EVIDENCE

Level III: Database case control study.

Quantifying the Effect of Diabetes on Surgical Hand and Forearm Infections

PURPOSE

Diabetes has long been established as a risk factor for hand and forearm infections. The purpose of this study was to review the effect of glycemic factors on outcomes among diabetic patients with surgical upper-extremity infections. We hypothesized that diabetic inpatients may benefit from stronger peri-infection glycemic control.

METHODS

A prospective cohort study enrolled diabetic and nondiabetic surgical hand and forearm infections over 3 years. Glycemic factors included baseline glycosylated hemoglobin, blood glucose (BG) at presentation, and inpatient BG. Poor baseline control was defined as glycosylated hemoglobin of 9.0% or greater and poor inpatient control as average BG of 180 mg/dL or greater. The main outcome of interest was the need for repeat therapeutic drainage. Multivariable logistic regression quantified the association between diabetic factors and this outcome.

RESULTS

The study involved 322 patients: 76 diabetic and 246 nondiabetic. Diabetic infections were more likely than nondiabetic infections to result from idiopathic mechanisms, occur in the forearm, and present as osteomyelitis, septic arthritis, and necrotizing fasciitis. Diabetic microbiology was more likely polymicrobial and fungal. After first drainage, diabetic patients were more likely to require repeat drainage and undergo eventual amputation. Among diabetic patients, poor inpatient control was associated with need for repeat drainage.

CONCLUSIONS

Diabetes exacerbates the burden of surgical upper-extremity infections: specifically, more proximal locations, deeper involved anatomy at presentation, broader pathogenic microbiology, increased need for repeat drainage, and higher risk for amputation. Among diabetic patients, poor inpatient glycemic control is associated with increased need for repeat drainage.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.

Diabetes and Healing Outcomes in Lower Extremity Fractures: A Systematic Review

OBJECTIVE

The purpose of this study was to review the rates of adverse healing outcomes following surgical fixation of lower extremity fractures in diabetic patients and matched controls.

MATERIALS AND METHODS

Searches of PubMed, MEDLINE, CINAHL and Embase were performed for studies published between the date of database inception and July 6, 2015. Patient characteristics and the incidence of adverse healing outcomes (nonunion, malunion, delayed union, infection and reoperation) were extracted from each study. The occurrence of each fracture healing complication was pooled and analyzed for comparisons between diabetic and non-diabetic patients. An odds ratio with a 95% confidence interval for each healing outcome was calculated between the diabetic and non-diabetic groups.

RESULTS

Diabetes was found to significantly increase rates of malunion, infection and reoperation in patients with surgically treated lower extremity fractures. In addition, when only peripheral lower extremity fractures (i.e. below the knee) were examined, diabetes significantly increased the rates of nonunion.

CONCLUSION

Diabetes substantially alters bone metabolism and soft tissue healing, posing a risk of adverse fracture healing and other complications. This systematic review provides evidence that the presence of diabetes significantly increases the risks of infection, malunion, nonunion and re-operation across a wide variety of surgically treated lower extremity fractures. This study provides prognostic information for clinicians and may aid in guiding treatment for this population.

Implementation of Preoperative Screening Criteria Lowers Infection and Complication Rates Following Elective Total Hip Arthroplasty and Total Knee Arthroplasty in a Veteran Population

BACKGROUND

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common procedures with a risk of complications. Attempting to minimize complications, our institution implemented preoperative screening criteria for patients undergoing elective total joint replacement. Our study aimed to determine if screening criteria lowered total complications and/or surgical site infections (SSI).

METHODS

Two groups of consecutive patients undergoing TKA and THA at a single Veterans Affairs facility were evaluated prior to and after implementation of screening criteria, 520 and 475 respectively. Screening criteria included hemoglobin A1c ≤7, hemoglobin ≥11, body mass index ≤35, and albumin ≥3.5. Groups were analyzed for demographics, preoperative comorbidities, and postoperative complications. Rates of total complications and SSI were compared. Average follow-up was at least 2 years with minimum of 1 year.

RESULTS

Demographics and comorbidities outside the screening criteria were similar. Total complication rate was reduced from 35.4% to 14.8% (P < .01) after implementation of screening criteria. For TKA, total complications were reduced from 33.1% to 15.0% (P < .01) and for THA they were reduced from 42.4% to 14.2% (P < .01). SSI rates for combined TKA and THA were reduced from 4.4% to 1.3% (P < .01). For knees, SSI was reduced from 4.6% to 1.3% (P = .01) and was statistically significant. For THA, SSI decreased from 3.8% to 1.2% (P < .05).

CONCLUSION

Our institution saw a statistically significant decrease in both SSI and total complications following implementation of preoperative screening criteria for elective TKA and THA.

Basal-bolus insulin therapy in postoperative inpatients with diabetes mellitus: directions for future quality-improvement initiatives

Aim

To determine variables associated with hyperglycemia and insulin therapy in postoperative inpatients with diabetes mellitus following a quality-improvement initiative.

Materials & methods

Patients with diabetes mellitus following an elective surgical procedure (n = 782; 877 surgical procedures) were selected.

Results

Age, hemoglobin A_1c corticosteroids, insulin therapy and year of surgery were associated (p < 0.01) with hyperglycemia. Hemoglobin A_1c, hyperglycemia, case mix index and corticosteroids were associated (p ≤ 0.03) with insulin therapy. Hyperglycemia and use of insulin varied by surgical specialty.

Conclusion

Data could be used to modify current treatment algorithms. Variations in hyperglycemia and insulin use by surgical specialty require further investigation.

Is hemoglobin A1c and perioperative hyperglycemia predictive of periprosthetic joint infection following total joint arthroplasty?: A systematic review and meta-analysis

OBJECTIVE

This meta-analysis aims to determine whether hemoglobin A1c (HbA1c) and perioperative hyperglycemia are associated with the increased risk of periprosthetic joint infection following total knee and hip arthroplasty.

METHODS

A systematic search is performed in Medline (1966-October 2017), PubMed (1966-October 2017), Embase (1980-October 2017), ScienceDirect (1985-October 2017), and the Cochrane Library. Only high-quality studies are selected. A meta-analysis is performed using Stata 11.0 software.

RESULTS

Six retrospective studies including 26,901 patients meet the inclusion criteria. The present meta-analysis indicates that there are significant differences between groups in terms of perioperative random blood glucose level [weighted mean difference (WMD) = 2.365, 95% confidence interval (95% CI): 1.802-2.929, P = .000] and perioperative hemoglobin A1c level (WMD = 3.266, 95% CI: 2.858-3.674, P = .000). No significant difference is found regarding body mass index (BMI) condition between groups (WMD = 0.027, 95% CI: -0.487 to 0.541, P = .919).

CONCLUSION

The present meta-analysis shows that high HbA1c and perioperative hyperglycemia are associated with a higher risk of periprosthetic joint infection following total joint arthroplasty. Screening of HbA1c and perioperative blood glucose is therefore an effective method to predict deep infection.

The impact of insulin dependence on short-term postoperative complications in diabetic patients undergoing total shoulder arthroplasty

BACKGROUND

The number of total shoulder arthroplasty (TSA) procedures performed is steadily increasing, and it is important to characterize predictors of postoperative complications for risk assessment models. Whereas diabetes has been associated with increased morbidity after TSA, the impact of insulin dependence on the risk profile of diabetic patients has not been described.

METHODS

The National Surgical Quality Improvement Program database from 2011-2014 was used to identify 5918 TSA cases. Patients were categorized as non-diabetes mellitus (non-DM), non-insulin-dependent diabetes mellitus (NIDDM), or insulin-dependent diabetes mellitus (IDDM). Thirty-day postoperative complication rates, length of stay (LOS), and readmission rates were compared across the diabetes groups. Multivariable logistic regression adjusting for demographics and comorbidity burden was performed to determine the independent association between insulin dependence and postoperative outcomes.

RESULTS

In bivariate analysis, NIDDM and IDDM were associated with multiple postoperative complications, including stroke, sepsis, wound complications, blood transfusion, and extended LOS. With multivariable logistic regression, however, NIDDM patients did not have significantly greater odds of any study end point relative to non-DM patients. IDDM patients had significantly greater odds for having any postoperative complication (odds ratio [OR], 1.53), stroke (OR, 13.63), blood transfusion (OR, 1.67), and extended LOS (OR, 1.38).

CONCLUSIONS

After adjustment for demographics and comorbidity burden, NIDDM patients had risk profiles similar to those of non-DM patients. IDDM was an independent predictor of multiple postoperative complications. Insulin dependence should be considered in the preoperative risk assessment of diabetic patients undergoing TSA.

Stress-induced hyperglycaemia and venous thromboembolism following total hip or total knee arthroplasty

Stress-induced hyperglycaemia is common during orthopaedic surgery. In addition, hyperglycaemia activates coagulation. The aim of the study was to assess whether stress-induced hyperglycaemia is associated with symptomatic or asymptomatic venous thromboembolism (VTE) following orthopaedic surgery. We performed post-hoc analyses in the four RECORD studies (REgulation of Coagulation in major Orthopaedic surgery reducing the Risk of Deep venous thrombosis and pulmonary embolism). Separate analyses were performed for patients undergoing elective total hip or knee replacement. Outcome measures were symptomatic VTE and “total VTE” (defined as the composite of symptomatic VTE, asymptomatic DVT assessed by per protocol venography and all cause mortality). Glucose levels were measured pre-op and 6 hours post-op, categorised into quartiles, based on the distribution in the respective cohorts. The influence of glucose, adjusted for body mass index, age, gender and diabetes mellitus on VTE was assessed by logistic regression analyses. A total of 12,383 patients were eligible for assessment of symptomatic VTE, and 8,512 patients were eligible for assessment of total VTE. Increased glucose levels after total hip replacement were associated with total VTE; adjusted odds ratio (OR) highest versus lowest quartile 1.9 (95% confidence interval [CI] 1.3 to 3.0). Furthermore, increase in glucose levels during total hip replacement was associated with total VTE (OR highest versus lowest quartile 1.8 (95%CI 1.2 to 2.8). This was not observed in patients undergoing total knee replacement, probably due to differences in the applied surgical procedures.

Serum Fructosamine: A Simple and Inexpensive Test for Assessing Preoperative Glycemic Control

BACKGROUND

Although the medical community acknowledges the importance of preoperative glycemic control, the literature is inconclusive and the proper metric for assessment of glycemic control remains unclear. Serum fructosamine reflects the mean glycemic control in a shorter time period compared with glycated hemoglobin (HbA1c). Our aim was to examine its role in predicting adverse outcomes following total joint arthroplasty.

METHODS

Between 2012 and 2013, we screened all patients undergoing total joint arthroplasty preoperatively using serum HbA1c, fructosamine, and blood glucose levels. On the basis of the recommendations of the American Diabetes Association, 7% was chosen as the cutoff for HbA1c being indicative of poor glycemic control. This threshold correlated with a fructosamine level of 292 μmol/L. All patients were followed and total joint arthroplasty complications were evaluated. We were particularly interested in retrieving details on surgical-site infection (superficial and deep). Patients with fructosamine levels of ≥292 μmol/L were compared with those with fructosamine levels of <292 μmol/L. Complications were evaluated in a univariate analysis followed by a stepwise logistic regression analysis.

RESULTS

A total of 829 patients undergoing primary total joint arthroplasty were included in the present study. There were 119 patients (14.4%) with a history of diabetes and 308 patients (37.2%) with HbA1c levels in the prediabetic range. Overall, 51 patients had fructosamine levels of ≥292 μmol/L. Twenty patients (39.2%) had a fructosamine level of ≥292 μmol/L but did not have an HbA1c level of ≥7%. Patients with fructosamine levels of ≥292 μmol/L had a significantly higher risk for deep infection (adjusted odds ratio [OR], 6.2 [95% confidence interval (CI), 1.6 to 24.0]; p = 0.009), readmission (adjusted OR, 3.0 [95% CI, 1.1 to 8.1]; p = 0.03), and reoperation (adjusted OR, 3.4 [95% CI, 1.2 to 9.2]; p = 0.02). In the current study with the given sample size, HbA1c levels of ≥7% failed to show any significant correlation with deep infection (p = 0.14), readmission (p = 1.0), or reoperation (p = 0.7).

CONCLUSIONS

Serum fructosamine is a simple and inexpensive test that appears to be a good predictor of adverse outcome in patients with known diabetes and those with unrecognized diabetes or hyperglycemia. Our findings suggest that fructosamine can serve as an alternative to HbA1c in the setting of preoperative glycemic assessment.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Predicting inpatient hypoglycaemia in hospitalized patients with diabetes: a retrospective analysis of 9584 admissions with diabetes

AIMS

To explore whether a quantitative approach to identifying hospitalized patients with diabetes at risk of hypoglycaemia would be feasible through incorporation of routine biochemical, haematological and prescription data.

METHODS

A retrospective cross-sectional analysis of all diabetic admissions (n=9584) from 1 January 2014 to 31 December 2014 was performed. Hypoglycaemia was defined as a blood glucose level of <4 mmol/l. The prediction model was constructed using multivariable logistic regression, populated by clinically important variables and routine laboratory data.

RESULTS

Using a prespecified variable selection strategy, it was shown that the occurrence of inpatient hypoglycaemia could be predicted by a combined model taking into account background medication (type of insulin, use of sulfonylureas), ethnicity (black and Asian), age (≥75 years), type of admission (emergency) and laboratory measurements (estimated GFR, C-reactive protein, sodium and albumin). Receiver-operating curve analysis showed that the area under the curve was 0.733 (95% CI 0.719 to 0.747). The threshold chosen to maximize both sensitivity and specificity was 0.15. The area under the curve obtained from internal validation did not differ from the primary model [0.731 (95% CI 0.717 to 0.746)].

CONCLUSIONS

The inclusion of routine biochemical data, available at the time of admission, can add prognostic value to demographic and medication history. The predictive performance of the constructed model indicates potential clinical utility for the identification of patients at risk of hypoglycaemia during their inpatient stay.

Enhancing Recovery After Total Knee Arthroplasty

There have been multiple successful efforts to improve and shorten the recovery period after elective total joint arthroplasty. The development of rapid recovery protocols through a multidisciplinary approach has occurred in recent years to improve patient satisfaction as well as outcomes. Bundled care payment programs and the practice of outpatient total joint arthroplasty have provided additional pressure and incentives for surgeons to provide high-quality care with low cost and complications. In this review, the evidence for modern practices are reviewed regarding patient selection and education, anesthetic techniques, perioperative pain management, intraoperative factors, blood management, and postoperative rehabilitation.

Can we predict postoperative complications in elderly Chinese patients with hip fractures using the surgical risk calculator?

Purpose

Hip fractures are associated with poor prognosis in elderly patients partly due to the high rate of postoperative complications. This study was aimed to investigate whether the surgical risk calculator is suitable for predicting postoperative complications in elderly Chinese patients with hip fractures.

Methods

The incidence of postoperative complications among 410 elderly patients with hip fractures was predicted by the surgical risk calculator and then compared with the actual value. The risk calculator model was evaluated using the following three metrics: Hosmer–Lemeshow test for the goodness-of-fit of the model, receiver operating characteristic curve (ROC) (also referred as C-statistic) for the predictive specificity and sensitivity, and the Brier’s score test for predictive accuracy.

Results

Preoperative risk factors including gender, age, preoperative functional status, American Society of Anesthesiologists grade, hypertension, dyspnea, dialysis, previous cardio-vascular history, and cerebrovascular disease were positively correlated with the incidence of postoperative complications in elderly patients with hip fractures. The predicted complication incidence rate was well matched with the actual complication rate by Hosmer–Lemeshow test. The model had high sensitivity and specificity for predicting the mortality rate of these patients with a C-statistic index of 0.931 (95% CI [0.883, 0.980]). The surgical calculator model had an accuracy of 90% for predicting the reoperation rate (Brier’s score <0.01).

Conclusions

The surgical risk calculator could be useful for predicting mortality and reoperation in elderly patients with hip fracture. Patients and surgeons may use this simple calculator to better manage the preoperative risks.

Outcomes of ACL Reconstruction in Patients with Diabetes

PURPOSE

Diabetes has been associated with adverse outcomes after various types of surgery. There are no previously published data regarding the effect of diabetes on outcomes from anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to test the hypotheses that diabetes is associated with worse clinical outcomes and a higher prevalence of subsequent surgeries after ACLR.

METHODS

Anterior cruciate ligament-deficient patients (n = 2198) undergoing unilateral ACLR from a multicenter prospective study were included. Patients who self-reported diabetes on the basis of comorbidity questions before surgery were identified from the database. They were compared with the remainder of the cohort who did not self-report diabetes. All patients were followed up for a minimum of 2 yr after their index surgery. A minimum 2-yr follow-up was attained on 1905/2198 (87%) via completed outcome questionnaires and 2096/2198 (95%) regarding subsequent surgery. The primary outcome measures were three validated outcome instruments. The secondary outcome measure was the incidence of additional surgery on the ipsilateral and contralateral knees.

RESULTS

Patients with diabetes had a significantly higher activity level at 2 yr (OR = 2.96; 95% CI, 1.30-6.77; P = 0.01), but otherwise slightly worse clinical outcomes, compared with patients without diabetes (OR range = 0.42-0.59). The prevalence of subsequent surgeries in patients with diabetes was not significantly different from the prevalence in patients without diabetes.

CONCLUSIONS

Patients with diabetes maintain a higher activity level after ACLR despite slightly lower patient-reported outcome scores compared with patients without diabetes and do not have a higher rate of subsequent surgery.

Improving Quality and Decreasing Cost by Reducing Re-admissions in Patients Undergoing Total Joint Arthroplasty

PURPOSE OF REVIEW

Total joint arthroplasty (TJA) has had an increased demand over the recent years. It is a successful procedure, and there are relatively few complications, but there is a high overall cost. There is a push to increase the quality of care, lessen complications, and decrease cost by reducing readmissions. This article will discuss the risk factors that can contribute to the complication and readmission rates following TJA.

RECENT FINDINGS

Several risk factors have been found to contribute to the complication and readmission rates following a TJA. It is important to understand these risk factors and mitigate them as much as possible in order to optimize the patient experience. There are risk factors that cannot be modified, and the treatment team as well as the patient should be made aware of these and account for them when making the decision whether to undergo elective primary TJA or not. In general, an increased number of risk factors is associated with increased complications and increased readmission rates. At our institution, we have used this knowledge to improve our outcomes and decrease costs. It is important to be mindful of risk factors for poor outcomes prior to performing TJA. This allows for the optimization of patients prior to undergoing surgery. This can lead to improved outcomes at a lower cost.

Is There a Threshold Value of Hemoglobin A1c That Predicts Risk of Infection Following Primary Total Hip Arthroplasty?

BACKGROUND

There remains little evidence to support a perioperative hemoglobin A1c (HbA_1c) level that could serve as a threshold for a significantly increased risk of deep postoperative infection in patients with diabetes mellitus (DM) following total hip arthroplasty (THA).

METHODS

A national administrative database was queried for patients who underwent primary THA with DM. Patients with an HbA_1c level within 3 months of surgery were identified and were stratified based on HbA_1c level in 0.5 mg/dL increments. The incidence of deep infection requiring operative intervention within 1 year for each group was identified and a receiver operating characteristic (ROC) and area under the curve (AUC) analysis was performed to determine a threshold value of the HbA_1c.

RESULTS

A total of 7736 patients who underwent THA with a perioperative HbA_1c level were included. The rate of infection ranged from 0.7% to 5.9%. The inflection point of the ROC curve corresponded to an HbA_1c level between 7.0 and 7.5 mg/dL (P = .001, specificity = 69%, sensitivity = 47%). The AUC for the ROC was 0.68. Patients with an HbA_1c level of 7.5 mg/dL or greater had a significantly higher risk of deep infection compared to patients below this threshold (odds ratio, 2.6; 95% CI, 1.9-3.4; P < .0001).

CONCLUSION

The risk of infection in patients with DM increases as the perioperative HbA_1c increases. However, in the present study, the HbA_1c threshold level calculated demonstrated low discrimination based on our AUC value, suggesting the HbA_1c test is poorly predictive of periprosthetic joint infection following THA in patients with DM.

Determining the Threshold for HbA1c as a Predictor for Adverse Outcomes After Total Joint Arthroplasty: A Multicenter, Retrospective Study

BACKGROUND

Although HbA1c is commonly used for assessing glycemic control before surgery, there is no consensus regarding its role and the appropriate threshold in predicting adverse outcomes. This study was designed to evaluate the potential link between HbA1c and subsequent periprosthetic joint infection (PJI), with the intention of determining the optimal threshold for HbA1c.

METHODS

This is a multicenter retrospective study, which identified 1645 diabetic patients who underwent primary total joint arthroplasty (1004 knees and 641 hips) between 2001 and 2015. All patients had an HbA1c measured within 3 months of surgery. The primary outcome of interest was a PJI at 1 year based on the Musculoskeletal Infection Society criteria. Secondary outcomes included orthopedic (wound and mechanical complications) and nonorthopedic complications (sepsis, thromboembolism, genitourinary, and cardiovascular complications). A regression analysis was performed to determine the independent influence of HbA1c for predicting PJI.

RESULTS

Overall 22 cases of PJI occurred at 1 year (1.3%). HbA1c at a threshold of 7.7 was distinct for predicting PJI (area under the curve, 0.65; 95% confidence interval, 0.51-0.78). Using this threshold, PJI rates increased from 0.8% (11 of 1441) to 5.4% (11 of 204). In the stepwise logistic regression analysis, PJI remained the only variable associated with higher HbA1c (odds ratio, 1.5; confidence interval, 1.2-2.0; P = .0001). There was no association between high HbA1c levels and other complications assessed.

CONCLUSION

High HbA1c levels are associated with an increased risk for PJI. A threshold of 7.7% seems to be more indicative of infection than the commonly used 7% and should perhaps be the goal in preoperative patient optimization.

Type 2 diabetes and in-hospital complications after revision of total hip and knee arthroplasty

PURPOSE

To assess the effect of type 2 diabetes (T2DM) on hospital outcomes such as in hospital postoperative complications (IHPC), length of hospital stay (LOHS) and in-hospital mortality (IHM) after the revision of total hip arthroplasty (RHA) and total knee arthroplasty (RKA) and to identify factors associated with IHPC among T2DM patients undergoing these procedures.

METHODS

We performed a retrospective study using the Spanish National Hospital Discharge Database, 2005-2014. We included patients who were ≥40 years old that had undergone RHA and RKA. For each T2DM patient, we selected a year-, gender-, age- and Charlson Comorbidity Index-matched non-diabetic patient.

RESULTS

We identified 44,055 and 39,938 patients who underwent RHA (12.72% with T2DM) and RKA (15.01% with T2DM). We matched 4,700 and 5,394 couples with RHA and RKA, respectively. Any IHPC was more frequent among patients with T2DM than among non-T2DM patients (19% vs. 15.64% in the RHA cohort and 12.94% vs. 11.09% in the RKA cohort, respectively). For patients who underwent RHA, postoperative infection (4.51% vs. 2.94%, p<0.001), acute post-hemorrhagic anemia (9.53% vs. 7.70%, p<0.001), mean LOHS and IHM were significantly higher in patients with T2DM. Among RKA patients, the incidence of acute posthemorrhagic anemia (7.21% vs. 5.62%; p = 0.001) and urinary tract infection (1.13% vs. 0.72%; p = 0.029) was significantly higher in patients with diabetes. Older age, obesity, infection due to internal joint prosthesis, myocardial infarction, congestive heart failure, mild liver disease and renal disease and emergency room admission were significantly associated with a higher risk of IHPC in T2DM patients. IHPC decreased over time only in T2DM patients who underwent RHA (OR 0.94, 95%CI 0.89-0.98).

CONCLUSIONS

Patients with T2DM who underwent RHA and RKA procedures had more IHPC after controlling for the effects of possible confounders. LOHS and IHM were also higher among RHA patients with diabetes. Older age, comorbidity, obesity and emergency room admission were strong predictors of IHPC in diabetic patients.

Patient selection for total ankle arthroplasty

Total ankle arthroplasty is a treatment option for end-stage osteoarthritis of the ankle, as is ankle arthrodesis. Many variables, including patient characteristics, are thought to influence clinical outcome and survival. As with any surgery, but especially with total ankle replacement (TAR), patient selection is considered critical for good (long-term) outcome. In this review, we summarize the available scientific evidence regarding patient characteristics and its influence on the results of TAR.

Prevention of Periprosthetic Joint Infection: Examining the Recent Guidelines

BACKGROUND

The global rise in infectious disease has led the Center for Disease Control and Prevention and the World Health Organization to release new guidelines for the prevention of surgical site infection.

METHODS

In this article, we summarize current recommendations based on level of evidence, review unresolved and unaddressed issues, and supplement them with new literature.

RESULTS

Although the guidelines discuss major issues in reducing surgical site infection, many questions remain unanswered.

CONCLUSION

These guidelines will hopefully help in setting a standard of care based on best evidence available and focus investigators on areas where evidence is lacking.

Is There an Association Between Hemoglobin A1C and Deep Postoperative Infection After TKA?

BACKGROUND

Despite substantial research into the use of glycemic markers to stratify infection risk in patients with diabetes mellitus, there is little evidence to support a perioperative hemoglobin A1c (HbA1c) level associated with an increased risk of deep postoperative infection after TKA.

QUESTIONS/PURPOSES

(1) Is there an association between perioperative HbA1c level in patients with diabetes and deep postoperative infection after primary TKA? (2) Is the perioperative HbA1c level in patients with diabetes a useful test as an independent predictor for postoperative infection after TKA?

METHODS

We queried the PearlDiver Patient Records Database Humana dataset for patients who underwent primary TKA. This is a for-fee insurance patient-records database that contains records for more than 20 million patients with orthopaedic diagnoses from 2007 to the second quarter of 2015. The data for patients from this study were taken from the Humana dataset since this is the only insurer that includes laboratory data among the available databases. Although it is difficult to calculate attrition in this database, in the current study the minimum number of patients with at least 1 year followup was 86%. Patients with diabetes who had an HbA1c level obtained within 3 months of surgery were identified, stratified based on their HbA1c level in 0.5 mg/dL increments, and then compared with patients with diabetes without an HbA1c level within 3 months of surgery. Patients who had an HbA1c level within 3 months of surgery had slightly higher rates of polyneuropathy, chronic renal failure, and chronic kidney disease Stages 2 and 3. Otherwise, these groups were similar regarding rates of peripheral vascular disease, microvascular ischemic disease, metabolic syndrome, gastroparesis, end stage renal disease, age, and gender. Deep infection was defined as an infection resulting in operative intervention within 1 year of the primary TKA, and the incidence of such intervention for each HbA1c group then was identified. A receiver operating characteristic (ROC) analysis was performed to determine a threshold value of the HbA1c, and an area under the curve (AUC) analysis was performed to measure the accuracy and clinical utility of HbA1c as an independent predictor for postoperative infection.

RESULTS

The rate of infection requiring operative intervention ranged from a low of 0.8% with an HbA1c of 5.49 mg/dL or less, up to 3.5% for patients with HbA1c level greater than 11.5 mg/dL. The ROC analysis indicated that the best threshold was an HbA1c of 8.0 mg/dL (1.7; 95% CI, 1.2-2.4 mg/dL; p = 0.004), however, the AUC of 0.548 (95% CI, 0.50-0.59; p = 0.025) indicated that this threshold was inaccurate and only slightly better than chance, and thus alone could not serve as an independent discriminator of infection risk.

CONCLUSIONS

The risk of deep postoperative infection requiring surgical intervention after TKA in patients with diabetes mellitus increases as the perioperative HbA1c increases. While a threshold HbA1c level of 8.0 mg/dL was identified, it cannot by itself serve as an independent predictor of postoperative infection in patients with diabetes mellitus because its sensitivity is so low. Future studies should determine what other confounders other than an elevated HbA1c level contribute to increased infection risk and whether decreasing HbA1c levels before TKA will decrease the subsequent risk of infection after surgery.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Inadequate pre-operative glycaemic control in patients with diabetes mellitus adversely influences functional recovery after total knee arthroplasty : Patients with impaired glycaemic control exhibit poorer functional outcomes at 1-year post-arthroplasty

PURPOSE

Whilst inadequate glycaemic control is associated with an increase in perioperative complications following total knee arthroplasty, the impact of glycaemic control in this at-risk patient group remains ill-defined. Identification of at-risk patients would allow targeted pre-operative glycaemic control intervention.

METHODS

One hundred consecutive patients with a diagnosis of diabetes mellitus and one hundred age, sex and BMI matched patients without diabetes undergoing total knee arthroplasty in a single institution were analysed between 2008 and 2013. Inadequate glycaemic control was defined as having an HbA1c of greater than 64 mmol/mol (8.0 % NGSP) measured within the 3 months before surgery. Patient demographics, diabetes management and complications of diabetes were recorded and used as explanatory variables to deliver a generalised linear model. This allows for relationships to be defined between change in patient-reported function (SF-36, WOMAC) and these explanatory variables.

RESULTS

The patient group with concomitant diabetes exhibited smaller improvements in WOMAC and SF-36 physical component summary at 1 year after knee arthroplasty. This effect was most pronounced in the subset of patients with inadequate glycaemic control recorded in the early pre-operative period.

CONCLUSION

Patients with diabetes, particularly those with inadequate glycaemic control, exhibit less improvement at 1 year following knee arthroplasty than patients without diabetes mellitus. Clinical focus on modulating this factor in this at-risk group is warranted.

LEVEL OF EVIDENCE

III.

Clinical Outcome Evaluation of Primary Total Knee Arthroplasty in Patients with Diabetes Mellitus

Background

The aim of this study was to evaluate the safety and clinical outcome of primary total knee arthroplasty in patients with diabetes mellitus.

Material/Methods

Among the patients who were treated with total knee arthroplasty, there were 98 patients (116 knees) associated with diabetes. Osteoarthritis was diagnosed in 90 patients and rheumatoid arthritis was diagnosed in 8 patients. Various degrees of preoperative knee deformities were found in 82 knees. The average fasting blood glucose was 9.8±3.6 mmol/L at admission.

Results

The clinical efficacy of TKA was satisfactory in patients with diabetes mellitus. Diabetic patients do not seem to have a significantly higher risk for infection and DVT after TKA. At the final follow-up time point, no prosthesis loosening was found and no revision was needed in any patients. The mean HSS scores increased and the excellent rate was 100%.

Conclusions

Using perioperative comprehensive assessment of heart and lung function, and by preventing infection and the formation of DVT, we achieved satisfactory early clinical efficacy of TKA in patients with diabetes mellitus.

Automated Diabetes Case Identification Using Electronic Health Record Data at a Tertiary Care Facility

Objective

To develop and validate a phenotyping algorithm for the identification of patients with type 1 and type 2 diabetes mellitus (DM) preoperatively using routinely available clinical data from electronic health records.

Patients and Methods

We used first-order logic rules (if-then-else rules) to imply the presence or absence of DM types 1 and 2. The “if” clause of each rule is a conjunction of logical and, or predicates that provides evidence toward or against the presence of DM. The rule includes International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes, outpatient prescription information, laboratory values, and positive annotation of DM in patients’ clinical notes. This study was conducted from March 2, 2015, through February 10, 2016. The performance of our rule-based approach and similar approaches proposed by other institutions was evaluated with a reference standard created by an expert reviewer and implemented for routine clinical care at an academic medical center.

Results

A total of 4208 surgical patients (mean age, 52 years; males, 48%) were analyzed to develop the phenotyping algorithm. Expert review identified 685 patients (16.28% of the full cohort) as having DM. Our proposed method identified 684 patients (16.25%) as having DM. The algorithm performed well—99.70% sensitivity, 99.97% specificity—and compared favorably with previous approaches.

Conclusion

Among patients undergoing surgery, determination of DM can be made with high accuracy using simple, computationally efficient rules. Knowledge of patients’ DM status before surgery may alter physicians’ care plan and reduce postsurgical complications. Nevertheless, future efforts are necessary to determine the effect of first-order logic rules on clinical processes and patient outcomes.

Prevention of periprosthetic joint infection: new guidelines

The World Health Organization (WHO) and the Centre for Disease Control and Prevention (CDC) recently published guidelines for the prevention of surgical site infection. The WHO guidelines, if implemented worldwide, could have an immense impact on our practices and those of the CDC have implications for healthcare policy in the United States. Our aim was to review the strategies for prevention of periprosthetic joint infection in light of these and other recent guidelines. Cite this article: Bone Joint J 2017;99-B(4 Supple B):3-10.