Andrew J. Pugely

Differences in short-term complications between spinal and general anesthesia for primary total knee arthroplasty.

BACKGROUND Spinal anesthesia has been associated with lower postoperative rates of deep-vein thrombosis, a shorter operative time, and less blood loss when compared with general anesthesia. The purpose of the present study was to identify differences in thirty-day perioperative morbidity and mortality between anesthesia choices among patients undergoing total knee arthroplasty. METHODS The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was searched to identify patients who underwent primary total knee arthroplasty between 2005 and 2010. Complications that occurred within thirty days after the procedure in patients who had been managed with either general or spinal anesthesia were identified. Patient characteristics, thirty-day complication rates, and mortality were compared. Multivariate logistic regression identified predictors of thirty-day morbidity, and stratified propensity scores were used to adjust for selection bias. RESULTS The database search identified 14,052 cases of primary total knee arthroplasty; 6030 (42.9%) were performed with the patient under spinal anesthesia and 8022 (57.1%) were performed with the patient under general anesthesia. The spinal anesthesia group had a lower unadjusted frequency of superficial wound infections (0.68% versus 0.92%; p = 0.0003), blood transfusions (5.02% versus 6.07%; p = 0.0086), and overall complications (10.72% versus 12.34%; p = 0.0032). The length of surgery (ninety-six versus 100 minutes; p < 0.0001) and the length of hospital stay (3.45 versus 3.77 days; p < 0.0001) were shorter in the spinal anesthesia group. After adjustment for potential confounders, the overall likelihood of complications was significantly higher in association with general anesthesia (odds ratio, 1.129; 95% confidence interval, 1.004 to 1.269). Patients with the highest number of preoperative comorbidities, as defined by propensity score-matched quintiles, demonstrated a significant difference between the groups with regard to the short-term complication rate (11.63% versus 15.28%; p = 0.0152). Age, female sex, black race, elevated creatinine, American Society of Anesthesiologists class, operative time, and anesthetic choice were all independent risk factors of short-term complication after total knee arthroplasty. CONCLUSIONS Patients undergoing total knee arthroplasty who were managed with general anesthesia had a small but significant increase in the risk of complications as compared with patients who were managed with spinal anesthesia; the difference was greatest for patients with multiple comorbidities. Surgeons who perform knee arthroplasty may consider spinal anesthesia for patients with comorbidities.

Incidence of and risk factors for 30-day readmission following elective primary total joint arthroplasty: analysis from the ACS-NSQIP.

Recently, the government has moved towards public reporting of 30-day readmission rates after elective primary total knee (TKA) and total hip arthroplasty (THA). We identified 11,814 and 8105 patients who underwent primary TKA and THA from the 2011 ACS NSQIP. Overall readmission rates within 30-days of surgery were 4.6% for TKA and 4.2% for THA. Complications associated with readmission were predominantly wound infections, sepsis, thromboembolic, cardiac, and respiratory related. In TKA, multivariate analysis identified age (P=0.002), male gender (P=0.03), cancer history (P=0.008), elevated BUN (P=0.002), a bleeding disorder (P<0.001) and high ASA class (P<0.001) as predictors of readmission. In THA, obesity (P=0.008), steroid use (P=0.037), a bleeding disorder (P=0.002), dependent functional status (P=0.022), and high ASA class (P<0.001) predicted readmission. Understanding characteristics associated with readmission will be essential for equitable patient risk stratification.

Outpatient surgery reduces short-term complications in lumbar discectomy: an analysis of 4310 patients from the ACS-NSQIP database.

Study Design. Propensity score–adjusted prospective cohort study. Objective. To compare the incidence of complications in patients undergoing single-level lumbar discectomy between the inpatient and outpatient settings, to determine baseline 30-day complication rates for lumbar discectomy, and to identify independent risk factors for complications. Summary of Background Data. Lumbar discectomy is the most common spinal procedure performed and can be done on an outpatient basis. Lower costs, greater patient satisfaction, and equivalent safety have been reported with outpatient surgery. Methods. Patients undergoing lumbar discectomy between 2005 and 2010 were selected from The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Patient selection was based on a single primary current procedural terminology code. To ensure comparable inpatient and outpatient cohorts, patients with multilevel procedures were excluded. Thirty-day postoperative complications and preoperative patient characteristics were identified and compared. Propensity score matching and multivariate logistic regression analysis were used to adjust for selection bias and identify predictors of 30-day morbidity. Results. Of the 4310 lumbar discectomy cases, 2658 (61.7%) underwent an inpatient hospital stay after surgery, whereas 1652 (38.3%) patients had outpatient surgery. Unadjusted overall complication rates (6.5% vs. 3.5%, P < 0. 0001) were higher in those undergoing inpatient surgery. After propensity score matching, overall complication rate was still higher with the inpatient cohort (5.4% vs. 3.5%, P = 0.0068). Adjusted comparison using multivariate logistic regression also demonstrated a significantly higher rate of complication for inpatients (odds ratio, 1.521; 95% confidence interval, 1.048–2.206). Age, diabetes, presence of preoperative wound infection, blood transfusion, operative time, and an inpatient hospital stay were all independent risk factors of short-term complication after lumbar discectomy. Conclusion. After adjusting for confounders using propensity score matching and multivariate logistic regression analysis, patients undergoing outpatient lumbar discectomy had lower overall complication rates than those treated as inpatients. Surgeons should consider outpatient surgery for lumbar discectomy in appropriate candidates.

A risk calculator for short-term morbidity and mortality after hip fracture surgery

Objective: Hip fractures are a common source of morbidity and mortality among the elderly. Although multiple prior studies have identified risk factors for poor outcomes, few studies have presented a validated risk stratification calculator. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was used to identify 4331 patients undergoing surgery for hip fracture between 2005 and 2010. Patient demographics, comorbidities, laboratory values, and operative characteristics were compared in a univariate analysis, and a multivariate logistic regression analysis was then used to identify independent predictors of 30-day morbidity and mortality. Weighted values were assigned to each independent risk factor and used to create predictive models of 30-day morbidity, minor complication risk, major complication risk, and total complication risk. The models were internally validated with randomly partitioned 80%/20% cohort groups. Results: Thirty-day mortality was 5.9% and morbidity was 30.0%. Patient age, especially age greater than 80 years [mortality: odds ratio (OR): 2.41, 95% confidence interval (CI): 1.17–4.99); morbidity: OR: 1.43, 95% CI: 1.05–1.94], and male gender (mortality: OR: 2.28, 95% CI: 1.61–3.22; morbidity: OR: 1.26, 95% CI: 1.03–1.54) were associated with both increased mortality and morbidity. An increased American Society of Anesthesia class had the highest negative impact on total complication incidence in the scoring models. Additionally, complete functional dependence, active malignancy, patient race, cardiopulmonary disease, laboratory derangements, prolonged operating time, and open versus percutaneous surgery independently influenced outcomes. Risk scores, based on weighted models, which included the aforementioned variables, predicted mortality (P < 0.001, C index: 0.702) and morbidity (P < 0.001, C index: 0.670) after hip fracture surgery. Conclusions: In this study, we have developed an internally validated method for risk stratifying patients undergoing hip fracture surgery, and this model is predictive of both 30-day morbidity and mortality. Our model could be useful for identifying high-risk individuals, for obtaining informed consent, and for risk-adjusted comparisons of outcomes between institutions. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Risk factors for thirty-day morbidity and mortality following knee arthroscopy: A review of 12,271 patients from the National Surgical Quality Improvement Program database

BACKGROUND Knee arthroscopy is among the most common orthopaedic surgical procedures. However, the incidence and risk factors for postsurgical morbidity and mortality remain poorly defined. METHODS The American College of Surgeons National Surgical Quality Improvement Program prospectively collects thirty-day morbidity and mortality data from more than 258 hospitals around the United States. We used Current Procedural Terminology codes to retrospectively query the database and identified 12,271 cases of elective knee arthroscopy performed from January 1, 2005, to December 31, 2010. Postoperative complications were divided into categories of minor morbidity, major morbidity or mortality, or any complication. The potential risk factors for complications were analyzed with use of univariate and multivariate analyses. RESULTS The overall incidence of any complication was 1.6% (199 patients). The major morbidity was 0.76% (ninety-three patients), which included one patient death (0.008%), and the minor morbidity was 0.86% (106 patients). The most frequent major complication was a return to the operating room. The most common minor complication was deep venous thrombosis or thrombophlebitis. The risk factors identified in the univariate analysis for any complication included black race, prior operation within thirty days, American Society of Anesthesiologists class, and operative time of >1.5 hours as compared with ≤1.5 hours (p < 0.05 for each). The independent risk factors identified in the multivariate analysis for any complication included black race (odds ratio, 1.81 [95% confidence interval, 1.13 to 2.89]), prior operation within thirty days (odds ratio, 6.33 [95% confidence interval, 1.45 to 27.66]), operative time of >1.5 hours (odds ratio, 1.84 [95% confidence interval, 1.21 to 2.78]), and age of forty to sixty-five years (odds ratio, 1.46 [95% confidence interval, 1.01 to 2.11]). CONCLUSIONS The incidence of complication following elective knee arthroscopy is low. The data presented here should be useful for providing prognostic information to patients during informed consent. Surgeons should be encouraged to minimize operative time whenever possible, and may wish to delay elective arthroscopy in patients who have had other recent surgical procedures.

The Effect of Smoking on Short-Term Complications Following Total Hip and Knee Arthroplasty

BACKGROUND Total joint arthroplasty is the most frequently performed orthopaedic procedure in the United States. The purpose of the present study was to identify differences in thirty-day morbidity and mortality following primary total hip and total knee arthroplasty according to smoking status and pack-year history of smoking. METHODS We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database to identify patients who had undergone primary total hip or total knee arthroplasty between 2006 and 2012. Patients were stratified by smoking status and pack-year history of smoking. Thirty-day rates of mortality, wound complications, and total complications were compared with use of univariate and multivariate analyses. RESULTS We identified 78,191 patients who had undergone primary total hip or total knee arthroplasty. Of these, 81.8% (63,971) were nonsmokers, 7.9% (6158) were former smokers, and 10.3% (8062) were current smokers. Current smokers had a higher rate of wound complications (1.8%) compared with former smokers and nonsmokers (1.3% and 1.1%, respectively; p < 0.001). Former smokers had a higher rate of total complications (6.9%) compared with current smokers and nonsmokers (5.9% and 5.4%, respectively; p < 0.001). Multivariate analysis identified current smokers as being at increased risk of wound complications (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.21 to 1.78), particularly deep wound infection, while both current smokers (OR, 1.18; 95% CI, 1.06 to 1.31) and former smokers (OR, 1.20; 95% CI, 1.08 to 1.34) were at increased total complication risk. Increasing pack-year history of smoking resulted in increasing total complication risk. CONCLUSIONS On the basis of our findings, current smokers have an increased risk of wound complications and both current and former smokers have an increased total complication risk following total hip or total knee arthroplasty.

Causes and Risk Factors for 30-day Unplanned Readmissions After Lumbar Spine Surgery

Study Design. Retrospective review of a prospective cohort. Objective. To determine the incidence, causes, and risk factors for 30-day unplanned readmissions after lumbar spine surgery. Summary of Background Data. The rising costs associated with lumbar spinal surgery have received national attention. Recently, the government has chosen to target 30-day readmissions as a quality measure. Few studies have specifically analyzed the incidence, causes, and risk factors for readmission in a multicenter patient cohort. Methods. A large, multicenter clinical registry was queried for all patients undergoing lumbar spine surgery in 2012. Current Procedural Terminology codes were used to select patients undergoing lumbar discectomy, laminectomy, anterior and posterior fusions, and multilevel deformity surgery. Thirty-day readmissions rates and causes were identified and analyzed. Univariate and multivariate logistic regression analyses were used to identify patient characteristics, comorbidities, and operative variables predictive of readmission. Results. Overall, 695 of 15,668 patients undergoing lumbar spine surgery had unplanned 30-day hospital readmissions (4.4%). When separated by procedure type, readmissions were lowest after discectomy, 3.3%, and highest after deformity surgery, 9.0% (P < 0.001). The top causes for readmission were wound-related (38.6%), pain-related (22.4%), thromboembolic (9.4%), and systemic infections (8.0%). Predictors of readmission included advanced patient age more than 80 years (P = 0.03), African American race (P = 0.03), recent weight loss (P = 0.04), chronic obstructive pulmonary disorder (P < 0.01), history of cancer (P = 0.04), creatinine more than 1.2 (P < 0.01), elevated ASA class (P = 0.01), operative time more than 4 hours (P = 0.01), and prolonged hospital length of stay more than 4 days (P < 0.01). Conclusion. Thirty-day unplanned readmission rates increased with procedure invasiveness. Both medical and surgical reasons contributed to readmission, many unavoidable. Surgeons should explore optimization measures for those at risk of early, unplanned readmission. Level of Evidence: 3

A comparison of hospital length of stay and short-term morbidity between the anterior and the posterior approaches to total hip arthroplasty

The efficacy of the anterior, relative to other operative approaches, in promoting earlier return to function after hip arthroplasty has not been well established. We retrospectively compared 41 anterior and 47 posterior approach cases. Mean hospital stay (2.9 vs. 4 days, p=0.001) and days to mobilization (2.4 vs. 3.2 days, p=0.006) were shorter with the anterior approach. After multivariate regression, the anterior approach remained a significant predictor of early discharge (p=0.009). Lateral femoral cutaneous nerve neuropraxia (17%) and fracture (2%), were more common in the anterior cohort, but all patients recovered without sequela. Overall, the anterior approach patients had earlier discharge and mobilization as compared to patients who received the posterior approach. Neuropraxia and fracture remain a concern, but the clinical significance was low in our cohort.

Database and Registry Research in Orthopaedic Surgery: Part I: Claims-Based Data.

The use of large-scale national databases for observational research in orthopaedic surgery has grown substantially in the last decade, and the data sets can be grossly categorized as either administrative claims or clinical registries. Administrative claims data comprise the billing records associated with the delivery of health-care services. Orthopaedic researchers have used both government and private claims to describe temporal trends, geographic variation, disparities, complications, outcomes, and resource utilization associated with both musculoskeletal disease and treatment. Medicare claims comprise one of the most robust data sets used to perform orthopaedic research, with >45 million beneficiaries. The U.S. government, through the Centers for Medicare & Medicaid Services, often uses these data to drive changes in health policy. Private claims data used in orthopaedic research often comprise more heterogeneous patient demographic samples, but allow longitudinal analysis similar to that offered by Medicare claims. Discharge databases, such as the U.S. National Inpatient Sample, provide a wide national sampling of inpatient hospital stays from all payers and allow analysis of associated adverse events and resource utilization. Administrative claims data benefit from the high patient numbers obtained through a majority of hospitals. Using claims, it is possible to follow patients longitudinally throughout encounters irrespective of the location of the institution delivering health care. Some disadvantages include lack of precision of ICD-9 (International Classification of Diseases, Ninth Revision) coding schemes. Much of these data are expensive to purchase, complicated to organize, and labor-intensive to manipulate--often requiring trained specialists for analysis. Given the changing health-care environment, it is likely that databases will provide valuable information that has the potential to influence clinical practice improvement and health policy for years to come.

The Incidence of and Risk Factors for 30-Day Surgical Site Infections Following Primary and Revision Total Joint Arthroplasty.

The authors assessed the incidence of and risk factors associated with 30-day surgical site infections (SSIs) following primary (p) and revision (r) THA and TKA. In total, 23,128 primary and 2170 revision TJAs were identified between 2005 and 2010 in the ACS NSQIP database. The 30-day SSI rates, overall and deep, were 1.1 and 0.1% for pTKA, 1.18 and 0.4% for pTHA, 1.68 and 0.7% for rTKA, and 2.9 and 1.7% for rTHA. After primary TJA, independent risk factors were BMI>40, hypertension, prolonged operative time, electrolyte disturbance and previous infection, and after revision TJA, dyspnea and bleeding disorder were risk factors. This study should help provide benchmark data for SSI following TJA.