Reduced postoperative morbidity in computer-navigated total knee arthroplasty: A retrospective comparison of 225,123 cases.

BACKGROUND: Total knee arthroplasty (TKA) is one of the most common elective surgical procedures in the United States, with more than 650,000 performed annually. Computer navigation technology has recently been introduced to assist surgeons with planning, performing, and assessing TKA bone cuts. The aim of this study is to assess postoperative complication rates after TKA performed using computer navigation assistance versus conventional methods. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried for unilateral TKA cases from 2008 to 2016. The presence of the CPT modifier for use of computer navigation was used to separate cases of computer-navigated TKA from conventional TKA. Multivariate and propensity-matched logistic regression analyses were performed to control for demographics and comorbidities. RESULTS: There were 225,123 TKA cases included; 219,880 were conventional TKA (97.7%) and 5,243 were navigated (2.3%). Propensity matching identified 4,811 case pairs. Analysis demonstrated no significant differences in operative time, length of stay, reoperation, or readmission, and no differences in rates of post-op mortality at 30 days postoperatively. Compared to conventional cases, navigated cases were at lower risk of serious medical morbidity (18% lower, p = 0.009) within the first 30 days postoperatively. CONCLUSION: After controlling for multiple known risk factors, navigated TKA patients demonstrated lower risk for medical morbidity, predominantly driven by lower risk for blood transfusion. Given these findings, computer-navigation is a safe surgical technique in TKA.

In Kinematically Aligned Total Knee Arthroplasty, Failure to Recreate Native Tibial Alignment Is Associated With Early Revision.

BACKGROUND: The goal of kinematically aligned (KA) total knee arthroplasty (TKA) is to restore native knee anatomy. However, there are concerns about patellofemoral tracking problems with this technique that lead to early revision. We measured the differences between preoperative anatomic alignment and postoperative component alignment in a consecutive series of KA TKA and evaluated the association between alignment changes and the likelihood of early revision. METHODS: The charts of 219 patients who underwent 275 KA TKA procedures were reviewed. Preoperative anatomic alignment and postoperative tibial and femoral component alignment were measured radiographically. The difference in component alignment compared with preoperative anatomic alignment was compared between patients who underwent aseptic revision and those who did not at a minimum of 12 months of follow-up. Receiver operating characteristic curves were created for statistically significant variables, and the Youden index was used to determine optimal alignment thresholds with regard to likelihood of revision surgery. RESULTS: Change in tibial component alignment compared with native alignment was greater (P = .005) in the revision group (5.0° ± 3.7° of increased varus compared with preoperative anatomic tibial angle) than in the nonrevision group (1.3° ± 4.2° of increased varus). The Youden index indicated that increasing tibial varus by >2.2° or more is associated with increased likelihood of revision. Preoperative anatomic alignment and change in femoral alignment and overall joint alignment (ie, Q angle) were not associated with increased likelihood of revision. CONCLUSION: Small increases in tibial component varus compared with native alignment are associated with early aseptic revision in patients undergoing KA TKA.

Readmissions After Distal Radius Fracture Open Reduction and Internal Fixation: An Analysis of 11,124 Patients.

PURPOSE: Distal radius fracture (DRF) open reduction and internal fixation (ORIF) is a common surgical procedure. This study assesses reasons and risk factors for readmission after DRF ORIF using the large sample size and follow-up of the American College of Surgeons National Surgical Quality Improvement Program database. METHODS: Adult patients who underwent DRF ORIF were identified in the 2011 to 2016 National Surgical Quality Improvement Program database. Patient demographics, comorbidity status, hospital metrics, and 30-day perioperative outcomes were tabulated. Readmission, time to readmission, and reason for readmission were assessed. Reasons for readmission were categorized. Risk factors for readmission were assessed with multivariate analyses. RESULTS: Of 11,124 patients who underwent DRF ORIF, 196 (1.76%) were readmitted within 30 days. Based on multivariate analysis, predictors of readmission (P < 0.05) were as follows: American Society of Anesthesiologist class > 3 (Odds ratio [OR] = 2.87), functionally dependent status (OR = 2.25), diabetes with insulin use (OR = 1.97), and staying in hospital after the index surgery (inpatient procedure, OR = 2.04). Readmissions occurred at approximately 14 days postoperatively. Of the recorded reasons for readmission after DRF ORIF, approximately one quarter were for surgical reasons, whereas over 75% of readmissions were for medical reasons unrelated to the surgery. CONCLUSION: This study found the rate of 30-day unplanned readmissions after DRF ORIF to be 1.76%. Demographic, comorbid, and perioperative factors predictive of readmission were defined. Most postoperative readmissions were for medical reasons unrelated to the surgical site and occurred at an average of approximately 2 weeks postoperatively. Multivariate analysis found that patients with increased American Society of Anesthesiologist class > 3, functional dependence, insulin-dependent diabetes, and those who underwent inpatient surgery for any reason were at a greater risk for readmission. Understanding these factors may aid in patient counseling and quality improvement initiatives, and this information should be used for risk stratification and risk adjustment of quality measures.

Management of Degenerative Spondylolisthesis: Analysis of a Questionnaire Study, Correlation With a National Sample, and Perioperative Outcomes of Treatment Options.

BACKGROUND: Surgical treatment for lumbar degenerative spondylolisthesis has been shown to provide better long-term outcomes than conservative treatment. However, there is variation in surgical approaches employed by surgeons. This study investigates current surgical practice patterns and compares perioperative outcomes of 3 common surgical treatments for this pathology. METHODS: A survey was administered to surgeons who attended the Lumbar Spine Research Society (LSRS) meeting in 2014. Data were extracted from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) from 2005 to 2014 to characterize the same responses. The 2 data sets were compared. Perioperative outcomes of those in the ACS-NSQIP posterior fusion subcohorts were characterized and compared. RESULTS: Posterior surgical approaches utilized by surgeons who responded to the LSRS survey were similar to those captured by ACS-NSQIP where 72% of those with degenerative spondylolisthesis were fused. Of those that were fused, 8% had an uninstrumented posterior fusion, 33% had an instrumented posterior fusion, and 59% had an instrumented posterior fusion with interbody. On multivariate analysis, there was no difference in risk of postoperative adverse events, readmission, or length of stay between these 3 common types of fusion. CONCLUSIONS: Practice patterns for the posterior management of lumbar degenerative spondylolisthesis were similar between LSRS survey responses and ACS-NSQIP data. The ACS-NSQIP perioperative outcome measures assessed were similar regardless of surgical technique. These findings highlight that cost-benefit considerations and longer-term outcomes have to be the measures by which surgical technique is chosen for degenerative spondylolisthesis.

Timing of Adverse Events Following Geriatric Hip Fracture Surgery: A Study of 19,873 Patients in the American College of Surgeons National Surgical Quality Improvement Program.

This study uses a prospective surgical registry to characterize the timing of 10 postoperative adverse events following geriatric hip fracture surgery. There were 19,873 patients identified who were ≥70 years undergoing surgery for hip fracture as part of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). The median postoperative day of diagnosis (and interquartile range) for myocardial infarction was 3 (1-5), cardiac arrest requiring cardiopulmonary resuscitation 3 (0-8), stroke 3 (1-10), pneumonia 4 (2-10), pulmonary embolism 4 (2-11), urinary tract infection 7 (2-13), deep vein thrombosis 9 (4-16), sepsis 9 (4-18), mortality 11 (6-19), and surgical site infection 16 (11-22). For the earliest diagnosed adverse events, the rate of adverse events had diminished by postoperative day 30. For the later diagnosed adverse events, the rate of adverse events remained high at postoperative day 30. Findings help to enable more targeted clinical surveillance, inform patient counseling, and determine the duration of follow-up required to study specific adverse events effectively. Orthopedic surgeons should have the lowest threshold for testing for each adverse event during the time period of greatest risk.

Adverse Events Following Posterior Lumbar Fusion: A Comparison of Spine Surgeons Perceptions and Reported Data for Rates and Risk Factors.

BACKGROUND: Postoperative complications and risks factors for adverse events play an important role in both decision making and patient expectation setting. The present study serves to contrast surgeons' perceived and reported rates of postoperative adverse events following posterior lumbar fusion (PLF) and to assess the accuracy of predicting the impact of patient factors on such outcomes. METHODS: A survey investigating perceived rates of adverse events and the impact of patient risk factors on them following PLF for degenerative conditions was distributed to spine surgeons at the Lumbar Spine Research Society (LSRS) 2016 annual meeting. For comparison, the corresponding rates and patient risk factors were assessed in patients undergoing elective PLF from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) data years 2011-2014. RESULTS: From the survey, there were 53 responses (response rate of 79%) from attending physicians at LSRS. From NSQIP, there were 16,589 patients who met the inclusion criteria. Adverse event rates estimated by the surgeons at LSRS were close to those determined by NSQIP data (no greater than 2.81% different). The largest differences were for deep vein thrombosis (overestimation of 2.81%, P < .001), anemia requiring transfusion (overestimation of 2.47%, P = .018), and urinary tract infection (overestimation of 2.29%, P < .001). Similarly, the estimated impact of patient factors was similar to the data (within relative risk of 2.02). The largest differences were for current smoking (overestimation of 2.02 relative risk, P < .001), insulin dependent diabetes (overestimation of 1.36, P < .001), and obesity (overestimation of 1.35, P < .001). CONCLUSIONS: The current study noted that surgeon estimates were relatively close to national numbers for estimating the adverse events and impact of patient factors on such outcomes after PLF for degenerative conditions. The estimates are roughly appropriate with a bias toward overestimation for planning and expectation setting.

Thromboembolic Events After Traumatic Vertebral Fractures: An Analysis of 190,192 Patients.

STUDY DESIGN: Retrospective cohort study OBJECTIVE.: To determine the rate of venous thromboembolism event (VTE) and risk factors for their occurrence in patients with vertebral fractures. SUMMARY OF BACKGROUND DATA: Deep vein thrombosis or pulmonary embolism (VTE) events are a significant source of potentially preventable morbidity and mortality in trauma patients. In patients with traumatic vertebral fractures, a common high-energy injury sometimes resulting in spinal cord injury, there is debate about what factors may be associated with such VTEs. METHODS: All patients with vertebral fractures in the American College of Surgeons National Trauma Data Bank Research Data Set (NTDB RDS) from years 2011 and 2012 were identified. Multivariate logistic regression was used to determine factors associated with the occurrence of VTE while considering patient factors, injury characteristics, and hospital course. RESULTS: A total of 190,192 vertebral fractures patients were identified. The overall rate of VTE was 2.5%. In multivariate analysis, longer inpatient length of stay was most associated with increased VTEs with an odds ratio (OR) of up to 96.60 (95% CI: 77.67 - 129.13) for length of stay longer than 28 days (compared to 0 - 3 days). Additional risk factors in order of decreasing odds ratios were older age (OR of up to 1.65 [95% CI: 1.45 - 1.87] for patients age 70 - 79 years [compared to age 18 - 29 years]), complete spinal cord injuries (OR: 1.49 [95% CI: 1.31 - 1.68]), cancer (OR: 1.37 [95% CI: 1.25 - 1.50]), and obesity (OR: 1.32 [95% CI: 1.18 - 1.48]). Multiple associated non-spinal injuries were also associated with increased rates of VTE. CONCLUSION: While the overall rate of VTE is relatively low after vertebral fractures, longer LOS and other defined factors to lesser extents were predisposing factors. By determining patients at greatest risk, protocols to prevent such adverse outcomes can be developed and optimized. LEVEL OF EVIDENCE: 3.

The Hand Surgeon Consultation Improves Patient Knowledge in a Hand Surgery Mission to Honduras.

BACKGROUND: The purpose of this study was to assess impact of the surgeon consultation and informed consent process on patient education in an international hand surgery mission compared with a US academic hand surgery practice. These two groups were selected to evaluate communication difficulties in a surgical mission setting compared with standard of care in a high-income country. METHODS: A multi-part survey was administered to patients presenting to a hand surgery mission during March 2012 and new patients of a university hand center in a 3-month period during 2011. Surveys were administered prior to and following surgeon consultation with one fellowship-trained hand surgeon. The survey assessed knowledge of basic hand anatomy, physiology, disease, individual diagnosis, and surgical risks. RESULTS: 71 patients participated in the study (university n=36, mission n=35). Pre-consultation quiz score averaged 58% in the university group versus 27% in the mission group. Post-consultation quiz scores averaged 62% in the university group versus 40% in the mission group. Only the mission group's quiz score increase was statistically significant. 93% of the university group reported learning about their condition and diagnosis, but only 40% demonstrated correct insight into their diagnosis. In the mission group, 73% reported learning about their condition and diagnosis while 53% demonstrated correct insight into their diagnosis. Although all consultations involved discussion of surgical risks, only 62% of the university group and 52% of the mission group recalled discussing surgical risks. CONCLUSIONS: The hand surgeon consultation was more effective in improving hand knowledge in the surgery mission group compared to in a university hand practice. This suggests that the surgeon consultation should be pursued despite communication barriers in surgical missions. However, the discrepancy between patient perception of knowledge gains and correct insight into diagnosis, and the deficit of patient retention of surgical risks need to be improved.

Discrepancies in the Definition of "Outpatient" Surgeries and Their Effect on Study Outcomes Related to ACDF and Lumbar Discectomy Procedures: A Retrospective Analysis of 45,204 Cases.

STUDY DESIGN: This is a retrospective study. OBJECTIVE: To study the differences in definition of "inpatient" and "outpatient" [stated status vs. actual length of stay (LOS)], and the effect of defining populations based on the different definitions, for anterior cervical discectomy and fusion (ACDF) and lumbar discectomy procedures in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. SUMMARY OF BACKGROUND DATA: There has been an overall trend toward performing ACDF and lumbar discectomy in the outpatient setting. However, with the possibility of patients who underwent outpatient surgery staying overnight or longer at the hospital under "observation" status, the distinction of "inpatient" and "outpatient" is not clear. MATERIALS AND METHODS: Patients who underwent ACDF or lumbar discectomy in the 2005-2014 ACS-NSQIP database were identified. Outpatient procedures were defined in 1 of 2 ways: either as being termed "outpatient" or hospital LOS=0. Differences in definitions were studied. Further, to evaluate the effect of the different definitions, 30-day outcomes were compared between "inpatient" and "outpatient" and between LOS>0 and LOS=0 for ACDF patients. RESULTS: Of the 4123 "outpatient" ACDF patients, 919 had LOS=0, whereas 3204 had LOS>0. Of the 13,210 "inpatient" ACDF patients, 337 had LOS=0, whereas 12,873 had LOS>0. Of the 15,166 "outpatient" lumbar discectomy patients, 8968 had LOS=0, whereas 6198 had LOS>0. Of the 12,705 "inpatient" lumbar discectomy patients, 814 had LOS=0, whereas 11,891 had LOS>0. On multivariate analysis of ACDF patients, when comparing "inpatient" with "outpatient" and "LOS>0" with "LOS=0" there were differences in risks for adverse outcomes based on the definition of outpatient status. CONCLUSIONS: When evaluating the ACS-NSQIP population, ACDF and lumbar discectomy procedures recorded as "outpatient" can be misleading and often did not correlate with same day discharge. These findings have significant impact on the interpretation of existing studies and define an area that needs clarification for future studies. LEVEL OF EVIDENCE: Level 3.

Injury patterns and risk factors for orthopaedic trauma from snowboarding and skiing: a national perspective.

PURPOSE: Alpine skiing and snowboarding are both popular winter sports that can be associated with significant orthopaedic injuries. However, there is a lack of nationally representative injury data for the two sports. METHODS: The National Trauma Data Bank was queried for patients presenting to emergency departments due to injuries sustained from skiing and snowboarding during 2011 and 2012. Patient demographics, comorbidities, and injury patterns were tabulated and compared between skiing and snowboarding. Risk factors for increased injury severity score and lack of helmet use were identified using multivariate logistic regression. RESULTS: Of the 6055 patients identified, 55.2 % were skiers. Sixty-one percent had fractures. Lower extremity fractures were the most common injury and occurred more often in skiers (p < 0.001). Upper extremity fractures were more common in snowboarders, particularly distal radius fractures (p < 0.001). On multivariate analysis, increased injury severity was independently associated with age 18-29, 60-69, 70+, male sex, a positive blood test for alcohol, a positive blood test for an illegal substance, and wearing a helmet. Lack of helmet use was associated with age 18-29, 30-39, smoking, a positive drug test for an illegal substance, and snowboarding. CONCLUSIONS: Young adults, the elderly, and those using substances were shown to be at greater risk of increased injury severity and lack of helmet use. The results of this study can be used clinically to guide the initial assessment of these individuals following injury, as well as for targeting preventive measures and education. LEVEL OF EVIDENCE: Prognostic Level III.

High Publication Rate of Abstracts Presented at Lumbar Spine Research Society Meetings.

BACKGROUND: Although publication rates from multiple orthopedic research conferences have been published in the literature, the publication rates of abstracts presented at the Lumbar Spine Research Society (LSRS) meetings have never been reported. The purpose of this study is to evaluate the publication rates from the LSRS annual meeting years 2008-2012 and then to compare those rates with that of other spine research society meetings. METHODS: Podium presentations from 2008 to 2012 and poster presentations from 2010 to 2012 were reviewed. For each presentation, a PubMed search was performed to determine if a full-text publication existed. χ2 tests were used to compare LSRS publication rates to those of other spine meetings. In addition, impact of published articles was evaluated by average citation count and average journal impact factor. RESULTS: From 2008 to 2012, a total of 332 podium and poster presentations were identified. The overall publication rate was 55.1% (183/332). For podium presentations, this was greatest in 2012 (66.0%) and lowest in 2008 (51.5%). For poster presentations, this was greatest in 2012 (53.6%) and lowest in 2010 (25.0%). The publication rate of presentations is statistically greater than the publication rates of Eurospine (37.8%, P < .001), North American Spine Society (40.0%, P < .001), The International Society for the Study of the Lumbar Spine (45.0%, P = .012), and the Scoliosis Research Society (47.0%, P = .042) but not statistically different than that of Cervical Spine Research Society (65.7%, P = .059). In addition, the average citation count per published article categorized by year ranged from 13 to 31. The average journal impact factor of published articles categorized by year ranged from 2.31 to 2.55. CONCLUSIONS: While LSRS is a relatively young society, these findings point to the high quality of presentations at this scientific meeting. These findings speak to the scientific rigor of presentations at LSRS. CLINICAL RELEVANCE: This study helps clinicians and scientists gauge the quality of a research meeting and make informed choices on which gatherings to attend.

Different Fusion Approaches for Single-level Lumbar Spondylolysis Have Similar Perioperative Outcomes.

STUDY DESIGN: Retrospective cohort study OBJECTIVE.: The aim of this study was to compare perioperative adverse events for patients with lumbar spondylolysis treated with transforaminal lumbar interbody fusion (TLIF), posterior spinal fusion (PSF), combined anterior and posterior fusion (AP fusion), or anterior lumbar interbody fusion (ALIF). SUMMARY OF BACKGROUND DATA: Previous cohort studies have shown similar long-term outcomes for different surgical approaches for this indication, but potential differences in 30-day perioperative adverse events have not been well characterized. METHODS: The present study uses data extracted from the American College of Surgeons National Surgical Quality Improvement Database. Patients undergoing fusion with different approaches for lumbar spondylolysis were identified. Propensity score matching was utilized to account for potential differences in demographic and comorbidity factors. Comparisons among perioperative outcomes were then made among the propensity score-matched study groups. RESULTS: Of 1077 cases of spondylolysis identified, 556 underwent TLIF, 327 underwent PSF, 108 underwent AP fusion, and 86 underwent ALIF. After propensity score matching, there were no differences in the rates of any of the 30-day individual adverse events studied and no differences in the aggregated groupings of any adverse event, serious adverse event, or minor adverse event. There was a significantly increased operative time in the AP fusion group, but there were no differences in hospital length of stay or readmission rates. CONCLUSION: Because perioperative adverse event rates were similar, even with a slightly longer operative time in the AP fusion group, these findings suggest that surgeon preference and long-term outcomes are better used to determine the recommendation of one surgical approach over another for single level fusions for lumbar spondylolysis. LEVEL OF EVIDENCE: 3.

Severity Weighting of Postoperative Adverse Events in Orthopedic Surgery.

Studies of adverse events (AEs) after orthopedic surgery commonly use composite AE outcomes. An example of such an outcome is any AE. These types of outcomes treat AEs with different clinical significance (eg, death, urinary tract infection) similarly. We conducted a study to address this shortcoming in research methodology by creating a single severity-weighted outcome that can be used to characterize the overall severity of a given patient's postoperative course. All orthopedic faculty members at 2 academic institutions were invited to complete a severity-weighting exercise in which AEs were assigned a percentage severity of death. Mean (standard error) severity weight for urinary tract infection was 0.23% (0.08%); blood transfusion, 0.28% (0.09%); pneumonia, 0.55% (0.15%); hospital readmission, 0.59% (0.23%); wound dehiscence, 0.64% (0.17%); deep vein thrombosis, 0.64% (0.19%); superficial surgical-site infection, 0.68% (0.23%); return to operating room, 0.91% (0.29%); progressive renal insufficiency, 0.93% (0.27%); graft/prosthesis/flap failure, 1.20% (0.34%); unplanned intubation, 1.38% (0.53%); deep surgical-site infection, 1.45% (0.38%); failure to wean from ventilator, 1.45% (0.48%); organ/space surgical-site infection, 1.76% (0.46%); sepsis without shock, 1.77% (0.42%); peripheral nerve injury, 1.83% (0.47%); pulmonary embolism, 2.99% (0.76%); acute renal failure, 3.95% (0.85%); myocardial infarction, 4.16% (0.98%); septic shock, 7.17% (1.36%); stroke, 8.73% (1.74%); cardiac arrest requiring cardiopulmonary resuscitation, 9.97% (2.46%); and coma, 15.14% (3.04%). Future studies may benefit from using this new severity-weighted outcome score.

Comparison of Perioperative Adverse Event Rates After Total Knee Arthroplasty in Patients With Diabetes: Insulin Dependence Makes a Difference.

BACKGROUND: Total knee arthroplasty (TKA) is an effective treatment option for patients with advanced osteoarthritis and has become one of the most frequently performed orthopedic procedures. With the increasing prevalence of diabetes mellitus (DM), the burden of its sequela and associated surgical complications has also increased. For these reasons, it is important to understand the association between DM and the rates of perioperative adverse events after TKA. METHODS: A retrospective cohort study was conducted using the American College of Surgeons National Surgical Quality Improvement Program database. Patients who underwent TKA between 2005 and 2014 were identified and characterized as having insulin-dependent DM (IDDM), non-insulin-dependent DM (NIDDM), or not having DM. Multivariate Poisson regression was used to control for demographic and comorbid factors and to assess the relative risks of multiple adverse events in the initial 30 postoperative days. RESULTS: A total of 114,102 patients who underwent TKA were selected (IDDM = 4881 [4.3%]; NIDDM = 15,367 [13.5%]; and no DM = 93,854 [82.2%]). Patients with NIDDM were found to be at greater risk for 2 of 17 adverse events studied relative to patients without DM. However, patients with IDDM were found to be at greater risk for 12 of 17 adverse events studied relative to patients without DM. CONCLUSION: In comparison with patients with NIDDM, patients with IDDM are at greater risk for many more perioperative adverse outcomes relative to patients without DM. These findings have important implications for patient selection, preoperative risk stratification, and postoperative expectations.

After Posterior Fusions for Adult Spinal Deformity, Operative Time is More Predictive of Perioperative Morbidity, Rather Than Surgical Invasiveness: A Need for Speed?

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The aim of this study was to determine the independent effects of operative time and surgical invasiveness on perioperative outcomes after posterior spinal fusions for adult spinal deformity. SUMMARY OF BACKGROUND DATA: Morbidity is high after posterior fusions for adult spinal deformity. Although previous reports have demonstrated an association between perioperative outcomes and the extent of correction and fusion (number of posterior levels fused, pelvic fixation, combined anterior-posterior fusion), no study has looked at the independent effects of the surgical invasiveness after controlling for operative time. METHODS: All adult patients, undergoing posterior spinal fusion for spinal deformity, were identified in the 2010 to 2014 National Surgical Quality Improvement Program (NSQIP) database. Multivariate analysis was used to determine the independent effects of longer operative timing and the surgical invasiveness (number of levels fused, anterior or transforaminal interbody fusions, osteotomies, and pelvic fixation) on 30-day complications. RESULTS: A total of 1540 patients undergoing posterior spinal fusion for adult spinal deformity were identified. The overall rate of complications was 15.3%. In multivariate analysis, greater operative timing was associated with increased inpatient complications [odds ratio (95% confidence interval, 95% CI) from 2.23 (1.25-3.98) for 7-8 hours to 4.46 (2.61-7.64) for 9+ hours; P < 0.001]. Although the number of levels fused, anterior/interbody fusions, osteotomies, and pelvic fixation were associated with complications on bivariate analysis, these factors were not associated with increased complications in multivariate analysis when controlling for other factors such as operative time. CONCLUSION: For adult deformity surgery, longer operative time appears to be a better predictor of the overall rate perioperative complications than surgical invasiveness in multivariate analysis. Rather than avoidance of a more extensive and invasive surgical procedure, which may be indicated to improve alignment and stability, these data suggest the importance of safely and efficiently minimizing overall operative time. LEVEL OF EVIDENCE: 4.

Comparison of Outpatient vs Inpatient Total Knee Arthroplasty: An ACS-NSQIP Analysis.

BACKGROUND: There has been a recent surge of interest in performing primary total knee arthroplasty (TKA) in the outpatient setting to reduce cost and increase patient satisfaction. Detailed information on the safety of outpatient TKA in large sample sizes is scarce. METHODS: Patients who underwent primary, elective TKA were identified in the 2005-2014 American College of Surgeons National Surgical Quality Improvement Program database. Outpatient procedure was defined as having a hospital length of stay of 0 days, whereas inpatient procedure was defined as having a length of stay ≥1 days. To reduce the effect of confounding factors and nonrandom assignment of treatment, propensity score matching was used. Multivariate analyses on the matched samples were used to compare the rates of adverse events that happened any time during the 30-day postoperative period, postdischarge adverse events, and readmissions between the outpatient and inpatient cohorts. RESULTS: A total of 112,922 TKA patients met the inclusion criteria. Of these, only 642 (0.57%) were outpatient procedures. Outpatients tended to be men, slightly younger, and have less comorbidity. After propensity matching, multivariate analysis revealed a higher rate of postdischarge blood transfusions (P < .001) in the outpatient cohort. There were no other significant differences in 30-day postoperative individual adverse events or readmissions. CONCLUSION: Based on the perioperative outcome measures studied here, outpatient TKA can be appropriately considered in select patients based on rates of overall perioperative adverse events and readmissions. However, higher surveillance of these patients postdischarge may be warranted.