Sergio Mendoza-Lattes

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.

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.

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

Dysphagia Following Anterior Cervical Arthrodesis Is Associated with Continuous, Strong Retraction of the Esophagus

BACKGROUND The prevalence of dysphagia after anterior cervical decompression and arthrodesis is estimated to be 50% within one month and 21% at twelve months. However, its exact etiology is not well understood. The objective of the present study was to explore the relationship between intraoperative intra-esophageal pressure due to surgical retraction, esophageal mucosal blood flow at the level of surgery, and postoperative dysphagia. Our hypothesis was that sustained elevated pressure on the esophagus during anterior cervical arthrodesis is associated with postoperative dysphagia. METHODS Seventeen selected patients scheduled for anterior cervical arthrodesis were studied. Throughout the procedure, intraluminal pressure in the upper esophageal sphincter was measured (mm Hg) with a custom-made manometer probe and mucosal perfusion was measured at the level of surgery with a laser Doppler flowmeter. The type of retraction chosen by the surgeon was noted. Postoperatively, the patients were specifically evaluated for dysphagia on the first postoperative day and at six weeks, three months, and six months postoperatively with use of the M.D. Anderson Dysphagia Inventory. RESULTS Four of the eleven patients who had dynamic retraction and five of the six patients who had static retraction during surgery had postoperative dysphagia. In the group of patients with dysphagia, the average M.D. Anderson Dysphagia Inventory score decreased from 93.8 +/- 12.1 preoperatively to 67.7 +/- 11.4 on the first postoperative day (p < 0.001). The patients with dysphagia had a significantly higher average intraluminal pressure (60.8 +/- 54.3 compared with 54.4 +/- 51.8 mm Hg; p < 0.0001) as well as significantly lower average mucosal perfusion (26.1 +/- 18.1 compared with 40.8 +/- 26.2 tissue perfusion units; p < 0.0001) in comparison with the asymptomatic patients. CONCLUSIONS Patients with dysphagia following anterior cervical arthrodesis were exposed to higher intraoperative esophageal pressure and decreased esophageal mucosal blood flow during surgical retraction as compared with patients without dysphagia. In this small series, dynamic retraction seemed to be associated with a lower prevalence of postoperative dysphagia.

Natural history of spinopelvic alignment differs from symptomatic deformity of the spine.

Study Design. Cross-sectional study and systematic review of the literature. Objective. Describe the natural history of spinopelvic alignment parameters and their behavior in patients with degenerative spinal deformity. Summary of Background Data. Normal stance and gait requires congruence between the spine-sacrum and pelvis-lower extremities. This is determined by the pelvic incidence (PI), and 2 positional parameters, the pelvic tilt, and sacral slope (SS). The PI also affects lumbar lordosis (LL), a positional parameter. The final goal is to position the bodys axis of gravity to minimize muscle activity and energy consumption. Methods. Two study cohorts were recruited: 32 healthy teenagers (Risser IV-V) and 54 adult patients with symptomatic spinal deformity. Standing radiographs were used to measure spinopelvic alignment and positional parameters (SS, PI, sacral-femoral distance [SFD], C7-plumbline [C7P], LL, and thoracic kyphosis). Data from comparable groups of asymptomatic individuals were obtained from the literature. Results. PI increases linearly with age (r2 = 0.8646) and is paralleled by increasing SFD (r2 = 0.8531) but not by SS. Patients with symptomatic deformity have higher SFD (42 ± 13.6 mm vs. 63.6 ± 21.6 mm; P < 0.001) and lower SS (42° ± 9.6° vs. 30.7° ± 13.6°; P < 0.001) but unchanged PI. The C7P also presents a linear increase throughout life (r2 = 0.8931), and is significantly increased in patients with symptomatic deformity (40 ± 37 mm vs. 70.3 ± 59.5 mm; P < 0.001). Conclusion. First, Gradual increase in PI is described throughout the lifespan that is paralleled by an increase in SFD, and is not by an increase in the SS. This represents a morphologic change of the pelvis. Second, Patients with symptomatic deformity of the spine present an increased C7P, thoracic hypokyphosis, reduced LL, and signs of pelvic retroversion (decreased LL and SS; increased SFD).

Increasing hospital charges for adolescent idiopathic scoliosis in the United States.

Study Design. Retrospective cohort study. Objective. To determine the trends and causes for increases in hospital charges in adolescent idiopathic scoliosis (AIS) fusions. Summary of Background Data. Trends in utilization rates, surgical procedure types, and hospital charges for AIS fusions have not been well investigated. Methods. We used International Classification of Diseases, Ninth Revision, billing codes to identify 29,594 AIS fusion cases from the National Inpatient Service (NIS) database between 2001 and 2011. Data were trended over time, and contrasted against other common procedures. To identify specific drivers of charges, we queried our own hospitals billing system, and averaged charges from 40 cases (10 cases for each of 4 yr studied). Dollar amounts were adjusted for inflation to 2011 dollars. Results. Utilization rates for AIS fusions have remained constant, whereas utilization of adult spinal fusions increased by 64% (P = 0.0004). Utilization of anterior thoracic fusions decreased by 80% (P < 0.0001). Mean hospital charges for AIS spinal fusions increased from

Thirty-Day Morbidity After Single-Level Anterior Cervical Discectomy and Fusion: Identification of Risk Factors and Emphasis on the Safety of Outpatient Procedures.

72,780 in 2001 to

Abnormally High Dislocation Rates of Total Hip Arthroplasty After Spinal Deformity Surgery.

155,278 in 2011 (113% increase), averaging 11.3% annually (P < 0.0001), with charges for adult spinal procedures increasing at a similar rate (13.4% annually, P < 0.0001). Charges for the other nonspine conditions increased to a lesser degree (range of 4.5%–6% annually, P < 0.001 for each). At our institution, spinal implant charges increased 27.6% annually, whereas surgeon charges decreased 0.5% annually, and all other charges increased only 5.2% annually. Over time, our surgeon used greater numbers of pedicle screws, and greater numbers of implants per surgery and per level fused (P < 0.05 for each). Implant charges were 28% of the total hospital bill in 2003, rising to 53% in 2012. Conclusion. Although utilization rates for AIS fusions have remained constant over time, hospital charges have increased substantively, and there has been a shift toward performing posterior only surgical procedures. This corresponds to the widespread adoption of pedicle screw–based constructs. Spinal implants may be the primary driver of increased charges. Strategies directed toward implant cost savings may thus have the largest impact. Level of Evidence: 4

The Impact of Renal Impairment on Short-term Morbidity Risk Following Lumbar Spine Surgeries.

BACKGROUND Risk factors for complication after single-level anterior cervical discectomy and fusion remain poorly defined. The purpose of this study was to identify the incidence and risk factors for complication from a large, prospectively collected database, with a separate emphasis on the safety of outpatient procedures. METHODS The American College of Surgeons National Surgical Quality Improvement Program prospectively collects thirty-day morbidity and mortality data from more than 480 hospitals around the United States. We retrospectively queried this database to identify cases of single-level elective anterior cervical discectomy and fusion. Univariate and multivariate analyses were used to identify risk factors for complication, and a propensity score model was used to create matched inpatient and outpatient cohorts. RESULTS Of 2914 cases identified, 597 (20.5%) received outpatient treatment and 2317 (79.5%) received inpatient treatment. The overall incidence of any systemic morbidity was 3.2%. There were five mortalities (0.2%), four in the inpatient cohort and one in the outpatient cohort. Patient age over sixty-five years, body mass index of >30 kg/m2, American Society of Anesthesiologists class of 3 or 4, current dialysis, current corticosteroid use, recent sepsis, and operative times longer than 120 minutes were each independent risk factors for complication in the multivariate analysis. After propensity score matching to control for comorbidities, there were no significant differences in complication rates between inpatients and outpatients, and outpatient treatment was not a risk factor for complication in the multivariate analysis. CONCLUSIONS Single-level elective anterior cervical discectomy and fusion had low complication rates, with no additional risk seen with outpatient as compared with inpatient procedures. It seems reasonable to consider inpatient admission for any patient with the risk factors identified here, particularly difficult airways. This information may be useful to surgeons performing informed consents for medical optimization and for selecting patients most appropriate for outpatient treatment. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Selective Thoracic Fusion of Lenke I and II Curves Affects Sagittal Profiles But Not Sagittal or Spinopelvic Alignment: A Case-Control Study.

BACKGROUND The purpose of this study was to determine the prevalence of concurrent spinopelvic fusion and THA and identify the risk of THA dislocation in patients with concurrent spinopelvic fusion. METHODS We retrospectively reviewed an institutional database of spinal deformity patients and the Humana Inc data set to identify patients with concurrent THA and spinopelvic fusion. The prevalence of concurrent THA and spinopelvic fusion was identified, as was the risk of dislocation for all cohorts. RESULTS Of 328 patients with spinopelvic fusions at our institution, 15 patients (4.6%) were found to have concurrent THA. Similarly, within the Humana database among 1049 patients with spinopelvic fusion, 4.6% had a concurrent THA. Among the 58,692 THA patients identified, only 0.1% had a concurrent spinopelvic fusion. A THA dislocation was observed in 3 of 15 patients (20.0%) and 3 of 18 THA (16.7%) within our institutional review. Within the Humana database, 8.3% of patients with THA and spinopelvic fusion went on to have a dislocation of their THA compared to 2.9% of patients with THA and no history of spinopelvic fusion (relative risk: 2.9 [1.2-7.6]). CONCLUSION Among patients with spinopelvic fusion, the prevalence of concurrent THA is 4.6%, and among primary THA patients, the prevalence of concurrent spinopelvic fusion is 0.1%. An alarmingly high THA dislocation rate has been demonstrated among THA patients with concurrent spinopelvic fusion at our institution (20%) and within a large national database (8.3%).