Impact of Compensated Cirrhosis Etiology on Postoperative Outcomes Following Total Knee Arthroplasty.

BACKGROUND: Cirrhotics often demonstrate worse outcomes than their non-cirrhotic counterparts following orthopedic surgery; however, there are limited arthroplasty-focused data on this occurrence. Additionally, variances in postoperative outcomes among the different etiologies of cirrhosis have not been well described. The aim of this study is to evaluate the effect compensated cirrhosis had on postoperative outcomes following elective total knee arthroplasty (TKA). METHODS: In total, 1,734,568 patients who underwent primary TKA from 2006 to 2013 were identified using the Medicare Claims Database. Patients were divided into those with a history of compensated cirrhosis and those with no history of liver disease. Subgroup analysis was performed based on the etiology of cirrhosis. Multivariate logistic regression was used to evaluate postsurgical outcomes of interest. RESULTS: Cirrhotic patients had higher risk of developing disseminated intravascular coagulation (odds ratio [OR] 2.76, P = .003), encephalopathy (OR 3.00, P < .001), and periprosthetic infection (OR 1.79, P < .001) compared to controls. Following subgroup analysis, alcoholic cirrhotics had high risk of periprosthetic infection (OR 2.12, P < .001), fracture (OR 3.28, P < .001), transfusion (OR 2.45, P < .001), and encephalopathy (OR 7.34, P < .001) compared to controls. Viral cirrhosis was associated with an increase in 90-day charges ($14,941, P < .001) compared to controls, while cirrhosis secondary to other causes was associated with few adverse outcomes compared to controls. CONCLUSION: Liver cirrhosis is an independent risk factor for increased perioperative morbidity and financial burden following TKA. Cirrhosis due to etiologies other than viral infections and alcoholism are associated with few adverse outcomes. Surgeons should be aware of these complications to properly optimize postoperative management.

Compensated Cirrhosis Is Associated With Increased Risk of Complications Following Total Hip Arthroplasty in a Large Medicare Database.

BACKGROUND: The aim of this study is to evaluate medical and surgical complications of liver cirrhosis patients following total hip arthroplasty (THA), with attention to different etiologies of cirrhosis and their financial burden following THA. METHODS: In total, 18,321 cirrhotics and 722,757 non-cirrhotics who underwent primary elective THA between 2006 and 2013 were identified from a retrospective database review. This cohort was further subdivided into 2 major etiologies of cirrhosis (viral and alcoholic cirrhosis) and other cirrhotic etiology. Cirrhotics were compared to non-cirrhotics for hospital length of stay, 90-day mean total charges and reimbursement, hospital readmission, and major medical and arthroplasty-specific complications. RESULTS: Cirrhosis was associated with increased rates of major medical complications (4.3% vs 2.4%; odds ratio [OR] 1.20, P < .001), minor medical complications, transfusion (3.4% vs 2.1%; OR 1.16, P = .001), encephalopathy, disseminated intravascular coagulation, and readmission (13.5% vs 8.6%; OR 1.18, P < .001) within 90 days. Cirrhosis was associated with increased rates of revision, periprosthetic joint infection, hardware failure, and dislocation within 1 year postoperatively (3.1% vs 1.6%; OR 1.37, P < .001). Cirrhosis independently increased hospital length of stay by 0.14 days (P < .001), and it independently increased 90-day charges and reimbursements by $13,791 (P < .001) and $1707 (P < .001), respectively. Viral and alcoholic cirrhotics had higher rates of 90-day and 1-year complications compared to controls-other causes only had higher rates of 90-day medical complications, encephalopathy, readmission, and 1-year revision, hardware failure, and dislocation compared to controls. CONCLUSION: Cirrhosis, especially viral and alcoholic etiologies, is associated with higher risk of early postoperative complications and healthcare utilization following elective THA.

Revision Joint Arthroplasty and Renal Transplant: A Matched Control Cohort Study.

BACKGROUND: There is little literature concerning clinical outcomes following revision joint arthroplasty in solid organ transplant recipients. The aims of this study are to (1) analyze postoperative outcomes and mortality following revision hip and knee arthroplasty in renal transplant recipients (RTRs) compared to non-RTRs and (2) characterize common indications and types of revision procedures among RTRs. METHODS: A retrospective Medicare database review identified 1020 RTRs who underwent revision joint arthroplasty (359 revision total knee arthroplasty [TKA] and 661 revision total hip arthroplasty [THA]) from 2005 to 2014. RTRs were compared to their respective matched control groups of nontransplant revision arthroplasty patients for hospital length of stay, readmission, major medical complications, infections, septicemia, and mortality following revision. RESULTS: Renal transplantation was significantly associated with increased length of stay (6.12 ± 7.86 vs 4.33 ± 4.29, P < .001), septicemia (odds ratio [OR], 2.52; 95% confidence interval [CI], 1.83-3.46; P < .001), and 1-year mortality (OR, 2.71; 95% CI, 1.51-4.53; P < .001) following revision TKA. Among revision THA patients, RTR status was associated with increased hospital readmission (OR, 1.23; 95% CI, 1.03-1.47; P = .023), septicemia (OR, 1.82; 95% CI, 1.41-2.34; P < .001), and 1-year mortality (OR, 2.65; 95% CI, 1.88-3.66; P < .001). The most frequent primary diagnoses associated with revision TKA and THA among RTRs were mechanical complications of prosthetic implant. CONCLUSION: Prior renal transplantation among revision joint arthroplasty patients is associated with increased morbidity and mortality when compared to nontransplant recipients.

Does Polycythemia Vera Increase Risk of Postoperative Complications Following Primary Total Joint Arthroplasty? A Retrospective Matched Control Cohort Study of 6932 Polycythemia Vera Patients.

BACKGROUND: There is sparsity of data on outcomes following joint arthroplasty among polycythemia vera (PV) patients. The aim of this study is to evaluate postoperative outcomes following primary total knee (TKA) and hip (THA) arthroplasty among PV patients. METHODS: A retrospective Medicare database review identified 6932 PV patients who underwent a primary total joint arthroplasty (4643 TKAs and 2289 THAs) from 2006 to 2013. A comparison of hospital length of stay, mortality, and the diagnosis of surgical site infections (SSIs), stroke, myocardial infarction, acute pulmonary embolism (PE), deep vein thrombosis (DVT), and other postoperative complications was made between PV patients undergoing TKA and THA and their respective matched control groups. RESULTS: PV was significantly associated with increased rates of acute PE (2.3% vs 1.6%; odds ratio [OR] 1.44, 95% confidence interval [CI] 1.17-1.75), DVT (4.2% vs 3.6%; OR 1.40, 95% CI 1.20-1.61, P < .001), postoperative hematoma (0.6% vs 0.4%; OR 1.57, 95% CI 1.03-2.28), and SSI (4.5% vs 3.6%; OR 1.25, 95% CI 1.08-1.44, P = .002) following TKA. Among PV patients who underwent a primary THA, PV was significantly associated with increased rate of acute PE (1.9% vs 1.4%; OR 1.40, 95% CI 1.01-1.88, P = .035), DVT (3.5% vs 2.6%; OR 1.32, 95% CI 1.04-1.66, P = .035), postoperative hematoma (1.1% vs 0.6%; OR 1.86, 95% CI 1.22-2.80), and 1-year mortality (2.2% vs 1.6%; OR 1.43, 95% CI 1.06-1.89, P = .016). CONCLUSION: PV was significantly associated with increased risk for DVT, PE, postoperative hematoma, SSI (TKA only), and 1-year mortality (THA only) following primary total joint arthroplasty.

Outcomes Following Revision Joint Arthroplasty Among Hemodialysis-Dependent Patients.

BACKGROUND: Hemodialysis (HD) dependence is known to impact the integrity of bone and has long been associated with metabolic bone disease and other adverse events postoperatively. The aim of this study is to analyze postoperative outcomes following revision hip and knee arthroplasty in hemodialysis-dependent (HDD) patients and to characterize the common indications for revision procedures among this patient population. METHODS: A total of 1779 HDD patients who underwent a revision joint arthroplasty (930 revision total knee arthroplasty [TKA] and 849 revision total hip arthroplasty [THA]) between 2005 and 2014 were identified from a retrospective database review. Our resulting study groups of revision TKA and THA HDD patients were compared to their respective matched control groups for hospital length of stay (LOS), 90-day mean total cost, hospital readmission, and other major medical and surgical complications. RESULTS: HD was significantly associated with increased LOS (7.7 ± 8.3 vs 4.8 ± 4.5; P < .001), mean 90-day total cost ($47,478 ± $33,413 vs $24,286 ± $21,472; P < .001), hospital readmission (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.96-2.58; P < .001), septicemia (OR, 3.18; 95% CI, 2.70-3.74; P < .001), postoperative infection (OR, 1.72; 95% CI, 1.50-1.98; P < .001), and mortality (OR, 3.99; 95% CI, 3.12-5.06; P < .001) following revision TKA. Among revision THA patients, HD was associated with increased LOS (9.4 ± 9.5 vs 5.7 ± 5.7; P < .001), mean 90-day total cost ($40,182 ± $27,082 vs $26,519 ± $22,856; P < .001), hospital readmission (OR, 2.33; 95% CI, 2.02-2.68; P < .001), septicemia (OR, 3.61; 95% CI, 3.05-4.27; P < .001), and mortality (OR, 3.55; 95% CI, 2.86-4.37; P < .001). CONCLUSION: HD remains a significant risk factor for increased LOS, mean total cost, hospital readmission, septicemia, and mortality following revision joint arthroplasty.

A Matched-Cohort Analysis of Outcomes in Patients with Hereditary Hemochromatosis After Anterior Cervical Discectomy and Fusion.

BACKGROUND: Hereditary hemochromatosis (HH) is a common autosomal recessive disorder. This disease affects gut iron transport, leading to iron overload, which affects immune function, coagulation mechanics, and bone health. Within the spine, HH contributes to decreased bone mineral density and accelerated intervertebral disc degeneration. The purpose of this study was to discover the differences in the rates of common 90-day postoperative complications and 1-year and 2-year surgical outcomes in patients with and without HH after anterior cervical discectomy and fusion (ACDF). METHODS: Using the PearlDiver database, patients with active diagnoses of HH before ACDF were matched to patients without HH using a 1:5 ratio on the basis of age, sex, body mass index, and comorbidities. Postoperative complications were assessed at 90 days, and 1-year and 2-year surgical outcomes were assessed. All outcomes and complications were analyzed using multivariate logistic regression with significance achieved at P < 0.05. RESULTS: Patients with HH had significantly higher rates of 1-year and 2-year reoperation rates compared with patients without HH (29.19% vs. 3.94% and 37.1% vs. 5.93%, respectively; P < 0.001). The rates of 90-day postoperative complications significantly increased in patients with HH including dysphagia, pneumonia, cerebrovascular accident, deep vein thrombosis, acute kidney injury, urinary tract infection, hyponatremia, surgical site infection, iatrogenic deformity, emergency department visit, and hospital readmission. CONCLUSIONS: Patients with HH undergoing ACDF showed increased 90-day postoperative complications and significantly increased rates of 1-year and 2-year reoperation compared with patients without HH. These findings suggest that iron overload may contribute to adverse outcomes in patients with HH undergoing 1-level and 2-level ACDF.

Carbon fiber lumbopelvic reconstruction following sacral giant cell tumor resection: illustrative case.

BACKGROUND: The use of carbon fiber or polyetheretherketone spine constructs has proven to be a safe and effective alternative to standard metal alloy. The mechanical properties of carbon fiber while unique provide a construct that is comparable in strength to previous titanium-based constructs and have additionally shown greater fatigue resistance. These constructs have been especially useful for the mechanical stabilization of the spine following tumor resection. The subsequent interference seen when imaging a patient with a traditional metallic construct is reduced and allows for improved tumor surveillance after the procedure, and a more accurate delivery of radiotherapy when indicated. OBSERVATIONS: This case report details the treatment of a 25-year-old female diagnosed with a sacral giant cell tumor. The authors discuss the use of a carbon fiber-reinforced polyetheretherketone for lumbopelvic reconstruction. LESSONS: Carbon fiber-reinforced polyetheretherketone with its radiolucency and rigidity is a reliable option for complex spinal reconstruction after tumor resection.

Increasing Cost Efficiency in Adult Spinal Deformity Surgery: Identifying Predictors of Lower Total Costs.

STUDY DESIGN: Retrospective study of a prospective multicenter database. OBJECTIVE: The purpose of this study was to identify predictors of lower total surgery costs at 3 years for adult spinal deformity (ASD) patients. SUMMARY OF BACKGROUND DATA: ASD surgery involves complex deformity correction. METHODS: Inclusion criteria: surgical ASD (scoliosis ≥20°, sagittal vertical axis [SVA] ≥5 cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°) patients >18 years. Total costs for surgery were calculated using the PearlDiver database. Cost per quality-adjusted life year was assessed. A Conditional Variable Importance Table used nonreplacement sampling set of 20,000 Conditional Inference trees to identify top factors associated with lower cost surgery for low (LSVA), moderate (MSVA), and high (HSVA) SRS Schwab SVA grades. RESULTS: Three hundred sixtee of 322 ASD patients met inclusion criteria. At 3-year follow up, the potential cost of ASD surgery ranged from $57,606.88 to $116,312.54. The average costs of surgery at 3 years was found to be $72,947.87, with no significant difference in costs between deformity groups (P > 0.05). There were 152 LSVA patients, 53 MSVA patients, and 111 HSVA patients. For all patients, the top predictors of lower costs were frailty scores <0.19, baseline (BL) SRS Activity >1.5, BL Oswestry Disability Index <50 (all P < 0.05). For LSVA patients, no history of osteoporosis, SRS Activity scores >1.5, age <64, were the top predictors of lower costs (all P < 0.05). Among MSVA patients, ASD invasiveness scores <94.16, no past history of cancer, and frailty scores <0.3 trended toward lower total costs (P = 0.071, P = 0.210). For HSVA, no history of smoking and body mass index <27.8 trended toward lower costs (both P = 0.060). CONCLUSION: ASD surgery has the potential for improved cost efficiency, as costs ranged from $57,606.88 to $116,312.54. Predictors of lower costs included higher BL SRS activity, decreased frailty, and not having depression. Additionally, predictors of lower costs were identified for different BL deformity profiles, allowing for the optimization of cost efficiency for all patients.Level of Evidence: 3.

A cost benefit analysis of increasing surgical technology in lumbar spine fusion.

BACKGROUND CONTEXT: Numerous advances have been made in the field of spine fusion, such as minimally invasive (MIS) or robotic-assisted spine surgery. However, it is unknown how these advances have impacted the cost of care. PURPOSE: Compare the economic outcomes of lumbar spine fusion between open, MIS, and robot-assisted surgery patients. STUDY DESIGN/SETTING: Retrospective review of a single center spine surgery database. PATIENT SAMPLE: Three hundred sixty propensity matched patients. OUTCOME MEASURES: Costs, EuroQol-5D (EQ5D), cost per quality adjusted life years (QALY). METHODS: Inclusion criteria: surgical patients >18 years undergoing lumbar fusion surgery. Patients were categorized into 3 groups based on procedure type: open, MIS, or robotic. Open patients undergoing poster spinal fusion were considered as the control group. MIS patients included those undergoing transforaminal or lateral lumbar interbody fusion with percutaneous screws. Robotic patients were those undergoing robot-assisted fusion. Propensity score matching was performed between all groups for the number of levels fused. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims for ICD-9 codes. For robotic cases, costs were reflective of operational fees and initial purchase cost. Complications and comorbidities and major complications and comorbidities were assessed according to CMS.gov manual definitions. QALYs and cost per QALY were calculated using a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs per QALY were calculated for both 1 year and life expectancy, assuming no loss of benefit. A 10,000 trial Monte Carlo simulation with probabilistic sensitivity analysis (PSA) assessed our model parameters and costs. RESULTS: Three hundred sixty propensity matched patients (120 open, 120 MIS, 120 robotic) met inclusion criteria. Descriptive statistics for the cohort were: age 58.8±13.5, 50% women, BMI 29.4±6.3, operative time 294.4±119.0, LOS 4.56±3.31 days, estimated blood loss 515.9±670.0 cc, and 2.3±2.2 average levels fused. Rates of post-op complications were significantly higher in robotic cases versus open and MIS (43% vs. 21% and 22% for open and MIS, p<.05). However, revision rates were comparable between all groups (3% open, 3% MIS, 5% robotic, p>.05). After factoring in complications, revisions, and purchasing and operating fees, the costs of robotic cases was significantly higher than both open and MIS surgery ($60,047.01 vs. $42,538.98 open and $41,471.21 MIS). In a subanalysis of 42 patients with baseline (BL) and 1Y EQ5D data, the cost per QALY at 1Y for open, MIS, and robot-assisted cases was $296,624.48, $115,911.69, and $592,734.30. If utility gained was sustained to life expectancy, the cost per QALY was $14,905.75, $5,824.71, $29,785.64 for open, MIS, and robot-assisted cases. Results of the PSA were consistent with MIS surgery having the most incremental cost effectiveness when compared to open and robotic surgery. CONCLUSIONS: Numerous advances have been made in the field of spine surgery, however, there has been limited discussion of the effect these advances have on economic outcomes. When matched for levels fused, robot-assisted surgery patients had significantly higher rates of complications and 30% higher costs of surgery compared to minimally invasive and open spine surgery patients. While 1 year economic outcomes were not optimal for robotic surgery cases, the projected costs per QALYs at life expectancy were well below established acceptable thresholds. The above findings may be reflective of an educational learning curve and emerging surgical technologies undergoing progressive refinement.

Does Arthroscopic Repair of Femoroacetabular Impingement Pathology Affect Clinical Outcomes after Ipsilateral Total Hip Arthroplasty?

PURPOSE: Arthroscopy for repair of femoroacetabular impingement (FAI) and related conditions is technically challenging, but remains the preferred approach for management of these hip pathologies. The incidence of this procedure has increased steadily for the past few years, but little is known about its potential long-term effects on future interventions. The purpose of this study was to evaluate whether prior arthroscopic correction of FAI pathology impacts postoperative complication rates in patients receiving subsequent ipsilateral total hip arthroplasty (THA) on a national scale. MATERIALS AND METHODS: A commercially available national database - PearlDiver Patients Records Database - identified primary THA patients from 2005 to 2014. Patients who had prior arthroscopic FAI repair (post arthroscopy group) were separated from those who did not (native hip group). Prior FAI repair was examined as a risk factor for complications following THA and a multivariable logistic regression analysis was applied to identify risk factors for complications following THA. RESULTS: A total of 11,061 patients met all inclusion and exclusion criteria; 10,951 in the native hip group and 110 in the post arthroscopy group. Prior FAI repair was not significantly associated with higher rates of 90-day readmission (P=0.585), aseptic dislocation/revision within 3 years (P=0.409), surgical site infection within 3 years (P=0.796), or hip stiffness within 3 years (P=0.977) after THA. CONCLUSION: Arthroscopic FAI repair is not an independent risk factor for complications following subsequent ipsilateral THA (level of evidence: III).

Outcomes Following Posterior Lumbar Fusion in Patients with Polycythemia Vera.

BACKGROUND: Polycythemia vera (PV) is a chronic myeloproliferative neoplasm that is associated with increased risk for venous and arterial thromboembolism. The aim of this study was to evaluate outcomes following elective posterior lumbar fusion (PLF) and/or posterior interbody fusion (PLIF) among patients with PV. METHODS: Using PearlDiver retrospective national database, Medicare patients <85 years old who underwent elective primary PLF (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 81.07) and/or PLIF (ICD-9-CM code 81.08) for degenerative lumbar spine pathologies during 2006-2013 were identified. Patients included in the PLF and/or PLIF cohort were separated into patients with a prior diagnosis of PV (ICD-9-CM code 238.4) and a control cohort of patients without PV. Comparisons of postoperative outcomes were made between the PV patient group and matched control group. Significance was set at 0.05. RESULTS: Selected study participants included 1491 patients with PV and 29,056 patients in the matched control group. Patients with PV had a significantly increased rate of 90-day acute pulmonary embolism (1.9% vs. 1.2%, odds ratio [OR] 1.65, 95% confidence interval [CI] 1.10-2.38, P = 0.010), 90-day lower extremity deep vein thrombosis (3.4% vs. 1.9%, OR 1.81, 95% CI 1.33-2.40, P < 0.001), and 1-year diagnosis of surgical site infection (5.4% vs. 4.2%, OR 1.30, 95% CI 1.02-1.63, P = 0.027) compared with patients without PV. Nonetheless, PV was not associated with other major medical complications, including stroke, myocardial infarction, and mortality, following PLF and/or PLIF. CONCLUSIONS: Patients with PV undergoing elective PLF and/or PLIF have a significantly increased risk for pulmonary embolism, lower extremity deep vein thrombosis, and surgical site infection.

Solid Organ Transplant Is Associated With Increased Morbidity and Mortality in Patients Undergoing One or Two-level Anterior Cervical Decompression and Fusion.

STUDY DESIGN: Retrospective database review OBJECTIVE.: The aim of this study was to analyze the implications of solid organ transplant (SOT) on postoperative outcomes following elective one or two-level anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Although SOTs have been associated with increased morbidity, postoperative outcomes in SOT recipients undergoing cervical spinal surgery are not well studied. METHODS: A retrospective database review of Medicare patients younger than 85 years who underwent an elective one to two-level ACDF from 2006-2013 was conducted. Following our exclusion criteria, patients were then divided into the following groups: those with a prior history of kidney, liver, heart or lung transplant (SOT group) and non-SOT patients. Both groups were compared for hospital length of stay, 90-day major medical complications, 90-day hospital readmission, 1-year surgical site infection (SSI), 1-year revision ACDF, and 1-year mortality. RESULTS: A total of 992 (0.5%) SOT recipients (1,144 organs) were identified out of 199,288 ACDF patients. SOT recipients had a significantly longer length of stay (2.32 vs. 5.22 days, p<0.001), higher rate of major medical complications (8.2% vs. 4.5%; OR 1.85, 95% CI 1.45-2.33, p<0.001) and hospital readmission (19.5% vs. 7.5%, OR 2.05, 95% CI 1.74-2.41, p<0.001). In addition, SOT patients had increased mortality within one year of surgery (5.8% vs. 1.3%; OR 3.01, 95% CI 2.26-3.94, p<0.001) compared to non-SOT patients. SOT was not independently associated with SSI (OR 1.25, 95% CI 0.85-1.75, p=0.230), and there was no significant difference in revision rate (0.9% vs. 0.5%; OR 1.54, 95% CI 0.73-2.82, p=0.202) between both groups. CONCLUSION: SOT is independently associated with longer hospital stay, increased rate of major medical complications, hospital readmission and mortality. Spine surgeons should be aware of the higher rates of morbidity and mortality in these patients and take it into consideration when developing patient-specific treatment plans. LEVEL OF EVIDENCE: 3.

A cost utility analysis of treating different adult spinal deformity frailty states.

The aim of this study was to investigate the cost utility of treating non-frail versus frail or severely frail adult spinal deformity (ASD) patients. 79 surgical ASD patients >18 years with available frailty and ODI data at baseline and 2-years post-surgery (2Y) were included. Utility data was calculated using the ODI converted to the SF-6D. QALYs utilized a 3% discount rate to account for decline to life expectancy (LE). Costs were calculated using the PearlDiver database. ICER was compared between non-operative (non-op.) and operative (op.) NF and F/SF patients at 2Y and LE. When compared to non-operative ASD, the ICER was $447,943.96 vs. $313,211.01 for NF and F/SF at 2Y, and $68,311.35 vs. $47,764.61 for NF and F/SF at LE. Frail and severely frail patients had lower cost per QALY compared to not frail patients at 2Y and life expectancy, and had lower ICER values when compared to a non-operative cohort of ASD patients. While these results support operative correction of frail and severely frail patients, it is important to note that these patients are often at worse baseline disability, which is closely related to frailty scores, and have more opportunity to improve postoperatively. Furthermore, there may be a threshold of frailty that is not operable due to the risk of severe complications that is not captured by this analysis. While future research should investigate economic outcomes at extended follow up times, these findings support the cost effectiveness of ASD surgery at all frailty states.

Obesity negatively affects cost efficiency and outcomes following adult spinal deformity surgery.

BACKGROUND CONTEXT: Obesity has risen to epidemic proportions within the United States. As the rates of obesity have increased, so has its prevalence among patients undergoing adult spinal deformity (ASD) surgery. The effect of obesity on the cost efficiency of corrective procedures for ASD has not been effectively evaluated. PURPOSE: To investigate differences in cost efficiency of ASD surgery for patients stratified by body mass index (BMI). STUDY DESIGN/SETTING: Retrospective review of a single-center ASD database. PATIENT SAMPLE: Five hundred five ASD patients. OUTCOME MEASURES: Complications, revisions, costs, EuroQol-5D (EQ5D), quality-adjusted life years (QALYs), cost per QALY. METHODS: ASD patients (scoliosis≥20°, SVA≥5 cm, PT≥25°, or TK ≥60°) ≥18, undergoing ≥4 level fusions were included. Patients were stratified into NIH-defined obesity groups based on their preoperative BMI: underweight 18.5< (U), normal 18.5 to 24.9 (N), overweight 25.0 to 29.9 (O), obese I 30.0 to 34.9 (OI), obese II 35.0 to 39.9 (OII), and obesity class III 40.0+ (OIII). Total surgery costs for each ASD obesity group were calculated. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims. Overall complications and major complications were assessed according to CMS definitions. QALYs and cost per QALY for obesity groups were calculated using an annual 3% discount up to life expectancy (78.7 years). RESULTS: In all, 505 patients met inclusion criteria. Baseline demographics and surgical details were: age 60.8±14.8, 67.6% female, BMI 28.8±7.30, 81.0% posterior approach, 18% combined approach, 10.1±4.2 levels fused, op time 441.2±146.1 minutes, EBL 1903.8±1594.7 cc, and LOS 8.7±10.7 days. There were 17 U, 154 N patients, 151 O patients, 100 OI, 51 OII, and 32 OIII patients. Revision rates by obesity group were: 0% U, 3% N patients, 3% O patients, 5% OI, 4% OII, and 6% for OIII patients. The total surgery costs by obesity group were: $48,757.86 U, $49,688.52 N, $47,219.93 O, $50,467.66 OI, $51,189.47 OII, and $53,855.79 OIII. In an analysis of patients with baseline and 1 Y EQ5D follow-up, the cost per QALY by obesity group was: $153,737.78 U, $229,222.37 N, $290,361.68 O, $493,588.47 OI, $327,876.21 OII, and $171,680.00 OIII. If that benefit was sustained to life expectancy, the cost per QALY was $8,588.70 U, $12,805.72 N, $16,221.32 O, $27,574.77 OI, $18,317.11 OII, and $9,591.06 for OIII. CONCLUSIONS: Among adult spinal deformity patients, those with BMIs in the obesity I, obesity II, or obesity class III range had more expensive total surgery costs. When assessing 1 year cost per QALY, obese patients had costs 32% higher than nonobese patients ($224,440.61 vs. $331,048.23). Further research is warranted on the utility of optimizing modifiable preoperative health factors for patients undergoing corrective adult spinal deformity surgery.

Pathogenesis of Posttraumatic Osteoarthritis of the Ankle.

Ankle osteoarthritis affects a significant portion of the global adult population. Unlike other joints, arthritis of the ankle often develops as a response to traumatic injury (intra-articular fracture) of the ankle joints. The full mechanism leading to posttraumatic osteoarthritis of the ankle (PTOAA) is poorly understood. These deficits in knowledge pose challenges in the management of the disease. Adequate surgical reduction of fractured ankle joints remains the gold standard in prevention. The purpose of this review is to thoroughly delineate the known pathogenesis of PTOAA, and provide critical updates on this pathology and new avenues to provide therapeutic management of the disease.

Recent Preoperative Lumbar Epidural Steroid Injection Is an Independent Risk Factor for Incidental Durotomy During Lumbar Discectomy.

STUDY DESIGN: Retrospective review. OBJECTIVE: To investigate the association between lumbar epidural steroid injection (LESI) and incidental durotomy (ID) in patients with a diagnosis of disc herniation undergoing a primary discectomy. METHODS: A Medicare patient database was queried for patients between the ages of 65 and 85 years who underwent a primary lumbar discectomy for a diagnosis of lumbar disc herniation or degeneration from 2008 to 2014. Our main cohort of 64 849 patients was then divided into 2 groups: patients who experienced a dural tear (N = 2369) and our matched (age, gender, and history of diabetes) control cohort of patients who did not (N = 62 480). All patients who had a history of LESI were further identified and stratified into 4 subgroups by duration between LESI and discectomy (<3 months, 3-6 months, 6 months to 1 year, and overall), and a comparison of the relative incidence of ID was made among these subgroups. A multivariate logistic regression analysis was employed to determine the relationship between LESI and ID. RESULTS: Overall incidence of ID was 3.7%. There was a significant difference in incidence of LESI (27.1% vs 35.0%, P < .001) between our control and ID groups. An adjusted odds ratio (OR) showed that prior LESI within 3 to 6 months (OR 1.47, 95% CI 1.20-1.81, P < .001) and within less than 3 months (OR 1.46, 95% CI 1.24-1.72, P < .001) of surgery were significantly associated with ID. CONCLUSION: LESI increases the risk of ID in patients who undergo a subsequent lumbar discectomy within 6 months of injection.