The American Orthopaedic Association's Own the Bone® database: a national quality improvement project for the treatment of bone health in fragility fracture patients

The American Orthopaedic Association initiated the Own the Bone (OTB) quality improvement program in 2009. Herein we show that the data collected through this program is similar to that collected in other large studies. Thus, the OTB registry functions as an externally valid cohort for studying fragility fracture patients.

INTRODUCTION

The American Orthopedic Association initiated the Own the Bone (OTB) quality improvement program in 2009 to improve secondary prevention of fragility fractures. In this study, we present a summary of the data collected by the OTB program and compare it to data from other large fragility fracture registries with an aim to externally validate the OTB registry.

METHODS

The OTB registry contained 35,038 unique cases of fragility fracture as of September, 2016. We report the demographics, presenting fracture characteristics, past fracture history, and bone mineral density (BMD) data and compare these to data from large fragility fracture studies across the world.

RESULTS

Seventy-three percent of the patients in the OTB registry were female, Caucasian, and post-menopausal. In 54.4% of cases, patients had a hip fracture; spine fractures were the second most common fracture type occurring in 11.1% of patients. Thirty-four percent of the patients had a past history of fragility fracture, and the most common sites were the spine and hip. The average femoral neck T-score was - 2.06. When compared to other studies, the OTB database showed similar findings with regard to patient age, gender, race, BMI, BMD profile, prior fracture history, and family history of fragility fractures.

CONCLUSION

OTB is the first and largest multi-center voluntary fragility fracture registry in the USA. The data collected through the OTB program is comparable to that collected in international studies. Thus, the OTB registry functions as an externally valid cohort for further studies assessing the clinical characteristics, interventions, and outcomes achieved in patients who present with a fragility fracture in the USA.

Subaxial Cervical Spine Injuries in the Polytrauma Patient

Management of cervical spine injuries in polytrauma patients involves a comprehensive assessment that consists of a physical examination and imaging studies to identify substantial injury. The management of diagnosed cervical spine injuries in polytrauma patients should be coordinated with the management of other injuries. Timely management is required in polytrauma patients with a spinal cord injury. A high oxygen saturation level must be maintained and a mean arterial blood pressure of 85 mm Hg is recommended. Reduction via traction or urgent surgical decompression, as indicated, should be considered. Reduction that is performed within a few hours postinjury may reverse neurologic deficits, and decompression that is performed within 24 hours postinjury increases the likelihood of substantial recovery. Neuroprotection with the use of methylprednisolone is not recommended in polytrauma patients with a cervical spine injury. Early surgical treatment is safe in polytrauma patients with a cervical spine injury who are adequately resuscitated. The surgical approach is directed by the fracture type and the requirements for decompression. Anterior surgical approaches are preferred in polytrauma patients with a cervical spine injury, and definitive surgical treatment may be delayed.

Applications of Three-Dimensional Printing in Orthopaedic Surgery

Orthopaedic surgeons should be aware of the variety of applications of three-dimensional printing, which range from rough-and-ready applications, such as rapid prototyping of implant designs with the use of polymers to the fabrication of patient-specific implants and custom implants with the use of the principles of metallurgy. The local manufacture of low-cost prosthetic devices in third-world nations is the best example of the potential application of three-dimensional printing. Orthopaedic surgeons should understand the multiple applications of three-dimensional printing, including prototyping of anatomy, implants, orthotics, patient-specific instrumentation, and implants that incorporate porous structures and accommodate complex anatomy, as well as the future of biologically active three-dimensional printing. It is helpful to be aware of the types of three-dimensional printing that are currently used in the clinical setting, those that are commercially available, and those under development.

Introduction to Additive Manufacturing and Three-Dimensional Printing in Orthopaedics

Additive manufacturing involves the construction of devices via the layer-by-layer deposition of materials. Additive manufacturing, which also is referred to as three-dimensional printing, is different from traditional machining, which involves the subtraction of material from a workpiece. Although traditional machining methods have been used in the field of manufacturing for decades, a recent rise in the commercial use of additive manufacturing has occurred in the field of orthopaedic surgery. Orthopaedic surgeons should understand the pertinent history of three-dimensional printing with regard to the field of manufacturing technology and the manner in which recent advances in additive manufacturing have allowed for new product designs with musculoskeletal applications. In addition, it is helpful to be aware of the regulatory aspects of additive manufacturing to ensure the safe and effective use of orthopaedic surgical devices created via three-dimensional printing.

Three-Dimensional Printing and Tissue Engineering in Orthopaedics

Additive manufacturing and three-dimensional printing technology may revolutionize tissue-engineering strategies. Many clinical needs, including multitissue regeneration, remain unmet among patients with orthopaedic conditions. Ongoing research efforts in three-dimensional printing, including cell-containing bioinks for bioprinting, have resulted in acellular and cellular biomaterials that may help regenerate or replace damaged or missing biologic tissues. Recent advances in additive manufacturing aid in the preservation of biologic activity, such as the retention of growth factors, which may affect the delivery of safe, cost-effective, and efficacious bone graft substitutes for orthopaedic patients.

Bone Mineral Density T-Scores Derived from CT Attenuation Numbers (Hounsfield Units): Clinical Utility and Correlation with Dual-energy X-ray Absorptiometry

BACKGROUND

Clinical computed tomography (CT) studies performed for other indications can be used to opportunistically assess vertebral bone without additional radiation or cost. Reference values for young women are needed to evaluate diagnostic accuracy and track changes in CT bone mineral density values across the lifespan. The purpose of this study was to determine reference values for lumbar trabecular CT attenuation (Hounsfield units [HU]) and determine the diagnostic accuracy of HU T-scores (T-score_HU) for identifying individuals with osteoporosis.

METHODS

We performed a retrospective single-center cohort study of patients undergoing CT of the lumbar spine. Reference values for lumbar spine Hounsfield units were determined from a reference sample of 190 young women aged 20-30 years undergoing CT scan of the lumbar spine. A separate sample of 252 older subjects undergoing CT and dual-energy X-ray absorptiometry (DXA) within a 6-month period that served as a validation cohort. Osteoporosis was defined by T-score_DXA ≤ -2.5. Reference values were determined for lumbar HU from L1 to L4 from the reference cohort (24.0 ± 2.9 years). T-score_HU was calculated in the validation cohort (58.9 ± 7.5 yrs). Receiver operating characteristic (ROC) curves were used to assess sensitivity and specificity of T-score_HU for this task.

RESULTS

Reference group HU ranged from 227 ± 42 at L3 to 236 ± 42 at L1 (P < 0.001). Validation group T-score_DXA was -0.7 ± 1.5 and -0.9 ± 1.2 at lumbar and femoral sites respectively. Mean T-score_HU was -2.3. T-score_HU of -3.0, corresponding to 110 HU, was 48% sensitive and 91% specific for osteoporosis in the validation group. ROC area under the curve ranged from 0.825 to 0.853 depending on lumbar level assessed.

CONCLUSIONS

Although lumbar trabecular HU T-scores are lower than DXA T-scores, thresholds can be selected to achieve high sensitivity and specificity when screening for osteoporosis. Patients with a lumbar T-score_HU ≤ -3.0 should be referred for additional evaluation. Further research into HU T-scores and clinical correlates may also provide a tool to assess changes in vertebral bone and the relationship to fracture risk across the lifespan.

Prevention of Surgical Site Infection in Spine Surgery

BACKGROUND

Spine surgery is complicated by an incidence of 1% to 9% of surgical site infection (SSI). The most common organisms are gram-positive bacteria and are endogenous, that is are brought to the hospital by the patient. Efforts to improve safety have been focused on reducing SSI using a bundle approach. The bundle approach applies many quality improvement efforts and has been shown to reduce SSI in other surgical procedures.

OBJECTIVE

To provide a narrative review of practical solutions to reduce SSI in spine surgery.

METHODS

Literature review and synthesis to identify methods that can be used to prevent SSI.

RESULTS

SSI prevention starts with proper patient selection and optimization of medical conditions, particularly reducing smoking and glycemic control. Screening for staphylococcus organisms and subsequent decolonization is a promising method to reduce endogenous bacterial burden. Preoperative warming of patients and timely administration of antibiotics are critical to prevent SSI. Skin preparation using chlorhexidine and alcohol solutions are recommended. Meticulous surgical technique and maintenance of sterile techniques should always be performed. Postoperatively, traditional methods of tissue oxygenation and glycemic control remain essential. Newer wound care methods such as silver impregnation dressing and wound-assisted vacuum dressing are encouraging but need further investigation.

CONCLUSION

Significant reduction of SSIs is possible, but requires a systems approach involving all stakeholders. There are many simple and low-cost components that can be adjusted to reduce SSIs. Systematic efforts including understanding of pathophysiology, prevention strategies, and system-wide quality improvement programs demonstrate significant reduction of SSI.

Behavioral responses of beluga whales (Delphinapterus leucas) to environmental variation in an Arctic estuary

Some Arctic estuaries serve as substrate rubbing sites for beluga whales (Delphinapterus leucas) in the summer, representing a specialized resource for the species. Understanding how environmental variation affects the species' behavior is essential to management of these habitats in coming years as the climate changes. Spatiotemporal and environmental variables were recorded for behavioral observations, during which focal groups of whales in an estuary were video-recorded for enumeration and behavioral analysis. Multiple polynomial linear regression models were optimized to identify the effects of spatiotemporal and environmental conditions on group size, composition, and the frequency of behaviors being performed. Results suggest that belugas take advantage of environmental variation to express behaviors that 1) protect young, e.g., bringing calves close to shore during cloudier days, obscuring visualization from terrestrial predators; 2) avoid predation, e.g., rubbing against substrates at higher Beaufort sea states to obscure visualization, and resting during low tides while swimming on outgoing tides to avoid stranding; and 3) optimize bioenergetic resources, e.g., swimming during lower Beaufort sea states and clearer days. Predictive models like the ones presented in this study can inform conservation management strategies as environmental conditions change in future years.

Validity of height loss as a predictor for prevalent vertebral fractures, low bone mineral density, and vitamin D deficiency

Many osteoporosis-related vertebral fractures are unappreciated but their detection is important as their presence increases future fracture risk. We found height loss is a useful tool in detecting patients with vertebral fractures, low bone mineral density, and vitamin D deficiency which may lead to improvements in patient care.

INTRODUCTION

This study aimed to determine if/how height loss can be used to identify patients with vertebral fractures, low bone mineral density, and vitamin D deficiency.

METHODS

A hospital database search in which four patient groups including those with a diagnosis of osteoporosis-related vertebral fracture, osteoporosis, osteopenia, or vitamin D deficiency and a control group were evaluated for chart-documented height loss over an average 3 1/2 to 4-year time period. Data was retrieved from 66,021 patients (25,792 men and 40,229 women).

RESULTS

A height loss of 1, 2, 3, and 4 cm had a sensitivity of 42, 32, 19, and 14% in detecting vertebral fractures, respectively. Positive likelihood ratios for detecting vertebral fractures were 1.73, 2.35, and 2.89 at 2, 3, and 4 cm of height loss, respectively. Height loss had lower sensitivities and positive likelihood ratios for detecting low bone mineral density and vitamin D deficiency compared to vertebral fractures. Specificity of 1, 2, 3, and 4 cm of height loss was 70, 82, 92, and 95%, respectively. The odds ratios for a patient who loses 1 cm of height being in one of the four diagnostic groups compared to a patient who loses no height was higher for younger and male patients.

CONCLUSIONS

This study demonstrated that prospective height loss is an effective tool to identify patients with vertebral fractures, low bone mineral density, and vitamin D deficiency although a lack of height loss does not rule out these diagnoses. If significant height loss is present, the high positive likelihood ratios support a further workup.

Evaluation of Adverse Events in Total Disc Replacement: A Meta-Analysis of FDA Summary of Safety and Effectiveness Data

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

The safety of new technology such as cervical total disc replacement (TDR) is of paramount importance and is best evaluated in randomized clinical trials (RCT). We compared complication risks of TDR to fusion using data from Investigational Device Exemptions.

METHODS

A systematic review of FDA Summary of Safety and Effectiveness reports of the 8 approved cervical TDRs was performed. These were all randomized controlled trials comparing anterior cervical discectomy and fusion (ACDF) to TDR. Important outcome variables were dysphagia, wound infection, neurologic injuries, heterotopic ossification, death, and secondary surgeries. A random effects model was selected a priori. Data on adverse events was abstracted and analyzed by calculating relative risk of ACDF to TDR by meta-analysis techniques.

RESULTS

The study included 3027 patients with 1377 randomized to ACDF and 1652 to TDR. No statistical differences were present between the 2 groups in dysphagia/dysphonia, hardware related, heterotopic ossification, death, and overall neurologic adverse events and incidence of neurologic deterioration. The relative risk of wound-related problems ACDF to TDR was 0.76 (95% confidence interval [CI] = 0.59, 0.98) favoring ACDF, which was statistically significant, but these were minor and never required a second surgical procedure for deep wound infection. The relative risk of ACDF to TDR in surgical-related neurologic events and secondary surgeries was 1.62 (95% CI = 1.04, 2.53) and 1.79 (95% CI = 1.17, 2.74), both favoring TDR.

CONCLUSIONS

Cervical TDR appears to be as safe as or safer than ACDF at 2-year follow-up.

Clinical height measurements are unreliable: a call for improvement

Height measurements are currently used to guide imaging decisions that assist in osteoporosis care, but their clinical reliability is largely unknown. We found both clinical height measurements and electronic health record height data to be unreliable. Improvement in height measurement is needed to improve osteoporosis care.

INTRODUCTION

The aim of this study is to assess the accuracy and reliability of clinical height measurement in a university healthcare clinical setting.

METHODS

Electronic health record (EHR) review, direct measurement of clinical stadiometer accuracy, and observation of staff height measurement technique at outpatient facilities of the University of Wisconsin Hospital and Clinics. We examined 32 clinical stadiometers for reliability and observed 34 clinic staff perform height measurements at 12 outpatient primary care and specialty clinics. An EHR search identified 4711 men and women age 43 to 89 with no known metabolic bone disease who had more than one height measurement over 3 months. The short study period and exclusion were selected to evaluate change in recorded height not due to pathologic processes.

RESULTS

Mean EHR recorded height change (first to last measurement) was -0.02 cm (SD 1.88 cm). Eighteen percent of patients had height measurement differences noted in the EHR of ≥2 cm over 3 months. The technical error of measurement (TEM) was 1.77 cm with a relative TEM of 1.04 %. None of the staff observed performing height measurements followed all recommended height measurement guidelines. Fifty percent of clinic staff reported they on occasion enter patient reported height into the EHR rather than performing a measurement. When performing direct measurements on stadiometers, the mean difference from a gold standard length was 0.24 cm (SD 0.80). Nine percent of stadiometers examined had an error of >1.5 cm.

CONCLUSIONS

Clinical height measurements and EHR recorded height results are unreliable. Improvement in this measure is needed as an adjunct to improve osteoporosis care.

Hospital charges associated with “never events”: comparison of anterior cervical discectomy and fusion, posterior lumbar interbody fusion, and lumbar laminectomy to total joint arthroplasty

OBJECTIVE

Beginning in 2008, the Centers for Medicare and Medicaid Service (CMS) determined that certain hospital-acquired adverse events such as surgical site infection (SSI) following spine surgery should never occur. The following year, they expanded the ruling to include deep vein thrombosis (DVT) and pulmonary embolism (PE) following total joint arthroplasty. Due to their ruling that “never events” are not the payers' responsibility, CMS insists that the costs of managing these complications be borne by hospitals and health care providers, rather than billings to health care payers for additional care required in their management. Data comparing the expected costs of such adverse events in patients undergoing spine and orthopedic surgery have not previously been reported.

METHODS

The California State Inpatient Database (CA-SID) from 2008 to 2009 was used for the analysis. All patients with primary procedure codes indicating anterior cervical discectomy and fusion (ACDF), posterior lumbar interbody fusion (PLIF), lumbar laminectomy (LL), total knee replacement (TKR), and total hip replacement (THR) were analyzed. Patients with diagnostic and/or treatment codes for DVT, PE, and SSI were separated from patients without these complication codes. Patients with more than 1 primary procedure code or more than 1 complication code were excluded. Median charges for treatment from primary surgery through 3 months postoperatively were calculated.

RESULTS

The incidence of the examined adverse events was lowest for ACDF (0.6% DVT, 0.1% PE, and 0.03% SSI) and highest for TKA (1.3% DVT, 0.3% PE, 0.6% SSI). Median inpatient charges for uncomplicated LL was $51,817, compared with $73,432 for ACDF, $143,601 for PLIF, $74,459 for THR, and $70,116 for TKR. Charges for patients with DVT ranged from $108,387 for TKR (1.5 times greater than index) to $313,536 for ACDF (4.3 times greater than index). Charges for patients with PE ranged from $127,958 for TKR (1.8 times greater than index) to $246,637 for PLIF (1.7 times greater than index). Charges for patients with SSI ranged from $168,964 for TKR (2.4 times greater than index) to $385,753 for PLIF (2.7 times greater than index).

CONCLUSIONS

Although incidence rates are low, adverse events of spinal procedures substantially increase the cost of care. Charges for patients experiencing DVT, PE, and SSI increased in this study by factors ranging from 1.8 to 4.3 times those for patients without such complications across 5 common spinal and orthopedic procedures. Cost projections by health care providers will need to incorporate expected costs of added care for patients experiencing such complications, assuming that the cost burden of such events continues to shift from payers to providers.

Spinal Adverse Events Severity System, version 2 (SAVES-V2): inter- and intraobserver reliability assessment

OBJECTIVE

Reporting of adverse events (AEs) in spinal surgery uses inconsistent definitions and severity grading, making it difficult to compare results between studies. The Spinal Adverse Events Severity System, version 2 (SAVES-V2) aims to standardize the classification of spine surgery AEs; however, its inter- and intraobserver reliability are unknown. The objective of this study was to assess inter- and intraobserver reliability of the SAVES-V2 grading system for assessing AEs in spinal surgery.

METHODS

Two multinational, multicenter surgical study groups assessed surgical case vignettes (10 trauma and 12 degenerative cases) for AE occurrence by using SAVES-V2. Thirty-four members of the Spine Trauma Study Group (STSG) and 17 members of the Degenerative Spine Study Group (DSSG) participated in the first round of case vignettes. Six months later, the same case vignettes were randomly reorganized and presented in an otherwise identical manner. Inter- and intraobserver agreement on the presence, severity, number, and type of AE, as well as the impact of the AE on length of stay (LOS) were assessed using intraclass correlation (ICC), Cohen's kappa value, and the percentage of participants in agreement.

RESULTS

Agreement on the presence of AEs ranged from 97% to 100% in the 2 groups. Severity classification showed substantial interobserver (ICC = 0.75 for both groups) and intraobserver (ICC = 0.70 in DSSG, 0.71 in STSG) agreement. Judgments on the number of AEs showed high interobserver agreement and moderate intraobserver agreement in both groups. Both the STSG and DSSG had high intraobserver agreement on the type of AE; interobserver agreement for AE type was high in the STSG and fair in the DSSG. Agreement on impact of the AE on LOS was excellent in the DSSG and fair in the STSG.

CONCLUSIONS

There was good agreement on the presence, severity, and number of AEs in both trauma and degenerative cases in using the SAVES-V2. This grading system is a simple, reliable tool for identifying and capturing AEs in spinal surgery.

A population-based review of bone morphogenetic protein: associated complication and reoperation rates after lumbar spinal fusion

OBJECT The authors compared the rates of postoperative adverse events and reoperation of patients who underwent lumbar spinal fusion with bone morphogenetic protein (BMP) to those of patients who underwent lumbar spinal fusion without BMP. METHODS The authors retrospectively analyzed the PearlDiver Technologies, Inc., database, which contains the Medicare Standard Analytical Files, the Medicare Carrier Files, the PearlDiver Private Payer Database (UnitedHealthcare), and select state all-payer data sets, from 2005 to 2010. They identified patients who underwent lumbar spinal fusion with and without BMP. The ICD-9-CM code 84.52 was used to identify patients who underwent spinal fusion with BMP. ICD-9-CM diagnosis codes identified complications that occurred during the initial hospital stay. ICD-9-CM procedural codes were used to identify reoperations within 90 days of the index procedure. The relative risks (and 95% CIs) of BMP use compared with no BMP use (control) were calculated for the association of any complication with BMP use compared with the control. RESULTS Between 2005 and 2010, 460,773 patients who underwent lumbar spinal fusion were identified. BMP was used in 30.7% of these patients. The overall complication rate in the BMP group was 18.2% compared with 18.7% in the control group. The relative risk of BMP use compared with no BMP use was 0.976 (95% CI 0.963-0.989), which indicates a significantly lower overall complication rate in the BMP group (p < 0.001). In both treatment groups, patients older than 65 years had a statistically significant higher rate of postoperative complications than younger patients (p < 0.001). CONCLUSIONS In this large-scale institutionalized database study, BMP use did not seem to increase the overall risk of developing a postoperative complication after lumbar spinal fusion surgery.

Exercise Capacity Correlates With Left Atrial Structural Remodeling as Detected by Late Gadolinium-Enhanced Cardiac Magnetic Resonance in Patients With Atrial Fibrillation

OBJECTIVES

This study hypothesized that left atrial structural remodeling (LA-TR) correlates with exercise capacity (EC) in a cohort of patients with atrial fibrillation (AF).

BACKGROUND

Late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging provides a method of assessing LA-TR in patients with AF.

METHODS

A total of 145 patients (32% female, mean age 63.4 ± 11.6 years of age) with AF (66 paroxysmal, 71 persistent, 8 long-standing persistent) presenting for catheter ablation were included in the study. All patients underwent LGE-CMR imaging as well as maximal exercise test using the Bruce protocol prior to catheter ablation of AF. EC was quantified by minutes of exercise and metabolic equivalent (MET) level achieved. LA-TR was quantified from LGE-CMR imaging and classified according to the Utah classification of LA structural remodeling (Utah stage I: <10% LA wall enhancement; Utah II: 10% to <20%; Utah III: 20% to <30%; and Utah IV: >30%). AF recurrence was assessed at 1 year from the date of ablation.

RESULTS

The average duration of exercise was 8 ± 3 min, and the mean MET achieved was 9.7 ± 3.2. METs achieved were inversely correlated with LA-TR (R² = 0.061; p = 0.003). The duration of exercise was also inversely correlated with LA-TR (R² = 0.071; p = 0.001). Both EC and LA-TR were associated with AF recurrence post ablation in univariate analysis, but only LA-TR and age were independently predictive of recurrence in multivariate analysis (p = 0.001). For every additional minute on the treadmill, subjects were 13% more likely to be free of AF 1 year post ablation (p = 0.047).

CONCLUSIONS

EC is inversely associated with LA-TR in patients with AF and is predictive of freedom from AF post-ablation.

The use of intraoperative triggered electromyography to detect misplaced pedicle screws: a systematic review and meta-analysis

OBJECT

Insertion of instruments or implants into the spine carries a risk for injury to neural tissue. Triggered electromyography (tEMG) is an intraoperative neuromonitoring technique that involves electrical stimulation of a tool or screw and subsequent measurement of muscle action potentials from myotomes innervated by nerve roots near the stimulated instrument. The authors of this study sought to determine the ability of tEMG to detect misplaced pedicle screws (PSs).

METHODS

The authors searched the US National Library of Medicine, the Web of Science Core Collection database, and the Cochrane Central Register of Controlled Trials for PS studies. A meta-analysis of these studies was performed on a per-screw basis to determine the ability of tEMG to detect misplaced PSs. Sensitivity, specificity, and receiver operating characteristic (ROC) area under the curve (AUC) were calculated overall and in subgroups.

RESULTS

Twenty-six studies were included in the systematic review. The authors analyzed 18 studies in which tEMG was used during PS placement in the meta-analysis, representing data from 2932 patients and 15,065 screws. The overall sensitivity of tEMG for detecting misplaced PSs was 0.78, and the specificity was 0.94. The overall ROC AUC was 0.96. A tEMG current threshold of 10–12 mA (ROC AUC 0.99) and a pulse duration of 300 µsec (ROC AUC 0.97) provided the most accurate testing parameters for detecting misplaced screws. Screws most accurately conducted EMG signals (ROC AUC 0.98).

CONCLUSIONS

Triggered electromyography has very high specificity but only fair sensitivity for detecting malpositioned PSs.

Open Versus Minimally Invasive Fixation Techniques for Thoracolumbar Trauma: A Meta-Analysis

Study Design Systematic literature review and meta-analysis of studies published in English. Objective This study evaluated differences in outcome variables between percutaneous and open pedicle screws for traumatic thoracolumbar fractures. Methods A systematic review of PubMed, Cochrane, and Embase was performed. The variables of interest included postoperative visual analog scale (VAS) pain score, kyphosis angle, and vertebral body height, as well as intraoperative blood loss and operative time. The results were pooled by calculating the effect size based on the standardized difference in means. The studies were weighted by the inverse of the variance, which included both within- and between-study error. Confidence intervals were reported at 95%. Heterogeneity was assessed using the Q statistic and I (2). Results After two-reviewer assessment, 38 studies were eliminated. Six studies were found to meet inclusion criteria and were included in the meta-analysis. The combined effect size was found to be in favor of percutaneous fixation for blood loss and operative time (p < 0.05); however, there were no differences in vertebral body height (VBH), kyphosis angle, or VAS scores between open and percutaneous fixation. All of the studies demonstrated relative homogeneity, with I (2) < 25. Conclusions Patients with thoracolumbar fractures can be effectively managed with percutaneous or open pedicle screw placement. There are no differences in VBH, kyphosis angle, or VAS between the two groups. Blood loss and operative time were decreased in the percutaneous group, which may represent a potential benefit, particularly in the polytraumatized patient. All variables in this study demonstrated near-perfect homogeneity, and the effect is likely close to the true effect.

What Are the 30-day Readmission Rates Across Orthopaedic Subspecialties?

BACKGROUND

The Centers for Medicare & Medicaid Services (CMS) now include hip and knee replacements in the Hospital Readmission Reduction Program. The 30-day readmission rate is an important quality metric; however, the incidence has not yet been defined across the numerous orthopaedic subspecialties. Elucidating the readmission rate for each subspecialty may indicate that certain services are being disincentivized by the CMS reimbursement program. Furthermore, the "planned" and "unplanned" definitions of readmission have not been well examined to determine their clinical relevance and representation of safe patient care. Therefore, reducing the 30-day readmission rate has become a top priority in orthopaedic quality assurance.

QUESTIONS/PURPOSES

(1) What are the 30-day readmission rates for the different orthopaedic subspecialties? (2) What are the risk factors associated with readmission within 30 days? (3) What are the causes of 30-day readmissions? (4) What is the interrater agreement among CMS, hospital, and clinician definitions of planned and unplanned readmissions?

METHODS

We retrospectively examined one tertiary care academic hospital's quality improvement database and identified 4792 discharges from the department of orthopaedics during a continuous 24-month period. Discharges were divided and analyzed according to the subspecialty of orthopaedic care. Demographics and comorbidities were extracted from the database and subjected to univariate and multivariate analysis to determine risk factors for 30-day readmission. Further chart review was conducted on all cases of 30-day readmission to identify causes. The authors' determination of planned versus unplanned was compared with two other definitions (hospital and CMS) and analyzed for agreement by using Fleiss' kappa for multiple rater.

RESULTS

The all-cause 30-day readmission rate was 4% (95% confidence interval [CI], 3.8-4.8). The unplanned readmission rate was 3% (95% CI, 2.8-3.8). After controlling for relevant confounding variables, we found that length of stay (odds ratio [OR], 1.10 per day; p < 0.001), American Society of Anesthesiologists score (OR, 1.89 per point; p < 0.001), and care under trauma (OR, 2.55; p < 0.001) or "other" (OR, 1.65; p = 0.009) as compared with joint subspecialty were associated with increased risk of readmission. Of the 160 unplanned readmissions, 93 (58%) were surgical and 67 (42%) were medical. The most common surgical cause was surgical site infection (38% of surgical readmissions) and the most common medical causes were gastrointestinal bleed, pulmonary embolus, and unrelated trauma (each 9% of medical readmissions). There was poor agreement (Fleiss' kappa = 0.120) among the three definitions of planned readmission.

CONCLUSIONS

There are important differences in the risk of readmission by subspecialty across orthopaedics and the CMS-driven disincentives may be applied unequally across these subspecialties. This could result in hospitals deemphasizing those service lines and could potentially limit access to care for the patients most in need. Avenues of readmission reduction should be further studied including telephone followup programs and outpatient management of threatened wounds. Clinical, hospital, and CMS definitions of planned readmission have poor agreement, suggesting that hospitals are being unnecessarily penalized. The CMS should develop a more clinically relevant definition of 30-day readmission to more accurately evaluate the rate of readmissions.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Intra-Wound Antibiotics and Infection in Spine Fusion Surgery: A Report from Washington State's SCOAP-CERTAIN Collaborative

BACKGROUND

Surgical site infection (SSI) after spine surgery is classified as a "never event" by the Centers for Medicare and Medicaid. Intra-wound antibiotics (IWA) have been proposed to reduce the incidence of SSI, but robust evidence to support its use is lacking.

METHODS

Prospective cohort undergoing spine fusion at 20 Washington State hospitals (July 2011 to March 2014) participating in the Spine Surgical Care and Outcomes Assessment Program (Spine SCOAP) linked to a discharge tracking system. Patient, hospital, and operative factors associated with SSI and IWA use during index hospitalizations through 600 days were analyzed using a random effects logistic model (index), and a time-to-event analysis (follow-up) using Cox proportional hazards.

RESULTS

A total of 9,823 patients underwent cervical (47%) or lumbar (53%) procedures (mean age, 58; 54% female) with an SSI rate of 1.1% during index hospitalization. Those with SSI were older, more often had diabetes mellitus, and more frequently underwent lumbar (versus cervical) fusion compared with those without SSI (all p < 0.01). Unadjusted rates of SSI during index hospitalization were lower in patients who received IWA (0.8% versus 1.5%). After adjustment for patient, hospital, and operative factors, no benefit was observed in those receiving IWA (odds ratio [OR] 0.65, 95% confidence interval [CI]: 0.42-1.03). At 12 mo, unadjusted rates of SSI were 2.4% and 3.0% for those who did and did not receive antibiotics; after adjustment there was no significant difference (hazard ratio [HR] 0.94, 95% CI: 0.62-1.42).

CONCLUSIONS

Whereas unadjusted analyses indicate a nearly 50% reduction in index SSI using IWA, we did not observe a statistically significant difference after adjustment. Despite its size, this study is underpowered to detect small but potentially relevant improvements in rates of SSI. It remains to be determined if IWA should be promoted as a quality improvement intervention. Concerns related to bias in the use of IWA suggest the benefit of a randomized trial.

Update on Biomaterials

Biomaterials are essential to the use and development of successful treatments for orthopaedic patients. Orthopaedic surgeons need to understand the expected clinical performance and the effects of implants in patients. Recent attempts to improve implant durability have resulted in adverse effects related to biomaterials and their relationship to patients. Examples of these adverse effects in hip arthroplasty include wear and corrosion of metal-on-metal bearings, trunnions, and tapered modular neck junctions. Conversely, polymers and ceramics have shown substantial improvements in durability. Improved implant compositions and manufacturing processes have resulted in ceramic head and acetabular liners with improved material properties and the avoidance of voids, which have, in the past, caused catastrophic fractures. Cross-linking of polyethylene with radiation and doping with antioxidants has substantially increased implant durability and is increasingly being used in joint prostheses other than the hip. Additive manufacturing is potentially a transformative process; it can lead to custom and patient-specific implants and to improvements in material properties, which can be optimized to achieve desired bone responses. Orthopaedic surgeons must understand the material properties and the biologic effects of new or altered biomaterials and manufacturing processes before use. In addition, a clear benefit to the patient must be proven based on superior preclinical results and high-quality clinical investigations before orthopaedic surgeons use new or altered biomaterials.

Adverse Event Recording and Reporting in Clinical Trials Comparing Lumbar Disk Replacement with Lumbar Fusion: A Systematic Review

Study Design Systematic review. Objectives (1) To compare the quality of adverse event (AE) methodology and reporting among randomized trials comparing lumbar fusion with lumbar total disk replacement (TDR) using established AE reporting systems; (2) to compare the AEs and reoperations of lumbar spinal fusion with those from lumbar TDR; (3) to make recommendations on how to report AEs in randomized controlled trials (RCTs) so that surgeons and patients have more-detailed and comprehensive information when making treatment decisions. Methods A systematic search of PubMed, the Cochrane collaboration database, and the National Guideline Clearinghouse through May 2015 was conducted. Randomized controlled trials with at least 2 years of follow-up comparing lumbar artificial disk replacement with lumbar fusion were included. Patients were required to have axial or mechanical low back pain of ≥3 months' duration due to degenerative joint disease defined as degenerative disk disease, facet joint disease, or spondylosis. Outcomes included the quality of AE acquisition methodology and results reporting, and AEs were defined as those secondary to the procedure and reoperations. Individual and pooled relative risks and their 95% confidence intervals comparing lumbar TDR with fusion were calculated. Results RCTs demonstrated a generally poor description of methods for assessing AEs. There was a consistent lack of clear definition or grading for these events. Furthermore, there was a high degree of variation in reporting of surgery-related AEs. Most studies lacked adequate reporting of the timing of AEs, and there were no clear distinctions between acute or chronic AEs. Meta-analysis of the pooled data demonstrated a twofold increased risk of AEs in patients having lumbar fusion compared with patients having lumbar TDR at 2-year follow-up, and this relative risk was maintained at 5 years. Furthermore, the pooled data demonstrated a 1.7 times greater relative risk of reoperation in the fusion group compared with lumbar TDR, although this risk decreased to 1.1 at 5-year follow-up. However, given the lack of quality and consistency in the methods of recording and reporting of AEs, we are unable to make a clear recommendation of one treatment over the other. Conclusions Based on the currently available literature, lumbar TDR appears to be comparable in safety to lumbar fusion. However, due to lack of consistency in reporting of AEs, it is difficult to make conclusions regarding the true safety profile of lumbar TDR. Standardization in AE reporting will significantly improve the reliability of the current literature.