Active biointegrated living electronics for managing inflammation.

Seamless interfaces between electronic devices and biological tissues stand to revolutionize disease diagnosis and treatment. However, biological and biomechanical disparities between synthetic materials and living tissues present challenges at bioelectrical signal transduction interfaces. We introduce the active biointegrated living electronics (ABLE) platform, encompassing capabilities across the biogenic, biomechanical, and bioelectrical properties simultaneously. The living biointerface, comprising a bioelectronics layout and a Staphylococcus epidermidis-laden hydrogel composite, enables multimodal signal transduction at the microbial-mammalian nexus. The extracellular components of the living hydrogels, prepared through thermal release of naturally occurring amylose polymer chains, are viscoelastic, capable of sustaining the bacteria with high viability. Through electrophysiological recordings and wireless probing of skin electrical impedance, body temperature, and humidity, ABLE monitors microbial-driven intervention in psoriasis.

Adipose-derived mesenchymal stem cells (MSCs) are a superior cell source for bone tissue engineering.

Effective bone regeneration through tissue engineering requires a combination of osteogenic progenitors, osteoinductive biofactors and biocompatible scaffold materials. Mesenchymal stem cells (MSCs) represent the most promising seed cells for bone tissue engineering. As multipotent stem cells that can self-renew and differentiate into multiple lineages including bone and fat, MSCs can be isolated from numerous tissues and exhibit varied differentiation potential. To identify an optimal progenitor cell source for bone tissue engineering, we analyzed the proliferative activity and osteogenic potential of four commonly-used mouse MSC sources, including immortalized mouse embryonic fibroblasts (iMEF), immortalized mouse bone marrow stromal stem cells (imBMSC), immortalized mouse calvarial mesenchymal progenitors (iCAL), and immortalized mouse adipose-derived mesenchymal stem cells (iMAD). We found that iMAD exhibited highest osteogenic and adipogenic capabilities upon BMP9 stimulation in vitro, whereas iMAD and iCAL exhibited highest osteogenic capability in BMP9-induced ectopic osteogenesis and critical-sized calvarial defect repair. Transcriptomic analysis revealed that, while each MSC line regulated a distinct set of target genes upon BMP9 stimulation, all MSC lines underwent osteogenic differentiation by regulating osteogenesis-related signaling including Wnt, TGF-ß, PI3K/AKT, MAPK, Hippo and JAK-STAT pathways. Collectively, our results demonstrate that adipose-derived MSCs represent optimal progenitor sources for cell-based bone tissue engineering.

In Vivo Analysis of Acromioclavicular Kinematics and Distance During Multiplanar Humeral Elevation.

BACKGROUND: Knowledge of acromioclavicular (AC) joint kinematics and distance may provide insight into the biomechanical function and development of new treatment methods. However, accurate data on in vivo AC kinematics and distance between the clavicle and acromion remain unknown. PURPOSE/HYPOTHESIS: The purpose of this study was to investigate 3-dimensional AC kinematics and distance during arm elevation in abduction, scaption, and forward flexion in a healthy population. It was hypothesized that AC kinematics and distance would vary with the elevation angle and plane of the arm. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 19 shoulders of healthy participants were enrolled. AC kinematics and distance were investigated with a combined dual fluoroscopic imaging system and computed tomography. Rotation and translation of the AC joint were calculated. The AC distance was measured as the minimum distance between the medial border of the acromion and the articular surface of the distal clavicle (ASDC). The minimum distance point (MDP) ratio was defined as the length between the MDP and the posterior edge of the ASDC divided by the anterior-posterior length of the ASDC. AC kinematics and distance between different elevation planes and angles were compared. RESULTS: Progressive internal rotation, upward rotation, and posterior tilt of the AC joint were observed in all elevation planes. The scapula rotated more upward relative to the clavicle in abduction than in scaption (P = .002) and flexion (P = .005). The arm elevation angle significantly affected translation of the AC joint. The acromion translated more laterally and more posteriorly in scaption than in abduction (P < .001). The AC distance decreased from the initial position to 75° in all planes and was significantly greater in flexion (P < .001). The MDP ratio significantly increased with the elevation angle (P < .001). CONCLUSION: Progressive rotation and significant translation of the AC joint were observed in different elevation planes. The AC distance decreased with the elevation angle from the initial position to 75°. The minimum distance between the ASDC and the medial border of the acromion moved anteriorly as the shoulder elevation angle increased. CLINICAL RELEVANCE: These results could serve as benchmark data for future studies aiming to improve the surgical treatment of AC joint abnormalities to restore optimal function.

Corrigendum to "Sox9 augments BMP2-induced chondrogenic differentiation by downregulating Smad7 in mesenchymal stem cells (MSCs)" [Genes & Diseases 4 (2017) 229-239].

[This corrects the article DOI: 10.1016/j.gendis.2017.10.004.].

Surgical Outcomes, Trends, and Risk Factors of Distal Triceps Repairs.

BACKGROUND: Distal triceps ruptures are rare, and complete ruptures are commonly treated with surgery. Studies of patients in small cohorts with distal triceps tear have reported outcomes and risk factors; however, large-scale data are scant. This study seeks to determine current trends, outcomes, and risk factors of distal triceps tears. METHODS: Within a large insurance claims database, distal triceps repair patients were identified through Current Procedural Terminology coding with concomitant distal triceps International Classification of Diseases, 9th Revision/10th Revision diagnosis codes and 1-year active status before and after surgery. Demographics, total costs, 90-day complications, and revision rates within 1 year of index surgery were analyzed. Logistic regression was performed for revision and complication rates using sex, age, and comorbidities (anabolic steroid use, diabetes, ischemic heart disease, tobacco use, rheumatoid arthritis, and chronic kidney disease). RESULTS: A total of 8143 patients were included in the cohort. Male patients and patients aged 40 to 59 years comprised most of the study population. The postoperative complication rate was 5.8%, and the 1-year revision rate was 2.6%. Male sex, age >60 years, ischemic heart disease, rheumatoid arthritis, and chronic kidney disease were statistically significant risk factors for higher 90-day complication rates. Anabolic steroid use significantly increased the risk of surgical revision. CONCLUSIONS: Distal triceps repairs in this large cohort study occur most frequently in men aged 40 to 59 years. Complications are generally low, with age >60 years, male sex, ischemic heart disease, rheumatoid arthritis, and chronic kidney disease as risk factors for 90-day complications and prior anabolic steroid use as a risk factor for 1-year revision surgery. This information can help to improve education and expectations of this procedure.

Qualitative and Quantitative Anatomy of the Deep Radioulnar Ligaments' Insertion on Ulna: Cadaveric, Histologic, and MRI Study.

PURPOSE: To qualitatively and quantitatively analyze the anatomic features of the insertion of deep radioulnar ligaments (RULs) and provide an anatomic basis for further studies. METHODS: The anatomic features of deep RUL insertion were observed macroscopically in 26 cadaveric wrists, after which the size of the deep RUL footprint and distance from the center of the footprint to the ulnar-sided margin of articular cartilage of the ulnar head were each measured. Five specimens were analyzed histologically to examine the attachment of the RUL on the ulna. In addition, we evaluated 21 asymptomatic wrists from healthy volunteers using 3.0 T magnetic resonance imaging. RESULTS: The insertion of the deep RUL was located mainly on the radial aspect of the ulnar fovea from the foveal center to the articular cartilage. The footprint of the deep RUL appeared in 3 different shapes. The maximal width, length, and area of the footprint of the deep RUL were 3.7 (95% confidence interval [CI], 3.3-4.0) mm, 8.4 (95% CI, 7.9-8.9) mm, and 26.3 (95% CI, 23.4-29.1) mm2, respectively. Histologic analyses showed the attachment of the deep RUL on the radial wall of the fovea exhibited a direct insertion with typical 4-layer structures. The deep RUL fibers formed an acute angle with the distal component of the triangular fibrocartilage complex. CONCLUSIONS: The deep RUL was inserted on the radial side of the ulnar fovea and not the foveal center; it had direct insertion on the radial wall continuous with articular cartilage, and the fibers in the direct insertion formed an acute angle with the distal component of the triangular fibrocartilage complex. CLINICAL RELEVANCE: Understanding the quantitative anatomy of the deep RUL insertion may help guide surgeons to perform an anatomic foveal repair of the triangular fibrocartilage complex in its native footprint.

Effect of Physical Therapy and Rehabilitation Timing on Rotator Cuff Repair Revisions and Capsulitis.

INTRODUCTION: One variable that could potentially affect failure of a rotator cuff repair (RCR) is the timing of beginning physical therapy (PT) after the procedure. Although many studies have demonstrated decreased stiffness with beginning PT early, studies have also demonstrated that early PT increases repair failure. The goal of this study was to identify revision surgery and capsulitis rates after RCRs from an available database and determine whether an association was present with the timing of PT post-RCR. METHODS: Medicare patients within the PearlDiver database who underwent RCR were stratified based on the timing of their first PT session postoperatively, and revision surgery and capsulitis rates were determined among the groups for both open and arthroscopic RCR. Demographics and comorbidities of the cohort were also used to formulate a multivariate analysis for revision surgery rate. RESULTS: The cohort consisted of 64,842 patients who underwent RCR and started PT within 13 weeks of surgery. Starting PT within 1 week postoperatively resulted in a significantly higher revision surgery rate compared with starting PT in weeks 2 to 5, 6 to 9, or 10 to 13 (6.9% vs. 3.6% among all other groups, P = <0.001). The multivariate analysis for revision surgery further demonstrated that starting PT within 1 week postoperatively was associated with a significantly higher rate of revision surgery compared with beginning PT after 1 week (OR = 2.086, P < 0.001). No association was found between timing of beginning PT and capsulitis rates. CONCLUSION: In the Medicare patient cohort, beginning PT within 1 week postoperatively was associated with a significantly higher revision surgery rate; however, no associated benefit was noted in capsulitis rates for beginning PT early. This calls into question the use of an early passive range of motion protocol for older patient cohort; however, further studies should be completed to conclusively determine the most efficacious time to begin rehabilitation post-RCR. LEVEL OF EVIDENCE: Level III.

Soft-Tissue Considerations in Shoulder Surgery in the Patient With Lymphedema.

Lymphedema is a chronic, progressive, and often debilitating condition that results in swelling of the affected tissue. Secondary lymphedema is most commonly recognized by unilateral swelling of the ipsilateral extremity after the treatment of cancer. It is estimated that nearly 1.45 million women suffer from breast cancer-related lymphedema in the United States. The number of patients suffering from upper extremity lymphedema is expected to increase because multimodal treatment of breast cancer increases the long-term survival after diagnosis. Because this population ages, the likelihood of encountering a patient with concurrent lymphedema and shoulder pathology requiring orthopaedic intervention is likely to rise. A patient with an already edematous arm and/or impaired drainage of that arm is likely to have different and more complex intraoperative and postoperative courses than patients with normal lymphatic drainage. Although a lymphedematous arm should not preclude surgical intervention, there are considerations when approaching shoulder surgery in the setting of upper extremity lymphedema that may help mitigate complications and aid the patient in their orthopaedic recovery.

Analysis of the Cost and Efficacy of Intra-Articular Knee Injections.

INTRODUCTION: Intra-articular joint injections have been used with the goal of providing patients with symptomatic relief. Recently, however, the efficacy of corticosteroid (CS) and hyaluronic acid (HA) injections in the management of knee osteoarthritis (OA) is questionable. In this analysis, we investigated the costs associated with injections by assessing overall use, conversion and average time to total knee arthroplasty (TKA), and reimbursement. METHODS: Patients aged 50 to 70 years with a knee-related diagnosis of pain, effusion, or OA were identified in the Humana insurance national data set. Patients who received intra-articular injections were stratified by the type and number of injection(s) received. The subsequent rates of TKA were compared with Kaplan-Meier curves for patients who underwent CS injections, HA injections, and a benchmarking cohort of patients with OA and no history of knee injections in the medical record. Average time to TKA was determined from index diagnosis, and total cost was compared using Wilcoxon rank sum analyses. RESULTS: A total of 778,686 patients were identified. Of these, 637,112 had no knee injection history, while 124,129 received CS and 17,445 received HA injections. The 10-year conversion to TKA was highest in HA cohort (31.6%), followed by the CS cohort (24.0%) and the noninjection cohort (7.3%) (P < 0.001). Time to TKA increased with number of injections for both injection types. For patients who underwent TKA, median cost was greater in HA ($16,687) and CS ($15,563) cohorts relative to noninjection cohort ($14,733) (P < 0.001). DISCUSSION: Compared with the noninjection cohort, both HA and CS cohorts experienced increased costs and increased time to TKA. However, while the cost incurred in HA cohort was greater than that in CS cohort, no appreciable benefit was demonstrated for conversion or time to TKA. Therefore, if intra-articular knee injections are indicated for the nonsurgical management of knee OA, the results of this study support CS over HA.

A Safe Interval between Preoperative Intra-articular Corticosteroid Injections and Subsequent Knee Arthroscopy.

The purpose of this study is to evaluate the influence of intra-articular corticosteroid injections prior to knee arthroscopy on the rate of postoperative infection and define a safe timing interval between intra-articular corticosteroid injections and subsequent knee arthroscopy. The PearlDiver Database was used to identify patients who underwent a knee arthroscopy from 2007 to 2017. Patients were sorted into an injection cohort if they received any intra-articular corticosteroid injections within 6 months before surgery and a control cohort if they received no such injections. The injection cohort was then stratified into subgroups based on the timing of the most recent injection. We identified two types of postoperative infection in the 6 months following surgery: a broad definition of infection using knee infection diagnoses, and a narrow definition of infection requiring surgical treatment. The effects of the timing of preoperative corticosteroid injections on the rates of postoperative infection were investigated. The rate of broadly defined postoperative infection was significantly higher in the 0 to 2 weeks injection group (6.90%, 20/290) than the control group (2.01%, 1,449/72,089, p < 0.001; odds ratio [OR]:3.61 [95% confidence interval [CI]: 2.29, 5.70]). We observed a significant difference regarding the rate of narrowly defined postoperative infection requiring surgical treatment between the 0 and 2 weeks injection group (1.38%, 4/290) and the control group (0.27%, 192/72,089, p < 0.001, OR:5.24 [95% CI: 1.94, 14.21]). No significant differences were observed between other subgroups and the control group in both types of postoperative infection. Intra-articular corticosteroid injections within 2 weeks of knee arthroscopy were statistically significantly associated with higher rates of postoperative infection. This is a Level III, retrospective comparative study.

Bony Hypertrophy in Vascularized Fibular Grafts.

Background: Vascularized fibula graft (VFG) transfer is an established method of repairing large skeletal defects resulting from trauma, tumor resection, or infection. It obviates the process of creeping substitution that conventional bone grafts undergo and therefore exhibits better healing and improved strength. The aim of this study is to evaluate hypertrophy in VFG. Methods: We retrospectively reviewed patients undergoing VFG and studied immediate and late postoperative radiographs. Orthogonal views were measured for width of graft cortex and intramedullary canal, as well as adjacent recipient bone. Changes were measured for total cross sectional area, cortical area, intramedullary area, and graft width. Results: Thirty patients were included in the analysis, with recipient sites including 3 forearm, 4 humerus, 12 tibia, and 11 femur. Mean follow-up was 7.6 years (0.5-24.9 years). Patients' mean age was 31 (16-59 years). Average hypertrophy was 254% in early postoperative period and 340% in the late postoperative period. There was rapid graft hypertrophy in early postoperative period that plateaued with time. The width of the graft increased over time but didn't exceed the width of the adjacent recipient bone. In the later postoperative period, the size of graft intramedullary canal increased. Upper and lower extremity grafts showed similar hypertrophy. Conclusions: Using VFG to treat large skeletal defects is an attractive option in part due to the graft's ability to hypertrophy. We describe an early period of periosteal hypertrophy, followed by endosteal hypertrophy. These processes have relevance to function, mechanical strength, and surgical decision-making.

Trends in Corticosteroid Injections for Treatment of Lateral Epicondylitis: An Analysis of 80,169 Patients.

INTRODUCTION: Corticosteroid (CS) injections are a frequently used treatment modality for lateral epicondylitis (LE) despite an increasing number of studies suggesting their lack of efficacy. The objective of this study was to review the annual utilization of CS injections for treatment of LE, as well as that of other nonsurgical treatments and surgical treatments, to understand how recent publications have affected the practice of physicians in treating LE. METHODS: Patients with LE from 2010 to 2017 were identified within a national insurance database and grouped by treatment modalities of CS injections, physical therapy, bracing treatment, and surgery. Epidemiologic and demographic data were reported using descriptive statistics. The number of patients receiving each treatment and the number of CS injections per patient were quantified for each year, and annual trends were analyzed using logistic regression. RESULTS: Among 80,169 qualifying patients, 16,476 received CS injections, 12,180 received physical therapy, 1,874 received bracing treatment, and 2,650 underwent surgery, with patients receiving multiple modalities being members of each respective group. We found a significant decrease in the proportion of patients with LE receiving CS injections from 23.3% in 2010 to 18.8% in 2017 (R2 = 0.956, P < 0.001). Interestingly, the number of CS injections per patient increased during this period from 1.33 to 1.83 (R2 = 0.843, P = 0.001). No notable changes in utilization trends for other modalities were found. DISCUSSION: Overall, our data support a decline in the use of CS injection as a treatment modality for LE from 2010 to 2017. Although correlational, this trend may reflect the increasing body of published evidence demonstrating the ineffectiveness of CS injections for the treatment of LE. In addition, the increasing number of injections per patient among those who received injections contrasts with the overall decrease in steroid utilization among all patients. Further study is needed to fully understand the mechanisms behind these trends.

Does lumbar spine fusion predispose patients to future total hip replacement?

OBJECTIVE: Hip-spine syndrome has been well studied since it was first described by Offierski and MacNab in 1983. Today, strong evidence links symptoms of hip and spine pathology to postsurgical outcomes. Recent studies have reported increased rates of hip dislocation in patients previously treated with total hip arthroplasty (THA) who had undergone lumbar fusion procedures. However, the effect of this link on native hip-joint degeneration remains an area of ongoing research. The purpose of this study was to characterize the relationship between use of lumbar fusion procedures and acceleration of hip pathology by analyzing the rate of future THA in patients with preexisting hip osteoarthritis. METHODS: This population-level, retrospective cohort study was conducted by using the PearlDiver research program. The initial patient cohort was defined by the presence of diagnosis codes for hip osteoarthritis. Patients were categorized according to use of lumbar fusion after diagnosis of hip pathology. Survival curves with respect to THA were generated by comparison of the no lumbar fusion cohort with the lumbar fusion cohort. To assess the impact of fusion construct length, the lumbar fusion cohort was then stratified according to the number of levels treated (1-2, 3-7, or ≥ 8 levels). Hazard ratios (HRs) were then calculated for the risk factors of number of levels treated, patient age, and sex. RESULTS: A total of 2,275,683 patients matched the authors' inclusion criteria. Log-rank analysis showed no significant difference in the rates of THA over time between the no lumbar fusion cohort (2,239,946 patients) and lumbar fusion cohort (35,737 patients; p = 0.40). When patients were stratified according to number of levels treated, again no differences in the incidence rates of THA over the study period were determined (p = 0.30). Patients aged 70-74 years (HR 0.871, p < 0.001), 75-79 years (HR 0.733, p < 0.001), 80-84 years (HR 0.557, p < 0.001), and ≥ 85 years (HR = 0.275, p < 0.001) were less likely to undergo THA relative to the reference group (patients aged 65-69 years). CONCLUSIONS: Although lumbar fusion was initially hypothesized to have a significant effect on rate of THA, lumbar fusion was not associated with increased need for future THA in patients with preexisting hip osteoarthritis. Additionally, there was no relationship between fusion construct length and rate of THA. Although lumbar fusion reportedly increases the risk of hip dislocation in patients with prior THA, these data suggest that lumbar fusion may not clinically accelerate native hip degeneration.

National Trends Show Declining Use of Arthroscopic Subacromial Decompression Without Rotator Cuff Repair.

PURPOSE: The goal of this study was to investigate trends in the United States for arthroscopic subacromial decompression (aSAD) and open SAD (oSAD) with and without rotator cuff repair (RCR) between 2010 and 2018. METHODS: The PearlDiver Mariner claims database was queried using CPT codes for open and arthroscopic subacromial decompression and rotator cuff repair. Patient cohorts were developed for those undergoing aSAD or oSAD between 2010 and 2018, then segmented by whether RCR was performed simultaneously. Annual incidence was analyzed, as were associated diagnosis codes, and concomitant shoulder-associated procedures performed on the same day. RESULTS: The PearlDiver Mariner dataset from 2010 to 2018 included 186,932 patients that underwent aSAD, while 9,263 patients underwent oSAD. The total incidence of aSAD declined from 118.0 to 71.3 per 100,000 (39.6% decrease) (P < .001). This change was due primarily to a decreasing incidence of aSAD performed without RCR, which declined from 66.3 to 25.5 per 100,000 (61.5% decrease) (P < .001). During the same period, the incidence of aSAD combined with RCR remained relatively stable, from 51.7 to 45.8 per 100,000 (11.5% decrease) (P = .27). The overall incidence of oSAD declined from 7.1 to 2.2 per 100,000 (68.1% decrease) (P < .001). CONCLUSIONS: The overall rate of aSAD has declined in recent years, primarily due to a large decrease in the incidence of aSAD without RCR as an isolated treatment for rotator cuff disorders. CLINICAL RELEVANCE: Prior studies have demonstrated a rising incidence of SAD; however, high-level clinical evidence and clinical practice guidelines have challenged its efficacy. It is important for orthopaedic surgeons to understand evolving national trends in management among their peers.

Acute Versus Delayed Reverse Shoulder Arthroplasty for the Primary Treatment of Proximal Humeral Fractures.

INTRODUCTION: Reverse total shoulder arthroplasty (rTSA) is gaining popularity as a treatment option for proximal humeral fractures in elderly patients. The impact of surgical timing on outcomes of primary rTSA is unclear. This study compared the rates of revision and complication, and surgery day cost of treatment between acute and delayed primary rTSA patients. METHODS: Elderly patients with proximal humeral fracture who underwent primary rTSA within a year of fracture were identified in a national insurance database from 2005 to 2014. Patients were separated into acute (<4 weeks) or delayed (>4 weeks) cohorts based on the timing of rTSA. The univariate 1-year rates of revision and complication and surgery day cost of treatment were assessed. Multivariate logistic regression analysis was conducted, accounting for the factors of age, sex, obesity, diabetes comorbidity, and tobacco use. RESULTS: Four thousand two hundred forty-five (82.6%) acute and 892 (17.4%) delayed primary rTSA patients were identified. Acute rTSA was associated with a higher surgery day cost (acute $15,770 ± $8,383, delayed $14,586 ± $7,271; P < 0.001). Delayed rTSA resulted in a higher 1-year revision rate (acute 1.7%, delayed 4.5%; P < 0.001) and surgical complication rates of dislocation (acute 2.8%, delayed 6.1%; P < 0.001) and mechanical complications (acute 1.9%, delayed 3.4%; P = 0.007). Multivariate analysis identified delayed primary treatment as independently associated with increased risk of revision (odds ratio: 2.29, 95% confidence interval 1.53 to 3.40; P < 0.001) and dislocation (OR: 2.05, 95% confidence interval 1.45 to 2.86; P < 0.001). CONCLUSION: Delayed primary rTSA was associated with higher short-term rates of revision and dislocation compared with acute primary rTSA. Our results suggest that delaying rTSA, whether because of attempted nonsurgical treatment or patients' lack of access, may result in increased complication and additional surgery. LEVEL OF EVIDENCE: Level III.

The Influence of Selective Serotonin Reuptake Inhibitors on Lumbar Arthrodesis.

STUDY DESIGN: Retrospective analysis using the PearlDiver national insurance claims database. OBJECTIVE: To investigate the relationship between chronic preoperative selective serotonin reuptake inhibitor (SSRI) prescriptions and nonunion following spine fusion surgery. SUMMARY OF BACKGROUND DATA: Contemporary literature has linked SSRIs to decreased bone mineral density and increased rates of future bone fracture. Furthermore, a recent murine model has suggested a potential role in the quality of fracture healing itself. METHODS: All single-level lumbar fusion patients were identified. The rate of nonunion diagnosis between 6 and 24 months following surgery was assessed. A stratified analysis of chronic SSRI use and a number of comorbidities was conducted, followed by a multiple logistic regression analysis of nonunion accounting for qualifying risk factors. Finally, subanalyses of individual procedure codes were carried out. RESULTS: In total, 7905 single-level lumbar fusion patients were included. In the multivariate analysis, chronic SSRI [odds ratio (OR): 1.558, P=0.004] and tobacco use (OR: 1.500, P=0.011) were identified as independent risk factors for nonunion, whereas patient age over 60 years (OR: 0.468, P<0.001) was observed to be negatively associated with nonunion. In the individual procedure subanalyses, SSRIs were significantly associated with nonunion in 2 of 3 univariate analyses and observed to be an independent risk factor for nonunion in 2 of the 3 procedure populations. CONCLUSIONS: These data suggest that patients treated concomitantly for mental health disorders with SSRIs before arthrodesis may be at an increased risk of postoperative nonunion. Closer follow-up may be indicated in this patient population.

Biomechanical comparison of five cannulated screw fixation strategies for young vertical femoral neck fractures.

Vertical femoral neck fractures in patients younger than 65 years of age often require hip-conserving surgeries. However, traditional fixation strategies using three parallel cannulated screws often fail in such patients due to an unfavorable biomechanical environment. This study compared different cannulated screw fixation techniques in patients via patient-specific finite element analysis with linear tetrahedral (C3D4) elements. Forty vertical femoral neck fracture models were created based on computed tomography images obtained from eight healthy participants. Five different fixation strategies: alpha, buttress, rhomboid, inverted triangle, and triangle were assessed in walking status. Biomechanical parameters including stiffness, interfragmentary motion in two directions (detachment and shearing), compression force, and maximal implant stress were evaluated. The mean relative coefficient of strain distribution between the finite element analysis and experiment was from 0.78 to 0.94. Stiffness was highest (p < .05) in the buttress group (923.1 N/mm), while interfragmentary motion was lowest (p < .05) in the alpha group. Maximal stress was highest (p < .05) in the buttress group and lowest in the alpha group. Shearing values were significantly lower in the alpha group than in the rhomboid group (p = .004). Moreover, Shearing values were significantly higher (p = .027), while detachment values were significantly lower (p = .027), in the inverted triangle than in the triangle group. Clinical significance: Our results suggest that alpha fixation is the most reliable and biomechanically efficient strategy for young patients with vertical femoral neck fractures. Regular and inverted triangular fixation strategies may be suitable for fractures of different skeletal constructions due to antidetachment/shearing abilities.

Comparing Bleeding and Thrombotic Rates in Spine Surgery: An Analysis of 119 888 Patients.

STUDY DESIGN: Retrospective, database review. OBJECTIVES: Examine the utilization rate of postoperative deep vein thrombosis (DVT) prophylaxis and compare the incidence and severity of bleeding and thrombotic complications in elective spine surgery patients. METHODS: We utilized PearlDiver, a national orthopedics claims database. All patients who underwent elective spine surgery from 2007 to 2017 were included. Patients were stratified by the presence of DVT prophylaxis drug codes, then by comorbidities for postoperative bleeding/thrombosis. The severity of all bleeding and thrombotic complications in each cohort was studied, including the incidence of complications requiring operative washout, diagnosis of pulmonary embolism, intensive care unit admission, and mortality. RESULTS: A total of 119 888 patients were included. The majority of patients (118 720, >99%) were not administered postoperative DVT chemoprophylaxis while a minority of patients (1168) were. The overall rates of bleeding and thrombotic complications within the population not receiving DVT prophylaxis were 1.96% and 2.45%, respectively (P < .001). The incidence of surgical intervention for a wound washout was 0.62% compared with 1.05% for pulmonary embolism (P < .001). Intensive care unit admission rates related to a wound washout procedure or pulmonary embolism also significantly differed (0.07% vs 0.34%, P < .001). There were no observed differences in mortality. When controlling for patient comorbidity, patients with atrial fibrillation, cancer, or a prior history of thrombotic complications experienced the greatest increased risks of postoperative thrombosis. CONCLUSIONS: DVT prophylaxis is not routinely utilized following elective spine procedures. We report that there exist specific populations which may receive benefit from these practices, although further study is necessary to determine optimal prevention strategies for both thrombotic and bleeding complications in spine surgery.

Chronic Preoperative Opioids Are Associated With Revision After Rotator Cuff Repair.

PURPOSE: We sought to clarify the relationship between chronic preoperative opioids and complications following rotator cuff repair. Specifically, we assessed revision, a definitive postoperative end point for surgical outcome. METHODS: This study used PearlDiver, a United States national insurance claims database. All patients undergoing rotator cuff repair from 2008 to 2018 were identified and stratified based on a minimum of 2 opioid prescriptions within the 6 months before surgery, with 1 prescription occurring within 0 to 3 months before surgery and a second prescription within 4 to 6 months before surgery. Univariate logistic regressions of risk factors were conducted, followed by multivariate analysis of comorbidities, including ongoing preoperative opioids, any preoperative nonsteroidal anti-inflammatory drug (NSAID) prescriptions, age, sex, diabetes, tobacco, and obesity. RESULTS: In total, 28,939 patients undergoing rotator cuff repair were identified, of whom 10,695 had opioid prescriptions within both 0 to 3 months and 4 to 6 months before index rotator cuff repair, whereas 18,244 had no opioid prescriptions within the 6-month preoperative period. In total, 977 (3.4%) patients underwent revision within 6 months, which increased to 1311 (4.5%) within 1 year of the index procedure. In the multivariate analysis controlling for age, preoperative NSAID prescriptions, tobacco, diabetes, obesity, and sex, we observed a significant association between chronic preoperative opioid prescriptions and rotator cuff repair revision (6-month odds ratio 1.12; P = .021, 1-year odds ratio 1.43; P < .001) following index procedure. CONCLUSIONS: We report increased rates of revision within both 6 months and 1 year in patients with prolonged preoperative opioid prescriptions. The opioid cohort had greater rates of preoperative NSAID use and tobacco use, which also were observed to be independent risk factors for revision at both timepoints. LEVEL OF EVIDENCE: III; Retrospective comparative study.

Do We Need to Wait 3 Months After Corticosteroid Injections to Reduce the Risk of Infection After Total Knee Arthroplasty?

BACKGROUND: Corticosteroid injections administered within 3 months before total knee arthroplasty (TKA) have been linked to increased risk of postoperative infection. However, it would be beneficial to further delineate the timing of injections to determine whether a narrower window exists for safe administration of corticosteroid injections. The purposes of our study were to (1) determine whether there were a different time frame between corticosteroid injection and primary TKA that increased infection risk and (2) determine risk factors associated with infection after TKA. METHODS: TKA patients were identified from a national database from 2007 to 2017 and stratified based on their history of corticosteroid injections within the 6-month preoperative period. Patients who received injections were stratified into biweekly cohorts by the timing of their most recent injection. The 1-year rate of postoperative infection treated by surgical débridement was compared between injection and noninjection cohorts. Univariate logistic regressions of risk factors and a multivariate analysis for patient comorbidities and injection cohorts associated with increased infection risk were conducted. RESULTS: In the 76,090 TKA patients identified, corticosteroid injection within 2 weeks before TKA increased the risk of postoperative infection (P = 0.02) and injections within 2 to 4 weeks trended toward increased infection in univariate regression. No significant differences were observed in any other injection time frames. In the multivariate analysis, injections within 2 weeks before TKA were identified as an independent risk factor (odds ratio: 2.89; P = 0.04) for postoperative infection. Additional risk factors included chronic obstructive pulmonary disease, coronary artery disease, diabetes, ischemic heart disease, obesity, rheumatoid arthritis, and tobacco, whereas female sex and patient aged older than 65 were protective. DISCUSSION: Our results suggest that TKA performed within four weeks of a corticosteroid injection may be associated with a higher risk of postoperative infection; however, delaying surgery more than four weeks may not provide additional infection risk reduction. Further prospective randomized studies are needed to determine the optimal timing of TKA after corticosteroid injections. LEVEL OF EVIDENCE: Level III.