In Vivo Ultrasound Shear Wave Elastography Assessment of Acute Compartment Syndrome in a Turkey Model.

OBJECTIVE: The aim of the work described here was to evaluate the objectivity and reproducibility of non-invasive intra-compartment pressure (ICP) measurement using ultrasound shear wave elastography (SWE) in a turkey model in vivo and to determine the biological and histologic changes in acute compartment syndrome (ACS). METHODS: Twenty-four turkeys were randomly divided into four groups based on the duration and fasciotomy of ACS created by infusion of up to 50 mm Hg in the tibialis muscle: group 1, ACS 2 h; group 2, ACS 4 h; group 3, ACS 2 h + fasciotomy 2 h; group 4, ACS 4 h + fasciotomy 2 h. For each turkey, the contralateral limb was considered the control. Time-synchronized measures of SWE and ICP from each leg were collected. Then turkeys were euthanized for histology and quantitative reverse transcription polymerase chain reaction (qRT-PCR) examination. RESULTS: All models created reproducible increases in ICP and SWE, which had a strong linear relationship (r = 0.802, p < 0.0001) during phase 1. SWE remained stable (50.86 ± 9.64 kPa) when ICP remained at 50.28 ± 2.17 mm Hg in phase 2. After fasciotomy, SWE declined stepwise and then normalized (r = 0.737, p < 0.0001). Histologically, the myofiber diameter of group 2 (82.31 ± 22.92 µm) and group 4 (90.90 ± 20.48 µm) decreased significantly (p < 0.01) compared with that of the control group (103.1 ± 20.39 µm); the interstitial space of all groups increased significantly (p < 0.01). Multifocal muscle damage revealed neutrophilic infiltration, degeneration, hemorrhage and necrosis, especially in group 4. Quantitative RT-PCR verified that interleukin-6 and heparin-binding EGF-like growth factor were significantly increased in group 4. CONCLUSION: SWE provided sensitive measurements correlating to ICP in a clinically relevant ACS animal model. Once ACS time was exceeded, progression to irreversible necrosis continued spontaneously, even after fasciotomy. SWE may help surgeons in the early detection, monitoring, prognosis and decision making on fasciotomy for ACS.

Intraoperative Surgeon Assessment of Bone: Correlation to Bone Mineral Density, CT Hounsfield units and Vertebral Bone Quality.

STUDY DESIGN: Retrospective observational study of consecutive patients. OBJECTIVE: The purpose of the study is to determine if a surgeon's qualitative assessment of bone intraoperatively correlates with radiologic parameters of bone strength. SUMMARY OF BACKGROUND DATA: Preoperative radiologic assessment of bone can include modalities such as CT Hounsfield Units (HUs), dual-energy x-ray absorptiometry bone mineral density (DXA BMD) with trabecular bone score (TBS) and MRI vertebral bone quality (VBQ). Quantitative analysis of bone with screw insertional torque and pull-out strength measurement has been performed in cadaveric models and has been correlated to these radiologic parameters. However, these quantitative measurements are not routinely available for use in surgery. Surgeons anecdotally judge bone strength, but the fidelity of the intraoperative judgement has not been investigated. METHODS: All adult patients undergoing instrumented posterior thoracolumbar spine fusion by one of seven surgeons at a single center over a 3-month period were included. Surgeons evaluated the strength of bone based on intraoperative feedback and graded each patient's bone on a 5-point Likert scale. Two independent reviewers measured preoperative CT HUs and MRI VBQ. BMD, lowest T-score and TBS were extracted from DXA within 2 years of surgery. RESULTS: Eighty-nine patients were enrolled and 16, 28, 31, 13 and 1 patients had Likert grade 1 (strongest bone), 2, 3, 4, and 5 (weakest bone), respectively. The surgeon assessment of bone correlated with VBQ (τ=0.15, P=0.07), CT HU (τ=-0.31, P<0.01), lowest DXA T-score (τ=-0.47, P<0.01), and TBS (τ=-0.23, P=0.06). CONCLUSION: Spine surgeons' qualitative intraoperative assessment of bone correlates with preoperative radiologic parameters, particularly in posterior thoracolumbar surgeries. This information is valuable to surgeons as this supports the idea that decisions based on feel in surgery have statistical foundation.

The Single Assessment Numeric Evaluation (SANE) after anterior cervical discectomy and fusion: A pilot study.

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To evaluate the single assessment numerical evaluation (SANE) as a patient reported outcomes measure (PROM) after anterior cervical discectomy and fusion (ACDF), by comparing to legacy measures. METHODS: We included all patients undergoing ACDF with at least one year of follow up with complete PROM data. Patients completed the Neck Disability Index (NDI), the RAND-36 and the EuroQual Five Dimension (EQ-5D) scale, as well as the one-question SANE, pre- and post-operatively. Validity of SANE compared with other PROMs was determined utilizing Pearson's correlation (ρ), proportional bias (B), responsiveness, minimal clinically important difference (MCID) and agreement. RESULTS: Sixty-nine patients were included. There were moderate-to-strong correlations at a minimum of one-year follow-up between the SANE and NDI (ρ = -0.73, P < 0.0001), RAND (ρ = 0.80, P < 0.0001), and EQ-5D (ρ = -0.66, P < 0.0001). No significant proportional bias was found for the SANE when compared to the RAND (B = 0.03, p = 0.99), NDI (B = -0.003, p = 0.99), or EQ-5D (B = -0.0007, p = 0.99). Responsiveness for SANE was statistically similar to all other PROMs. The MCID for SANE was determined to be 10.5, with 42% of patients achieving the MCID. Bland-Altman plots demonstrated high agreement between all PROMs. CONCLUSION: We found the SANE score provides clinically important patient outcomes data after ACDF, despite only requiring answering one question. The SANE performs comparably to more burdensome health questionnaires. The SANE score may offer spine surgeons the option to easily and quickly collect clinically relevant data on their surgical patients.

Cervical Paraspinal Muscle Fatty Degeneration Is Not Associated with Muscle Cross-sectional Area: Qualitative Assessment Is Preferable for Cervical Sarcopenia.

BACKGROUND: Sarcopenia, defined as decreased skeletal mass, is an independent marker of frailty that is not accounted for by other risk-stratification methods. Recent studies have demonstrated a clear association between paraspinal sarcopenia and worse patient-reported outcomes and complications after spine surgery. Currently, sarcopenia is characterized according to either a quantitative assessment of the paraspinal cross-sectional area or a qualitative analysis of paraspinal fatty infiltration on MRI. No studies have investigated whether the cervical paraspinal cross-sectional area correlates with fatty infiltration of the cervical paraspinal muscles on advanced imaging. QUESTION/PURPOSE: Do patients undergoing anterior cervical discectomy and fusion (ACDF) with increasing paraspinal fatty degeneration on advanced imaging also demonstrate decreased cervical paraspinal cross-sectional area? METHODS: Between 2011 and 2017, 98 patients were prospectively enrolled in a database of patients undergoing one- to three-level ACDF for degenerative conditions at a single institution. To be eligible for this prospective study, patients were required to undergo an MRI before surgery, be older than 18 years, and have no previous history of cervical spine surgery. Two independent reviewers, both surgeons not involved in the patients' care and who were blinded to the clinical outcomes, retrospectively assessed the paraspinal cross-sectional area and Goutallier classification of the right-sided paraspinal muscle complex. We then compared the patients' Goutallier grades with their paraspinal cross-sectional area measurements. We identified 98 patients for inclusion. Using the Fuchs modification of the Goutallier classification, we classified the fatty degeneration of 41 patients as normal (Goutallier Grades 0 to 1), that of 47 patients as moderate (Grade 2), and that of 10 patients as severe (Grades 3 to 4). We used ANOVA to compare all means between groups. RESULTS: There was no difference in the mean paraspinal cross-sectional area of the obliquus capitus inferior (normal 295 ± 81 mm2; moderate 317 ± 104 mm2; severe 300 ± 79 mm2; p = 0.51), multifidus (normal 146 ± 59 mm2; moderate 170 ± 70 mm2; severe 192 ± 107 mm2; p = 0.11), or sternocleidomastoid (normal 483 ± 150 mm2; moderate 468 ± 149 mm2; severe 458 ± 183 mm2; p = 0.85) among patients with mild, moderate, and severe fatty infiltration based on Goutallier grading. There was a slightly greater longus colli cross-sectional area in the moderate and severe fatty infiltration groups (74 ± 22 mm2 and 66 ± 18 mm2, respectively) than in the normal group (63 ± 15 mm2; p = 0.03). CONCLUSION: Because our study demonstrates minimal association between paraspinal cross-sectional area and fatty infiltration of the cervical paraspinals, we recommend that physicians use the proven qualitative assessment of paraspinal fatty infiltration during preoperative evaluation of patients who are candidates for ACDF. Future studies investigating the relationship between cervical paraspinal cross-sectional area and patient-reported outcomes after ACDF are necessary to lend greater strength to this recommendation. LEVEL OF EVIDENCE: Level III, diagnostic study.

Comparison of Costs and Postoperative Outcomes between Vertebroplasty and Kyphoplasty for Osteoporotic Vertebral Compression Fractures: Analysis from a State-Level Outpatient Database.

BACKGROUND: Vertebral cement augmentation techniques are routinely used to treat osteoporotic vertebral compression fractures (VCFs). In the current study, we used a state-level outpatient database to compare costs and postoperative outcomes between vertebroplasty and kyphoplasty. METHODS: We queried the 2016 Florida State-Ambulatory Surgery Database of the Healthcare Cost and Utilization Project for patients undergoing thoracolumbar vertebroplasty or kyphoplasty for osteoporotic VCFs. Demographic and clinical characteristics, as well as postoperative outcomes were compared between the 2 groups. RESULTS: A total of 105 patients (11.6%) who underwent vertebroplasty and 801 patients (88.4%) who underwent kyphoplasty were identified. Patients undergoing kyphoplasty were more likely to stay overnight or longer, with the P value trending toward significance (kyphoplasty with >1 day stay: 7.4% vs. vertebroplasty with >1 day stay: 1.9%; P = 0.086). Patients undergoing vertebroplasty had a significantly higher rate of discharge to home routine compared with patients undergoing kyphoplasty (97.1% [n = 102] vs. 94.1% [n = 754]; P < 0.001). Undergoing kyphoplasty was also associated with higher index admission costs ($40,706 vs. $18,965; P < 0.001) and higher readmission costs ($27,038 vs. $11,341; P = 0.046). The rates of 30-day and 90-day readmission were similar between the 2 groups (all P > 0.05). The rates of 30-day, 90-day, and overall readmission because of a new-onset fracture were also similar (all P > 0.05). However, vertebroplasty had a higher rate of readmissions associated with a procedure within a year (21.9% [n = 23] vs. 14.5% [n = 116]; P = 0.047). CONCLUSIONS: Our analyses from a state-level database of patients undergoing vertebroplasty and kyphoplasty for osteoporotic VCFs show similar postoperative outcomes for the 2 procedures but a higher cost for kyphoplasty.

An empiric analysis of 5 counter measures against surgical site infections following spine surgery-a pragmatic approach and review of the literature.

BACKGROUND CONTEXT: Surgical site infections (SSI) following spine surgery are debilitating complications to patients and costly to the healthcare system. PURPOSE: Review the impact and cost effectiveness of 5 SSI prevention interventions on SSI rates in an orthopedic spine surgery practice at a major quaternary healthcare system over a 10-year period. STUDY DESIGN: Retrospective observational study. PATIENT SAMPLE: All of the surgical patients of the 5 spine surgeons in our department over a 10-year period were included in this study. OUTCOME MEASURES: SSI rates per year, standardized infection ratios (SIR) for laminectomies and fusions during the most recent 3-year period, year of implementation, and frequency of use of the different interventions, cost of the techniques. METHODS: The SSI prevention techniques described in this paper include application of intrawound vancomycin powder, wound irrigation with dilute betadine solution, preoperative chlorhexidine gluconate scrubs, preoperative screening with nasal swabbing, and decolonization of S. aureus, and perioperative antibiotic administration. Our institution's infection prevention and control data were analyzed for the yearly SSI rates for the orthopedic spine surgery department from 2006 to 2016. In addition, our orthopedic spine surgeons were polled to determine with what frequency and duration they have been using the different SSI prevention interventions. RESULTS: SSI rates decreased from almost 6% per year the first year of observation to less than 2% per year in the final 6 years of this study. A SIR of less than 1.0 for each year was observed for laminectomies and fusions for the period from 2013 to 2016. All surgeons polled at our institution uniformly used perioperative antibiotics, Hibiclens scrub, and the nasal swab protocol since the implementation of these techniques. Some variability existed in the frequency and duration of betadine irrigation and application of vancomycin powder. A cost analysis demonstrated these methods to be nominal compared with the cost of treating a single SSI. CONCLUSIONS: It is possible to reduce SSI rates in spine surgery with easy, safe, and cost-effective protocols, when implemented in a standardized manner.

Does patient selection account for the perceived cost savings in outpatient spine surgery? A meta-analysis of current evidence and analysis from an administrative database.

OBJECTIVEFrom 1994 to 2006 outpatient spinal surgery increased 5-fold. The perceived cost savings with outcomes comparable to or better than those achieved with inpatient admission for the same procedures are desirable in an era where health expenditures are scrutinized. The increase in outpatient spine surgery is also driven by the proliferation of ambulatory surgery centers. In this study, the authors hypothesized that the total savings in outpatient spine surgery is largely driven by patient selection and biases toward healthier patients.METHODSA meta-analysis assessed patient selection factors and outcomes associated with outpatient spine procedures. Pooled odds ratios and mean differences were calculated using a Bayesian random-effects model. The authors extended this analysis in a novel way by using the results of the meta-analysis to examine cost data from an administrative database of academically affiliated hospitals. A Bayesian approach with priors informed by the meta-analysis was used to compare costs for inpatient and outpatient performance of anterior cervical discectomy and fusion (ACDF) and lumbar laminectomy.RESULTSSixteen studies with a total of 370,195 patients met the inclusion criteria. Outpatient procedures were associated with younger patient age (mean difference [MD] -2.34, 95% credible interval [CrI] -4.39 to -0.34) and no diabetes diagnosis (odds ratio [OR] 0.78, 95% CrI 0.54-0.97). Outpatient procedures were associated with a lower likelihood of reoperation (OR 0.42, 95% CrI 0.16-0.80), 30-day readmission (OR 0.39, 95% CrI 0.16-0.74), and complications (OR 0.29, 95% CrI 0.15-0.50) and with lower overall costs (MD -$121,392.72, 95% CrI -$216,824.81 to -$23,632.92). Additional analysis of the national administrative data revealed more modest cost savings than those found in the meta-analysis for outpatient spine surgeries relative to inpatient spine surgeries. Estimated cost savings for both younger patients ($555 for those age 30-35 years [95% CrI -$733 to -$374]) and older patients ($7290 for those age 65-70 years [95% CrI -$7380 to -$7190]) were less than the overall cost savings found in the meta-analysis.CONCLUSIONSCompared to inpatient spine surgery, outpatient spine surgery was associated with better short-term outcomes and an initial reduction in direct costs. A selection bias for outpatient procedures toward younger, healthier patients may confound these results. The additional analysis of the national database suggests that cost savings in the outpatient setting may be less than previously reported and a result of outpatient procedures being offered more frequently to younger and healthier individuals.

The 2016 American Orthopaedic Association-Japanese Orthopaedic Association Traveling Fellowship.

The American Orthopaedic Association-Japanese Orthopaedic Association (AOA-JOA) Traveling Fellowship, which began in 1992 as a collaborative effort between the 2 orthopaedic communities, is aimed at fostering leadership among early-career surgeons through clinical, academic, and cultural exchange. Over 3 weeks, we experienced an extraordinary journey that led us across nearly 800 miles of the picturesque Japanese countryside, with stops at 6 distinguished academic centers. The opportunity to become personally acquainted with orthopaedic leaders in Japan, learn from their experiences, and immerse ourselves in the ancient and storied culture of a beautiful country was one that we will not soon forget. Along the way, we accumulated a wealth of information while enjoying the legendary hospitality of the Japanese people. There is a ubiquitous challenge in delivering cost-effective, accessible health care while maintaining a commitment to education and research. The U.S. orthopaedic community may take solace in the fact that our Japanese colleagues stand with us as partners in this pursuit, and our relationship with them continues to grow stronger through endeavors such as the AOA-JOA Traveling Fellowship. We look forward to honoring our Japanese colleagues in 2017 when we host them in the United States.

Retrospective Analysis of Long-Term Outcomes After Combat Injury: A Hidden Cost of War.

BACKGROUND: During the conflicts in Iraq and Afghanistan, 52,087 service members have been wounded in combat. The long-term sequelae of these injuries have not been carefully examined. We sought to determine the relation between markers of injury severity and the subsequent development of hypertension, coronary artery disease, diabetes mellitus, and chronic kidney disease. METHODS AND RESULTS: Retrospective cohort study of critically injured US military personnel wounded in Iraq or Afghanistan from February 1, 2002 to February 1, 2011. Patients were then followed until January 18, 2013. Chronic disease outcomes were assessed by International Classification of Diseases, 9th edition codes and causes of death were confirmed by autopsy. From 6011 admissions, records were excluded because of missing data or if they were for an individual's second admission. Patients with a disease diagnosis of interest before the injury date were also excluded, yielding a cohort of 3846 subjects for analysis. After adjustment for other factors, each 5-point increment in the injury severity score was associated with a 6%, 13%, 13%, and 15% increase in incidence rates of hypertension, coronary artery disease, diabetes mellitus, and chronic kidney disease, respectively. Acute kidney injury was associated with a 66% increase in rates of hypertension and nearly 5-fold increase in rates of chronic kidney disease. CONCLUSIONS: In Iraq and Afghanistan veterans, the severity of combat injury was associated with the subsequent development of hypertension, coronary artery disease, diabetes mellitus, and chronic kidney disease.

Identification of optimal control compartments for serial near-infrared spectroscopy assessment of lower extremity compartmental perfusion.

Near-infrared spectroscopy (NIRS) has shown promise in detecting ischemic changes in acute compartment syndrome. The objectives of this study were to 1) assess the correlation in NIRS values between upper and lower extremity control sites for bilateral lower extremity trauma and 2) investigate the effect of skin pigmentation on NIRS values. Forty-four volunteers (14 male, 30 female) were monitored over separate 1-hour sessions. NIRS leads were placed over leg and upper extremity compartments. Colorimeters were used to document skin pigmentation. NIRS values between corresponding contralateral compartments were extremely well correlated (r = 0.76-0.90). Upper extremity NIRS values were correlated to leg values in the following order: volar (r = 0.65-0.71), dorsal (r = 0.36-0.60), and deltoid (r = 0.42-0.51). A negative correlation was observed between melanin and NIRS values. Analogous leg compartments are the optimal site of control for each other. The volar forearm may be the best upper extremity control. Skin pigmentation may affect absolute NIRS values.

Correlation of Short Form-36 and disability status with outcomes of arthroscopic acetabular labral debridement.

BACKGROUND: Arthroscopic debridement is the standard of care for the treatment of acetabular labral tears. The Short Form-36 has not been used to measure hip arthroscopy outcomes, and the impact of disability status on hip arthroscopy outcomes has not been reported. HYPOTHESIS: Short Form-36 subscale scores will demonstrate good correlation with the modified Harris hip score, but patients undergoing disability evaluation will have significantly worse outcome scores. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The records of active-duty soldiers who underwent hip arthroscopy at the authors' institution were retrospectively reviewed. Forty consecutive patients who underwent hip arthroscopy for the primary indication of labral tear formed the basis of the study group. Patients completed the modified Harris hip score, the Short Form-36 general health survey, and a subjective overall satisfaction questionnaire. RESULTS: Thirty-three patients, with a mean age of 34.6 years, were available for follow-up at a mean of 25.7 months postoperatively. Fourteen (43%) patients were undergoing medical evaluation boards (military equivalent of workers' compensation or disability claim). Pearson correlation coefficients for comparing the Short Form-36 Bodily Pain, Physical Function, and Physical Component subscale scores to the modified Harris hip score were 0.73, 0.71, and 0.85, respectively (P < .001). The mean modified Harris hip score was significantly lower in patients on disability status than in those who were not (92.4 vs 61.1; P < .0001). The Short Form-36 subscale scores were significantly lower in disability patients (P < .02). Patient-reported satisfaction rates (70% overall) were 50% for those undergoing disability evaluations and 84% for those who were not (P < .04). There was no significant difference in outcomes based on patient age, surgically proven chondromalacia, or gender for military evaluation board status. CONCLUSION: The Short Form-36 demonstrated good correlation with the modified Harris hip score for measuring outcomes after arthroscopic partial limbectomy. Arthroscopic debridement yielded a high percentage of good results when patients undergoing disability evaluations were excluded. Disability status may be a negative predictor of success after hip arthroscopy.