Resilience and Patient-Reported Outcomes in Patients Undergoing Orthopedic Hand Surgery

BACKGROUND

Previous studies have examined the impact of resiliency on postoperative outcomes in other orthopedic domains, but none to date have done so for hand surgery.

METHODS

We performed a retrospective analysis of prospectively collected data of patients undergoing hand surgery at a single institution. We included patients with complete preoperative outcomes scores and 6-month follow-up. All patients completed the Brief Resilience Scale (BRS), Disabilities of the Arm, Shoulder, and Hand (DASH) Score, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), Veterans RAND 12-Item Health Survey (VR-12), and Numeric Rating Scale (NRS) for pain. Patients were stratified into high-resiliency (HR) and low-resiliency (LR) groups based on the preoperative BRS score, and outcomes between groups were compared.

RESULTS

We identified 91 patients who underwent hand procedures and completed full preoperative and postoperative outcomes measures. There were no observed preoperative differences between the groups in all outcomes scores except the VR-12 Mental Component Score. Postoperatively, the HR group had superior DASH, QuickDASH, and VR-12 (mental and physical component) scores than the LR group. Postoperative pain, as measured by the NRS, was significantly lower in the HR group despite there being no preoperative difference. A larger percentage of patients in the HR group met the minimal clinically important difference in all outcomes except for the VR-12 Mental Component Scores.

CONCLUSIONS

Patients with high preoperative resilience appear to have significantly better clinical outcomes following hand surgery with superior DASH, QuickDASH, and VR-12 scores at 6-month follow-up.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic study/Level IV evidence.

Direct thermal injury to the popliteal artery after total knee arthroplasty

Vascular damage after total knee arthroplasty is rare. However, delayed diagnosis and management may cause adverse outcomes for patients. In particular, direct thermal injury to the popliteal artery after total knee arthroplasty is extremely rare. A 74-year-old woman presented to another institution with a left popliteal artery injury after left total knee arthroplasty. Arteriography revealed total occlusion of the popliteal artery, and emergency surgery was performed. Because of the total occlusion of the popliteal artery due to severe direct thermal injury, anastomosis was performed in an end-to-end fashion with a right great saphenous vein graft. At the time of discharge, she had no specific symptoms other than pain at the surgical site, with a palpable left dorsalis pedis pulse. While performing total knee arthroplasty, the anatomical position of the popliteal artery should be carefully considered to prevent injury.

Late tibial interference screw extrusion following anterior cruciate ligament reconstruction: A case report

INTRODUCTION

Interference screws are used as back-up fixation in anterior cruciate ligament reconstructions. Historically these were composed of metal, but recently surgeons have switched to using bioabsorbable screws as they cause less symptoms and are biomedically advantageous. Usually these screws are absorbed by the body within one to two years after surgery.

CASE PRESENTATION

A 32-year-old male presented with aseptic extrusion of his intact tibial bioabsorbable interference screw eight years following successful anterior cruciate ligament reconstruction.

MANAGEMENT AND OUTCOMES

Patient underwent laboratory evaluation and magnetic resonance imaging to rule out infection as an underlying cause. He went on to heal the wound without complication.

CONCLUSION

Late aseptic extrusion of tibial interference screw can occur; however, infectious etiologies should be carefully ruled out.

Surgical Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Surgical Microscope vs Surgical Loupes: A Comparative Study

BACKGROUND

Minimally invasive transforaminal interbody fusion (MIS-TLIF) is an effective procedure for lumbar spine diseases. The procedure can be done using a surgical microscope (SM) or surgical loupes (SL) magnification. However, there are no studies that compared outcomes between using these 2 magnifying devices in the MIS-TLIF procedure. The purpose of this study was to compare clinical outcomes, perioperative complications, and radiographic parameters of MIS-TLIF using SM compared with SL magnification.

METHODS

We included all patients undergoing 1-level MIS-TLIF between January 2017 and December 2019. Type of magnification (SM vs SL), operative time, blood loss, perioperative complications, cross-sectional area of the spinal canal, and fusion rates were analyzed. Clinical outcomes measurement using the visual analog scale (VAS) and Oswestry Disability Index (ODI) were compared between groups.

RESULTS

A total of 100 patients had underwent MIS-TLIF (SM group: 62; SL group: 38). Operative time (SM: 182.7 ± 41.5 vs SL: 165.6 ± 32.6 minutes, P = 0.043) was significantly shorter in the SL group, with a mean difference of 17.2 minutes and a 10.4% increase in operative time between SL and SM. Blood loss (SM: 187.4 ± 176.4 vs SL: 215.6 ± 99.4 mL, P = 0.36) was not different between groups, with a mean difference of 28.2 mL. Both the SM group and SL group demonstrated no significant differences in improvement from baseline in VAS back, VAS legs, ODI score, and cross-sectional area of the spinal canal. There was also no significant difference in complication rates and fusion rates between groups.

CONCLUSIONS

Our study found no difference between intraoperative use of SL compared with SM in clinical outcomes through the 12-month follow-up timepoint. However, the use of SM resulted in an increased average operative time of 17 minutes compared with the SL group.

CLINICAL RELEVANCE

Intraoperative use of SM and SL magnification in MIS-TLIF provides similar outcomes except prolonged operative time in the SM group.

LEVEL OF EVIDENCE: 3

Physician-Rating Websites and Social Media Usage: A Global Survey of Academic Orthopaedic Surgeons: AOA Critical Issues

The relationship between orthopaedic surgeons and the internet is complicated. Social media allows surgeons to educate their patients while marketing to them at the same time. Conversely, patients are able to better communicate with their surgeons while anonymously rating their service and expertise. This study aims to look at the complex relationship between surgeons and social media use.

Is Self-reported Return to Duty an Adequate Indicator of Return to Sport and/or Return to Function in Military Patients?

BACKGROUND

In the military, return-to-duty status has commonly been used as a functional outcome measure after orthopaedic surgery. This is sometimes regarded similarly to return to sports or as an indicator of return to full function. However, there is variability in how return-to-duty data are reported in clinical research studies, and it is unclear whether return-to-duty status alone can be used as a surrogate for return to sport or whether it is a useful marker for return to full function.

QUESTIONS/PURPOSES

(1) What proportion of military patients who reported return to duty also returned to athletic participation as defined by self-reported level of physical activity? (2) What proportion of military patients who reported return to duty reported other indicators of decreased function (such as nondeployability, change in work type or level, or medical evaluation board)?

METHODS

Preoperative and postoperative self-reported physical profile status (mandated physical limitation), physical activity status, work status, deployment status, military occupation specialty changes, and medical evaluation board status were retrospectively reviewed for all active-duty soldiers who underwent orthopaedic surgery at Madigan Army Medical Center, Joint Base Lewis-McChord from February 2017 to October 2018. Survey data were collected on patients preoperatively and 6, 12, and 24 months postoperatively in all subspecialty and general orthopaedic clinics. Patients were considered potentially eligible if they were on active-duty status at the time of their surgery and consented to the survey (1319 patients). A total of 89% (1175) were excluded since they did not have survey data at the 1 year mark. Of the remaining 144 patients, 9% (13) were excluded due to the same patient having undergone multiple procedures, and 2% (3) were excluded for incomplete data. This left 10% (128) of the original group available for analysis. Ninety-eight patients reported not having a physical profile at their latest postoperative visit; however, 14 of these patients also stated they were retired from the military, leaving 84 patients in the return-to-duty group. Self-reported "full-time duty with no restrictions" was originally used as the indicator for return to duty; however, the authors felt this to be too vague and instead used soldiers' self-reported profile status as a more specific indicator of return to duty. Mean length of follow-up was 13 ± 3 months. Eighty-three percent (70 of 84) of patients were men. Mean age at the preoperative visit was 35 ± 8 years. The most common surgery types were sports shoulder (n = 22) and sports knee (n = 14). The subgroups were too small to analyze by orthopaedic procedure. Based on active-duty status and requirements of the military profession, all patients were considered physically active before their injury or surgery. Return to sport was determined by asking patients how their level of physical activity compared with their level before their injury (higher, same, or lower). We identified the number of other indicators that may suggest decreased function by investigating change in work type/level, self-reported nondeployability, or medical evaluation board. This was performed with a simple survey.

RESULTS

Of the 84 patients reporting return to duty at the final follow-up, 67% (56) reported an overall lower level of physical activity. Twenty-seven percent (23) reported not returning to the same work level, 32% (27) reported being nondeployable, 23% (19) reported undergoing a medical evaluation board (evaluation for medical separation from the military), and 11% (9) reported a change in military occupation specialty (change of job description).

CONCLUSION

Return to duty is commonly reported in military orthopaedics to describe postoperative functional outcome. Although self-reported return to duty may have value for military study populations, based on the findings of this investigation, surgeons should not consider return to duty a marker of return to sport or return to full function. However, further investigation is required to see to what degree this general conclusion applies to the various orthopaedic subspecialties and to ascertain how self-reported return to duty compares with specific outcome measures used for particular procedures and subspecialties.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

VA/DoD Clinical Practice Guideline: Diagnosis and Treatment of Low Back Pain

DESCRIPTION

In September 2017, the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) approved the joint Clinical Practice Guideline (CPG) for Diagnosis and Management of Low Back Pain. This CPG was intended to provide healthcare providers a framework by which to evaluate, treat, and manage patients with low back pain (LBP).

METHODS

The VA/DoD Evidence-Based Practice Work Group convened a joint VA/DoD guideline development effort that included a multidisciplinary panel of practicing clinician stakeholders and conformed to the Institute of Medicine's tenets for trustworthy clinical practice guidelines. The guideline panel developed key questions in collaboration with the ECRI Institute, which systematically searched and evaluated the literature through September 2016, developed an algorithm, and rated recommendations by using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. A patient focus group was also convened to ensure patient values and perspectives were considered when formulating preferences and shared decision making in the guideline.

RECOMMENDATIONS

The VA/DOD LBP CPG provides evidence-based recommendations for the diagnostic approach, education and self-care, non-pharmacologic and non-invasive therapy, pharmacologic therapy, dietary supplements, non-surgical invasive therapy, and team approach to treatment of low back pain.

Awareness of middle sacral artery pathway: A cadaveric study of the presacral area

PURPOSE

To assess the anatomic path of the middle sacral artery (MSA) at the presacral area and its relationship to the spinal midline during an axial lumbar interbody fusion (AxiaLif) approach.

METHODS

Fifty human cadavers (25 males, 25 females) were used in this study. A transabdominal approach was used to expose the anterior aspect of the L5/S1 intervertebral disc and the presacral space. We measured the size and distance from the spinal midline at the following positions: (a) middle of the L5/S1 disc level, (b) 1 cm below the sacral promontory (SP), and (c) 2 cm below the SP. Each parameter was measured three times by two observers, and the mean value analyzed.

RESULTS

The MSA was present and originated from the left common iliac artery in all cadavers with a mean width of 2.14 mm. The position of the MSA in relation to the midline was most commonly on the left side (LS, 56%) followed by the right side (RS, 34%) and midline (ML, 10%). In the LS group, the distance from the midline is relatively constant in the three measured positions with a mean value of (a) 1.78 mm (range, 0-8.17 mm), (b) 2.08 mm (range, 0-7.10 mm), and (c) 2.06 mm (range, 0-9.76 mm). In the RS group, the distance from the midline increased from cephalad to caudad, with a mean value of (a) 1.44 mm (range, 0-9.64 mm), (b) 2.19 mm (range, 0-9.95 mm), and (c) 2.92 mm (range, 0-10.03 mm).

CONCLUSIONS

Our study found the presacral anatomic path of the MSA was most commonly at the left of midline. In addition, the right-sided MSA variant had increasing distance from the midline along its anatomic path from cephalad to caudad. Our findings suggest an AxiaLif approach at the left of midline may place the MSA at greatest risk.

Inhibitory effects of herbal decoction Ojeoksan on proliferation and migration in vascular smooth muscle cells

The proliferation of vascular smooth muscle cells plays a crucial role in pathogenesis of cardiovascular disease. The principal objective of this study was to determine the effects of Ojeoksan (OJS) on human aortic smooth muscle cell (HASMC) proliferation induced by tumor necrosis factor α (TNF-aα). Thymidine incorporation after TNF-α treatment was increased and this effect was inhibited significantly by OJS treatment. HASMC proliferation and migration by kinetic live cell imaging were also reduced by treatment with OJS. TNF-α induced the expression of cyclins/cyclin-dependent kinases (CDKs) and reduced the expression of p21^waf1/cip1/p27^kip1. However, OJS also attenuated the expression of TNF-α-induced cell-cycle regulatory proteins. The results of Western blot analysis demonstrated that the TNF-α treated HASMC secreted gelatinases, probably including MMP-2/-9, which may be involved in the invasion and migration of HASMC. Additionally, OJS suppressed the mRNA expression levels of matrix metalloproteinase-2/-9 (MMP-2/-9) in a dose-dependent manner. OJS inhibited the production of TNF-α-induced hydrogen peroxide (H₂O₂) and the formation of DCF-sensitive intracellular reactive oxygen species (ROS). Further, OJS suppressed the nuclear translocation and phosphorylation of inhibitor of kappa B-α (IκB-α) of nuclear factor κB (NF-κB) under TNF-α conditions. Our results demonstrate that OJS exerts inhibitory effects on TNF-α-induced HASMC proliferation and migration, suggesting the involvement of the inhibition of both MMP-2 and MMP-9 expressions, and the downregulation of ROS/NF-κB signaling. Thus, herbal decoction OJS may be a possible therapeutic approach to the inhibition of cardiovascular disease including atherosclerosis.

High Resiliency Linked to Short-Term Patient Reported Outcomes and Return to Duty Following Arthroscopic Knee Surgery

Introduction

Resilience is a psychometric construct of a patient’s ability to recover from adversity and has been used to predict outcomes but its use in orthopedics has been limited. The purpose of this study was to examine the association between resilience and outcomes.

Materials and Methods

We performed a retrospective analysis of prospectively collected data of patient who underwent sports knee surgery at a single institution performed by 6 orthopedic surgeons from January 2017 to December 2017. We included active-duty patients with complete preoperative outcomes and a minimum of 6 month follow-up. All patients completed the Brief Resilience Scale (BRS), Veteran’s Rand-12 (VR-12), Patient-Reported Outcomes Measurement Information System 43 (PROMIS-43), International Knee Documentation Committee function score (IKDC), and Knee Injury and Osteoarthritis Outcome Score (KOOS). Patients were divided into low resilience (LR) and high resilience (HR) groups based on a score of less than 24 for low and greater than or equal to 24 according to BRS. Outcomes were then compared.

Results

We identified 50 active-duty patients who had complete preoperative and postoperative outcomes at a minimum of 6 months. Mean preoperative and postoperative BRS were significantly different (25.8 HR v 18.6 LR, p < 0.001). We found a difference in postop KOOS in pain, sports, and short form (pain 70.9 HR v 55.7 LR, p = 0.03; sports 50.3 HR v 32.2 LR, p = 0.03; short form (72.1 HR v 62.5 LR, p = 0.04). Similarly, there was a significant difference in postoperative IKDC score (58.0 HR v 44.0 LR, p = 0.03). Similarly we found significant differences in postoperative PROMIS-43 (anxiety 44.4 HR v 60.3 LR, p = 0.004; depression 41.6 HR v 58.1 LR, p = 0.004; fatigue 45.1 HR v 58.6 LR, p = 0.001; sleep 52.6 HR v 62.5 LR, p = 0.02; social participation 36.2 HR v 47.6 LR, p < 0.001). Postoperative VR-12 mental was also statistically different between the two groups (53.5 HR v 41.6 LR; p = 0.01). In addition, 2.3% of the HR group changed MOS as a result of their sports knee surgery compared to 22.2% of the LR group.

Conclusions

Active-military patients with high preoperative resilience appear to have significantly better early postoperative outcomes following sports knee surgery in terms of PROMIS-43, KOOS, and IKDC. There was also a lower rate of changing MOS secondary to sports knee surgery in patients with high resilience.

Postoperative Seroma Formation After Posterior Cervical Fusion with Use of RhBMP-2: A Report of Two Cases

CASE

We present 2 cases of postoperative seroma formation following posterior cervical fusion with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2).

CONCLUSION

Although some who advocate for the off-label use of rhBMP-2 in patients undergoing posterior cervical spine fusion believe it to be safe, relatively little has been published regarding complication rates. We believe that rhBMP-2 carries a risk of seroma formation in patients who undergo posterior cervical fusion, which necessitates the use of a postoperative drain. Surgeons should have a low threshold for obtaining postoperative magnetic resonance imaging in a symptomatic patient.

Lumbar computed tomography scans are not appropriate surrogates for bone mineral density scans in primary adult spinal deformity

OBJECTIVE

The authors examined the correlation between lumbar spine CT Hounsfield unit (HU) measurements and bone mineral density measurements in an adult spinal deformity (ASD) population.

METHODS

Patients with ASD were identified in the records of a single institution. Lumbar CT scans were reviewed, and the mean HU measurements from L1–4 were recorded. Bone mineral density (BMD) was assessed using femoral neck and lumbar spine dual-energy x-ray absorptiometry (DEXA). The number of patients who met criteria for osteoporosis was determined for each imaging modality.

RESULTS

Forty-eight patients underwent both preoperative DEXA and CT scanning. Forty-three patients were female and 5 were male. Forty-seven patients were Caucasian and one was African American. The mean age of the patients was 62.1 years. Femoral neck DEXA was more likely to identify osteopenia (n = 26) than lumbar spine DEXA (n = 8) or lumbar CT HU measurements (n = 6) (p < 0.001). There was a low-moderate correlation between lumbar spine CT and lumbar spine DEXA (r = 0.463, p < 0.001), and there was poor correlation between lumbar spine CT and femoral neck DEXA (r = 0.303, p = 0.036).

CONCLUSIONS

Despite the opportunistic utility of lumbar spine CT HU measurements in identifying osteoporosis in patients undergoing single-level fusion, these measurements were not useful in this cohort of ASD patients. The correlation between femoral neck DEXA and HU measurements was poor. DEXA assessment of BMD in ASD patients is essential to optimize the care of these complicated cases.

Biomechanical Stability of a Stand-Alone Interbody Spacer in Two-Level and Hybrid Cervical Fusion Constructs

STUDY DESIGN

In vitro human cadaveric biomechanical analysis.

OBJECTIVE

To evaluate the segmental stability of a stand-alone spacer (SAS) device compared with the traditional anterior cervical plate (ACP) construct in the setting of a 2-level cervical fusion construct or as a hybrid construct adjacent to a previous 1-level ACP construct.

METHODS

Twelve human cadaveric cervical spines (C2-T1) were nondestructively tested with a custom 6-degree-of-freedom spine simulator under axial rotation (AR), flexion-extension (FE), and lateral bending (LB) at 1.5 N m loads. After intact analysis, each specimen underwent instrumentation and testing in the following 3 configurations, with each specimen randomized to the order of construct: (A) C5-7 SAS; (B) C5-6 ACP, and C6-7 SAS (hybrid); (C) C5-7 ACP. Full range of motion (ROM) data at C5-C7 was obtained and analyzed by each loading modality utilizing mean comparisons with repeated measures analysis of variance with Sidak correction for multiple comparisons.

RESULTS

Compared with the intact specimen, all tested constructs had significantly increased segmental stability at C5-C7 in AR and FE ROM, with no difference in LB ROM. At C5-C6, all test constructs again had increased segmental stability in FE ROM compared with intact (10.9° ± 4.4° Intact vs SAS 6.6° ± 3.2°, P < .001; vs.Hybrid 2.9° ± 2.0°, P = .005; vs ACP 2.1° ± 1.4°, P < .001), but had no difference in AR and LB ROM. Analysis of C6-C7 ROM demonstrated all test groups had significantly greater segmental stability in FE ROM compared with intact (9.6° ± 2.7° Intact vs SAS 5.0° ± 3.0°, P = .018; vs Hybrid 5.0° ± 2.7°, P = .018; vs ACP 4.4° ± 5.2°, P = .005). Only the hybrid and 2-level ACP constructs had increased stability at C6-C7 in AR ROM compared with intact, with no difference for all test groups in LB ROM. Comparison between test constructs demonstrated no difference in C5-C7 and C6-C7 segmental stability in all planes of motion. However, at C5-C6 comparison between test constructs found the 2-level SAS had significantly less segmental stability compared to the hybrid (6.6° ± 3.2° vs 2.9° ± 2.0°, P = .025) and ACP (6.6° ± 3.2° vs 2.1° ± 1.4°, P = .004).

CONCLUSIONS

Our study found the currently tested SAS device may be a reasonable option as part of a 2-level hybrid construct, when used below an adjacent 1-level ACP, but should be used with careful consideration as a 2-level SAS construct. Consequences of decreased segmental stability in FE are unknown; however, optimal immediate fixation stability is an important surgical principle to avoid loss of fixation, segmental kyphosis, interbody graft subsidence, and pseudarthrosis.

Mechanisms of vasorelaxation induced by total flavonoids of Euphorbia humifusa in rat aorta

Euphorbia humifusa Willd. (EH), rich in flavonoids, has long been used for the treatment of bacillary dysentery and enteritis in China, and is known to have antioxidant, hypotensive and hypolipidemic properties. However, the vasorelaxant effect of total flavonoids of EH (TFEH) and action mechanisms are not clearly defined yet. The aim of the present study was to investigate the effects of TFEH on the vascular tension and its underlying mechanisms. Experiments were performed in rat thoracic aorta using the organ bath system. TFEH (0.01 - 100 μg/ml) caused a concentration-dependent vasorelaxation, which was dependent on a functional endothelium, and were significantly attenuated by inhibitors of endothelial NO synthase, its upstream signaling pathway, PI3K/Akt, and soluble guanylate cyclase, but not by blockade of K_Ca channel, K_ATP channel, cyclooxygenase, muscarinic and β-adrenergic receptors. Extracellular Ca²⁺ depletion, and pre-treatment with modulators of the store-operated Ca²⁺ entry channels, Gd³⁺ and 2-aminoethyl diphenylborinate, significantly attenuated the TFEH-induced vasorelaxation. Our findings suggest that TFEH elicit vasorelaxation via endothelium-dependent NO-cGMP pathway through activation of PI3K/Akt- and Ca²⁺-eNOS-NO signaling. Further, it is suggested that TFEH-induced activation of the NO-soluble guanylate cyclase-cGMP-protein kinase G signaling relaxes vascular smooth muscle cells through an inhibition of the L-type Ca²⁺ channel activity.

Effects of cell death-inducing DFF45-like effector B on meat quality traits in Berkshire pigs

Cell death-inducing DFF45-like effector (CIDE) B is a member of the CIDE family of apoptosis-inducing factors. In the present study, we detected a single nucleotide polymorphism (SNP), c.414G>A, which corresponds to the synonymous SNP 414Arg, in CIDE-B in the Berkshire pigs. We also analyzed the relationships between the CIDE-B SNP and various meat quality traits. The SNP was significantly associated with post-mortem pH_24h, water-holding capacity (WHC), fat content, protein content, drip loss, post-mortem temperature at 12 h (T12) and 24 h (T24) in a co-dominant model (P < 0.05). A significant association was detected between the SNP and post-mortem pH_24h, fat content, protein content, drip loss, shear force, and T24 in gilts; and color parameter b*, WHC, and T24 in barrows (P < 0.05). The SNP was significantly correlated with the fat content, and CIDE-B mRNA expression was significantly upregulated during the early stage of adipogenesis, suggesting that CIDE-B may contribute towards initiation of adipogenesis (P < 0.05). Furthermore, CIDE-B mRNA was strongly expressed in the liver, kidney, large intestine, and small intestine, and weakly expressed in the stomach, lung, spleen, and white adipose tissue. These results indicate that the CIDE-B SNP is closely associated with meat quality traits and may be a useful DNA marker for improving pork quality.

Mantidis ootheca induces vascular relaxation through PI3K/AKT-mediated nitric oxide-cyclic GMP-protein kinase G signaling in endothelial cells

Mantidis ootheca (Sang Piao Xiao) is well known mantis eggs in a foamy pouch. The purpose of the present study was to investigate the underlying cellular mechanisms of the nitric oxide (NO)-releasing property of the aqueous extract of Mantidis ootheca (AMO) in rat aorta and vascular endothelial cells. AMO was examined for its vascular relaxant effect in isolated phenylephrine-precontracted rat thoracic aortic rings. The roles of the nitric oxide (NO) signaling in the AMO-induced effects were tested in human umbilical vein endothelial cells (HUVECs). HUVEC treated with AMO produced higher amount of NO compared to control. However, AMO-induced increases in NO production were blocked by pretreatment with N^G-nitro-L-arginine methylester (L-NAME) or wortmannin. AMO increased in phosphorylation levels of endothelial nitric oxide synthase (eNOS) and Akt in HUVECs, which were attenuated by a NOS and Akt inhibitors. In aortic ring, AMO-induced dose-dependent relaxation of phenylephrine-precontracted aorta was abolished by removal of functional endothelium. Pretreatment with L-NAME, ¹H-[1,2,4]-oxadiazolo-[4,3-alpha]-quinoxalin-1-one (ODQ), and KT5823 inhibited the AMO-induced vasorelaxation. Similarly, wortmannin and LY-294002, an inhibitors of the phosphatidylinositol 3-kinase (PI3K), an upstream signaling molecule of eNOS, attenuated the AMO-induced vasorelaxation. Moreover, AMO-induced increases in cGMP production were blocked by pretreatment with L-NAME or ODQ. The vasorelaxant effect of AMO was attenuated by tetraethylammonium, 4-aminopyridine, and glibenclamide. We conclude that AMO relaxed vascular smooth muscle via endothelium-dependent activation of PI3K/Akt-mediated NO-cGMP-PKG signaling pathway and possible involvement of K⁺ channel.

Complications Associated With Bone Morphogenetic Protein in the Lumbar Spine

Complications associated with the use of recombinant human bone morphogenetic protein in the lumbar spine include retrograde ejaculation, ectopic bone formation, vertebral osteolysis and subsidence, postoperative radiculitis, and hematoma and seroma. These complications are controversial and remain widely debated. This article discusses the reported complications and possible implications for the practicing spine surgeon. Understanding the complications associated with the use of recombinant human bone morphogenetic protein and the associated controversies allows for informed decision making by both the patient and the surgeon. [Orthopedics. 2017; 40(2):e229-e237.].

Characteristics of combat-related spine injuries: a review of recent literature

Injuries to the spinal column in combat casualties sustained during the conflicts in Iraq and Afghanistan are common, and the highest in reported wartime history. High-energy blast mechanisms from improved explosive devices have resulted in complex polytrauma and injury patterns, which are often markedly different from those injuries encountered in civilian trauma. Herein, we review the most current literature with regard to the distinct types of combat-related spine injuries/concomitant comorbidities sustained in Operations Enduring Freedom, Iraqi Freedom and New Dawn.

Association between a non-synonymous HSD17B4 single nucleotide polymorphism and meat-quality traits in Berkshire pigs

Single nucleotide polymorphisms (SNPs) are useful genetic markers that allow correlation of genetic sequences with phenotypic traits. It is shown here that HSD17B4, a bifunctional enzyme mediating dehydrogenation and anhydration during β-oxidation of long-chain fatty acids, contains a non-synonymous SNP (nsSNP) of chr2:128,825,976A>G, c.2137A>G, I690V, within the sterol carrier protein-2 domain of the HSD17B4 gene, by RNA-Seq of liver RNA. The HSD17B4 mRNA was highly expressed in the kidney and liver among various other tissues in four pig breeds, namely, Berkshire, Duroc, Landrace, and Yorkshire. The nsSNP was significantly associated with carcass weight, backfat thickness, and drip loss (P < 0.05). Furthermore, HSD17B4 may play a crucial role during the early stages of myogenesis when expression of its mRNA was significantly high. In conclusion, HSD17B4 may serve as a possible regulator of muscle development, and its identification should help to select for improved economic traits of Berkshire pigs such as carcass weight, backfat thickness, and drip loss.

Clinical and Radiographic Outcomes of Transforaminal Lumbar Interbody Fusion in Patients with Osteoporosis

Study Design Retrospective review. Objective To compare clinical outcomes after transforaminal lumbar interbody fusion (TLIF) in patients with and patients without osteoporosis. Methods We reviewed all patients with 6-month postoperative radiographs and computed tomography (CT) scans for evaluation of the interbody cage. CT Hounsfield unit (HU) measurements of the instrumented vertebral body were used to determine whether patients had osteoporosis. Radiographs and CT scans were evaluated for evidence of implant subsidence, migration, interbody fusion, iatrogenic fracture, or loosening of posterior pedicle screw fixation. Medical records were reviewed for persistence of symptoms or recurrence of symptoms. Results The final data analysis included 18 (20.5%) patients with osteoporosis and 70 (79.5%) patients without osteoporosis. Males comprised 50% of patients with osteoporosis, and 64.3% of patients without osteoporosis. The mean age was significantly higher in the osteoporotic group (65.2 years) versus the nonosteoporotic group (56.9 years; p < 0.0001). We found significantly higher rates of subsidence (72.2 versus 45.7%, p = 0.05) and iatrogenic fractures (16.7% versus 1.4%, p = 0.03) in the osteoporotic group. In addition, the osteoporotic group had significantly higher radiographic complication rates compared with the nonosteoporotic group (77.8 versus 48.6%, p = 0.03). There was no difference between groups for revision surgery (16.6 versus 14.3%, p = 0.78) or postoperative symptoms (44.4% versus 50.0%, p = 0.69). Conclusions Our data demonstrated significantly increased rates of cage subsidence, iatrogenic fracture, and overall radiographic complications in patients with osteoporosis. However, these radiographic complications did not predispose patients with osteoporosis to an increased risk of surgical revision or worse clinical outcomes.

Operative management of complex lumbosacral dissociations in combat injuries

BACKGROUND CONTEXT

As war injury patterns have changed throughout Operations Iraqi and Enduring Freedom (OIF and OEF), a relative increase in the incidence of complex lumbosacral dissociation (LSD) injuries has been noted. Lumbosacral dissociation injuries are an anatomical separation of the spinal column from the pelvis, and represent a manifestation of severe, high-energy trauma.

PURPOSE

This study aimed to assess the clinical outcomes of combat-related LSD injuries at a mean of 7 years following operative treatment.

STUDY DESIGN

This is a retrospective review.

PATIENT SAMPLE

We identified 20 patients with operatively managed LSDs.

OUTCOME MEASURES

Time from injury to arrival in the United States, operative details, fixation methods, postoperative complications, time to retirement from military service, disability, and ambulatory status at latest follow-up.

METHODS

We performed a retrospective review of outcomes of all patients with operatively managed combat-related LSD from January 1, 2003 to December 31, 2011.

RESULTS

Twenty patients met inclusion criteria and were treated as follows: posterior spinal fusion (12, 60%), sacroiliac screw fixation (7, 35%), and combined anterior-posterior fusion for associated L3 burst fracture (1, 5%). The mean age was 28.2±6.4 years old. The most common mechanism of injury was mounted improvised explosive device (IED, 55%). On average, 2.2 spinal regions were injured per patient. Neurologic dysfunction was present in 15 patients. Three patients underwent operative stabilization of their injuries before evacuation to the United States. Four patients had a postoperative wound infection and two patients underwent reoperation. Mean follow-up was 85.9 months (range: 39.7-140.8 months). At most recent follow-up, seventeen patients were no longer on active duty military service. Eight patients had persistent bowel dysfunction and nine patients had persistent bladder dysfunction. Fifteen patients reported chronic low back pain. Seventeen were ambulating and five had documentation of running following surgery.

CONCLUSIONS

This is the largest series of operatively managed LSD in patients currently reported. Our series suggests that combat-related LSD injuries frequently result in persistent, long-term neurologic dysfunction, disability, and chronic pain. Operative management carries a high postoperative risk of infection. However, a select group of patients are highly functional at latest follow-up.

Correlation and Reliability of Cervical Sagittal Alignment Parameters between Lateral Cervical Radiograph and Lateral Whole-Body EOS Stereoradiograph

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To evaluate the correlation and reliability of cervical sagittal alignment parameters obtained from lateral cervical radiographs (XRs) compared with lateral whole-body stereoradiographs (SRs).

METHODS

We evaluated adults with cervical deformity using both lateral XRs and lateral SRs obtained within 1 week of each other between 2010 and 2014. XR and SR images were measured by two independent spine surgeons using the following sagittal alignment parameters: C2-C7 sagittal Cobb angle (SCA), C2-C7 sagittal vertical axis (SVA), C1-C7 translational distance (C1-7), T1 slope (T1-S), neck tilt (NT), and thoracic inlet angle (TIA). Pearson correlation and paired t test were used for statistical analysis, with intra- and interrater reliability analyzed using intraclass correlation coefficient (ICC).

RESULTS

A total of 35 patients were included in the study. We found excellent intrarater reliability for all sagittal alignment parameters in both the XR and SR groups with ICC ranging from 0.799 to 0.994 for XR and 0.791 to 0.995 for SR. Interrater reliability was also excellent for all parameters except NT and TIA, which had fair reliability. We also found excellent correlations between XR and SR measurements for most sagittal alignment parameters; SCA, SVA, and C1-C7 had r > 0.90, and only NT had r < 0.70. There was a significant difference between groups, with SR having lower measurements compared with XR for both SVA (0.68 cm lower, p < 0.001) and C1-C7 (1.02 cm lower, p < 0.001). There were no differences between groups for SCA, T1-S, NT, and TIA.

CONCLUSION

Whole-body stereoradiography appears to be a viable alternative for measuring cervical sagittal alignment parameters compared with standard radiography. XR and SR demonstrated excellent correlation for most sagittal alignment parameters except NT. However, SR had significantly lower average SVA and C1-C7 measurements than XR. The lower radiation exposure using single SR has to be weighed against its higher cost compared with XR.

Persistent axial neck pain after cervical disc arthroplasty: a radiographic analysis

BACKGROUND CONTEXT

There is very little literature examining optimal radiographic parameters for placement of cervical disc arthroplasty (CDA), nor is there substantial evidence evaluating the relationship between persistent postoperative neck pain and radiographic outcomes.

PURPOSE

We set out to perform a single-center evaluation of the radiographic outcomes, including associated complications, of CDA.

DESIGN

This is a retrospective review.

PATIENT SAMPLE

Two hundred eighty-five consecutive patients undergoing CDA were included in the review.

OUTCOME MEASURES

The outcome measures were radiological parameters (preoperative facet arthrosis, disc height, CDA placement in sagittal and coronal planes, heterotopic ossification [HO] formation, etc.) and patient outcomes (persistent pain, recurrent pain, new-onset pain, etc.).

METHODS

We performed a retrospective review of all patients from a single military tertiary medical center from August 2008 to August 2012 undergoing CDA. Preoperative, immediate postoperative, and final follow-up films were evaluated. The clinical outcomes and complications associated with the procedure were also examined.

RESULTS

The average radiographic follow-up was 13.5 months and the rate of persistent axial neck pain was 17.2%. For patients with persistent neck pain, the rate of HO formation per level studied was 22.6%, whereas the rate was significantly lower for patients without neck pain (11.7%, p=.03). There was no significant association between the severity of HO and the presence of neck pain. Patients with a preoperative diagnosis of cervicalgia, compared to those without cervicalgia, were significantly more likely to experience continued neck pain postoperatively (28.6% vs. 13.1%, p=.01). There were no differences in preoperative facet arthrosis, pre- or postoperative disc height, segmental range of motion, or placement of the device relative to the posterior edge of the vertebral body.However, patients with implants more centered between the uncovertebral joints were more likely to experience posterior neck pain (p=.03).

CONCLUSIONS

We found that posterior axial neck pain is relatively frequent after CDA, and patients with persistent neck pain were significantly more likely to have preoperative cervicalgia and develop HO postoperatively. We also found that patients with implants that were placed off-centered were less likely to also complain of neck pain, although the reasons for this finding remain unclear.

Late Amputation Following Refracture After Removal of Multiplanar Circular External Fixator for Treatment of Severe Combat-Related Tibial Fracture: A Case Report

CASE

The multiplanar circular external fixator is commonly used in the treatment of severe combat-related tibial fractures. We present the case of a patient who sustained a refracture after removal of such a fixator. This complication contributed to failure of the limb salvage and ultimately resulted in the patient undergoing transtibial amputation.

CONCLUSION

The choice to pursue limb salvage or amputation must be a shared decision between the patient and provider. This discussion must now include the possibility of refracture if limb salvage is pursued using multiplanar circular external fixation. Further study is also required to define fracture stability after the removal of a multiplanar circular external fixator.

Reoperation after in-theater combat spine surgery

BACKGROUND CONTEXT

The ideal timing of surgical decompression or stabilization following combat-related spine injury remains unclear.

PURPOSE

The study aims to determine the etiology and factors related to reoperation following evacuation to the United States after undergoing in-theater spine surgery.

STUDY DESIGN

This is a retrospective analysis.

PATIENT SAMPLE

The sample includes 13 patients with combat-related spine injuries undergoing revision spine surgery.

OUTCOME MEASURES

The outcome measures were time to arrival in the United States, time to reoperation, indications for revision, operative details, further revision surgery, infection rate, complications after reoperation, and most recent clinical follow-up information.

METHODS

This is a retrospective analysis of patients undergoing spine surgery designated as injured during the Global War on Terrorism between July 2003 and July 2013. Inpatient and outpatient medical records, operative reports, and imaging studies were reviewed.

RESULTS

The mean time to index surgery was 1.6 days. The mechanisms of injury included five gunshot wounds, three improvised explosive devices (IED), two helicopter crashes, one motor vehicle accident, and two other mechanisms (fall and crush injury). The mean injury severity score (ISS) was 22.7 (range: 13-45). There were six cervical, seven thoracic, eight lumbar, and two sacral injuries, with a mean of 1.8±1.0 spinal regions injured per patient. Twelve patients had a spinal cord injury, four of which were AIS (American Spinal Association Impairment Scale). Three patients underwent spinal stabilization on the date of injury, and one patient had three separate spine surgeries while downrange before arrival. Four patients underwent fixation in theater. There was a mean of 5.5 days from injury to arrival in the United States, and the mean time to revision fixation was 11.2 days post-index surgery (range: 4-14 days). Revision indications included instability or progressive kyphosis (N=6), and two of these patients had decompression without instrumentation downrange. Other indications included inadequate decompression (N=4), infection, persistent drainage, and epidural hematoma. At a mean of 5.5-year follow-up, all patients were medically retired from service, with minimal neurologic improvement.

CONCLUSIONS

Our study found that instability or progressive kyphosis and incomplete decompression were the most common indications for reoperation after evacuation to the United States. Our data provide additional understanding of the potential etiologies of failure and reoperation following in-theater combat spine surgery, and may help avoid such complications.

Decision making for upper instrumented vertebra in thoracolumbar/lumbar adolescent idiopathic scoliosis: can we stop below the end vertebra?

Sudo H, Kaneda K, Shono Y, Iwasaki N. Selection of the upper vertebra to be instrumented in the treatment of thoracolumbar and lumbar adolescent idiopathic scoliosis by anterior correction and fusion surgery using dual-rod instrumentation: a minimum 12-year follow-up study. Spine J. 2016:16:281-7 (in this issue).

Traumatic Migration of the Bryan Cervical Disc Arthroplasty

Study Design Case study. Objective To describe a case of dislodgment and migration of the Bryan Cervical Disc (Medtronic Sofamor Danek, Memphis, Tennessee, United States) arthroplasty more than 6 months after implantation secondary to low-energy trauma. Methods The inpatient, outpatient, and radiographic medical records of a patient with traumatic migration of the Bryan Cervical Disc arthroplasty were reviewed. The authors have no relevant disclosures to report. Results A 36-year-old man with chronic left upper extremity radiculopathy underwent uncomplicated Bryan Cervical Disc arthroplasty at C5-C6, with complete resolution of his symptoms. Approximately 6 months after his index procedure, he sustained low-energy trauma to the posterior cervical spine, after being struck by a book falling from a shelf. The injury forced his neck into flexion, and though he did not have recurrence of his radiculopathy symptoms, radiographs demonstrated anterior migration of the arthroplasty device. He underwent revision to anterior cervical diskectomy and fusion. Conclusions Although extremely rare, it is imperative that surgeons consider the potential for failure of osseous integration in patients undergoing cervical disk arthroplasty, even beyond 3 to 6 months postoperatively. This concern is especially relevant to press-fit or milled devices like the Bryan Cervical Disc arthroplasty, which lack direct fixation into adjacent vertebral bodies. We are considering modification of our postoperative protocol to improve protection of the device after implantation, even beyond 3 months postoperatively.

Rumex acetosa L. induces vasorelaxation in rat aorta via activation of PI3-kinase/Akt- AND Ca(2+)-eNOS-NO signaling in endothelial cells

Rumex acetosa L. (RA) (Polygonaceae) is an important traditional Chinese medicine (TCM) commonly used in clinic for a long history in China and the aerial parts of RA has a wide variety of pharmacological actions such as diuretic, anti-hypertensive, anti-oxidative, and anti-cancer effects. However, the mechanisms involved are to be defined. The purpose of the present study was to evaluate the vasorelaxant effect and define the mechanism of action of the ethanol extract of Rumex acetosa L. (ERA) in rat aorta. ERA was examined for its vascular relaxant effect in isolated phenylephrine-precontracted rat thoracic aorta and its acute effects on arterial blood pressure. In addition, the roles of the nitric oxide synthase (NOS)-nitric oxide (NO) signaling in the ERA-induced effects were tested in human umbilical vein endothelial cells (HUVECs). The phosphorylation levels of Akt and eNOS were assessed by Western blot analysis in the cultured HUVECs. ERA induced endothelium-dependent vasorelaxation. The ERA-induced vasorelaxation was abolished by L-NAME (an NOS inhibitor) or ODQ (a sGC inhibitor), but not by indomethacin. Inhibition of PI3-kinase/Akt signaling pathway markedly reduced the ERA-induced vasorelaxation. In HUVECs, ERA increased NO formation in a dose-dependent manner, which was inhibited by L-NAME and by removing extracellular Ca(2+). In addition, ERA promoted phosphorylation of Akt and eNOS, which was prevented by wortmannin and LY294002, indicating that ERA induces eNOS phosphorylation through the PI3-kinase/Akt pathway. Further, in anesthetized rats, intravenously administered ERA decreased arterial blood pressure in a dose-dependent manner through an activation of the NOS-NO system. In summary, the ERA- induced vasorelaxation was dependent on endothelial integrity and NO production, and was mediated by activation of both the endothelial PI3-kinase/Akt- and Ca(2+)-eNOS-NO signaling and muscular NO-sGC-cGMP signaling.

Bilateral pedicle screw fixation provides superior biomechanical stability in transforaminal lumbar interbody fusion: a finite element study

BACKGROUND CONTEXT

Transforaminal lumbar interbody fusion (TLIF) is increasingly popular for the surgical treatment of degenerative lumbar disease. The optimal construct for segmental stability remains unknown.

PURPOSE

To compare the stability of fusion constructs using standard (C) and crescent-shaped (CC) polyetheretherketone TLIF cages with unilateral (UPS) or bilateral (BPS) posterior instrumentation.

STUDY DESIGN

Five TLIF fusion constructs were compared using finite element (FE) analysis.

METHODS

A previously validated L3-L5 FE model was modified to simulate decompression and fusion at L4-L5. This model was used to analyze the biomechanics of various unilateral and bilateral TLIF constructs. The inferior surface of the L5 vertebra remained immobilized throughout the load simulation, and a bending moment of 10 Nm was applied on the L3 vertebra to recreate flexion, extension, lateral bending, and axial rotation. Various biomechanical parameters were evaluated for intact and implanted models in all loading planes.

RESULTS

All reconstructive conditions displayed decreased motion at L4-L5. Bilateral posterior fixation conferred greater stability when compared with unilateral fixation in left lateral bending. More than 50% of intact motion remained in the left lateral bending with unilateral posterior fixation compared with less than 10% when bilateral pedicle screw fixation was used. Posterior implant stresses for unilateral fixation were six times greater in flexion and up to four times greater in left lateral bending compared with bilateral fixation. No effects on segmental stability or posterior implant stresses were found. An obliquely-placed, single standard cage generated the lowest cage-end plate stress.

CONCLUSIONS

Transforaminal lumbar interbody fusion augmentation with bilateral posterior fixation increases fusion construct stability and decreases posterior instrumentation stress. The shape or number of interbody implants does not appear to impact the segmental stability when bilateral pedicle screws are used. Increased posterior instrumentation stresses were observed in all loading modes with unilateral pedicle screw/rod fixation, which may theoretically accelerate implant loosening or increase the risk of construct failure.

Return to sports after surgery to correct adolescent idiopathic scoliosis: a survey of the Spinal Deformity Study Group

BACKGROUND CONTEXT

There are no guidelines for when surgeons should allow patients to return to sports and athletic activities after spinal fusion for adolescent idiopathic scoliosis (AIS). Current recommendations are based on anecdotal reports and a survey performed more than a decade ago in the era of first/second-generation posterior implants.

PURPOSE

To identify current recommendations for return to sports and athletic activities after surgery for AIS.

STUDY DESIGN/SETTING

Questionnaire-based survey.

PATIENT SAMPLE

Adolescent idiopathic scoliosis after corrective surgery.

OUTCOME MEASURES

Type and time to return to sports.

METHODS

A survey was administered to members of the Spinal Deformity Study Group. The survey consisted of surgeon demographic information, six clinical case scenarios, three different construct types (hooks, pedicle screws, hybrid), and questions regarding the influence of lowest instrumented vertebra (LIV) and postoperative physical therapy.

RESULTS

Twenty-three surgeons completed the survey, and respondents were all experienced expert deformity surgeons. Pedicle screw instrumentation allows earlier return to noncontact and contact sports, with most patients allowed to return to running by 3 months, both noncontact and contact sports by 6 months, and collision sports by 12 months postoperatively. For all construct types, approximately 20% never allow return to collision sports, whereas all surgeons allow eventual return to contact and noncontact sports regardless of construct type. In addition to construct type, we found progressively distal LIV resulted in more surgeons never allowing return to collision sports, with 12% for selective thoracic fusion to T12/L1 versus 33% for posterior spinal fusion to L4. Most respondents also did not recommend formal postoperative physical therapy (78%). Of all surgeons surveyed, there was only one reported instrumentation failure/pullout without neurologic deficit after a patient went snowboarding 2 weeks postoperatively.

CONCLUSIONS

Modern posterior instrumentation allows surgeons to recommend earlier return to sports after fusion for AIS, with the majority allowing running by 3 months, noncontact and contact sports by 6 months, and collision sports by 12 months.

Intrasite vancomycin powder for the prevention of surgical site infection in spine surgery: a systematic literature review

BACKGROUND CONTEXT

Deep surgical site infections (SSIs) following spinal surgery are a significant burden to the patient, patient's family, and the health-care system. Because of increasing pressures to reduce SSIs and control costs, some spine surgeons have begun placing lyophilized vancomycin powder directly into the surgical wound at the conclusion of the procedure. However, the literature supporting this practice remains limited.

PURPOSE

To review the current literature examining the use of prophylactic intrasite vancomycin powder to control SSIs in spinal surgery and determine if any standard recommendations can be made.

STUDY DESIGN

A systematic review.

METHODS

Ovid Medline and PubMed were searched to identify English language articles.

RESULTS

No current guidelines are available for the use of intrasite vancomycin powder in preventing SSIs, and no standard dosage for the drug exists. Based on the limited literature and evidence currently available, there appears to be a protective effect of intrasite vancomycin powder on the incidence of SSI, without evidence of side effects. However, case reports do exist describing the systemic side effects after intrasite vancomycin powder during spine surgery.

CONCLUSIONS

The interpretation of the available evidence supporting the use of intrasite vancomycin powder in surgical wounds is limited, and its extrapolation should be performed with caution. Despite the lack of significant high-quality evidence available in the literature, many surgeons have adopted this practice; anecdotally, it continues to provide protection from infection without apparent significant risk of side effects.

Treatment of symptomatic intraosseous pneumatocyst using intraoperative navigation

Intraosseous pneumatocysts are benign air-containing lesions that are most often found in the spine and pelvis and are nearly always treated nonoperatively. Although rarely clinically symptomatic, studies have shown pneumatocysts to be present in up to 10% of computed tomography (CT) scans of the pelvis and spine. Radiographic characteristics of these lesions include a localized collection of gas with a thin sclerotic rim, no bony destruction, no soft tissue masses, and no medullary abnormalities. Computed tomography is the diagnostic study of choice, with Hounsfield units ranging from -580 to -950, showing a gas-containing lesion. Few studies have described the management of symptomatic pneumatocysts, and all reported cases concern underwater divers, presumably because of greater pressure cycling and barotrauma encountered while underwater diving. The goal of this report is to describe the intraoperative CT-guided navigation and percutaneous injection of calcium sulfate-calcium phosphate composite bone graft substitute material for the treatment of a symptomatic pneumatocyst in the ilium of a Navy dive instructor. The patient reported a 1-year history of increasing buttock pain with increased depth of diving, consistently reproduced by diving past a depth of 20 to 30 feet. To the authors' knowledge, this is the first description in the English literature of the operative treatment of an intraosseous pneumatocyst of the ilium. The use of intraoperative CT guidance permitted accurate percutaneous localization, decompression, and filling of the lesion with synthetic bone graft substitute, with complete early relief of symptoms. At 6-month follow up, the patient had reached diving depths of 170 feet without pain.

Central cord syndrome: is operative treatment the standard of care?

Brodell DW, Jain A, Elfar JC, Mesfin A. National trends in the management of central cord syndrome: an analysis of 16,134 patients. Spine J 2015;15:435-42 (in this issue).

Operative treatment of new onset radiculopathy secondary to combat injury

We set out to describe combat-related spine trauma over a 10-year period, and thereby determine the frequency of new onset radiculopathy secondary to injuries sustained in support of combat operations. We performed a retrospective analysis of a surgical database at three military institutions. Patients undergoing spine surgery following a combat-related injury in Afghanistan or Iraq between July 2003 and July 2013 were evaluated. We identified 105 patients with combat-related (Operations Enduring and Iraqi Freedom) spine trauma requiring operative intervention. Of these, 15 (14.3%) patients had radiculopathy as their primary complaint after injury. All patients were diagnosed with herniated nucleus pulposus. The average age was 39 years, with 80% injured in Iraq and 20% in Afghanistan. The most common mechanism of injury was mounted improvised explosive device (33%). The cervical spine was most commonly involved (53%), followed by lumbar spine (40%). Average time from injury to surgery was 23.4 months; 53% of patients had continued symptoms following surgery, and two patients had at least one revision surgery. Two patients were medically retired because of their symptoms. This study is the only of its kind evaluating the operative treatment of traumatic radiculopathy following combat-related trauma. We identified a relatively high rate of radiculopathy in these patients.

Pulmonary function following adult spinal deformity surgery: minimum two-year follow-up

BACKGROUND

The literature regarding pulmonary function in adult patients with spinal deformity is limited, and the effect of spinal deformity surgery on pulmonary function has not been clearly understood. We hypothesized that adult patients with spinal deformity who had preoperative pulmonary impairment (a percent-predicted value of <65% forced expiratory volume in one second [FEV1] as measured by pulmonary function test) or who were undergoing revision surgery may be at risk for exacerbated decline in pulmonary function.

METHODS

Pulmonary function test results were prospectively collected for 164 adult patients with spinal deformity (mean age, 45.9 years) who underwent surgical treatment at a single institution and were followed for a minimum of two years (mean, 2.8 years). One hundred (61%) of the patients underwent primary surgery, and sixty-four (39%) of the patients had revision surgery. For the majority of patients (77%), a posterior-only surgical approach was used. Radiographs for 154 patients were analyzed for major thoracic and sagittal T5-T12 curve magnitude/correction.

RESULTS

For all patients, we noted a significant change in major thoracic Cobb angle, from a mean of 47.4° to 24.9°(p < 0.001), and in sagittal Cobb angle, from a mean of 35.5° to 30.0°(p < 0.001), as well as a significant decline in absolute and percent-predicted pulmonary function values, with percent-predicted FEV1 and percent-predicted forced vital capacity (FVC) decreasing 5.3% (p < 0.001) and 5.7% (p < 0.001), respectively. A clinically significant decline (a decline of ≥10% in percent-predicted FEV1) was observed in 27% of the patients. The number of patients with pulmonary impairment increased nonsignificantly from seventeen (10%) preoperatively to twenty-three (14%) after surgery (p = 0.31). Patients with preoperative pulmonary impairment demonstrated a significant improvement in absolute and percent-predicted FEV1 after surgery compared with those without preoperative impairment (2.7% compared with -6.2%; p < 0.001). Patients who underwent revision surgery did not differ from primary surgery patients in terms of postoperative percent-predicted results. However, revision surgery more frequently resulted in a significant decline in pulmonary function (twenty-three patients [36%] compared with twenty-two [22%]; p = 0.05). There was no difference in pulmonary function when comparing surgical approaches (anterior/combined anterior-posterior or posterior-only) or when comparing results by upper-instrumented vertebra (UIV).

CONCLUSIONS

We found a significant decline in absolute and percent-predicted results of pulmonary function tests following surgical correction for spinal deformity in adults.

Effects of rod reduction on pedicle screw fixation strength in the setting of Ponte osteotomies

BACKGROUND CONTEXT

The use of a rod reduction device can have deleterious consequences on pedicle screw pullout strength (POS) in the thoracic spine. However, posterior-only osteotomies in the thoracic spine are often performed to improve flexibility of the spine and offset forces of deformity correction maneuvers.

PURPOSE

To investigate the effect on pedicle screw POS caused by the rod reduction technique in the presence of facet osteotomies in the thoracic spine.

STUDY DESIGN/SETTING

The study is a biomechanical study using human cadaveric spine specimens.

METHODS

Thoracic Ponte osteotomies were performed on 3 thoracic levels in 15 cadaveric specimens. The right rod was contoured with a 5-mm residual gap at the middle level and was reduced using a rod reduction device. On the left side (paired control), a rod with no mismatch was placed. Biomechanical testing was performed with tensile load to failure "in line" with the screw axis and POS measured in Newtons (N).

RESULTS

After rod reduction, thoracic pedicle screw POS was significantly decreased (40%) compared with the control (419±426 N vs. 708±462 N, p=.002) and remained statistically significant after adjusting for bone mineral density (BMD) (p=.05). Eleven (73%) of the pedicle screws had visible pullout/failure during the reduction attempt and occurred irrespective of BMD.

CONCLUSIONS

Despite thoracic Ponte osteotomies and increased flexibility of the spinal segments, the rod reduction device still significantly decreased pedicle screw POS, typically resulting in outright failure of the screw-bone interface. Therefore, rod reduction technique of any kind should be performed with caution as it frequently results in suboptimal pedicle screw fixation.

Multifocal intraosseous ganglioneuroma

We report a case of asymptomatic intraosseous ganglioneuroma of the ilium, which was initially misdiagnosed as polyostotic fibrous dysplasia. Our patient presented with multiple asymptomatic skeletal lesions. Despite extensive work-up of our patient to rule out metastatic disease, we were unable to find a primary source; biopsy showed intraosseous ganglioneuroma of the ilium. To the best of our knowledge, we report an exceedingly rare pathologic entity; only 3 cases have been described of intraosseous ganglioneuroma from spontaneous cytomaturation of metastatic neuroblastoma. Knowledge of the natural history of ganglioneuroma is limited, but patients with primary and multifocal disease appear to have benign histologic tumor appearance and excellent prognoses. Similar to previous studies, the rarity of this tumor and its nonspecific radiographic and clinical presentation resulted in the correct diagnosis only after histopathologic analysis. Because intraosseous ganglioneuroma may mimic fibrous dysplasia it should be considered in the differential diagnosis of benignappearing skeletal lesions, particularly if the patient has a history of neuroblastoma.

Do stand-alone interbody spacers with integrated screws provide adequate segmental stability for multilevel cervical arthrodesis?

BACKGROUND CONTEXT

Some postoperative complications after anterior cervical fusions have been attributed to anterior cervical plate (ACP) profiles and the necessary wide operative exposure for their insertion. Consequently, low-profile stand-alone interbody spacers with integrated screws (SIS) have been developed. Although SIS constructs have demonstrated similar biomechanical stability to the ACP in single-level fusions, their role as a stand-alone device in multilevel reconstructions has not been thoroughly evaluated.

PURPOSE

To evaluate the acute segmental stability afforded by an SIS device compared with the traditional ACP in the setting of a multilevel cervical arthrodesis.

STUDY DESIGN

In vitro human cadaveric biomechanical analysis.

METHODS

Thirteen human cadaveric cervical spines (C2-T1) were nondestructively tested with a custom 6 df spine simulator under axial rotation, flexion-extension, and lateral bending loading. After intact analysis, eight single-levels (C4-C5/C6-C7) from four specimens were instrumented and tested with ACP and SIS. Nine specimens were tested with C5-C7 SIS, C5-C7 ACP, C4-C7 ACP, C4-C7 ACP+posterior fixation, C4-C7 SIS, and C4-C7 SIS+posterior fixation. Testing order was randomized with each additional level instrumented. Full range of motion (ROM) data were obtained and analyzed by each loading modality, using mean comparisons with repeated measures analysis of variance. Paired t tests were used for post hoc analysis with Sidak correction for multiple comparisons.

RESULTS

No significant difference in ROM was noted between the ACP and SIS for single-level fixation (p>.05). For multisegment reconstructions (two and three levels), the ACP proved superior to SIS and intact condition, with significantly lower ROM in all planes (p<.05). When either the three-level SIS or ACP constructs were supplemented with posterior lateral mass fixation, there was a greater than 80% reduction in ROM under all testing modalities (p<.05), with no significant difference between the ACP and SIS constructs (p>.05).

CONCLUSIONS

The SIS device may be a reasonable option as a stand-alone device for single-level fixation. However, SIS devices should be used with careful consideration in the setting of multilevel cervical fusion. However, when supplemented with posterior fixation, SIS devices are a sound biomechanical alternative to ACP for multilevel fusion constructs.

Outcomes following cervical disc arthroplasty: a retrospective review

Cervical disc arthroplasty has emerged as a viable technique for the treatment of cervical radiculopathy and myelopathy, with the proposed benefit of maintenance of segmental range of motion. There are relatively few, non-industry sponsored studies examining the outcomes and complications of cervical disc arthroplasty. Therefore, we set out to perform a single center evaluation of the outcomes and complications of cervical disc arthroplasty. We performed a retrospective review of all patients from a single military tertiary medical center undergoing cervical disc arthroplasty from August 2008 to August 2012. The clinical outcomes and complications associated with the procedure were evaluated. A total of 219 consecutive patients were included in the review, with an average follow-up of 11.2 (±11.0)months. Relief of pre-operative symptoms was noted in 88.7% of patients, and 92.2% of patients were able to return to full pre-operative activity. There was a low rate of complications related to the anterior cervical approach (3.2% with recurrent laryngeal nerve injury, 8.9% with dysphagia), with no device/implant related complications. Symptomatic cervical radiculopathy is a common problem in both the civilian and active duty military populations and can cause significant disability leading to loss of work and decreased operational readiness. There exist several surgical treatment options for appropriately indicated patients. Based on our findings, cervical disc arthroplasty is a safe and effective treatment for symptomatic cervical radiculopathy and myelopathy, with a low incidence of complications and high rate of symptom relief.

Systematic review and meta-analysis of minimally invasive transforaminal lumbar interbody fusion rates performed without posterolateral fusion

The need for posterolateral fusion (PLF) in addition to interbody fusion during minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) has yet to be established. Omitting a PLF significantly reduces overall surface area available for achieving a solid arthrodesis, however it decreases the soft tissue dissection and costs of additional bone graft. The authors sought to perform a meta-analysis to establish the fusion rate of MIS TLIF performed without attempting a PLF. We performed an extensive Medline and Ovid database search through December 2010 revealing 39 articles. Inclusion criteria necessitated that a one or two level TLIF procedure was performed through a paramedian MIS approach with bilateral posterior pedicle screw instrumentation and without posterolateral bone grafting. CT scan verified fusion rates were mandatory for inclusion. Seven studies (case series and case-controls) met inclusion criteria with a total of 408 patients who underwent MIS TLIF as described above. The mean age was 50.7 years and 56.6% of patients were female. A total of 78.9% of patients underwent single level TLIF. Average radiographic follow-up was 15.6 months. All patients had local autologous interbody bone grafting harvested from the pars interarticularis and facet joint of the approach side. Either polyetheretherketone (PEEK) or allograft interbody cages were used in all patients. Overall fusion rate, confirmed by bridging trabecular interbody bone on CT scan, was 94.7%. This meta-analysis suggests that MIS TLIF performed with interbody bone grafting alone has similar fusion rates to MIS or open TLIF performed with interbody supplemented with posterolateral bone grafting and fusion.

Cardiovascular effects of ethanol extract of Rubus chingii Hu (Rosaceae) in rats: an in vivo and in vitro approach

Rubus chingii Hu (Rosaceae) is an important traditional Chinese medicine that has been used to improve function of the kidney and treat excessive polyuria. However, the effects of Rubus chingii on the cardiovascular system and its pharmacological mechanisms of action have not been studied. The aim of the present study was to evaluate the cardiovascular effects of ethanol extract of Rubus chingii (ERC) in rats. The changes in systolic blood pressure and heart rate of rats and vascular tone of aortic rings in in vitro were measured using pressure transducer and force transducer, respectively, connected to a multichannel recording system. ERC decreased systolic blood pressure and heart rate in a concentration-dependent manner. ERC induced vasorelaxation in a concentration-dependent manner. The ERC-induced vasorelaxation was not observed in the absence of the endothelium. The vasorelaxant effect of ERC was significantly attenuated by inhibition of endothelial NO synthase (eNOS), soluble guanylyl cyclase (sGC), or Ca(2+) entry from extracellular sources with L-NAME, ODQ, diltiazem, or extracellular Ca(2+) depletion, respectively. Similarly, an inhibition of Akt with wortmannin attenuated the ERC-induced vasorelaxation. Modulators of the store-operated Ca(2+) entry, thapsigargin, Gd(3+), and 2-aminoethyl diphenylborinate markedly attenuated the ERC-induced vasorelaxation. Furthermore, 4-aminopyridine an inhibitor of voltage-dependent K(+) (KV) channel, significantly attenuated the ERC-induced vasorelaxation. However, tetraethylammonium and glibenclamide, had no significant effect on the ERC-induced vasorelaxation. Indomethacin, atropine, and propranolol had no effects on the ERC-induced vasorelaxation. The present study demonstrates that ERC induces vasorelaxation via endothelium-dependent two-step signaling: an activation of the Ca(2+)-eNOS-NO signaling in the endothelial cells and then subsequent stimulation of the NO-sGC-cGMP-KV channel signaling in the vascular smooth muscle cells. The Akt-eNOS pathway is also suggested to be involved in this relaxation. Also, the findings suggest that the ERC-induced vasorelaxation is closely related to the hypotensive action of the agent.

Incidence and morbidity of concomitant spine fractures in combat-related amputees

BACKGROUND CONTEXT

High-energy blasts are the most frequent cause of combat-related amputations in Operations Iraqi and Enduring Freedom (OIF/OEF). The nondiscriminating effects of this mechanism often result in both appendicular and axial skeletal injuries. Despite this recognized coincident injury pattern, the incidence and consequence of spine fractures in trauma-related combat amputees are unknown.

PURPOSE

This study sought to determine the incidence and morbidity of the associated spine fractures on patients with traumatic lower extremity amputation sustained during OIF/OEF.

STUDY DESIGN/SETTING

Retrospective case control.

PATIENT SAMPLE

Two hundred twenty-six combat-related lower extremity amputees presenting to a single institution and injured between 2003 and 2008 were included for analysis.

OUTCOME MEASURES

Physiologic and functional outcome measures were used to determine the influence of spine fractures on combat amputees. Physiologic measures included intensive care unit (ICU) admission rates, injury severity score (ISS), rate of narcotic/neuropathic pain use, and heterotopic ossification (HO) rates. Functional outcome measures included return-to-duty rates and ambulatory status at final follow-up.

METHODS

Data from 300 consecutive combat-related lower extremity amputations were retrospectively reviewed and grouped. Group 1 consisted of amputees with associated spine fractures, and Group 2 consisted of amputees without spine fractures. The results of the two groups were compared with regard to initial presentation and final functional outcomes.

RESULTS

A total of 226 patients sustained 300 lower extremity amputations secondary to combat-related injuries, the most common mechanism being an improvised explosive device. Twenty-nine of these patients had a spine fracture (13%). Group 1 had a higher ISS than Group 2 (30 vs. 19, p<.001). Group 1 patients were also more likely to be admitted to the ICU (86% vs. 46%, p<.001). Furthermore, Group 1 patients had a significantly higher rate of HO in their residual limbs (82% vs. 55%, p<.005).

CONCLUSIONS

The incidence of spine fractures in combat-related amputees is 13%. The results suggest that combat-related amputees with spine fractures are more likely to sustain severe injuries to other body systems, as indicated by the significantly higher ISS and rates of ICU admission. This group also had a significantly higher rate of HO formation, which may be attributable to the greater local and/or systemic injuries sustained by these patients.

The ventral lamina and superior facet rule: a morphometric analysis for an ideal thoracic pedicle screw starting point

BACKGROUND CONTEXT

With the increasing popularity of thoracic pedicle screws, the freehand technique has been espoused to be safe and effective. However, there is currently no objective, definable landmark to assist with freehand insertion of pedicle screws in the thoracic spine. With our own increasing surgical experience, we have noted a reproducible and unique anatomic structure known as the ventral lamina.

PURPOSE

We set out to define the morphologic relationship of the ventral lamina to the superior articular facet (SAF) and pedicle, and describe an optimal medial-lateral pedicle screw starting point in the thoracic spine.

STUDY DESIGN

We conducted an in vitro fresh-frozen human cadaveric study.

METHODS

One hundred fifteen thoracic spine vertebral levels were evaluated. After the vertebral body was removed, Kirschner wires were inserted retrograde along the four boundaries of the pedicle. Using digital calipers, we measured width of the SAF and pedicle at the isthmus, and from the borders of the SAF to the boundaries of the pedicle. We calculated the morphologic relationship of the ventral lamina and the center of the pedicle (COP) to the SAF.

RESULTS

Two hundred twenty-nine pedicles were measured, with one pedicle excluded because of fracture of the SAF during disarticulation. The ventral lamina was clearly identifiable at all levels, forming the roof of the spinal canal and confluent with the medial pedicle wall (MPW). The mean distance from the SAF midline to the MPW was 1.36±1.23 mm medial. The MPW was lateral to SAF midline in 34 pedicles (14.85%) and, on average, was a distance of 0.52±0.51 mm lateral. The mean distance from the SAF midline to the COP was 2.17±1.38 mm lateral. The COP was medial to SAF midline in only 11 pedicles (4.80%).

CONCLUSIONS

The ventral lamina is an anatomically reproducible structure located consistently medial to the SAF midline (85%). We also found the COP consistently lateral to the SAF midline (95%). Based on these morphologic findings, the medial-lateral starting point for thoracic pedicle screws should be 2 to 3 mm lateral to the SAF midline (superior facet rule), allowing screw placement in the COP and avoiding penetration into the spinal canal.

Timing of surgical staging in adult spinal deformity surgery: is later better?

Hassanzadeh H, Gjolaj JP, El Dafrawy MH, et al. The timing of surgical staging has a significant impact on the complications and functional outcomes of adult spinal deformity surgery. Spine J 2013;13:1717-22 (in this issue).

The biomechanical consequences of rod reduction on pedicle screws: should it be avoided?

BACKGROUND CONTEXT

Rod contouring is frequently required to allow for appropriate alignment of pedicle screw-rod constructs. When residual mismatch is still present, a rod persuasion device is often used to achieve further rod reduction. Despite its popularity and widespread use, the biomechanical consequences of this technique have not been evaluated.

PURPOSE

To evaluate the biomechanical fixation strength of pedicle screws after attempted reduction of a rod-pedicle screw mismatch using a rod persuasion device.

METHODS

Fifteen 3-level, human cadaveric thoracic specimens were prepared and scanned for bone mineral density. Osteoporotic (n=6) and normal (n=9) specimens were instrumented with 5.0-mm-diameter pedicle screws; for each pair of comparison level tested, the bilateral screws were equal in length, and the screw length was determined by the thoracic level and size of the vertebra (35 to 45 mm). Titanium 5.5-mm rods were contoured and secured to the pedicle screws at the proximal and distal levels. For the middle segment, the rod on the right side was intentionally contoured to create a 5-mm residual gap between the inner bushing of the pedicle screw and the rod. A rod persuasion device was then used to engage the setscrew. The left side served as a control with perfect screw/rod alignment. After 30 minutes, constructs were disassembled and vertebrae individually potted. The implants were pulled in-line with the screw axis with peak pullout strength (POS) measured in Newton (N). For the proximal and distal segments, pedicle screws on the right side were taken out and reinserted through the same trajectory to simulate screw depth adjustment as an alternative to rod reduction.

RESULTS

Pedicle screws reduced to the rod generated a 48% lower mean POS (495±379 N) relative to the controls (954±237 N) (p<.05) and significantly decreased work energy to failure (p<.05). Nearly half (n=7) of the pedicle screws had failed during the reduction attempt with visible pullout of the screw. After reduction, decreased POS was observed in both normal (p<.05) and osteoporotic (p<.05) bone. Back out and reinsertion of the screw resulted in no significant difference in mean POS, stiffness, and work energy to failure (p>.05).

CONCLUSIONS

In circumstances where a rod is not fully seated within the pedicle screw, the use of a rod persuasion device decreases the overall POS and work energy to failure of the screw or results in outright failure. Further rod contouring or correction of pedicle screw depth of insertion may be warranted to allow for appropriate alignment of the longitudinal rods.