Orthopedics Commons^™

Tonebp Regulates The Hyperosmotic Expression Of Aquaporin 1 And 5 In The Intervertebral Disc., Joseph Snuggs, Steven Tessier, R A B Bunning, Irving Shapiro, Makarand V Risbud, Christine Lyn Le Maitre

Department of Orthopaedic Surgery Faculty Papers

The central region of the intervertebral disc (IVD) is rich in proteoglycans, leading to a hyperosmotic environment, which fluctuates with daily loading. The cells of the nucleus pulposus (NP cells) have adapted to this environment via the function of tonicity enhancer binding protein (TonEBP), and NP cells have been shown to express several water channels known as aquaporins (AQP). We have previously shown that AQP1 and 5 decrease during IVD degeneration. Here, the regulation of AQP1 and 5 by hyperosmotic conditions and the role of TonEBP in this regulation was investigated. AQP1 and 5 gene expression was upregulated by hyperosmotic …

Genetic Murine Models Of Spinal Development And Degeneration Provide Valuable Insights Into Intervertebral Disc Pathobiology., J. Melrose, S. Tessier, M. V. Risbud

Department of Orthopaedic Surgery Faculty Papers

Disc degeneration and associated back and neck pain elicits a substantial burden on healthcare systems and the individuals affected, necessitating the development of novel therapeutic strategies. This goal can only be achieved by a better understanding of intervertebral disc development, homeostasis and pathogenesis. A number of genetic and in-bred murine models are reviewed to underscore the importance of the mouse as an animal model of choice for the assessment of intervertebral disc pathobiology. Appraisals of the differences between mouse and human musculoskeletal systems and proteoglycan structures are also included. A number of important target pathways and molecules have been identified, …

Collagen Structure-Function Mapping Informs Applications For Regenerative Medicine., James D San Antonio, Olena Jacenko, Andrzej Fertala, Joseph P R O Orgel

Department of Orthopaedic Surgery Faculty Papers

Type I collagen, the predominant protein of vertebrates, assembles into fibrils that orchestrate the form and function of bone, tendon, skin, and other tissues. Collagen plays roles in hemostasis, wound healing, angiogenesis, and biomineralization, and its dysfunction contributes to fibrosis, atherosclerosis, cancer metastasis, and brittle bone disease. To elucidate the type I collagen structure-function relationship, we constructed a type I collagen fibril interactome, including its functional sites and disease-associated mutations. When projected onto an X-ray diffraction model of the native collagen microfibril, data revealed a matrix interaction domain that assumes structural roles including collagen assembly, crosslinking, proteoglycan (PG) binding, and …

Local Injections Of Β-Ngf Accelerates Endochondral Fracture Repair By Promoting Cartilage To Bone Conversion., Kevin O. Rivera, Fabrizio Russo, Ryan M. Boileau, Ryan E. Tomlinson, Theodore Miclau, Ralph S. Marcucio, Tejal A. Desai, Chelsea S. Bahney

Department of Orthopaedic Surgery Faculty Papers

There are currently no pharmacological approaches in fracture healing designed to therapeutically stimulate endochondral ossification. In this study, we test nerve growth factor (NGF) as an understudied therapeutic for fracture repair. We first characterized endogenous expression of Ngf and its receptor tropomyosin receptor kinase A (TrkA) during tibial fracture repair, finding that they peak during the cartilaginous phase. We then tested two injection regimens and found that local β-NGF injections during the endochondral/cartilaginous phase promoted osteogenic marker expression. Gene expression data from β-NGF stimulated cartilage callus explants show a promotion in markers associated with endochondral ossification such as Ihh, Alpl, …

Three Decades Of Research On Recombinant Collagens: Reinventing The Wheel Or Developing New Biomedical Products?, Andrzej Fertala

Department of Orthopaedic Surgery Faculty Papers

Collagens provide the building blocks for diverse tissues and organs. Furthermore, these proteins act as signaling molecules that control cell behavior during organ development, growth, and repair. Their long half-life, mechanical strength, ability to assemble into fibrils and networks, biocompatibility, and abundance from readily available discarded animal tissues make collagens an attractive material in biomedicine, drug and food industries, and cosmetic products. About three decades ago, pioneering experiments led to recombinant human collagens' expression, thereby initiating studies on the potential use of these proteins as substitutes for the animal-derived collagens. Since then, scientists have utilized various systems to produce native-like …

Bioactivating A Bone Substitute Accelerates Graft Incorporation In A Murine Model Of Vertical Ridge Augmentation, Jinlong Chen, Xue Yuan, Zhijun Li, Daniel J Bahat, Jill A Helms

Department of Orthopaedic Surgery Faculty Papers

OBJECTIVE: Compared to autologous bone grafts, allogeneic bone grafts integrate slowly, which can adversely affect clinical outcomes. Here, our goal was to understand the molecular mechanisms underlying graft incorporation, and then test clinically feasible methods to accelerate this process.

METHODS: Wild-type and transgenic Wnt "reporter" mice were used in a vertical ridge augmentation procedure. The surgery consisted of tunneling procedure to elevate the maxillary edentulous ridge periosteum, followed by the insertion of bone graft. Micro-computed tomographic imaging, and molecular/cellular analyses were used to follow the bone graft over time. Sclerostin null mice, and mice carrying an activated form of β-catenin …

Osseous Changes Following Reverse Total Shoulder Arthroplasty Combined With Latissimus Dorsi Transfer: A Case Series, Jason S Klein, Peter S Johnston, Benjamin W Sears, Manan S Patel, Armodios M Hatzidakis, Mark D. Lazarus

Department of Orthopaedic Surgery Faculty Papers

Background: This is the first report on the incidence of proximal humerus osseous changes and associated clinical consequences in reverse total shoulder arthroplasty combined with a latissimus dorsi tendon transfer (RTSA+LDT).

Methods: A multicenter, retrospective review identified all patients who had undergone a primary RTSA+LDT and had at least 3-month radiographic follow-up between 2012 and 2017. Data collection included demographics, oral steroid use, repair technique for LDT fixation, radiographic humeral osseous changes, complications, and need for revision surgery.

Results: Twenty-four patients were included with an average age of 70.7 ± 7.9 years and follow-up of 16.3 (3-50) months. Ten patients …

The Role Of Nerves In Skeletal Development, Adaptation, And Aging., Ryan E Tomlinson, Blaine A Christiansen, Adrienne A Giannone, Damian C Genetos

Department of Orthopaedic Surgery Faculty Papers

The skeleton is well-innervated, but only recently have the functions of this complex network in bone started to become known. Although our knowledge of skeletal sensory and sympathetic innervation is incomplete, including the specific locations and subtypes of nerves in bone, we are now able to reconcile early studies utilizing denervation models with recent work dissecting the molecular signaling between bone and nerve. In total, sensory innervation functions in bone much as it does elsewhere in the body-to sense and respond to stimuli, including mechanical loading. Similarly, sympathetic nerves regulate autonomic functions related to bone, including homeostatic remodeling and vascular …

Reliability And Validity Of The English Version Of The Aospine Prost (Patient Reported Outcome Spine Trauma), Said Sadiqi, Marcel F Dvorak, Alex R. Vaccaro, Gregory D. Schroeder, Marcel W Post, Lorin M Benneker, Frank Kandziora, S Rajasekaran, Klaus J Schnake, Emiliano N Vialle, F Cumhur Oner

Department of Orthopaedic Surgery Faculty Papers

STUDY DESIGN: Multicenter validation study.

OBJECTIVE: The aim of this study was to translate and adapt the AOSpine PROST (Patient Reported Outcome Spine Trauma) into English, and test its psychometric properties among North-American spine trauma patients.

SUMMARY OF BACKGROUND DATA: In the absence of an outcome instrument specifically designed and validated for traumatic spinal column injury patients, it is difficult to measure the effect size of various treatment options. The AOSpine Knowledge Forum Trauma initiated a project and developed the AOSpine PROST consisting of 19 items.

METHODS: Patients were recruited from two level-1 North-American trauma centers. For concurrent validity, next …

The Role Of Machine Learning In Spine Surgery: The Future Is Now, Michael Chang, Jose A Canseco, Kristen Nicholson, Neil Patel, Alex R. Vaccaro

Department of Orthopaedic Surgery Faculty Papers

The recent influx of machine learning centered investigations in the spine surgery literature has led to increased enthusiasm as to the prospect of using artificial intelligence to create clinical decision support tools, optimize postoperative outcomes, and improve technologies used in the operating room. However, the methodology underlying machine learning in spine research is often overlooked as the subject matter is quite novel and may be foreign to practicing spine surgeons. Improper application of machine learning is a significant bioethics challenge, given the potential consequences of over- or underestimating the results of such studies for clinical decision-making processes. Proper peer review …

Description And Reliability Of The Aospine Sacral Classification System, Alex R. Vaccaro, Gregory D. Schroeder, Srikanth N. Divi, Christopher K Kepler, Conor P Kleweno, James C. Krieg, Jefferson R Wilson, Jörg H Holstein, Mark Kurd, Reza Firoozabadi, Luiz R Vialle, F Cumhur Oner, Frank Kandziora, Jens R Chapman, Klaus J Schnake, Lorin M Benneker, Marcel F Dvorak, Shanmuganathan Rajasekaran, Emiliano N Vialle, Andrei F Joaquim, Mohammad Mostafa El-Sharkawi, Gaurav R Dhakal, Eugen C Popescu, Rishi M Kanna, S P J Muijs, Jin W Tee, Carlo Bellabarba

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: Several classification systems exist for sacral fractures; however, these systems are primarily descriptive, are not uniformly used, have not been validated, and have not been associated with a treatment algorithm or prognosis. The goal of the present study was to demonstrate the reliability of the AOSpine Sacral Classification System among a group of international spine and trauma surgeons.

METHODS: A total of 38 sacral fractures were reviewed independently by 18 surgeons selected from an expert panel of AOSpine and AOTrauma members. Each case was graded by each surgeon on 2 separate occasions, 4 weeks apart. Intrarater reproducibility and interrater …

A Surgeon's Handedness In Direct Anterior Approach-Hip Replacement., Xiangpeng Kong, Minzhi Yang, Alvin Ong, Renwen Guo, Jiying Chen, Yan Wang, Wei Chai

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: The impact of handedness on clinical outcomes was easily overlooked in hip replacement. This study aimed to find whether the component positioning and hip function were affected by the handedness in total hip arthroplasty (THA) through direct anterior approach (DAA).

METHODS: Total 102 patients who underwent bilateral DAA-THAs simultaneously between May 2016 and November 2018 in our institute were reviewed. All surgeries were operated by one right-handed surgeon. Their demographic, cup positioning, stem alignment, femoral stem fit, Harris hip score (HHS), intraoperative and postoperative complications were used to evaluate the role of handedness in DAA.

RESULTS: The inclination of …

Acute Opioid Withdrawal Mimicking Postoperative Joint Infection Following Anterior Cruciate Ligament (Acl) Reconstruction: A Case Report., Qingwu Kong, Martin Griffis, Brandon J Shallop, Amrit S Khalsa, Kyle Brougham, Paul A Marchetto

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND A short course of opioid narcotics is often prescribed for postoperative anterior cruciate ligament (ACL) reconstruction pain management. Unfortunately, there is a well-documented incidence of opioid withdrawal syndrome (OWS) following short-term use of these medications. OWS can present with symptoms such as influenza-like illness. It is important to differentiate OWS from infectious illnesses, especially after surgery. CASE REPORT We present a case of OWS in a patient who underwent ACL reconstruction 7 days prior. The patient's OWS symptoms were similar to symptoms of a postoperative infection. The knee was aspirated, and the analysis of the aspirate was not concerning …

Prospective Study Of Military Special Operations Medical Personnel And Lower Extremity Fracture Immobilization In An Austere Environment, Kevin Martin, Trevor Mcbride, Alicia Unangst, Jaime Chisholm

Department of Orthopaedic Surgery Faculty Papers

Background: Austere fracture immobilization equipment and techniques are often overlooked, with few studies critically evaluating the process. The purpose of this study was to evaluate current austere splinting techniques and equipment used for lower extremity fractures while field testing a new 1-step spray-on foam splint.

Methods: This is a prospective analysis of austere splinting techniques. A cadaveric model with a distal third tibia-fibula fracture was used for testing. The specimens were placed in an austere environment and participants immobilized the injury with standard equipment (structural aluminum malleable [SAM] splint, 6-in. ACE wrap) while being critically evaluated. The specimens were also …

Sustaining The National Spinal Cord Injury Registry Of Iran (Nscir-Ir) In A Regional Center: Challenges And Solutions, Zahra Azadmanjir, Zahra Mohtasham-Amiri, Seyed-Mahdi Ziabari, Leila Kochakinejad, Hamid Haidari, Guilan University Of Medical Sciences, Hadis Sabour, Zahra Khazaeipour, Mahdi Sharif-Alhoseini, Zahra Ghodsi, Abbas Amirjamshidi, Farshad Akbarzadeh, Kazem Zendehdel, Amir Azarhomayouon, Khatereh Naghdi, Gerard Oreilly, Ellen Merete, Alexander Vaccaro, Edward C. Benzel, Seyed Behzad Jazayeri, Vafa Rahimi-Movaghar

Department of Orthopaedic Surgery Faculty Papers

Background: The National Traumatic Spinal Cord Injury Registry in Iran (NSCIR-IR), was implemented initially in three hospitals as a pilot phase from 11 Oct 2015 to 19 Jun 2016 and has been active in eight centers from 19 Jun 2016. Poursina Hospital, a trauma care referral center in Rasht, Guilan Province of Iran is one of the registry sites, and has been involved in registering eligible patients since 1 Jan 2016. This study aimed to identify the challenges and solutions for sustaining the NSCIR-IR in a regional center.

Methods: This was a mixed-methods study. For the quantitative analysis, a retrospective …

Correlation Of Early Outcomes And Intradiscal Interleukin-6 Expression In Lumbar Fusion Patients., John D Koerner, Dessislava Z Markova, Greg D Schroeder, Christopher L Antonacci, Joseph Mendelis, Alexander R Vaccaro, D Greg Anderson, Chris K Kepler

Department of Orthopaedic Surgery Faculty Papers

OBJECTIVE: To determine if there is correlation between intradiscal levels of interleukin-6 (IL-6) and early outcome measures in patients undergoing lumbar fusion for painful disc degeneration.

METHODS: Intervertebral disc tissue was separated into annulus fibrosus/nucleus pulposus and cultured separately in vitro in serum-free medium (Opti-MEM). Conditioned media was collected after 48 hours. The concentration of IL-6 was quantified using enzyme-linked immunosorbent assay. Pearson correlation coefficients quantified relationships between IL-6 levels and pre- and postoperative visual analogue scale (VAS) back pain and Oswestry Disability Index (ODI), as well as change in VAS/ODI.

RESULTS: Sixteen discs were harvested from 9 patients undergoing …

Proton Pump Inhibitor Use Affects Pseudarthrosis Rates And Influences Patient-Reported Outcomes., John J. Mangan, Srikanth N. Divi, James Mckenzie, Justin D. Stull, William Conaway, David S. Casper, Dhruv K.C. Goyal, Kristen J. Nicholson, Matthew S. Galetta, Scott C. Wagner, I. David Kaye, Mark Kurd, Barrett I. Woods, Kristen E. Radcliff, Jeffrey A. Rihn, D. Greg Anderson, Alan S. Hilibrand, Alex R. Vaccaro, Gregory D. Schroeder, Christopher K. Kepler

Department of Orthopaedic Surgery Faculty Papers

Study Design: Retrospective cohort review.

Objectives: Cervical pseudarthrosis is a frequent cause of need for revision anterior cervical discectomy and fusion (ACDF) and may lead to worse patient-reported outcomes. The effect of proton pump inhibitors on cervical fusion rates are unknown. The purpose of this study was to determine if patients taking PPIs have higher rates of nonunion after ACDF.

Methods: A retrospective cohort review was performed to compare patients who were taking PPIs preoperatively with those not taking PPIs prior to ACDF. Patients younger than 18 years of age, those with less than 1-year follow-up, and those undergoing surgery …

National Trends In Total Hip Arthroplasty For Traumatic Hip Fractures: An Analysis Of A Nationwide All-Payer Database., Anthony J Boniello, Alexander M Lieber, Kevin Denehy, Priscilla Cavanaugh, Yehuda E Kerbel, Andrew Star

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: Hemiarthroplasty (HA) has traditionally been the treatment of choice for elderly patients with displaced femoral neck fractures. Ideal treatment for younger, ambulatory patients is not as clear. Total hip arthroplasty (THA) has been increasingly utilized in this population however the factors associated with undergoing HA or THA have not been fully elucidated.

AIM: To examine what patient characteristics are associated with undergoing THA or HA. To determine if outcomes differ between the groups.

METHODS: We queried the Nationwide Inpatient Sample (NIS) for patients that underwent HA or THA for a femoral neck fracture between 2005 and 2014. The NIS …

A Prospective Study Comparing Tendon-To-Bone Interface Healing Using An Interposition Bioresorbable Scaffold With A Vented Anchor For Primary Rotator Cuff Repair In Sheep., Jeremiah Easley, Christian Puttlitz, Eileen Hackett, Cecily Broomfield, Lucas Nakamura, Michael Hawes, Charles Getz, Mark Frankle, Patrick St Pierre, Robert Tashjian, P Dean Cummings, Joseph Abboud, Derek Harper, Kirk Mcgilvray

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: The purpose of this study was to evaluate the biomechanical and histologic properties of rotator cuff repairs using a vented anchor attached to a bioresorbable interpositional scaffold composed of aligned PLGA (poly(l-lactide-co-glycoside)) microfibers in an animal model compared to standard anchors in an ovine model.

METHODS: Fifty-six (n = 56) skeletally mature sheep were randomly assigned to a repair of an acute infraspinatus tendon detachment using a innovative anchor-PLGA scaffold device (Treatment) or a similar anchor without the scaffold (Control). Animals were humanely euthanized at 7 and 12 weeks post repair. Histologic and biomechanical properties of the repairs were …

Fracture Repair Requires Trka Signaling By Skeletal Sensory Nerves., Zhu Li, Carolyn A Meyers, Leslie Chang, Seungyong Lee, Zhi Li, Ryan Tomlinson, Ahmet Hoke, Thomas L Clemens, Aaron W James

Department of Orthopaedic Surgery Faculty Papers

Bone is richly innervated by nerve growth factor-responsive (NGF-responsive) tropomyosin receptor kinase A-expressing (TrKa-expressing) sensory nerve fibers, which are required for osteochondral progenitor expansion during mammalian skeletal development. Aside from pain sensation, little is known regarding the role of sensory innervation in bone repair. Here, we characterized the reinnervation of tissue following experimental ulnar stress fracture and assessed the impact of loss of TrkA signaling in this process. Sequential histological data obtained in reporter mice subjected to fracture demonstrated a marked upregulation of NGF expression in periosteal stromal progenitors and fracture-associated macrophages. Sprouting and arborization of CGRP+TrkA+ sensory nerve fibers …

Volume Changes After Traumatic Spinal Cord Injury In Animal Studies - A Systematic Review, Mahdi Sharif-Alhoseini, Fariba Vahedi, Mahmoud Omidbeigi, Marzieh Sharifi, Zahra Hassannejad, Shayan Abdollah Zadegan, Motahareh Rezvan, Mona Mokhatab, Kiavash Sajadi, Aida Shakouri-Motlagh, Farhad Shokraneh, Alexander R. Vaccaro, Vafa Rahimi Movaghar

Department of Orthopaedic Surgery Faculty Papers

There are limited data on the lesion volume changes following spinal cord injury (SCI). In this study, a meta-analysis was performed to evaluate the volume size changes of the injured spinal cord over time among animal studies in traumatic SCI. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive electronic search of English literature of PubMed and EMBASE databases from 1946 to 2015 concerning the time-dependent changes in the volume of the spinal cord following mechanical traumatic SCI. A hand-search was also performed for non-interventional, non-molecular, and non-review studies. Quality appraisal, data extraction, …

Nucleus Pulposus Primary Cilia Alter Their Length In Response To Changes In Extracellular Osmolarity But Do Not Control Tonebp-Mediated Osmoregulation., Hyowon Choi, Vedavathi Madhu, Irving M. Shapiro, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

The nucleus pulposus (NP) cells adapt to their physiologically hyperosmotic microenvironment through Tonicity-responsive enhancer binding protein (TonEBP/nuclear factor of activated T-cell5 [NFAT5])-mediated osmoregulation. Primary cilia in different organs serve diverse roles including osmosensing, but its contribution to NP cell osmoadaptive response is unknown. A high percentage of cultured primary NP cells possessed primary cilia that changed length in response to osmotic stimuli. Stable silencing of Intraflagellar Transport 88 (Ift88) or Kinesin Family Member 3 A (Kif3a) to inhibit the formation of primary cilia did not affect hyperosmotic upregulation of TonEBP. While ShKif3a blocked hyperosmotic increase of TonEBP-Transactivation Domain (TAD) activity, …

Meta-Analysis A Myriad Of Data - Is It Helpful?, James Harrop

Department of Orthopaedic Surgery Faculty Papers

No abstract provided.

Equine Or Porcine Synovial Fluid As A Novel Ex Vivo Model For The Study Of Bacterial Free-Floating Biofilms That Form In Human Joint Infections, Jessica M. Gilbertie, Lauren V. Schnabel, Noreen J. Hickok, Megan E. Jacob, Brian P. Conlon, Irving Shapiro, Javad Parvizi, Thomas P. Schaer

Department of Orthopaedic Surgery Faculty Papers

Bacterial invasion of synovial joints, as in infectious or septic arthritis, can be difficult to treat in both veterinary and human clinical practice. Biofilms, in the form of free-floating clumps or aggregates, are involved with the pathogenesis of infectious arthritis and periprosthetic joint infection (PJI). Infection of a joint containing an orthopedic implant can additionally complicate these infections due to the presence of adherent biofilms. Because of these biofilm phenotypes, bacteria within these infected joints show increased antimicrobial tolerance even at high antibiotic concentrations. To date, animal models of PJI or infectious arthritis have been limited to small animals such …

The Impact Of Cholesterol Deposits On The Fibrillar Architecture Of The Achilles Tendon In A Rabbit Model Of Hypercholesterolemia., Andrzej Steplewski, Jolanta Fertala, Ryan Tomlinson, Kevth'er Hoxha, Lin Han, Ocean Thakar, Jason Klein, Joseph A. Abboud, Andrzej Fertala

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: Increased tendon pain and tendon damage is a significant complication related to hyperlipidemia. Unlike the well-established pathogenesis associated with increased serum concentrations of total cholesterol, triglycerides, and low-density lipoprotein in atherosclerotic cardiovascular disease, the role of hyperlipidemia in promoting tendon damage remains controversial and requires mechanistic clarity.

METHODS: In this study, we analyzed the consequences of hypercholesterolemia on the integrity of the collagen-based architecture of the Achilles tendon. The Achilles tendons from rabbits fed with normal-cholesterol (nCH) and high-cholesterol (hCH) diets were analyzed. We studied the morphology of tendons, distribution of lipids within their collagen-rich milieu, the relative amounts …

Comparison Of Surgical Outcomes Of The Posterior And Combined Approaches For Repair Of Cervical Fractures In Ankylosing Spondylitis., Panya Luksanapruksa, Paul William Millhouse, Victor Carlson, Thanase Ariyawatkul, Joshua Heller, Christopher K. Kepler

Department of Orthopaedic Surgery Faculty Papers

STUDY DESIGN: Retrospective cohort study.

PURPOSE: To evaluate surgical outcomes and complications of cervical spine fractures in ankylosing spondylitis (CAS) patients who were treated using either the posterior (P) or combined approach (C).

OVERVIEW OF LITERATURE: Ankylosing spondylitis typically causes progressive spinal stiffness that makes patients susceptible to spinal fractures. CAS is a highly unstable condition. There is contradictory evidence regarding which treatment option, the posterior or the combined approach, yields superior clinical results.

METHODS: A single institution database was reviewed for data in the period 1999 to 2015. All CAS patients who underwent posterior or combined instrumented fusion were …

Tendinosis Develops From Age- And Oxygen Tension-Dependent Modulation Of Rac1 Activity., Rowena Mcbeath, Richard W. Edwards, Brian J. O'Hara, Mitchell G. Maltenfort, Susan M. Parks, Andrzej Steplewski, A. Lee Osterman, Irving M. Shapiro

Department of Orthopaedic Surgery Faculty Papers

Age-related tendon degeneration (tendinosis) is characterized by a phenotypic change in which tenocytes display characteristics of fibrochondrocytes and mineralized fibrochondrocytes. As tendon degeneration has been noted in vivo in areas of decreased tendon vascularity, we hypothesized that hypoxia is responsible for the development of the tendinosis phenotype, and that these effects are more pronounced in aged tenocytes. Hypoxic (1% O₂ ) culture of aged, tendinotic, and young human tenocytes resulted in a mineralized fibrochondrocyte phenotype in aged tenocytes, and a fibrochondrocyte phenotype in young and tendinotic tenocytes. Investigation of the molecular mechanism responsible for this phenotype change revealed that …

Aospine—Spine Trauma Classification System: The Value Of Modifiers: A Narrative Review With Commentary On Evolving Descriptive Principles, Srikanth N. Divi, Md, Gregory D. Schroeder, Md, Cumhur Oner, Md, Phd, Frank Kandziora, Md, Phd, Klaus J. Schnake, Md, Marcel F. Dvorak, Md, Lorin M. Benneker, Md, Jens R. Chapman, Md, Alex R. Vaccaro, Md, Phd, Mba

Department of Orthopaedic Surgery Faculty Papers

Study Design: Narrative review.

Objectives: To describe the current AOSpine Trauma Classification system for spinal trauma and highlight the value of patient-specific modifiers for facilitating communication and nuances in treatment.

Methods: The classification for spine trauma previously developed by The AOSpine Knowledge Forum is reviewed and the importance of case modifiers in this system is discussed.

Results: A successful classification system facilitates communication and agreement between physicians while also determining injury severity and provides guidance on prognosis and treatment. As each injury may be unique among different patients, the importance of considering patient-specific characteristics is highlighted in this review. In …

Management Of Acute Traumatic Central Cord Syndrome: A Narrative Review, Srikanth N. Divi, Gregory D. Schroeder, John J. Mangan, Madeline Tadley, Wyatt L. Ramey, Jetan H. Badhiwala, Michael G. Fehlings, F. Cumhur Oner, Frank Kandziora, Lorin M. Benneker, Emiliano N. Vialle, Shanmuganathan Rajasekaran, Jens R. Chapman, Alexander R. Vaccaro

Department of Orthopaedic Surgery Faculty Papers

Study Design: Narrative review.Objectives:To provide an updated overview of the management of acute traumatic central cord syndrome (ATCCS).

Methods: A comprehensive narrative review of the literature was done to identify evidence-based treatment strategies forpatients diagnosed with ATCCS.

Results: ATCCS is the most commonly encountered subtype of incomplete spinal cord injury and is characterized by worsesensory and motor function in the upper extremities compared with the lower extremities. It is most commonly seen in thesetting of trauma such as motor vehicles or falls in elderly patients. The operative management of this injury has been historicallyvariable as it can be seen in …

Ultrasound-Triggered Antibiotic Release From Peek Clips To Prevent Spinal Fusion Infection: Initial Evaluations., Lauren J. Delaney, Daniel Macdonald, Jay Leung, Keith Fitzgerald, Alex M. Sevit, John R. Eisenbrey, Neil Patel, Flemming Forsberg, Christopher K. Kepler, Taolin Fang, Steven M. Kurtz, Noreen J. Hickok

Department of Orthopaedic Surgery Faculty Papers

Despite aggressive peri-operative antibiotic treatments, up to 10% of patients undergoing instrumented spinal surgery develop an infection. Like most implant-associated infections, spinal infections persist through colonization and biofilm formation on spinal instrumentation, which can include metal screws and rods for fixation and an intervertebral cage commonly comprised of polyether ether ketone (PEEK). We have designed a PEEK antibiotic reservoir that would clip to the metal fixation rod and that would achieve slow antibiotic release over several days, followed by a bolus release of antibiotics triggered by ultrasound (US) rupture of a reservoir membrane. We have found using human physiological fluid …