Orthopedics Commons^™

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 …

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 …

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 …

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 …

A Novel Handheld Robotic-Assisted System For Unicompartmental Knee Arthroplasty: Surgical Technique And Early Survivorship., Andrew K. Battenberg, Nathan A. Netravali, Jess H. Lonner

Department of Orthopaedic Surgery Faculty Papers

Technology, including robotics, has been developed for use in unicompartmental knee arthroplasty (UKA) to improve accuracy and precision of bone preparation, implant positioning, and soft tissue balance. The NAVIO™ System (Smith and Nephew, Pittsburgh, PA, United States) is a handheld robotic system that assists surgeons in planning implant positioning based on an individual patient's anatomy and then preparing the bone surface to accurately achieve the plan. The surgical technique is presented herein. In addition, initial results are presented for 128 patients (mean age 64.7 years; 57.8% male) undergoing UKA with NAVIO. After a mean of follow-up period of 2.3 years, …

Functional And Structural Studies Of Tolloid-Like 1 Mutants Associated With Atrial-Septal Defect 6., Lukasz Sieron, Marta Lesiak, Izabela Schisler, Zofia Drzazga, Andrzej Fertala, Aleksander L. Sieron

Department of Orthopaedic Surgery Faculty Papers

Inactive mammalian tolloid-like 1 (tll1) and mutations detected in tolloid-like 1 (TLL1) have been linked to the lack of the heart septa formation in mice and to a similar human inborn condition called atrial-septal defect 6 (ASD6; OMIM 613087, formerly ASD II). Previously, we reported four point mutations in TLL1 found in approximately 20% of ASD6 patients. Three mutations in the coding sequence were M182L, V238A, and I629V. In this work, we present the effects of these mutations on TLL1 function. Three recombinant cDNA constructs carrying the mutations and one wild-type construct were prepared and then expressed in HT-1080 cells. …