Does fracture-extension into the pars interarticularis alter outcomes in odontoid failure? a technical note on pars interarticularis osteotomy and atlantoaxial distraction arthrodesis.

PURPOSE: Odontoid process fractures can extend rostral into the C2 arch. We investigated the clinical impact of a concurrent fracture of the pars interarticularis on odontoid failure. To overcome the surgical challenges related to the morphology of these fractures, we describe a novel surgical strategy using atlantoaxial joint distraction arthrodesis. METHODS: We conducted a single centre cohort study of 13 consecutive patients with odontoid fractures extending into the pars treated between June 2016 and June 2018. Criteria for a stable fibrous non-union were: Atlanto-Dens Interval (ADI) < 3 mm, Posterior Atlanto-Dens Interval (PADI) > 14 mm and lack of symptomatic motion at the fracture site. Atlantoaxial instability was defined as greater than 50% subluxation across the C1-C2 joint. Return to pre-injury performance status was considered a satisfactory clinical outcome. RESULTS: The mean age of the patient population was 77.2 years (SD 11.9). The mean follow-up time was 15 months (SD 5.2). 69% had an associated atlantoaxial instability (P-value 0.0005). Cervical orthosis treatment was associated with a high non-union rate (70%) (P-value 0.04) although it did not affect the overall clinical outcome. 2 cases presented with cord compression were treated surgically with pars interarticularis osteotomy and atlantoaxial distraction arthrodesis. CONCLUSIONS: Odontoid fracture with extension into the pars interarticularis often present with atlantoaxial instability and may result in stable fibrous non-union if treated non-operatively. The C1-C2 segment can be stabilised with atlantoaxial distraction arthrodesis achieved through an osteotomy of the pars interarticularis.

Mesenchymal stem cells in regenerative medicine: Focus on articular cartilage and intervertebral disc regeneration.

Musculoskeletal disorders represent a major cause of disability and morbidity globally and result in enormous costs for health and social care systems. Development of cell-based therapies is rapidly proliferating in a number of disease areas, including musculoskeletal disorders. Novel biological therapies that can effectively treat joint and spine degeneration are high priorities in regenerative medicine. Mesenchymal stem cells (MSCs) isolated from bone marrow (BM-MSCs), adipose tissue (AD-MSCs) and umbilical cord (UC-MSCs) show considerable promise for use in cartilage and intervertebral disc (IVD) repair. This review article focuses on stem cell-based therapeutics for cartilage and IVD repair in the context of the rising global burden of musculoskeletal disorders. We discuss the biology MSCs and chondroprogenitor cells and specifically focus on umbilical cord/Wharton's jelly derived MSCs and examine their potential for regenerative applications. We also summarize key components of the molecular machinery and signaling pathways responsible for the control of chondrogenesis and explore biomimetic scaffolds and biomaterials for articular cartilage and IVD regeneration. This review explores the exciting opportunities afforded by MSCs and discusses the challenges associated with cartilage and IVD repair and regeneration. There are still many technical challenges associated with isolating, expanding, differentiating, and pre-conditioning MSCs for subsequent implantation into degenerate joints and the spine. However, the prospect of combining biomaterials and cell-based therapies that incorporate chondrocytes, chondroprogenitors and MSCs leads to the optimistic view that interdisciplinary approaches will lead to significant breakthroughs in regenerating musculoskeletal tissues, such as the joint and the spine in the near future.

Mesenchymal stem cells in regenerative medicine: opportunities and challenges for articular cartilage and intervertebral disc tissue engineering.

Defects of load-bearing connective tissues such as articular cartilage and intervertebral disc (IVD) can result from trauma, degenerative, endocrine, or age-related disease. Current surgical and pharmacological options for the treatment of arthritic rheumatic conditions in the joints and spine are ineffective. Cell-based surgical therapies such as autologous chondrocyte transplantation (ACT) have been in clinical use for cartilage repair for over a decade but this approach has shown mixed results. This review focuses on the potential of mesenchymal stem cells (MSCs) as an alternative to cells derived from patient tissues in autologous transplantation and tissue engineering. Here we discuss the prospects of using MSCs in regenerative medicine and summarize the advantages and disadvantages of these cells in articular cartilage and IVD tissue engineering. We discuss the conceptual and practical difficulties associated with differentiating and pre-conditioning MSCs for subsequent survival in a physiologically harsh extracellular matrix, an environment that will be highly hypoxic, acidic, and nutrient deprived. Implanted MSCs will be exposed to traumatic physical loads and high levels of locally produced inflammatory mediators and catabolic cytokines. We also explore the potential of culture models of MSCs, fully differentiated cells and co-cultures as "proof of principle" ethically acceptable "3Rs" models for engineering articular cartilage and IVD in vitro for the purpose of replacing the use of animals in arthritis research.

Posttraumatic C5 Palsy After Application of Hard Collar in Ankylosing Spondylitis.

BACKGROUND: Ankylosing spondylitis (AS) is a systemic enthesopathy. In its presence, spinal fractures are often unstable. Acknowledging the preinjury level of kyphosis is key in the management of cervical fractures, and placement into a hard collar has been shown to result in life-threatening spinal cord complications. CASE DESCRIPTION: This report presents the unique case of a patient with AS who developed a unilateral C5 palsy after the application of a hard collar for a C5/6 fracture, to our knowledge the first such case presented to date. The patient subsequently went on to an anterior fixation and partially recovered from the C5 palsy/injury. After the case report is an examination of the currently available literature and evidence exploring the factors that may contribute to C5 palsy after the application of a collar for acute fracture in AS. CONCLUSIONS: We described the first case in the literature of a posttraumatic C5 palsy after application of a hard collar in AS. This report and literature review should act to underscore the importance of respecting a preexisting rigid kyphotic deformity in cervical fractures but also to stimulate further thoughts and investigations into what may contribute to a posttraumatic C5 palsy.

Vertebral compression fractures.

This review gives a practical guide to the investigation and management of osteoporotic vertebral compression fractures. With an ageing population, the burden of disease and health system costs attributable to this common injury continue to rise. This article outlines the epidemiology, clinical and radiological assessment of vertebral compression fractures, and key decisions that must be made in their management. It reviews the indications and evidence for conservative vs operative treatment, discusses the rationale for vertebroplasty, kyphoplasty and spinal stabilization, and looks at outcomes in this vulnerable patient population. It also reviews key evidence underlying decision making including National Institute for Health and Care Excellence guidelines.