Andrew Z. Mo

The posterior ligamentous complex (PLC) provides critical structural support in the thoracolumbar spine. Its role in resisting progressive flexion is particularly important at the thoracolumbar junction due to the transition from the rigid thoracic spine to the more mobile lumbar region. Each component of the PLC contains anatomic features that contribute to both the structure and function of the PLC as a whole. Understanding the nuances of each structure is important in determining injury severity and may serve as a foundation for future directions of research. Violation of the PLC results in an unstable spine, thus requiring surgical management. It is associated with greater injury severity and neurologic deficit in patients who sustain thoracolumbar fractures, which adds complexity to the postoperative course and patient outcomes. Although plain radiographs and CT scans provide reliable indirect measures of PLC disruption, these modalities may be subject to diminished sensitivity based on patient positioning and do not directly measure soft-tissue injury. Modern classification systems include the integrity of the PLC in surgical decision making, and care must be taken to scrutinize the possibility of ligamentous disruption before proceeding with nonsurgical management to avoid adverse patient outcomes.

» Coccydynia is a painful condition affecting many patients at the terminal caudal end of the spine. » An understanding of coccyx anatomy and variations of morphology is necessary for proper diagnosis. A multifactorial etiology for pain may be responsible for this clinical entity. » Several treatment options exist. Successful outcomes for patients depend on individual patient characteristics and the etiology of pain.

Purpose: To evaluate the AOSpine Thoracolumbar Spine Injury Classification System and if it is reliable and reproducible when applied to the paediatric population globally. Methods: A total of 12 paediatric orthopaedic surgeons were asked to review MRI and CT imaging of 25 paediatric patients with thoracolumbar spine traumatic injuries, in order to determine the classification of the lesions observed. The evaluators classified injuries into primary categories: A, B and C. Interobserver reliability was assessed for the initial reading by Fleiss's kappa coefficient (k_F) along with 95% confidence intervals (CI). For A and B type injuries, sub-classification was conducted including A0-A4 and B1-B2 subtypes. Interobserver reliability across subclasses was assessed using Krippendorff's alpha (α_k) along with bootstrapped 95% CIs. A second round of classification was performed one-month later. Intraobserver reproducibility was assessed for the primary classifications using Fleiss's kappa and sub-classification reproducibility was assessed by Krippendorff's alpha (α_k) along with 95% CIs. Results: In total, 25 cases were read for a total of 300 initial and 300 repeated evaluations. Adjusted interobserver reliability was almost perfect (kF = 0.74; 95% CI 0.71 to 0.78) across all observers. Sub-classification reliability was substantial (α_k= 0.67; 95% CI 0.51 to 0.81), Adjusted intraobserver reproducibility was almost perfect (kF = 0.91; 95% CI 0.83 to 0.99) for both primary classifications and for sub-classifications (α_k = 0.88; 95% CI 0.83 to 0.93). Conclusion: The inter- and intraobserver reliability for the AOSpine Thoracolumbar Spine Injury Classification System was high amongst paediatric orthopaedic surgeons. The AOSpine Thoracolumbar Spine Injury Classification System is a promising option as a uniform fracture classification in children. Level of Evidence: III

Os odontoideum is a rare entity of the second cervical vertebra, characterized by a circumferentially corticated ossicle separated from the body of C2. The ossicle is a distinct entity from an odontoid fracture or a persistent ossiculum terminale. The diagnosis may be made incidentally on imaging obtained for the workup of neck pain or neurologic signs and symptoms. Diagnosis usually can be made with plain radiographs. MRI and CT can assess spinal cord integrity and C1-C2 instability. The etiology of os odontoideum is a topic of debate, with investigative studies supporting both congenital and traumatic origins. A wide clinical range of symptoms exists. Symptoms may present as nondescript pain or include occipital-cervical pain, myelopathy, or vertebrobasilar ischemia. Asymptomatic cases without evidence of radiologic instability are typically managed with periodic observation and serial imaging. The presence of atlantoaxial instability or neurological dysfunction necessitates surgical intervention with instrumentation and fusion for stability.

Background: There is no uniform classification in the pediatric population for thoracolumbar (TL) fractures, nor any operative guidelines. This study evaluates the AOSpine TL spine injury classification in the pediatric population and compares it to the thoracolumbar injury classification system (TLICS), which has previously been validated in pediatric spine trauma. Methods: Twenty-eight patients with operative TL injuries were identified from 2006 to 2016. Inclusion criteria included available imaging, operative records, age r = 0.75; 95% confidence interval, CI = 0.51 to 0.98; P < .001). Concordance between PLC integrity by each classification and intraoperative evaluation was 96% (27/28) of cases (k = 0.91; 95% CI = 0.73 to 1.08). Neurologic status was 100% concordant between the AOSpine TL spine injury classification and TLICS. Conclusion: There is high statistical correlation between the AOSpine TL spine injury classification and TLICS, and to intraoperative evaluation of the PLC, suggesting that the AOSpine TL spine injury classification is applicable to the pediatric population. Level of evidence: III.

Case: Gorham-Stout disease (GSD) is a rare entity that is marked by progressive osteolysis and bone resorption. A 14-year-old boy who was being followed for scoliosis presented with a marked curve progression and kyphoscoliosis. Imaging revealed osteolysis of the posterior elements and the ribs, suggestive of GSD. The structural compromise threatened spinal cord compression. Preoperative sirolimus therapy was initiated to stabilize the disease prior to corrective instrumentation. A biopsy specimen that was obtained at the time of instrumentation showed lymphatic vascular spaces consistent with GSD. Sirolimus therapy with the addition of bisphosphonate therapy was continued postoperatively. Conclusion: To our knowledge, this case report is the first to describe sirolimus therapy combined with surgery for GSD of the spine. The patient did well with consecutive medical optimization and surgical intervention, including postoperative sirolimus and bisphosphonate therapy.