BACKGROUND-The national field trauma triage guidelines have been widely implemented in US trauma systems, but never prospectively validated. We sought to prospectively validate the guidelines, as applied by out-of-hospital providers, for identifying high-risk trauma patients.

Introduction: Despite advances in trauma care, missed injury remains a significant cause of morbidity and mortality in trauma worldwide. In England, few have published their missed injury rates and there are no recent data for London. In 2010 London trauma networks were restructured and the impact on missed injury rates is not known. This study aimed to determine the incidence of missed orthopaedic injury for adult trauma patients at St George's Hospital, London, and to analyse missed injuries and comment on risk factors. Method: Trauma patients were recorded prospectively at the daily trauma meeting from July to September 2012. The researcher attended clinical activities and reviewed the patient notes and radiology reports daily whilst each patient was an inpatient until discharge. Missed injuries were defined as fractures or dislocations discovered more than 12 h after arrival in the emergency department. The notes for missed injury patients were reviewed again at six months. Missed injury details were recorded/analysed. Results: Three hundred and forty three adult trauma patients were referred to trauma and orthopaedics in the threemonth study period; 5 (1.5%) had a missed injury and 148 (43.1%) had an ISS>15. All missed injuries occurred in these major trauma patients, giving an incidence of 5/148 (3.4%). Four were extremity injuries and one was cervical. All missed injury patients had a GCS of 15/15, were admitted outside normal working hours, were direct admissions and had wholebody CT. Conclusions: At 3.4% our missed injury incidence is comparable to those published from similar major trauma centres. This provides recent London data following the restructuring of trauma networks.

Introduction: Lumbar spinal stenosis is degenerative narrowing of the spinal canal and/or intervertebral foramen causing compression of the spinal cord and nerve roots. Traditional decompression techniques can often cause significant trauma and vertebral instability. This paper evaluates a method of increasing pedicle length to decompress the spinal and intervertebral foramen, which could be done minimally invasive.Methods: Three Sawbone (Sawbones Europe, Sweden) and 1 cadaveric lumbar spine underwent bilateral pedicle distraction at L4. A pedicle channel was drilled between the superior articular process and transverse process into the vertebral body. The pedicles underwent osteotomy at the midpoint. Screws were inserted bilaterally and fixated distraction of 0 mm, 2 mm, 4 mm and 6 mm. CT images were taken at each level of distraction. Foramen area was measured in the sagittal plane at L3/4. Spinal canal area was measured at L4 in the axial images. The cadaver was used to evaluate safety of osteotomy and soft tissue interactions preventing distraction. Statistical analysis was by student paired t-test and Pearson rank test.Results: Increasing distraction led to greater Spinal canal area. From 4.27 cm2 to 5.72 cm2 (p = 0.002) with 6 mm distraction. A Maximal increase of 34.1%. Vertebral foramen area also increased with increasing pedicle distraction. From 2.43 cm2 to 3.22 cm2 (p = 0.022) with 6 mm distraction. A maximal increase of 32.3%. The cadaver spinal canal increased in area by 21.7%. The vertebral foramen increased in area by 36.2% (left) and 22.6% (right).Discussion: For each increase in pedicle distraction the area of the spinal and vertebral foramen increases. Pedicle distraction could potentially be used to alleviate spinal stenosis and root impingement. A potential osteotomy plane could be at the midpoint of the pedicle with minimal risk to nerve roots and soft tissue restrictions to prevent distraction.