The optimal management of patients with the diagnosis of a spinal epidural abscess (SEA) remains controversial. The purpose of this study was to describe the clinical characteristics of patients presenting with spontaneous SEA and to correlate presentation and treatment with clinical and neurological outcome.

A retrospective review of the medical records and radiology of patients with a diagnosis of SEA, treated between September 2003 and December 2010, at a tertiary referral hospital was performed. A total of 46 patients were identified including 27 males and 19 females. Mean age was 61 years (range, 30 – 86 years). At presentation, all patients had axial pain and 67% had a neurological deficit, out of which one third had paraplegia or quadriplegia. 32% patients were febrile. Diabetes was the most common risk factor (30%) followed by malignancy (17%), intravenous drug use (6%) and alcoholism (2%).

Organisms were cultured in 44 patients with Methicillin Sensitive Staphylococcus Aureus most common (68%), followed by Methicillin Resistant Staphylococcus Aureus (14%). The epidural abscess was located in the lumbar spine in 24 patients, thoracic spine in 11 patients and cervical spine in 11 patients. 61% of patients had a concurrent source of septic focus on presentation, including psoas abscess (24%), facet joint septic arthritis (15%), pneumonia (11%), infective endocarditis (7%) and urosepsis (4%). 26% of patients were treated non-operatively, with computed tomography-guided aspiration and/or intravenous antibiotics based on cultures, whereas 74% underwent surgical decompression with or without fusion in combination with antibiotics. The mean inpatient hospital stay was 42 days (range, 2 – 742 days) and 34% of patients required an average of 40 days of Intensive Care Unit admission. At time discharge from hospital, of the patients managed nonoperatively, 33% had improved neurological function, 17% had worsened neurological function, 17% died and data was unavailable in 33%. Of the patients treated with surgery, 74% had improved neurological function, 6% remained unchanged, 6% had worsened neurologic function, 6% died and data was unavailable in 9% at time of discharge.

SEA remains a severe condition associated with multiple septic foci and significant morbidity. Surgical decompression combined with antibiotics is associated with superior neurologic recovery compared with non-operative management, however a significant proportion of patients still deteriorate or die. Early diagnosis and management may prevent or reduce permanent neurologic deficit.

Centre Hospitalo-Universitaire de Bordeaux, Service de Pathologie du la Colonne Vertébrale, Bordeaux, France.

Assessment of cervical lordosis using a standardised digital acquisition procedure in the normal population

Three independent reviewers measured static lordosis. The EOS¯ system, which utilises low dose radiation and provides reliable standardized digital 2D acquisition with 3D reconstruction was employed. Measurements were carried out twice by every examiner on two different occasions.

Cohort of the general public of 180 subjects divided into 4 groups (both sexes individually, age less than 40 and greater than 50 individually). None had any previous history of spinal disorders or sagittal imbalance. General cervical lordosis (C2 to C7) as well as upper and lower cervical lordosis were assessed.

Cervical lordosis in the general population has a very wide range in both sexes. Overall cervical lordosis was 37 degrees. Lower cervical lordosis (superior endplate of C4 to inferior endplate of C7) demonstrated an average of 16 degrees, and upper cervical lordosis was found to be 21 degrees.

No particular age group or sex was more prone to having lesser/greater lordosis.

Current literature is sparse and provides large ranges, different standards and variable methods for assessing standard cervical lordosis. Overall cervical lordosis is very variable amongst the sexes and age groups. We provide a standard set of values which help to provide the spinal surgeon with values to aim for when seeking to restore cervical lordosis.

Introduction Hyaline cartilage is a barrier to osteosarcoma invasion, however the mechanisms behind this resistance remain unclear. The aim of this study was to examine the temporo-spatial pattern of osteosarcoma growth and invasion of local tissue structures, including epiphyseal cartilage, and to investigate the molecular mechanisms behind the resistance of cartilage to malignant invasion.

Methods An in vivo mouse model of osteosarcoma was used, whereby osteosarcoma cells were orthotopically injected into the tibiae of nude mice. Animals were sacrificed at weekly timepoints. Control and tumour limbs were processed for histological examination of tumors at different stages of disease progression. Routine Haematoxylin & Eosin staining was used to examine morphology, and immunohistochemical staining using antibodies against proangiogenic vascular endothelial growth factor (VEGF) and anti-angiogenic pigment epithelium-derived factor (PEDF) was performed. PEDF from mouse liver was cloned into a mammalian expression vector in order to generate stably-transfected osteosarcoma cell lines.

Results Hyaline cartilage of the growth plate and articular surface was resistant to local invasion by osteosarcoma in all sections examined, despite increasing tumor size as well as extensive intra- and extra-osseous destruction. All tumours showed immunostaining for VEGF but not for PEDF. In the most advanced cases, only the lowermost layers of the hypertrophic zone of the growth plate were eroded. These layers displayed strong immunostaining for the potent angiogenic factor VEGF, and weak to absent immunostaining for PEDF. By contrast, the resting, proliferative and upper hypertrophic layers, which were resistant to osteosarcoma invasion in the cases studied, showed high expression levels of the potent anti-angiogenic factor PEDF.

Conclusions These results confirm that the balance of angiogenesis, influenced by pro and anti-angiogenic factors, determines tumour growth and invasion. Given the localization of PEDF specifically to the resistant cartilaginous layers and its exceptionally potent anti-angiogenic effects, there are exciting prospects for the use of PEDF in treatment for osteosarcoma as well as other cancers. To this end, we have established osteosarcoma cell lines that over-express PEDF and are currently characterizing these cells in vitro and assessing the propensity of PEDF to suppress tumour invasion in vivo. Growth plate cartilage is resistant to invasion by osteosarcoma. PEDF is likely to play an important role in this resistance. As such, it may have therapeutic applications in osteosarcoma as well as other malignancies.

In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source.