Lumbo-pelvic lordosis and the pelvic radius technique in the assessment of spinal sagittal balance: strengths and caveats.

INTRODUCTION: The two main methodologies described for the assessment of spinal sagittal alignment are the pelvic radius (PR) technique and that based on measures of the Pelvic Incidence (PI) and Spino-Sacral Angle (SSA). Both methods stress the fundamental relationship between the anatomical position and orientation of the sacrum within the pelvis and the spinal curves above. The aim of the current study was to assess the strengths and potential weaknesses of the PR technique. The PR technique uses measures based on a line (the PR), drawn between the hip axis and the posterior corner of the S1 endplate. The angle formed between the PR line and the sacral endplate, PRS1, is a developmental measure of sacropelvic morphology. Geometrically, PI and PRS1 are approximately complementary angles and both reflect reciprocal alterations in pelvic tilt (for PI) or angulation (for PRS1) and the slope of the S1 endplate. The angle formed between PR and T12, the PR-T12, reflects a combined measure of pelvic morphology and lumbar lordosis. It appears to be a useful measure, which provides a simple and rapid assessment of lumbopelvic sagittal balance, but only in the presence of a congruent thoracic curvature. MATERIALS AND METHODS: After reviewing the literature, published measures made using the PR technique were compared to measures taken from a substantial patient population (479 adult patients). CONCLUSIONS: Errors can occur using the PR technique if the PRT12 is viewed in isolation from the thoracic kyphosis. We found the ratio of the thoracic kyphosis to lumbar lordosis (T4-T12/T12-S1) to be a useful predictor of congruent sagittal alignment, which may alert the clinician to situations where use of the PR-T12 in isolation may be misleading.

Incidental hemangioblastoma of the filum terminale.

Filum terminale hemangioblastoma is an extremely rare tumour with only a few case reports in the literature. The natural history is unknown but benign as well as more aggressive presentations have been reported. The authors present the first such lesion discovered incidentally and discuss the available literature.

Pituitary apoplexy can mimic subarachnoid haemorrhage clinically and radiologically.

Pituitary apoplexy is when there is acute haemorrhage into a pituitary adenoma. It presents with headache and altered consciousness with loss of pituitary function. Many cases have bitemporal hemianopia. Subarachnoid haemorrhage is in the differential diagnosis, but does not cause a similar visual field defect. Magnetic resonance imaging is required to diagnose the pituitary tumour. An elderly man who presented with acute headache, and who was initially diagnosed with subarachnoid haemorrhage but re-presented with features of pituitary apoplexy, is described.

Closed cranial meningocele with no communication to the CNS.

We present a case of two separate closed parietal meningoceles without communication to the CNS and not in the midline. This is the first such case reported in the literature.

Is the recommended target of 4 hours from head injury to emergency craniotomy achievable?

Guidelines recommend that head-injured patients who require life-saving decompressive surgery should undergo surgery within 4 h. To assess the compliance with this recommendation 100 consecutive head-injured patients admitted to a regional neurosurgical unit (RNU) were studied. Time points from head injury to craniotomy were documented and analysed. Twenty-four patients underwent emergency craniotomy, only one being operated on within 4 h. In this cohort of patients there was no relationship between timing of surgery and outcome. In order to investigate whether it is possible to reduce delays in transportation time, theoretical models were created to determine whether direct transfer to the RNU would be faster by land or air ambulance.

Radioimmunodetection: technical problems and methods of improvement.

Radioimmunodetection (RAID) is a technique which uses radiolabelled antibodies to visualize tumours, taking advantage of antigens preferentially expressed by malignant tissue. Gamma radiation emitted by radioisotopes can be detected using an external gamma camera (RAID), or intraoperatively with a hand-held Geiger counter (radioimmunoguided surgery, RIGS). RAID has significant inherent problems. Many have been overcome as a result of nearly 50 years of research, and others still remain as obstacles precluding the routine use of the technique. This article summarizes the technical limitations of RAID and outlines the relative successes of the methods evolved to overcome them.