Vertebroplasty-percutaneous cement augmentation of osteoporotic vertebrae is an efficient procedure for the treatment of painful vertebral fractures. From a prospectively monitored series of 70 patients with 193 augmented vertebrae for osteoporotic and metastatic lesions, we analysed a group of 17 patients suffering from back pain due to osteoporotic fractures. The reinforcement of 45 vertebral bodies in these patients led to a significant and lasting pain reduction (P < 0.01 ). The presented technique is useful, as, in one session, at least four injections can be performed when required, allowing the prophylactic reinforcement of adjacent vertebrae as well. The use of a low-viscosity polymethyl methacrylate (PMMA) in combination with a non-ionic liquid contrast dye provides a reliable and safe procedure. Extraosseous cement leakage was seen in 20% of the interventions; however, none of them had clinical sequelae.

While there is consensus in the literature that blood vessels are confined to the outer anulus fibrosus of normal adult intervertebral disc, debate continues whether there is a vascular in-growths into inner parts of the intervertebral disc during degeneration. We therefore tested the hypothesis that vascular in-growth is not a distinct feature of disc degeneration. The specific endothelial cell marker CD 31 (PECAM) was used to immunohistochemically investigate 42 paraffin-embedded complete mid-sagittal human intervertebral disc sections of various ages (0-86 years) and varying extent of histomorphological degeneration. Additionally, 20 surgical disc samples from individuals (26-69 years) were included in this study. In discs of fetal to infantile age, blood vessels perforated the cartilaginous end plate and extended into the inner and outer anulus fibrosus, but not into the nucleus pulposus. In adolescents and adults, no blood vessels were seen except for the outer zone of the anulus fibrosus adjacent to the insertion to ligaments. The cartilaginous end plate remained free of vessels, except for areas with circumscribed destruction of the end plate. In advanced disc degeneration, no vessels were observed except for those few cases with complete, scar-like disc destruction. However, some rim lesions and occasionally major clefts were surrounded by a small network of capillary blood vessels extending into deeper zones of the anulus fibrosus. A subsequent morphometric analysis, revealed slightly "deeper" blood vessel extension in juvenile/adolescent discs when compared to young, mature and senile adult individuals with significantly "deeper" extension in the posterior than anterior anulus. The analysis of the surgical specimens showed that only sparse capillary blood vessels which did not extend into the nucleus pulposus even in major disc disruption. Our results show that vascular invasion deeper than the periphery was not observed during disc degeneration, which supports the hypothesis that vascular in-growth is not a distinct feature of disc degeneration.

Spinal canal dimensions are assumed to play a significant role with regard to the development of symptoms in individuals with disc herniations. The literature is inconclusive on the significance of spinal canal size as a risk factor for sciatica, mainly because of study design problems. The objective of this study, therefore, was to test the hypothesis that spinal canal dimensions are a significant risk factor for the development of sciatica, comparing symptomatic and asymptomatic individuals. Thirty symptomatic patients undergoing lumbar discectomy and 45 asymptomatic volunteers were investigated by clinical and MRI examination. The size of the spinal canal and thecal sac as well as the midsagittal spinal canal diameter were measured using a point counting method and scanner software, respectively. Differences between the groups were compared separately for each level L3/4 to L5/S1. The intra- and inter-observer error ranged between 0.95 and 0.99 for all measurements. In symptomatic patients, the dimensions of the spinal canal and thecal sac as well as the midsagittal spinal canal diameter were smaller at all disc levels. Unpaired t-test demonstrated a significant difference, ranging from P<0.05 to P<0.001. When controlled for age, sex and body height, the odds ratio for a symptomatic disc herniation increased to as high as 35, depending on the spinal level, when the size of the spinal canal was smaller than the mean for controls by two standard deviations or more. In symptomatic patients, spinal canal dimensions are significantly smaller than those in asymptomatic individuals. Spinal canal dimension is an important factor discriminating patients from control subjects. A clinically relevant grading system for disc herniation should therefore be based on the spatial relationship between herniated disc material and neurogenic structures.

Short segment pedicle instrumentation for thoracolumbar burst fracture is known to fail due to lack of anterior support. Additional transpedicular grafting and dorsolateral fusion were offered to prevent its failure. The purpose of this study was to analyse the clinical and radiological outcome in two identical groups of patients treated with short segment pedicle instrumentation and posterolateral fusion with and without inter- and intracorporal transpedicular bone grafting. The clinical and radiological results of two identical groups of patients with thoracolumbar burst fractures were analysed. 15 patients (2 f, 13 m), mean age 35 years, were treated with bisegmental fixation with the fixateur interne and unisegmental fusion. Further 15 patients (3 f, 12 m), mean age 34 years, obtained additional intra- and intercorporal bone grafting. The implants were removed 15 resp. 13 months post surgery. Latest clinical and radiological follow-up was at 61/24 months. The clinical results were identical in both groups. Radiological measurements showed a significant loss of correction for all three measured angles (vertebral kyphosis, unisegmental kyphosis and bisegmental kyphosis) in both groups. However, patients with transpedicular bone grafting showed less loss of bony, vertebral kyphosis. Neither dorsolateral fusion nor dorsolateral fusion with transpedicular bone grafting could prevent loss of angular corrections.