Abstract

Vertebral compression fractures are very common. 250,000 are diagnosed annually in the United States with 80% due to osteoporosis¹. Symptomatic relief with conservative therapy is often difficult to achieve. The consequence of significant pain is deterioration in quality of life and often in level of function. They independently increase mortality rate¹.

Balloon kyphoplasty is a relatively new technique which stabilises the vertebral body and restores saggital spinal alignment. Excellent pain relief and improved functional outcome is reported^2,3. We aim to confirm this.

All patients receiving balloon kyphoplasty treatment at Derby Hospitals NHS Trust from April 2006 to August 2010 were entered prospectively onto a database. Visual Analogue Score (VAS) for pain and Oswestry Disability Index (ODI) for function were recorded. Technical data including number of levels, cement volume, screening time and kyphosis correction was recorded.

198 patients underwent balloon kyphoplasty between April 2006 and August 2010. Some data was incomplete. 105 patients had sufficient data for meaningful analysis. 170 levels were operated on in 105 patients. 65% (n=68) of patients were female and the average age was 74.

The average pre-operative visual analogue score (VAS) was 8.2. This decreased to 4.0 in the immediate postoperative period. This dramatic improvement remained and was 4.1 at 6 weeks, 3.3 at 6 months and 3.6 at 1 year. The average pre-operative Oswestry disability index (ODI) was 58. This improved to 47 in the immediate post-operative period. At 6 weeks this had improved further to 40 and further improvements were seen at 6 months (ODI 37) and 1 year (ODI 38).

Balloon kyphoplasty should be considered in all patients with ongoing pain following an acute vertebral compression fracture that doesn't respond to conservative treatment.

Consecutive case series

To evaluate the efficacy of a strict stepwise radioanatomical procedure protocol in avoiding neurological complications through tool malplacement in fluoroscopy guided percutaneous procedures of the thoracic spine.

Fluoroscopy guided percutaneous access to thoracic vertebral bodies is technically demanding. There is a trend towards computed tomography (CT) guidance on grounds of perceived lesser risk of spinal canal instrument malplacement. CT is however not always readily accessible and a safe technique for fluoroscopy guided procedures therefore desirable.

350 consecutive fluoroscopy guided percutaneous procedures (biopsy, vertebroplasty or kyphoplasty) covering all thoracic vertebral levels T1-T12 were performed according to a strict stepwise radioanatomical protocol. The crucial step of the protocol was not to advance the tool beyond the anterior-posterior (ap) projection of the medial pedicle wall until the tip of the instrument had been verified to have reached the posterior vertebral cortex in the lateral projection. The neurological status of patients was assessed through clinical examination prior to, immediately after the procedure and before discharge.

Percutaneous instrument placement in the targeted thoracic vertebral body was achieved in all cases and the stepwise radioanatomical protocol was followed in all cases. There was no case of neurological deterioration in the case series.

Conclusion: Attention to radiographic landmarks, specifically not crossing the ap projection of the medial pedicle cortex prior to reaching the posterior vertebral wall in the lateral projection, allows neurologically safe performance of fluoroscopy guided percutaneous procedures of the thoracic spine. This simple protocol is particularly useful when access to CT is limited.

Background: It is often useful to gauge the flexibility of curves while assessing patients with scoliosis. Our aim was to discover if there were any reliable x-ray predictors of stiffness.

Methods: Previously the flexibility index has been shown to be an accurate measure of curve stiffness. A random selection of fifty x-ray sets was analyzed for parameters that might predict flexibility. These were then compared to the flexibility index generated from bending films. We recorded age; Cobb angle; bending film Cobb angle; Perdriolle rotation assessment; percentage wedging of the apical vertebrae and translation of the apex of the curve from a central sacral/cervical line. We then calculated the flexibility index. All measurements were taken from immediately pre operative standing AP x-rays and fulcrum bending films (1). The group was then assessed as a whole and subgroups were analyzed. Large curves (> 50 degrees) were compared to small (< 50 degrees) curves and thoracic curves were compared with thoracolumbar curves. Correlation between the flexibility index and the other parameters was then studied. We used Pearson correlation coefficient for parametric data and the Spearman rank correlation coefficient to study the non parametric data. P values were then assigned using a statistics software package.

Results: Age and apical translation were not related to curve stiffness. The Cobb angle was the only strong predictor of flexibility (p-0.002) looking at all curve types together. The Cobb angle was, however, more useful in larger curves and did not reach statistical significance in the small curve subgroup. In small curves Perdriolle rotational assessment was a more useful measurement (p-0.02). In the thoracic curve subgroup the percentage wedge of the apical vertebrae was a strong predictor (p-0.007).

Conclusion: Our sample had a strong bias toward an adolescent age group (5–61) mean age 17 and probably did not have enough of a spread to demonstrate the previous relationship between age and stiffness (2). The study re enforces the value of the Cobb angle in predicting curve stiffness but suggests caution using it in smaller curves. It also suggests a role for Perdriolle measurement in small curves and percentage apical wedge in thoracic curves.