The effect of patient positioning on the relative position of the aorta to the thoracic spine

PURPOSE

Detailed knowledge of the anatomy of the thoracic aorta is crucial for thoracolumbar spinal surgery. The purpose of the present study is to describe the relative displacement of the aorta to the spine in supine, prone and prone position with padding. Improved understanding of the magnitude and direction of this often-overlooked change could benefit preoperative planning and decision-making.

METHODS

A total of 200 patients underwent CT scan of the thoracic spine in the standard supine, prone and prone position with padding. Axial CT images from T4 to T12, in all three different positions, were selected and the following parameters were measured: (a) distance B connecting left pedicle entry point to the edge of the aortic wall and (b) projections Bx and By, representing the minimum AP depth and horizontal displacement of the aortic wall relative to the left pedicle entry point O.

RESULTS

There was a significant difference in the distance B between the three different positions across all thoracic vertebrae levels, confirming that positioning significantly affects aorta's relative position. Moreover, in the prone position with padding at the level of T6, the aortic wall lies at a minimum distance from the left pedicular axis and thus from the typical screw trajectory.

CONCLUSION

The results of this study show that prone positioning for posterior thoracolumbar approach affects significantly the anatomic relationship of the aorta to the spine. Surgeons should be aware that standard supine CT evaluation represents a static technique, which can differ considerably from surgical reality. These slides can be retrieved from electronic supplementary material.

Fracture non-union: Can biomarkers predict outcome?

Delayed bone healing and non-union occurs in approximately 10-15% of long bone fractures. Both pathologies may result in prolonged period of pain, disability and repetitive operative interventions. Despite intense investigations and progress done in understanding the pathophysiologic processes governing bone healing, the diagnostic tools have not been altered. The clinical findings and radiographic features remain the two important landmarks of diagnosing non-union and even when the diagnosis is established there is debate on the ideal timing and mode of intervention. Emerging evidence suggest that there are certain molecules and genes that can serve as predictors of potentially unsuccessful fracture union. This article summarises the current evidence on the available 'bio-markers'to predict fracture non-union.

Efficacy of prolonged antimicrobial chemotherapy for brucellar spondylodiscitis

The standard treatment of brucellar spondylitis with a combination of two antibiotics for 6-12 weeks is associated with high rates of treatment failure and relapse. The present study aimed to assess the safety and efficacy of a treatment strategy based on the prolonged administration of a triple combination of suitable antibiotics. Eighteen patients with brucellar spondylitis were treated with a combination of at least three suitable antibiotics (doxycycline, rifampin, plus intramuscular streptomycin or cotrimoxazole or ciprofloxacin) until the completion of at least 6 months of treatment, when clinical, radiological and serology re-evaluation was performed. If necessary, the treatment was continued with additional 6-month cycles, until resolution or significant improvement of clinical and radiological findings, or for a maximum of 18 months. At presentation, the median age was 66 years (range, 42-85 years) with male predominance. The median duration of therapy was 48 weeks (range 24-72 weeks). Treatment was discontinued early because of side-effects in only one patient. Surgical intervention was required for three patients. At the end of treatment all patients had a complete response. After completion of treatment, all patients were followed up with regular visits. During the follow-up period (duration 1-96 months, median 36.5 months), no relapses were observed. In conclusion, prolonged (at least 6 months) administration of a triple combination of suitable antibiotics appears to be an effective treatment for brucellar spondylitis.

Renal artery stenting for renal insufficiency in solitary kidney in 26 patients

OBJECTIVE

to present our experience with stent placement in renal arteries in solitary kidneys for treating renal insufficiency.

DESIGN

retrospective analysis.

MATERIALS

in 26 patients with solitary kidney (17 men, 9 women, mean age: 63 years), presented with renal insufficiency (se-creat >0.144 mmol/l), stent was placed in a stenosed renal artery. We analysed the clinical outcome, based on the level of creatinine at 3 months following the procedure. Clinical benefit was considered when there was a decrease compared to the baseline creatinine by >20% or a stabilisation of the creatinine value (+/-20% of the baseline).

RESULTS

in 16 of the 26 patients (62%), clinical benefit was achieved. However, 38% of the study population, renal function continued to deteriorate. Baseline creatinine value was the single best predictor for clinical benefit achievement (odds ratio: 13; 95% confidence intervals: 1.6-107, p=0.01).

CONCLUSION

renal stenting results in improvement or stabilisation of renal function in the majority of the patients with solitary kidneys and renal artery stenosis, presenting with renal insufficiency. Because best outcome was observed mainly in those patients with not progressed renal insufficiency, intervention should be focused on that group.