John Devine

STUDY DESIGN: Systematic review. OBJECTIVE: To document the incidence and consequences of vascular injury in lumbosacral surgery, to identify factors contributing to this injury, and to determine whether there are any effective measures to decrease the occurrence of vascular injury. SUMMARY OF BACKGROUND DATA: Anterior lumbosacral surgery encompasses all aspects of spine surgery, including trauma, deformity, and degenerative conditions. Although it has theoretical advantages, anterior lumbosacral surgery carries with it certain definite risks, one of the most critical of which is injury to the surrounding vasculature. It is important for both the patient and the surgeon to understand the risks, patterns, and outcomes of injury to the vascular structures associated with this surgery. METHODS: A systematic review of the English-language literature was undertaken for articles published between January 1993 and December 2008. Electronic databases and reference lists of key articles were searched to identify published studies examining vascular injury in anterior lumbosacral surgery. Vascular injury was defined as any case in which a suture was required to control bleeding. Two independent reviewers assessed the strength of literature using the Grading of Recommendations Assessment, Development, and Evaluation criteria assessing quality, quantity, and consistency of results. Disagreements were resolved by consensus. RESULTS: A total of 88 articles were initially screened, and 40 ultimately met the predetermined inclusion criteria. Vascular injuries after anterior lumbosacral surgeries were rare (<5%). Venous laceration was more common than arterial laceration, and most venous injuries occurred during retraction of the great vessels. In most cases, the overall clinical outcome after vascular injury was not adversely affected. L4-L5 exposure was associated with increased vascular injury in some studies but not others. Vascular injury occurred more frequently in laparoscopic compared with open anterior lumbar interbody fusion. CONCLUSION: Vascular injury in anterior lumbosacral surgery remains low, with reports being <5%. The consequences of injury seem rare, but may include thrombosis, pulmonary embolism, and prolonged hospitalization. Exposure and surgery at L4-L5 may be associated with a higher risk of injury than that at L5-S1, though the data are not consistent.

OBJECT: The authors evaluated the effects of pilot hole preparation technique on insertional torque and axial pullout resistance in osteoporotic thoracic and lumbar vertebrae. METHODS: Using a probe technique and fluoroscopy, 102 pedicle screws were placed in 51 dual-energy x-ray absorptiometry-proven osteoporotic thoracic and lumbar levels. Screws were inserted using the same-size tapping, one-size-under tapping, or no-tapping technique. Insertional torque and axial pullout resistance were measured. Analysis of variance, Fisher exact test, and regression analysis were performed. Same-size tapping decreased pullout resistance in the lumbar spine. There was no effect on pullout resistance in the thoracic spine. Pullout resistance values were lower for all insertion techniques in the upper thoracic spine. Insertional torque and bone mineral density correlated with pullout resistance in the thoracic and lumbar spine. CONCLUSIONS: Tapping decreased pedicle screw pullout resistance in the osteoporotic human lumbar spine, although it did not affect pullout strength in the thoracic spine. Tapping decreased insertional torque in upper thoracic levels. Surgeons should optimize overall construct rigidity when placing thoracic pedicle screws in patients with spinal segment osteoporosis.

OBJECTIVE: The aim of this study was to examine the Mangled Extremity Severity Score (MESS) in a combat setting. METHODS: Data on extremity injuries were collected from a forward surgical team. MESS and Revised Trauma Score values were retrospectively calculated for each patient. Student's t test was used to compare amputated and salvaged limbs. RESULTS: A total of 60 extremities was identified in 49 patients. There were 10 major vascular repairs (20%). MESS values differed significantly for the eight amputations performed (mean MESS, 7.87 +/- 1.91) and 50 salvaged extremities (mean MESS, 2.44 +/-_ 0.438; p = 0.001). CONCLUSIONS: A MESS of >7 correlated with amputation, thus validating the MESS in a combat setting. A young average patient age and high-energy injury mechanism on the battlefield leave ischemic time and shock as the most important factors in dictating whether a MESS is >7 or <7.

Patients with "idiopathic-like" spinal deformities associated with syringomyelia were retrospectively reviewed. Ten patients had surgical stabilization of their curvatures with at least a 2-year follow-up, and an additional five patients were evaluated for deformity pattern with <2 years of follow-up. Paralytic curve patterns, scoliosis associated with spina bifida, congenital scoliosis, or other associated syndromes were discarded. All 10 patients with surgery who were followed for an average of 46 months lost 10 degrees correction above, through, or below the instrumented segments. A total of 50% lost correction through the instrumented segments. Anterior fusion stabilized the instrumented portion of the spine better than posterior instrumentation alone. Eighty percent of the 15 patients had thoracic kyphosis >40 degrees. Only one patient was lordoscoliotic. Syringomyelia deformities tend to be kyphoscoliotic in 80% of cases and behave more like paralytic curvatures postoperatively. MRI is recommended for apparent idiopathic scoliotic curvatures that are kyphoscoliotic and not lordoscoliotic.