Do position and size matter? An analysis of cage and placement variables for optimum lordosis in PLIF reconstruction.

Purpose: To examine monosegmental lordosis after posterior lumbar interbody fusion (PLIF) surgery and relate lordosis to cage size, shape, and placement.

Methods: Eighty-three consecutive patients underwent single-level PLIF with paired identical lordotic cages involving a wide decompression and bilateral facetectomies. Cage parameters relating to size (height, lordosis, and length) and placement (expressed as a ratio relative to the length of the inferior vertebral endplate) were recorded.

Development and validation of a subject-specific finite element model of the functional spinal unit to predict vertebral strength.

Finite element models of an isolated vertebral body cannot accurately predict compressive strength of the spinal column because, in life, compressive load is variably distributed across the vertebral body and neural arch. The purpose of this study was to develop and validate a patient-specific finite element model of a functional spinal unit, and then use the model to predict vertebral strength from medical images. A total of 16 cadaveric functional spinal units were scanned and then tested mechanically in bending and compression to generate a vertebral wedge fracture.

Universal No-fault Compensation is Associated With Improved Return to Work Rates in Spine Fusion.

Study Design: Retrospective cohort study and systematic literature review.

Objective: To examine the influence of "universal no-fault compensation" upon return-to-work rates in patients undergoing lumbar spinal fusion, and then to make comparison with workers' compensation (WC) and non-workers' compensation (non-WC) claimants.

Summary Of Background Data: Compensation has an adverse influence upon outcomes and return to work in lumbar spinal fusion.

Pathogenesis of Vertebral Anterior Wedge Deformity: A 2-Stage Process?

Study Design: Biomechanical and radiographical study on cadaveric spines.

Objective: To explain the pathogenesis of vertebral "anterior wedge" deformity, which causes senile kyphosis.

Summary Of Background Data: This deformity arises with minimal trauma and is difficult to reproduce in cadaveric spines.

Is kyphoplasty better than vertebroplasty at restoring form and function after severe vertebral wedge fractures?

Background Context: The vertebral augmentation procedures, vertebroplasty and kyphoplasty, can relieve pain and facilitate mobilization of patients with osteoporotic vertebral fractures. Kyphoplasty also aims to restore vertebral body height before cement injection and so may be advantageous for more severe fractures.

Purpose: The purpose of this study was to compare the ability of vertebroplasty and kyphoplasty to restore vertebral height, shape, and mechanical function after severe vertebral wedge fractures.

Intervertebral disc decompression following endplate damage: implications for disc degeneration depend on spinal level and age.

Study Design: Mechanical and morphological studies on cadaveric spines.

Objective: To explain how spinal level and age influence disc degeneration arising from endplate fracture.

Summary Of Background Data: Disc degeneration can be initiated by damage to a vertebral body endplate, but it is unclear why endplate lesions, and patterns of disc degeneration, vary so much with spinal level and age.

The risks of overly effective postoperative epidural analgesia.

Continuous epidural analgesia is frequently used to provide supplemental postoperative pain control. Epidural analgesia has the potential to mask the early symptoms that signal impending complications after even routine surgical procedures. We report a case of sciatic nerve palsy following epidural anesthesia after an uncomplicated leg length correction.