Assessment of Paraspinal Muscle Cross-sectional Area After Lumbar Decompression: Minimally Invasive Versus Open Approaches.

Study Design: A retrospective, blinded analysis of imaging studies.

Summary Of Background Data: To evaluate changes in paraspinal muscle cross-sectional area (CSA) after surgical treatment for lumbar stenosis and to compare these changes between minimally invasive and standard open approaches. The open approach to lumbar stenosis is effective, but it involves retraction and resection of muscle from the spinous process, which can result in ischemia and denervation of paraspinal musculature and may lead to muscle atrophy and pain.

The microendoscopic decompression of lumbar stenosis: a review of the current literature and clinical results.

Lumbar stenosis is a well-defined pathologic condition with excellent surgical outcomes. Empiric evidence as well as randomized, prospective trials has demonstrated the superior efficacy of surgery compared to medical management for lumbar stenosis. Traditionally, lumbar stenosis is decompressed with open laminectomies.

Evaluation of change in muscle activity as a result of posterior lumbar spine surgery using a dynamic modeling system.

Study Design: A commercially available musculoskeletal model of the lumbar spine was modified to study the change in muscle activation as a result of posterior lumbar surgery at the L3-L4 and L4-L5 segments.

Objective: To evaluate how graded resection of the lumbar paraspinal muscles as a result of posterior lumbar surgery affects muscle activity for a variety of movement tasks.

Summary Of Background Data: Several in vivo studies compare the change in functional outcome of the paraspinal muscles following surgery.

A biomechanical evaluation of graded posterior element removal for treatment of lumbar stenosis: comparison of a minimally invasive approach with two standard laminectomy techniques.

Study Design: A validated finite element model of the intact lumbar spine (L1-S1) was modified to study the biomechanical changes as a result of surgical alteration for treatment of stenosis at L3-L4 and L4-L5 using 2 established techniques and 1 new minimally invasive technique.

Objective: To investigate the impact of graded posterior element removal associated with new surgical techniques on postoperative segmental motion and loading in the annulus.

Summary Of Background Data: Several studies have shown that laminectomy increases and produces segmental instability unless fusion is performed.

Biomechanical comparison of traditional and minimally invasive intradural tumor exposures using finite element analysis.

Background: Minimally invasive approaches to intradural pathology have evolved in part in an effort to reduce approach related destabilization of the spine. No biomechanical data exist however evaluating the effects of traditional and minimally invasive exposures.

Methods: A finite element model of the lumbar spine was generated, and a simulated open laminectomy and a modified hemilaminectomy at L4 were performed.