Journal of spinal disorders
-
Previous imaging studies have shown little difference in the degree of disc degeneration between L4-L5 and L5-S1. We hypothesized that because the morphology of the iliolumbar ligament affects the stability of the lumbosacral junction, then it could determine the lower lumbar disc degeneration. ⋯ The iliolumbar ligament was shorter in group A than in group B or C, and was oriented significantly more posteriorly in group A than in groups B or C. The morphology of the iliolumbar ligament, especially its length and direction, can be a factor influencing the development of disc degeneration at L4-L5 and L5-S1.
-
One hundred fourteen patients (64 men, 50 women) with prior lumbar disc surgery underwent a reexploration for intractable back and/or leg pain. The finding in revision surgery included disc herniation in 89 cases (78%), epidural fibrosis in 14 cases (12.2%), adhesive arachnoiditis in 4 cases (3.5%), isolated lateral spinal stenosis in 3 cases (2.6%), and iatrogenic instability in 4 cases (3.5%). Review of operative reports of patients who underwent a first operation in our institute revealed that seven cases (12.5%) had a second laminotomy without a discectomy in addition to the previous laminotomy and discectomy performed in the same session. ⋯ It is concluded that recurrent disc disease is the most important cause of reexploration. This fact dictates a careful preoperative workup and discectomy in the first intervention. The likelihood of occurrence of disc herniation in the negative laminotomy level (i.e., laminotomy without discectomy procedure) also requires a careful preoperative radiologic workup before lumbar disc surgery.
-
Changes in spinal column height have been observed in response to different stress environments including vibration, gravity inversion, space flight, traction, and increased loading. Alterations in spinal height are dependent on body forces, externally applied forces, and properties of the discs and are considered relevant to understanding the normal and pathologic behavior of the spine. This study presents a sagittal plane, viscoelastic model of the spine that quantified the height change behavior of the human spine subjected to axial compressive forces similar to those experienced during quiet standing. ⋯ For degenerated discs, the model predicted a similar instantaneous height loss but a 28% greater height loss after 8 h. These results suggest that the majority of spinal height loss is a direct result of intervertebral disc deformation and about two thirds of the total height loss occurs immediately on axial loading of the spine. Based on these findings, diurnal height changes in the spine are predicted to be much greater than previously believed.
-
Confusion surrounding low back pain syndrome may partially be resolved in a select small group of patients by instituting a provocative intraarticular injection of a combination of a local anesthetic and a steroid. This approach enables one to determine whether the sacroiliac joint (SIJ) is the site of origin of the low back pain syndrome. We carried out a study of 71 computed tomography (CT)-guided injections in 58 patients with noninflammatory etiology. ⋯ The effect wore off in 2-14 days in 90% of the patients. We conclude that CT guidance is the best method of precise needle placement, and thus CT-guided anesthetic injection is the most specific confirmatory test for diagnosing the SIJ arthritis. In addition, in noninflammatory conditions, the role of intraarticular injection is primarily for diagnostic purposes and it has little or no therapeutic benefit.
-
Anatomical and biomechanical data have suggested that pedicle screw fixation at the sacrum is optimum in the anteromedial direction into the S1 vertebral body, yet the possibility of posterior iliac crest interference with this screw pathway has been considered but not defined. This study aimed to determine if the anteromedial direction of screw placement into the vertebral body is possible in all cases at S1 and to assess the limiting effect of the posterior iliac crest. Computed tomography scans of the upper sacrum at the S1 pedicle parallel to the sacral endplate were examined in 100 patients. ⋯ On only three occasions (1.5%) was the ideal screw corridor not possible because of posterior iliac crest overlap. In each case, this occurred only unilaterally and when the widest of the screw corridors (12.5 mm) was used. Both the distance between the posterior iliac crests and the space available for optimum screw placement are greater in females than males.