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Management of Back Pain in Patients with Previous Back Surgery

The 80,000 or so patients a year who continue to have chronic, disabling back pain after one or more spinal surgeries are said to have failed back surgery syndrome. There are no controlled studies to guide physicians in the management of these patients. Six anatomical abnormalities of the spine most commonly result in back surgery, and 7 undesirable outcomes lead to failed back surgery syndrome. On the basis of 5 large retrospective studies and our clinical experience, we suggest a systematic approach to these patients. This approach is focused on determination of the specific anatomical abnormality responsible for ongoing symptoms, an abnormality that may or may not be related to the initial abnormality for which surgery was performed. One or more of 5 nonsurgical treatment options may be useful to prevent the need for further surgery, as each subsequent surgery has a lower likelihood of success.

Characterization of a Femoral Segmental Nonunion Model in Laboratory Rats: Report of a Novel Surgical Technique

The literature is lacking conclusive results regarding the exact mechanism of maximizing the fracture healing stages with minimal traumatic side effects. This observation mandates the development of a novel surgical procedure using small animals as a model to study fracture healing in the presence of osteoinductive agents. Previously, stabilization of osteotomies in small animal models has mainly been accomplished using Kirschner wires, but the rats tremendous ability to heal an osteotomy stabilized by this method has masked the effects of osteoinductive agents. Thus, this study proposes using a modified 20-hole, 1.5-mm stainless-steel plate to stabilize a 5-mm segmental defect. Thirty of 32 adult male rats were fully weight-bearing within 2 days and were followed over a 15-week period. Two animals showed evidence of fixation failure due to technical error, and the animals were humanely sacrificed. At the end of the study, the fractures were stable with significantly less bone formation evident when compared to controls (p <. 001). Therefore, this technique can effectively be used to evaluate compounds that will enhance bone formation and allows for stable fixation of the control with minimal callus formation or bony ingrowth. The goal of this article is to allow other investigators to reproduce this technique as well as outline the advantages and disadvantages of this novel plating technique versus the former Kirschner wire technique for the study of osteoinductive agents using small animals as a model.

Dynamic anterior cervical plating for multi-level spondylosis: Does it help?

Study design: Randomized controlled trial. Objective: To compare fusion rates, time to fusion, complication rates and subsidence between 1) a static, 2) a dynamic angulation, and 3) a dynamic translation plate in anterior cervical discectomy and fusion for symptomatic degenerative cervical disease. Methods: Thirty-six patients with two level, symptomatic cervical degenerative changes requiring surgery were randomized in a blinded fashion to receive a statically locked plate, Cervical Spine Locking Plate (CSLP) (Synthes, Paoli, PN, USA), an Atlantis Vision® Anterior Cervical Plate System (Medtronic, Memphis, TN, USA) which allows angular dynamization, or a Premier® Anterior Cervical Plate System (Medtronic) which allows translational dynamization. Structured data collection and measurement protocols were used. Intervertebral composite allograft cages were used in all groups. Identical external immobilization and antiinflammatory medication protocols were followed. X-rays were obtained at preset time points postoperatively. Assessment of the primary outcomes was blinded. Rate of and time to fusion, graft/instrumentation complications, subsidence, and reoperation for adjacent level disease were measured. Paired t-test and three-way Analysis of Variance test (ANOVA) were used to assess statistical differences between groups. Results: The three groups were similar demographically. Fusion rates in the CSLP, Atlantis and Premier plate groups were 100%, 91%, and 92% respectively. Mean time to fusion was 6.1, 8.3 and 6.3 months respectively but differences were not statistically significant. Mean subsidence in the groups was 1.9, 1.6, and 2.6 mm respectively. Subsidence was found even for the static (CSLP) plate, but no statistically significant differences were found. Conclusions: We found no clinical advantage of dynamic plates over static plates with regards to fusion rates, time to fusion, subsidence, complications, or adjacent-level surgery. Static plating allows for subsidence at similar levels to dynamic plating. Methods evaluation and class of evidence (CoE) Methodological principle: Study design: RCT • Cohort Case control Case series Concealed allocation (RCT) Intent to treat (RCT) • Blinded/independent evaluation of primary outcome • Complete follow-up of ≥85%* • Adequate sample size Control for confounding† • Evidence class: II *Reliable data are data such as mortality or reoperation. †Authors must provide a description of robust baseline characteristics, and control for those that are unequally distributed between treatment groups. The definiton of the different classes of evidence is available on page 83.

A preliminary report on the effects of sustained administration of corticosteroid on traumatized disc using the adult male rat model.

Study Design A novel degenerative disc disease model and sustained delivery method for corticosteroid in male Sprague-Dawley albino rats. Objectives To develop a model of degenerative disc disease and to determine the effect of continuous sustained release of corticosteroid on the process of degeneration within the traumatized disc. Summary of Background Data The current modalities of treating symptomatic degenerative disc disease are either conservative or surgical. However, there is no cure for the degenerative process and prevention, therefore, is the ideal treatment. An understanding of the mechanisms involved in disc degeneration is crucial to develop new methods for prevention and treatment, including appropriate delivery systems and dosages of repair factors. Methods The L5-L6 intervertebral disc was pierced with a 23-gauge needle in 18 rats. The animals received either sham or corticosterone-charged tricalcium phosphate ceramic capsules. The rats were euthanized at 4 weeks. Chondrocytes in the transition zone areas were counted and compared statistically. Results The surgical technique induced degeneration of the nucleus without evidence of inflammation at adjacent levels when compared with nontraumatized controls. The number of chondrocytes per area was significantly less in the sham group than in the control group. Corticosteroid treatment showed chondrocyte numbers similar to control in 4 of 5 different views of the disc. The anterior region of the disc had 50% less chondrocytes per area than the control; however, the chondrocyte numbers were 50% greater than in the same site from discs of sham animals. Conlcusions The results show the development of a degenerative disc animal model that can be used to test the effects of growth enhancing factors in disc repair. Administration of continuous sustained release of corticosterone can slow the process of degeneration within the traumatized disc in the rat model.