The effects of dexamethasone on bone fusion in an experimental model of posterolateral lumbar spinal arthrodesis

2001 ◽  
Vol 94 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Paul D. Sawin ◽  
Curtis A. Dickman ◽  
Neil R. Crawford ◽  
M. Stephen Melton ◽  
William D. Bichard ◽  
...  

Object. The use of corticosteroid agents during the healing phase after spinal arthrodesis remains controversial. Although anecdotal opinion suggests that corticosteroids may inhibit bone fusion, such an effect has not been substantiated in clinical trials or laboratory investigations. This study was undertaken to delineate the effect of exogenous corticosteroid administration on bone graft incorporation in an experimental model of posterolateral lumbar fusion. Methods. An established, well-validated model of lumbar intertransverse process spinal fusion in the rabbit was used. Twenty-four adult New Zealand white rabbits underwent L5–6 bilateral posterolateral spinal fusion in which autogenous iliac crest bone graft was used. After surgery, the animals were randomized into two treatment groups: a control group (12 rabbits) that received intramuscular injections of normal saline twice daily and a dexamethasone group (12 rabbits) that received intramuscular dexamethasone (0.05 mg/kg) twice daily. After 42 days, the animals were killed and the integrity of the spinal fusions was assessed by radiography, manual palpation, and biomechanical testing. In seven (58%) of the 12 control rabbits, solid posterolateral fusion was achieved. In no dexamethasone-treated rabbits was successful fusion achieved (p = 0.003). Tensile strength and stiffness of excised spinal segments were significantly lower in dexamethasone-treated animals than in control animals (tensile strength 91.4 ± 30.6 N and 145.3 ± 48.2, respectively, p = 0.004; stiffness 31.4 ± 11.6 and 45.0 ± 15.2 N/mm, respectively, p = 0.02). Conclusions. The corticosteroid agent dexamethasone inhibited bone graft incorporation in a rabbit model of single-level posterolateral lumbar spinal fusion, inducing a significantly higher rate of nonunion, compared with that in saline-treated control animals.

2002 ◽  
Vol 97 (4) ◽  
pp. 460-463 ◽  
Author(s):  
Ashley R. Poynton ◽  
Fengyu Zheng ◽  
Emre Tomin ◽  
Joseph M. Lane ◽  
G. Bryan Cornwall

Object. The authors studied the effect of a resorbable graft containment device in a rabbit posterolateral lumbar spinal fusion model. Methods. Twenty rabbits were divided into four groups: autologous bone graft (ABG), ABG with the MacroPore containment device (ABG + MP), demineralized bone matrix (DBM), and DBM with the containment device (DBM + MP). Fusion mass was assessed at 6 weeks with high-resolution radiography and volumetric computerized tomography. The graft containment device was associated with alteration of the fusion mass structure and significant enhancement of fusion mass volume (ABG versus ABG + MP, p = 0.027; DBM versus DBM + MP, p = 0.043). Conclusions. A bioabsorbable protective graft containment device successfully enhanced posterolateral spinal fusion mass volume.


1996 ◽  
Vol 84 (2) ◽  
pp. 166-173 ◽  
Author(s):  
Charles G. diPierro ◽  
Gregory A. Helm ◽  
Christopher I. Shaffrey ◽  
James B. Chadduck ◽  
Scott L. Henson ◽  
...  

✓ A new surgical technique for the treatment of lumbar spinal stenosis features extensive unilateral decompression with undercutting of the spinous process and, to preserve stability, uses contralateral autologous bone fusion of the spinous processes, laminae, and facets. The operation was performed in 29 patients over a 19-month period ending in December of 1991. All individuals had been unresponsive to conservative treatment and presented with low-back pain in addition to signs and symptoms consistent with neurogenic claudication or radiculopathy. Nine had undergone previous lumbar decompressive surgery. The minimum and mean postoperative follow-up times were 2 and 2 1/2 years, respectively. The mean patient age was 64 years; only two patients were younger than 50 years of age. Of the patients with neurogenic claudication, 69% reported complete pain relief at follow-up review. Of those with radicular symptoms, 41% had complete relief and 23% had mild residual pain that was rated 3 or less on a pain—functionality scale of 0 to 10. For the entire sample, this surgery decreased pain from 9.2 to 3.3 (p < 0.0001) on the scale. Sixty-nine percent of patients were satisfied with surgery. Low-back pain was significantly relieved in 62% of all patients (p < 0.0001). Low-back pain relief correlated negatively with number of levels decompressed (p < 0.05). To assess fusion, follow-up flexion/extension radiographs were obtained, and no motion was detected at the surgically treated levels in any patient. The results suggest that this decompression procedure safely and successfully treats not only the radicular symptoms caused by lateral stenosis but also the neurogenic claudication symptoms associated with central stenosis. In addition, the procedure, by using contralateral autologous bone fusion along the laminae and spinous processes, can preserve stability without instrumentation.


2004 ◽  
Vol 4 (6) ◽  
pp. 669-674 ◽  
Author(s):  
P. Justin Tortolani ◽  
Andrew E. Park ◽  
John Louis-Ugbo ◽  
Emad S. Attallah-Wasef ◽  
Chaiwat Kraiwattanapong ◽  
...  

1978 ◽  
Vol 48 (6) ◽  
pp. 970-974 ◽  
Author(s):  
A. Everette James ◽  
William J. Flor ◽  
Gary R. Novak ◽  
Ernst-Peter Strecker ◽  
Barry Burns

✓ The central canal of the spinal cord has been proposed as a significant compensatory alternative pathway of cerebrospinal fluid (CSF) flow in hydrocephalus. Ten dogs were made hydrocephalic by a relatively atraumatic experimental model that simulates the human circumstance of chronic communicating hydrocephalus. The central canal was studied by histopathology and compared with 10 normal control dogs. In both groups the central canal of the spinal cord was normal in size, configuration, and histological appearance. In this experimental model dilatation of the canal and increased movement of CSF does not appear to be a compensatory alternative pathway.


1992 ◽  
Vol 76 (6) ◽  
pp. 1012-1016 ◽  
Author(s):  
Robert A. Feldman ◽  
Richard C. Karl

✓ Three patients who developed Ogilvie's syndrome following lumbar spinal surgery are described. Ogilvie's syndrome, also known as pseudo-obstruction of the colon, is characterized by massive cecal distention without mechanical obstruction. If this condition is not recognized and not promptly treated, it may be complicated by cecal perforation, a life-threatening hazard. The etiology, diagnosis, management, and potential relationship between lumbar spinal surgery and Ogilvie's syndrome are discussed.


2005 ◽  
Vol 3 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Amir Hasharoni ◽  
Yoram Zilberman ◽  
Gadi Turgeman ◽  
Gregory A. Helm ◽  
Meir Liebergall ◽  
...  

Object. The authors hypothesized that spinal fusion can be achieved and monitored by using cell-mediated gene therapy. Mesenchymal stem cells (MSCs) genetically engineered to express recombinant human bone morphogenetic protein—2 (rhBMP-2) conditionally, were implanted into the paraspinal muscles of mice to establish spinal fusion. The goal was to demonstrate an MSC-based gene therapy platform in which controlled gene expression is used to obtain spinal fusion in a murine model. Methods. Mesenchymal stem cells expressing the rhBMP-2 gene were injected into the paravertebral muscle in mice. Bone formation in the paraspinal region was longitudinally followed by performing micro—computerized tomography scanning, histological studies, and an analysis of osteocalcin expression to demonstrate the presence of engrafted engineered MSCs. The minimal period of rhBMP-2 expression by the engineered MSCs required to induce fusion was determined. The results of this study demonstrate that genetically engineered MSCs induce bone formation in areas adjacent to and touching the posterior elements of the spine. This newly formed bone fuses the spine, as demonstrated by radiological and histological studies. The authors demonstrate that injected cells induce active osteogenesis at the site of implantation for up to 4 weeks postinjection. They found that a 7-day induction of rhBMP-2 expression in genetically engineered MSCs was sufficient to form new bone tissue, although the quantity of this bone increased as longer expression periods were implemented. Conclusions. After their injection genetically engineered MSCs can efficiently form new bone in the paraspinal muscle of the mouse to obtain spinal fusion. The extent and quantity of this newly formed bone can be monitored by controlling the duration of rhBMP-2 gene expression.


1994 ◽  
Vol 81 (5) ◽  
pp. 699-706 ◽  
Author(s):  
Gerald F. Tuite ◽  
Joseph D. Stern ◽  
Stephen E. Doran ◽  
Stephen M. Papadopoulos ◽  
John E. McGillicuddy ◽  
...  

✓ All patients who underwent decompressive lumbar laminectomy in the Washtenaw County, Michigan metropolitan area during a 7-year period were studied for the purpose of defining long-term outcome, clinical correlations, and the need for subsequent fusion. Outcome was determined by questionnaire and physical examination from a cohort of 119 patients with an average follow-up evaluation interval of 4.6 years. Patients graded their outcome as much improved (37%), somewhat improved (29%), unchanged (17%), somewhat worse (5%), and much worse (12%) compared to their condition before surgery. Poor outcome correlated with the need for additional surgery, but there were few additional significant correlations. No patient had a lumbar fusion during the study interval. The outcome after laminectomy was found to be less favorable than previously reported, based on a patient questionnaire administered to an unbiased patient population. Further randomized, controlled trials are therefore necessary to determine the efficacy of lumbar fusion as an adjunct to decompressive lumbar laminectomy.


1977 ◽  
Vol 46 (6) ◽  
pp. 825-829 ◽  
Author(s):  
Henry D. Messer ◽  
Gregory S. Lenchner ◽  
John C. M. Brust ◽  
Stanley Resor

✓ The authors report the case of a patient with spinal abscess in whom operation was withheld because of severe concomitant medical problems. Conservative management resulted in apparent cure.


Sign in / Sign up

Export Citation Format

Share Document