Architectural Changes in the Medial Gastrocnemius on Sonography after Nerve Ablation in Healthy Adults

Architectural changes in healthy muscle after denervation have not yet been reported. This study aimed to investigate architectural changes in the medial head of the gastrocnemius muscle (GCM) after aesthetic tibial nerve ablation in healthy adults using ultrasonography (US). The effects of tibial nerve ablation were verified by visual observation and surface electromyography analysis. US images of medial GCMs were taken by one trained physician using B-mode and real-time US with a linear-array probe before nerve ablation, at 1 week after nerve ablation and at 3 months after nerve ablation in an anatomic standing position with the feet about shoulder-width apart in 19 healthy adults (17 females and 2 males). Muscle thickness was significantly reduced on the left side at 1 week and 3 months after the procedure and on the right side at 3 months after the procedure (p<0.050). Although fascicle length was not significantly changed, pennation angle was significantly reduced on both sides at 3 months after the procedure (p<0.050). Muscle thickness and pennation angle of the muscle fascicle were significantly reduced, although fascicle length was not significantly changed, after tibial nerve ablation in the medial GCM of healthy adults.

Epidural Neuroplasty with Single Bolus Injection versus Continuous Infusion of Steroid in Patients with Spinal Stenosis

OBJECTIVE: To compare the efficacy of epidural adhesiolysis with a single bolus steroid injection (EAS) and continuous steroid infusion (EAC).METHOD: Thirty-one patients were allocated to the EAS group (10 patients) and EAC group (21 patients). EAS received single bolus of 10 mg of dexamethasone. EAC received a total of 96 mL dexamethasone solution (20.0 mg of dexamethasone) for 48 hrs. Oswestry Disability Index (ODI) was evaluated before, one month after the procedure. Three months after the procedure, the Patient’s Global Impression of Change (PGIC) was evaluated.RESULTS: Pre-treatment ODI was 38.3 ± 3.1 in EAS and 46.40 ± 4.0 in EAC. One month later, ODI was decreased to 35.60 ± 3.33, 43.08 ± 6.96 in each group (p=0.174). Three months later, 2 patients in the EAS (20.0%) and 8 patients in EAC (38.1%) showed ‘much improvement’ in PGIC, 5 patients in EAS (50.0%) and 6 patients in EAC (38.1%) showed ‘slight improvement’, 3 patients in EAS (30.0%) and 7 patients in EAC (33.3%) showed ‘no improvement’ (χ2=1.588, p=0.510).CONCLUSION: Epidural adhesiolysis with continuous infusion did not show any superiority than single bolus injection.

In Vitro Evaluation of Fusiform-Shaped Stents for Wide-Neck Intracranial Aneurysm Treatment / 신경중재치료의학

PURPOSE: Wide-neck aneurysms (WNAs) associated with a dilated parent artery (PA) are not uncommon morphological abnormalities and usually cause inappropriate wall apposition and incomplete neck coverage of a tubular stent in stent-assisted coiling of aneurysms. We aimed to introduce a fusiform-shaped stent (FSS) and test its effectiveness in treating intracranial WNAs associated with a dilated PA using a three-dimensional (3D) model. MATERIALS AND METHODS: Two FSS types were designed with the middle one-third segment dilated by 10% (FSS10) and 20% (FSS20) and were compared with the tubular-shaped stent (TSS). A patient-specific 3D WNA model was prototyped and produced, and in vitro stent placement was performed. Angiographic images of the three stent types were analyzed and compared using predetermined parameters. RESULTS: The stent lumens were significantly larger in FSS10 and FSS20 than in TSS in the middle segments (P=0.046), particularly FSS20 (P=0.018). The non-covered area at the ostium tended to be smaller in FSS10 and FSS20 than in TSS, but the difference was not significant (P>0.05). The stent length was significantly longer in FSS10 and FSS20 than in TSS. The stent cell size was significantly larger in FSS than in TSS. CONCLUSION: Better vessel wall apposition and aneurysmal neck coverage was observed for FSS than for TSS. No significant difference was observed between FSS10 and FSS20.

Thermal-Induced Osteonecrosis of Adjacent Vertebra after Intradiscal Electrothermal Therapy

A 42-year-old man was admitted to our hospital with complaints of low back pain and intermittent right thigh pain. Twelve weeks before admission, the patient received intradiscal electrothermal therapy (IDET) at a local hospital. The patient still reported low back pain after the procedure that was managed with narcotic analgesics. Follow-up magnetic resonance imaging (MRI) was performed, and his referring physician thought the likely diagnosis was spondylodiscitis at the L4–5 spinal segment with a small epidural abscess. At admission to our department, the patient reported aggravated low back pain. Blood test results, including the erythrocyte sedimentation rate and C-reactive protein levels, were slightly elevated. Biopsy samples of the L4, L5 vertebral bodies and disk were obtained. The material underwent aerobic, anaerobic, fungal, mycobacterial cultures and histologic examination. Results of all cultures were negative. Histologically, necrosis of the bone was evident from the number of empty osteocyte lacunae. In addition, there was no evidence of infection based on biopsy results. No antibiotic treatment was administered on discharge. Repeat computed tomography and MRI performed 12 months after IDET showed a bony defect in the L4 and L5 vertebral bodies, and a decrease in the size of the L4–5 intervertebral disc lesion. We report a case of lumbar vertebral osteonecrosis induced by IDET and discuss etiology and radiologic features.

Digital Subtraction Cystography for Detection of Communicating Holes of Spinal Extradural Arachnoid Cysts

OBJECTIVE: The purpose of this study was to demonstrate the usefulness of digital subtraction cystography to identify communicating holes between a spinal extradural arachnoid cyst (SEAC) and the subarachnoid space prior to cyst removal and hole closure. MATERIALS AND METHODS: Six patients with SEAC were enrolled in this retrospective study. Digital subtraction cystography and subsequent CT myelography were performed for every patient. The presence and location of the communicating holes on cystography were documented. We evaluated the MRI characteristics of the cysts, including location, size, and associated spinal cord compression; furthermore, we reviewed cystographic images, CT myelograms, procedural reports, and medical records for analysis. If surgery was performed after cystography, intraoperative findings were compared with preoperative cystography. RESULTS: The location of the communicating hole between the arachnoid cyst and the subarachnoid space was identified by digital subtraction cystography in all cases (n = 6). Surgical resection of SEAC was performed in 4 patients, and intraoperative location of the communicating hole exactly corresponded to the preoperative identification. CONCLUSION: Fluoroscopic-guided cystography for SEAC accurately demonstrates the presence and location of dural defects. Preoperative digital subtraction cystography is useful for detection of a communicating hole between a cyst and the subarachnoid space.

Diagnostic yield of computed tomography-guided bone biopsy and clinical outcomes of tuberculous and pyogenic spondylitis

BACKGROUND/AIMS: This study aimed to evaluate the efficacy of computed tomography (CT)-guided bone biopsy for the diagnosis of spinal infection and compared the clinical outcomes between tuberculous and pyogenic spinal infections. METHODS: The retrospective cohort study included patients who received CT-guided bone biopsy at a tertiary hospital over the 13 years. RESULTS: Among 100 patients, 67 had pyogenic spondylitis and 33 had tuberculous spondylitis. Pathogens were isolated from bone specimens obtained by CT-guided biopsy in 42 cases, with diagnostic yields of 61% (20/33) for tuberculous spondylitis and 33% (22/67) for pyogenic spondylitis. For 36 culture-proven pyogenic cases, Staphylococcus aureus was the most commonly isolated organism. Patients with pyogenic spondylitis more frequently presented with fever accompanied by an increase in inflammatory markers than did those with tuberculosis. Among all patients who underwent surgery, the incidence of late surgery performed one month after diagnosis was higher in patients with tuberculous infection (56.3%) than in those with pyogenic disease (23.3%, p = 0.026). CONCLUSIONS: Results obtained by CT-guided bone biopsy contributed to prompt diagnoses of spinal infections, especially those caused by tuberculosis. Despite administration of anti-tuberculous agents, patients with tuberculous spondylitis showed an increased tendency to undergo late surgery.

Diffuse Large B-Cell Lymphoma Mimicking Schwannoma of Lumbar Spine

A rare case of solitary diffuse large B-cell lymphoma arising from the lumbar spinal nerve root is reported. A 37-year-old man presented with a 3-month history of progressive numbness and paraparesis in both legs. The initial diagnosis was benign primary intradural extramedullary tumor including schwannoma and meningioma. Histopathological examination revealed diffuse large B-cell lymphoma. While a well-defined T1 isointense mass is common in primary spinal schwannoma, the present case was atypical and had a yellowish neural component. The pathogenesis and radiological findings of spinal diffuse large B-cell lymphoma are discussed and related literature is reviewed.

Superficial Siderosis of the Central Nervous System Originating from the Thoracic Spine: A Case Report

Superficial siderosis of the central nervous system(SSCNS) is a rare disease characterized by hemosiderin deposition on the surface of the central nervous system. We report a case of SSCNS originating from the thoracic spine, presenting with neurological deficits including, sensorineuronal hearing loss, ataxia, and corticospinal and dorsal column tract signs. The patient underwent dural repair with an artificial dural patch. Clinical findings were elicited by neurological examination, imaging studies, and intraoperative findings, and these were addressed through literature review.

Surgical Management with Radiation Therapy for Metastatic Spinal Tumors Located on Cervicothoracic Junction : A Single Center Study

OBJECTIVE: The cervicothoracic junction (CTJ) is a biomechanically and anatomically complex region that has traditionally posed problems for surgical access. In this retrospective study, we describe our clinical experiences of the treatment of metastatic spinal tumors at the CTJ and the results. METHODS: From June 2006 to December 2011, 23 patients who underwent surgery for spinal tumors involving the CTJ were enrolled in our study. All of the patients were operated on through the posterior approach, and extent of resection was classified as radical, debulking, and simple neural decompression. Adjuvant radiation therapy (RT) was also considered. Visual analog scale score for pain assessment and Medical Research Council (MRC) grade for motor weakness were used, while pre- and post-operative performance status was evaluated using the Eastern Cooperative Oncology Group (ECOG). RESULTS: Almost all of the patients were operated using palliative surgical methods (91.3%, 21/23). Ten complications following surgery occurred and revision was performed in four patients. Of the 23 patients of this study, 22 showed significant pain relief according to their visual analogue scale scores. Concerning the aspect of neurological and functional recovery, mean MRC grade and ECOG score was significantly improved after surgery (p<0.05). In terms of survival, radiation therapy had a significant role. Median overall survival was 124 days after surgery, and the adjuvant-RT group (median 214 days) had longer survival times than prior-RT (63 days) group. CONCLUSION: Although surgical procedure in CTJ may be difficult, we expect good clinical results by adopting a palliative posterior surgical method with appropriate preoperative preparation and postoperative treatment.

Symptomatic Large Spinal Extradural Arachnoid Cyst: A Case Report

Spinal extradural arachnoid cysts (SEACs) are relatively rare cause of compressive myelopathy. SEACs can be either congenital or acquired, but the etiology and the mechanism for their development are still unclear. A number of cases have been reported in the literature, and the one-way valve mechanism is the most widely accepted theory which explains the expansion of cysts and spinal cord compression. We report two cases of SEAC in this article. Patients had intermittent, progressive cord compressing symptoms. MRI image showed large SEAC which caused compression of the spinal cord. Pre-operative cystography and CT myelography were performed to identify the communicating tract. Pre-operative epidural cystography showed a fistulous tract. The patients underwent primary closure of the dural defect which was a communicating tract. The operative finding (nerve root herniation through the tract) suggested that the SEAC developed through a check-valve mechanism. Postoperatively, the patients had no surgical complications and symptoms were relieved. Based on our experience, preoperative identification of the communicating tract is important in surgical planning. Although surgical excision is the standard surgical treatment, primary closure of the dural defect which was a communicating tract can be an acceptable surgical strategy.

Minimally Invasive Option Using Percutaneous Pedicle Screw for Instability of Metastasis Involving Thoracolumbar and Lumbar Spine : A Case Series in a Single Center

OBJECTIVE: To report a minimally invasive treatment option using percutaneous pedicle screw fixation with adjuvant treatment for metastatic thoraco-lumbar and lumbar spinal tumors. METHODS: This is a retrospective study of charts of patients with spinal metastases. All were older than 18 years of age and were considered to have more than 3 months of life expectancy. The patients had single or two level lesions, and compression fracture or impending fracture. Exclusion criterion was metastasis showing severe epidural compression with definite neurological symptoms. Usually spinal segments from one level above to below pathology were stabilized. Visual analog scale (VAS) score for pain assessment and Frankel scale for neurological deficit were used, while pre- and post-operative performance status was evaluated using the Eastern Cooperative Oncology Group (ECOG). RESULTS: Twelve patients (nine men, three women; median age 54.29 years) underwent surgery. All patients presented with back pain with/without radicular pain. There were no early complications and perioperative mortalities. Following surgery, a significant difference between average pre- and post-operative VAS scores was found (p=0.003). Overall, 91.8% of patients (11/12) experienced improvement in their ECOG score post-operatively. The mean ambulation time was 196.9 days [95% confidence interval (CI), 86.2-307.6 days; median, 97 days]. During follow-up, nine patients died and the mean overall survival time in enrolled twelve patients was 249.9 days (95% CI, 145.3-354.4 days; median, 176 days). CONCLUSION: Minimally invasive treatment using percutaneous pedicle screw fixation with adjuvant treatment is a good alternative treatment option for potential instability of the thoraco-lumbar and lumbar spinal metastasis.

Survival-Related Factors of Spinal Metastasis with Hepatocellular Carcinoma in Current Surgical Treatment Modalities : A Single Institute Experience

OBJECTIVE: Recently, the survival of patients with hepatocellular carcinoma (HCC) has been prolonged with improvements in various diagnostic tools and medical treatment modalities. Consequently, spine metastases from HCC are being diagnosed more frequently. The accurate prediction of prognosis plays a critical role in determining a patient's treatment plan, including surgery for patients with spinal metastases of HCC. We investigated the clinical features, surgical outcomes, and prognostic factors of HCC presenting with spine metastases, in patients who underwent surgery. METHODS: A retrospective review was conducted on 33 HCC patients who underwent 36 operations (three patients underwent surgical treatment twice) from February 2006 to December 2013. The median age of the patients was 56 years old (range, 28 to 71; male : female=30 : 3). RESULTS: Overall survival was not correlated with age, sex, level of metastases, preoperative Child-Pugh classification, preoperative ambulatory function, preoperative radiotherapy, type of operation, administration of Sorafenib, or the Tokuhashi scoring system. Only the Tomita scoring system was shown to be an independent prognostic factor for overall survival. Comparing the Child-Pugh classification and ambulatory ability, there were no statistically differences between patients pre- and post-operatively. CONCLUSION: The Tomita scoring system represents a practicable and highly predictive prognostic tool. Even though surgical intervention may not restore ambulatory function, it should be considered to prevent deterioration of the patient's overall condition. Additionally, aggressive management may be needed if there is any ambulatory ability remaining.

Enlarged Parent Artery Lumen at Aneurysmal-Neck Segment in Wide-Necked Distal Internal Carotid Artery Aneurysms / 신경중재치료의학

PURPOSE: Hypothesizing that the parent artery (PA) diameter of the aneurysm-neck segment is larger than those of normal segments, especially in wide-necked aneurysm cases, we conducted 3D angiographic analyses in wide-necked aneurysm cases focusing on the luminal morphologic change of the PA. MATERIALS AND METHODS: Under the approval of local IRB, we enrolled 26 patients with distal internal carotid artery (ICA) aneurysms, which were treated with stent assisted coiling. The PA diameters along the centerline were measured at 6 points with built-in software by two observers. Those 6 points were P1 and P2 proximally, P3 and P4 at the aneurysm ostium margins, and P5 and P6 distally. We performed an ANOVA test and a Bonferroni method for post hoc analyses. Linear regression analysis was performed to find any morphologic influencing factors. RESULTS: There were 20 distal ICA aneurysms out of 26 consecutive cases after exclusion. The differences in diameter at each point were statistically significant (p<0.0001). On post hoc analyses, the difference between P4 and P5 was significant both in maximum and mean PA diameters (p<0.0001 and p<0.001, respectively). Multivariate analyses failed to reveal any morphological influencing factor. CONCLUSION: PAs harboring a wide-necked aneurysm requiring stent assistance for coiling showed significant enlargement of the lumen, especially at the distal transition segment of the aneurysm ostium and the PA.

Idiopathic Hypertrophic Spinal Pachymeningitis with an Osteolytic Lesion

Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a chronic, progressive, inflammatory disorder characterized by marked fibrosis of the spinal dura mater with unknown etiology. According to the location of the lesion, it might induce neurologic deficits by compression of spinal cord and nerve root. A 58-year old female with a 3-year history of progressive weakness in both lower extremities was referred to our institute. Spinal computed tomography (CT) scan showed an osteolytic lesion involving base of the C6 spinous process with adjacent epidural mass. Magnetic resonance imaging (MRI) revealed an epidural mass involving dorsal aspect of cervical spinal canal from C5 to C7 level, with low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images. We decided to undertake surgical exploration. At the operation field, there was yellow colored, thickened fibrous tissue over the dura mater. The lesion was removed totally, and decompression of spinal cord was achieved. Symptoms improved partially after the operation. Histopathologically, fibrotic pachymeninges with scanty inflammatory cells was revealed, which was compatible with diagnosis of idiopathic hypertrophic pachymeningitis. Six months after operation, motor power grade of both lower extremities was normal on physical examination. However, the patient still complained of mild weakness in the right lower extremity. Although the nature of IHSP is generally indolent, decompressive surgery should be considered for the patient with definite or progressive neurologic symptoms in order to prevent further deterioration. In addition, IHSP can present as an osteolytic lesion. Differential diagnosis with neoplastic disease, including giant cell tumor, is important.

Spinal Metastasis of Thymic Carcinoma as a Rare Manifestation: A Summary of 7 Consecutive Cases

BACKGROUNDS: Thymic carcinomas are very rare tumors that are often associated with extrathoracic metastasis to other organs. However, it is well known that thymic carcinomas rarely metastasize to the spine, and the prognosis, treatment, and natural course of this disease are not yet standardized. METHODS: We describe seven thymic carcinoma patients with spinal metastasis who were diagnosed and treated in our institute from January 2006 to December 2011. We performed surgical treatment and adjuvant chemotherapy and/or radiation therapy, in consideration of each individual disease's course, and we regularly followed up the patients. RESULTS: Of the seven patients, five were male and two were female. Six had metastases in the thoracic spine, and one had metastases in the lumbar spine. An extradural lesion was found in five patients, and two patients had both extradural and intradural lesions. The period from the primary diagnosis to spinal metastases varied widely (range, 1.23-14 years). After surgery, all patients showed an improvement of back pain and radicular pain. Two patients were lost to follow-up, but the other five maintained ambulatory function until their final follow-up. Four patients died because of pulmonary complications accompanied with the disease's progression. One patient died from uncontrolled brain metastases. After surgery, the median survival was 204+/-111.43 days. CONCLUSION: Because metastasis to the spine from thymic carcinoma is very rare, there are no treatment guidelines. Nevertheless, we suggest that appropriate surgical management of the metastatic lesion is necessary for the preservation of the patient's quality of life during survival.

Intramedullary Sarcoidosis Presenting with Delayed Spinal Cord Swelling after Cervical Laminoplasty for Compressive Cervical Myelopathy

Sarcoidosis is a systemic disease of unknown etiology that may affect any organ in the body. The nervous system is involved in 5-16% of cases of sarcoidosis. Here, we report a case of intramedullary sarcoidosis presenting with delayed spinal cord swelling after laminoplasty for the treatment of compressive cervical myelopathy. A 56-year-old woman was admitted to our hospital complaining of upper extremity pain and gait disturbance. The patient had undergone laminoplasty for compressive cervical myelopathy 3 months previously. Follow-up magnetic resonance imaging revealed a large solitary intramedullary lesion with associated extensive cord swelling, signal changes, and heterogeneous enhancement of spinal cord from C2 to C7. Spinal cord biopsy revealed non-necrotizing granulomas with signs of chronic inflammation. The final diagnosis of sarcoidosis was based upon laboratory data, imaging findings, histological findings, and the exclusion of other diagnoses. Awareness of such presentations and a high degree of suspicion of sarcoidosis may help arrive at the correct diagnosis.

Mid-term Clinical Outcomes of Stand-alone Posterior Interbody Fusion with Rectangular Cages: A 4-year-minimum Follow-up

OBJECTIVE: We sought to determine minimum 4 years of clinical outcomes including fusion rate, revision rate and complications of patients who underwent placement of rectangular stand-alone cages. METHODS: Thirty-three cases of degenerative spine that had been followed for at least 4-years were reviewed retrospectively. Cages were inserted at L4-L5 level or L5-S1 in 27 or in 6 cases respectively. Visual analogue scale (VAS), Odom's criteria, fusion rate, intervertebral disc height and lumbar lordosis were determined pre- and post-operatively on standing x-rays. Amount of intra- and postoperative blood loss, total volume transfused, duration of surgery and perioperative complications were also evaluated. RESULTS: The mean VAS score of back pain and sciatica were improved from 8.0 and 7.0 points to 3.4 and 2.4 during 1 years follow-up visit and the scores was raised gradually. Also, during the follow-up, 94% of patients showed excellent or good outcomes by the Odom's criteria. Intervertebral disc height was increased from 8.2+/-1.4mm to 9.2+/-1.9mm at the first year of follow-up, however, found to be decreased and stabilized to 8.3+/-1.8mm after 2 years. The fusion rate was approximately 91% after 4 year postoperative. The segmental angle of lordosis was increased significantly by two years but it was not maintained after four years. A statistically insignificant change in total lumbar lordosis was also observed. Three patients (9%) had experienced perioperative complications. CONCLUSION: The use of rectangular stand-alone cages for posterior lumbar interbody fusion (PLIF) resulted in a various degree of subsidence and demonstrate very low complication rate, high functional stability and improved clinical outcomes in patients with degenerative lumbar disc disease.

Charcot Arthropathy of the Lumbosacral Spine Mimicking a Vertebral Tumor after Spinal Cord Injury

Charcot spinal arthropathy is a rare, progressive type of vertebral joint degeneration that occurs in the setting of any preexisting condition characterized by decreased afferent innervation to the extent that normal protective joint sensation in the vertebral column is impaired. The authors report on a case of Charcot arthropathy of the lower lumbar spine mimicking a spinal tumor following cervical cord injury.

Is the Cross-sectional Area after Unilateral Open Door Laminoplasty Wider than that after Midline Splitting Laminoplasty ? : Mathematical Approach

OBJECTIVE: The aim of this study was to compare geometrically cross-sectional areas of two different laminoplasty techniques in same opening size. Some investigators have studied the expanded areas of the two different techniques using imaging study. Although it is unclear that postoperative spinal canal is correlated with the surgical outcome we just focused on mathematical and geometrical correlation of the expandable area with surgical opening size in different laminoplasty techniques. METHODS: To predict the expandable area by a midline splitting technique and a unilateral open door technique, we placed an imaginary isosceles triangle in the spinal canal and drew graphs for the equation of the expandable areas in same opening size using the Pythagorean theorem and mathematical program. To substitute the constant figures of mathematical formula we estimated the normal cervical spine CT scans of 50 Korean adults. RESULTS: We subtracted the imaginary triangle from the spinal canal and were left with the remaining area of the spinal canal that was not changed before and after surgery. In same opening size the expandable area by the midline splitting technique was same but slightly wider than the unilateral open door technique, irrespective of the triangular shape. For a normal isosceles triangle the results were the same. CONCLUSION: Using mathematical proof, the expandable area after the midline splitting technique was same but slightly larger than that after the unilateral open door technique, irrespective of the size of the lamina opening.

Implementation and Outcomes of a Critical Pathway for Lumbar Laminectomy or Microdiscectomy

OBJECTIVE: The aim of this study is to implement a critical pathway (CP) for patients undergoing lumbar laminectomy or microdiscectomy and describe the results before and after the CP in terms of length of hospital stay and cost. METHODS: From March 2008 to February 2009, 61 patients underwent lumbar laminectomy or microdiscectomy due to stenosis or one- or two-level disc herniation in our department and were included in the prepathway group. After development and implementation of the CP in March 2009, 58 patients were applicable for the CP, and these were classified as the postpathway group. RESULTS: The CP, which established a 6-day hospital stay (5 bed-days), was fulfilled by 42 patients (72.4%) in the postpathway group. The mean length of stay was 5.4 days in the postpathway group compared to 6.9 days in the prepathway group, demonstrating a 20% reduction, which was a statistically significant difference (p< or =0.000). There was a statistically significant reduction in charges for bed and nursing care (p=0.002). CONCLUSION: Implementation of a CP for lumbar laminectomy or microdiscectomy produced significant decreases in length of hospitalization and charges for bed and nursing care. We believe that this CP reduces the unnecessary use of hospital resources without increasing risk of adverse events.