Clinical effects and mid-term follow-up analysis of para-split laminotomy for lumbar spinal canal tumors / 国际外科学杂志

Objective:To investigate the surgical outcome and prognostic factors of para-split laminotomy for removal of lumbar spinal canal tumors.Methods:Retrospectively review the clinical data of 35 patients suffering lumbar spinal canal tumors, who underwent the para-split laminotomy for tumor resection in Department of Neurosurgery, Clinical Medical College of Yangzhou University from October 2016 to August 2019, including 16 males and 19 females, and the age was(40.1±10.6)years. Intraoperative blood loss, operation time, tumor resection, tumor pathological results, perioperative complications were observed. Follow-up situations, including tumor recurrence, bony fusion of laminae and spinal stability. Follow-up using outpatient examination and telephone interview was performed by the end of August 2022. The JOA back pain scoring system was used to evaluate the neurological function of the spinal cord, and paired t-test were performed to compare the overall preoperative and postoperative spinal cord neurological function scores. Linear regression and multiple linear regression were used to analyze the prognostic factors. Measurement data of normal distribution were expressed as mean±standard deviation ( ± s), and the comparison before and after operation was performed by paired t-test. Mearsurement data of skewed distribution were expressed as M( Q1, Q3). Count data were expressed as cases. Results:The tumors of 35 patients were resected completely. The median blood loss was 100(75, 140)mL and the average operative duration was (181.1±42.7) min. The postoperative pathological results were as follows: 24 neurilemmomas, 6 meningiomas, 4 ependymomas and 1 neurofibroma. There were no surgery-related complications occurred. The postoperative follow-up ranged from 36 to 69 months, with no tumor recurrence or spinal instability, and bony fusion of laminae seen in some patients on CT imaging. The overall spinal cord neurological function scores of pre and post operation were(19.5±3.4)versus(25.4±2.2), Paired t-test analysis revealed a significant difference between the overall postoperative spinal cord neurological function scores and the preoperative scores, and the postoperative scores were better than the preoperative scores( P<0.05). Multiple linear regression analysis showed a positive correlation between preoperative JOA scores and postoperative JOA scores, and postoperative JOA scores has negative correlation with tumor volume and the age at the time of operation ( P<0.05). Conclusion:Para-split laminotomy with less damage to the posterior spinal structures can effectively improve the neurological function of the spinal cord and protect the stability of the lumbar spine in patients with lumbar spinal canal tumors, and the better the preoperative neurological function of the spinal cord, the better the prognosis of patients, and the smaller the tumor volume, the better the prognosis.

Intradural Spinal Arachnoid Cyst in a Pediatric Patient: A Case Report

The present case reports a 13-year-old patient with an intradural arachnoid cyst, which manifested itself with a sudden loss of strength and sensitivity in the lower and upper limbs and a severe pain in the cervical and thoracic region. On examination, a lesion displayed as an intradural hematoma; however, a laminotomy was performed and it was realized that the lesion was an arachnoid spinal cyst of the cervical-dorsal spine.

Evaluation of Functional Outcome of Laminectomy and Laminotomy for The Surgical Management of Lumber Spine Stenosis: An Institutional Based Study

Background: Lumbar spinal stenosis (LSS) is commonly seenin the elderly especially owing to the aging of the spine.Growing in the facet joints, ligamentum flavum hypertrophy,disc degeneration, and osteophytes cause the spinal canal toconstrict and accordingly result in spinal cord and nerve rootcompression. If conservative treatments fail, surgicalintervention will be considered as the next treatment. Surgicaldecompression for LSS is indicated in a patient with intractablepain, neurogenic claudication, and motor weakness,accompanied by compromised spinal canal. Laminectomy forLSS is considered the standard surgical option to which othertechniques are compared. Ascertaining superiority of adecompression technique necessitates establishing if anydifferences exist in the complication rates and the functionaland symptomatic outcomes.Aim of the Study: To evaluate functional outcome oflaminectomy and laminotomy for the surgical management oflumber spine stenosis.Materials and Methods: The present study was conducted inthe Department of Orthopaedics, NIIMS Medical College,Jaipur, Rajasthan, India. For the study, patients with confirmedLSS (both lateral and/or central) on MR imaging who had failedconservative management, were considered for operativemanagement. Patients with spondylolisthesis, or scoliosis andthose who had undergone fusion, discectomies or furtherrevisions were excluded from the study. Following exclusions,50 patients were enrolled; 30 underwent a laminectomy withoutfusion and 20 underwent either a bilateral or unilaterallaminotomy.Results: We observed that VAS pain score decreased 6weeks post operatively for patients who underwentlaminectomy and laminotomy, however there was slightincrease in the pain score at 1-year post operatively. Theresults on comparison were found to be statically significant.Conclusion: Within the limitations of the present study, it canbe concluded that both surgeries were equally effective inimproving pain and disability.

Predictors of Reoperation after Microdecompression in Lumbar Spinal Stenosis

OBJECTIVE: The risk factors of reoperation after microdecompression (MD) for lumbar spinal stenosis (LSS) are unclear. In this study, we presented the outcomes of MD for degenerative LSS and investigated the risk factors associated with reoperation. METHODS: A retrospective review was conducted using the clinical records and radiographs of patients with LSS who underwent MD. For clinical evaluation, we used the Japanese Orthopedic Association (JOA) scoring system for low back pain, body mass index, and Charlson comorbidity index. For radiological evaluation, disc height, facet angle, and sagittal rotation angle were measured in operated segments. Also the Modic change and Pfirrmann grade for degeneration in the endplate and disc were scored. RESULTS: Forty-three patients aged 69±9 years at index surgery were followed for 48±25 months. The average preoperative JOA score was 6.9±1.6 points. The score improved to 9.1±2.1 points at the latest follow-up (p0.1. Patients with Pfirrmann grade IV and lower lumbar segment had a 29.1% rate of reoperation (p=0.001), whereas patients without these factors had a 0% rate of reoperation. CONCLUSION: Moderate disk degeneration (Pfirrmann IV) in lower lumbar segments is a risk factor of disk herniation or foraminal stenosis requiring reoperation after MD in LSS.

Lumbar Interspinous Process Fixation and Fusion with Stand-Alone Interlaminar Lumbar Instrumented Fusion Implant in Patients with Degenerative Spondylolisthesis Undergoing Decompression for Spinal Stenosis

STUDY DESIGN: Prospective cohort study. PURPOSE: To assess the ability of a stand-alone lumbar interspinous implant (interspinous/interlaminar lumbar instrumented fusion, ILIF) associated with bone grafting to promote posterior spine fusion in degenerative spondylolisthesis (DS) with vertebral instability. OVERVIEW OF LITERATURE: A few studies, using bilateral laminotomy (BL) or bilateral decompression by unilateral laminotomy (BDUL), found satisfactory results in stenotic patients with decompression alone, but others reported increased olisthesis, or subsequent need for fusion in DS with or without dynamic instability. METHODS: Twenty-five patients with Grade I DS, leg pain and chronic low back pain underwent BL or BDUL and ILIF implant. Olisthesis was 13% to 21%. Follow-up evaluations were performed at 4 to 12 months up to 25 to 44 months (mean, 34.4). Outcome measures were numerical rating scale (NRS) for back and leg pain, Oswestry disability index (ODI) and short-form 36 health survey (SF-36) of body pain and function. RESULTS: Fusion occurred in 21 patients (84%). None had increased olisthesis or instability postoperatively. Four types of fusion were identified. In Type I, the posterior part of the spinous processes were fused. In Type II, fusion extended to the base of the processes. In Type III, bone was present also around the polyetheretherketone plate of ILIF. In Type IV, even the facet joints were fused. The mean NRS score for back and leg pain decreased by 64% and 80%, respectively. The mean ODI score was decreased by 52%. SF-36 bodily pain and physical function mean scores increased by 53% and 58%, respectively. Computed tomography revealed failed fusion in four patients, all of whom still had vertebral instability postoperatively. CONCLUSIONS: Stand-alone ILIF with interspinous bone grafting promotes vertebral fusion in most patients with lumbar stenosis and unstable Grade I DS undergoing BL or BDUL.

Postoperative Expansion of Dural Sac Cross-Sectional Area after Unilateral Laminotomy for Bilateral Decompression: Correlation with Clinical Symptoms

OBJECTIVE: Dural sac cross-sectional area (DSCSA) is a way to measure the degree of central spinal canal compression. The objective was to investigate the correlation between the expansion ratio of DSCSA after unilateral laminotomy for bilateral decompression (ULBD) and the clinical results for lumbar spinal stenosis. METHODS: We retrospectively reviewed the clinical data and radiographs of 103 patients who underwent ULBD for symptomatic spinal stenosis in one year. We compared preoperative and postoperative clinical data and DSCSA and evaluated the correlation between clinical and radiographic measurements. RESULTS: There was a significant increase of DSCSA after ULBD (p=0.000) and mean expansion ratio of DSCSA was 203.7+/-147.2%(range -32.9-826.1%). Clinical outcomes, measured by VAS and ODI were improved significantly not only in early postoperative period, but also in the last follow-up. However, there were no statistically significant correlations between the preoperative DSCSA and clinical symptoms, Perioperative expansion ratio of DSCSA and clinical parameters were also not correlated to the improvement of clinical symptoms significantly in both early postoperative phase and last follow-up. CONCLUSION: Our result indicates that the DSCSA itself has a definite limitation to be correlated to the clinical symptoms, and thus meticulous correlation between the clinical presentation and MRI imaging is essential in determination of surgical treatment.

Surgical Tips to Preserve the Facet Joint during Microdiscectomy

Lumbar microdiscectomy (MD) is the gold standard for treatment of lumbar disc herniation. Generally, the surgeon attempts to protect the facet joint in hopes of avoiding postoperative pain/instability and secondary degenerative arthropathy. We believe that preserving the facet joint is especially important in young patients, owing to their life expectancy and activity. However, preserving the facet joint is not easy during lumbar MD. We propose several technical tips (superolateral extension of conventional laminotomy, oblique drilling for laminotomy, and additional foraminotomy) for facet joint preservation during lumbar MD.

Minimum 3-Year Outcomes in Patients with Lumbar Spinal Stenosis after Bilateral Microdecompression by Unilateral or Bilateral Laminotomy

OBJECTIVE: Lumbar spine stenosis (LSS) can result in symptomatic compression of the neural elements, requiring surgical treatment if conservative management fails. Minimally invasive surgery has come to be more commonly used for the treatment of LSS. The current study describes outcomes of bilateral microdecompression by unilateral or bilateral laminotomy (BML) for degenerative LSS after a minimum follow-up period of 3 years and investigates factors that result in a poor outcome. METHODS: Twenty-one patients who were followed-up for at least 3 years were included in this study. For clinical evaluation, the Japanese Orthopedic Association (JOA) scoring system for low back pain was used. The modified grading system of Finneson and Cooper was used for outcome assessment. Radiographic evaluation was also performed for spondylolisthesis, sagittal rotation angle, and disc height. RESULTS: Twenty-one patients (10 men, 11 women) aged 53-82 years (64.1+/-8.9 years) were followed-up for a minimum of 3 years (36-69 months). During follow-up, two patients underwent reoperation. Average preoperative JOA score and clinical symptoms, except persistent low back pain, improved significantly at the latest follow-up. There were no significant differences in radiological findings preoperatively and postoperatively. Thirteen patients (61.9%) had excellent to fair outcomes. CONCLUSION: BML resulted in a favorable and persistent outcome for patients with degenerative LSS without radiological instability over a mid-term follow-up period. Persistent low back pain unrelated to postoperative instability adversely affects mid-term outcomes.

Cervical Pedicle Screw Placement in Sawbone Models and Unstable Cervical Traumatic Lesions by Using Para-Articular Mini-Laminotomy: A Novice Neurosurgeon's Experience / 대한신경손상학회지

OBJECTIVE: This retrospective study was conducted to analyze the novice neurosurgeon's experience of cervical pedicle screw placement by using the technique with direct exposure of pedicle via para-articular mini-laminotomy. METHODS: Fifteen sawbone models of subaxial spine were used (124 pedicles) to evaluate efficacy of repetitive training improving accuracy of cervical pedicle screw insertion. After that, we retrospectively reviewed 9 consecutive patients presented with traumatic cervical lesion. A total 38 cervical pedicle screws had been inserted. We analyzed the direction and grade of pedicle perforation on the postoperative computed tomography scan, and learning curve by using sawbone model. RESULTS: In sawbone model group, the correct position was found in 102 (82.3%) screws, and the incorrect position in 22 (17.7%) screws. The incidence of incorrect screw position was 26.9% in the initial 9 sawbone model, and 0% after that. Among the 38 screws inserted in 9 patients, the correct position was found in 36 (94.7%) screws, and the incorrect position in a 2 (5.3%) screw. There was no neurovascular complications related with cervical pedicle screw insertion. CONCLUSION: In vitro training to insert pedicle screw by using sawbone models could improve an accuracy of cervical pedicle screw placement by using this technique. Preliminary result revealed that cervical pedicle screw placement would be feasible and provide good clinical results in traumatic cervical lesions.

Surgical Treatment of T1-2 Disc Herniation with T1 Radiculopathy: A Case Report with Review of the Literature

The prevalence of intervertebral disc herniation (IDH) of the thoracic spine is rare compared to the cervical or lumbar spine. In particular, IDH of the upper thoracic spine is extremely rare. We report the case of T1-2 IDH and its treatment, with a literature review. A 37-year-old male patient visited our hospital due to radiating pain at the left upper extremity and weakness of grip power. In cervical spine magnetic resonance images, T1-2 disc space showed herniated disc material and compressed T1 root was identified. Laminoforaminotomy was performed with a posterior approach. The radiating pain and weakness of grip power improved immediately after the surgery. Of patients who show radiating pain or numbness at the medial aspect of forearm, or weakness of intrinsic muscle of hand, can be suspected to have T1 radiculopathy. A detailed physical examination and a radiologic evaluation including this area should be required for the T1 radiculopathy.

Radiological Analysis of Symptomatic Complications after Bilateral Laminotomy for Lumbar Spinal Stenosis

OBJECTIVE: The purpose of this study was to describe the various symptomatic complications following decompressive bilateral laminotomy for treating lumbar spinal stenosis. METHODS: Out of 878 patients who underwent decompressive laminotomy from 2006 through 2008, 178 patients who were able to be followed for a minimum of 24 months were included in this study. The mean age at the time of surgery was 64.4 years (range, 38-79), and the average follow-up period was 32.7 months. The development of symptomatic complications was observed using simple radiographs and MR imaging during the follow-up period. Imaging and clinical complications were focused on postoperative spondylolisthesis, disc herniation, and facet cysts, and were analyzed according to developmenttime, the degree of symptom, and their course. RESULTS: Postoperative simple radiographs revealed that eight out of 178 patients (4.4%) had developed symptomatic spondylolisthesis and six required an interbody fusion procedure. Five patients with disc herniation (2.8%) at the level of the decompressive bilateral laminotomy site underwent another operation within 24 months after the first surgery. In two patients, disc herniations developed within 1 month after surgery. Three (1.7%) out of 178 patients showed facet cysts but all symptoms were relieved by conservative treatment. Spontaneous regression of the cysts was observed during the follow-up period. CONCLUSIONS: Although decompressive bilateral laminotomy for spinal stenosis is believed to effective and reduces the need for fusion, various symptomatic complications were observed after this procedure. It is important to be aware of the possibility for these various complications to improve the surgical outcome.

Laminotomy with Continuous Irrigation in Patients with Pyogenic Spondylitis in Thoracic and Lumbar Spine

OBJECTIVE: Pyogenic spondylitis often results in acute neurological deterioration requiring adequate surgical intervention and appropriate antibiotic treatment. The purpose of this study was to conduct an analysis of the clinical effect of continuous irrigation via laminotomy in a series of patients with pyogenic spondylitis in thoracic and lumbar spine. METHODS: The authors conducted a retrospective investigation of 31 consecutive patients with pyogenic thoracic and lumbar spondylitis who underwent continuous irrigation through laminotomy from 2004 to 2008. The study included 22 men and 9 women, ranging in age from 38 to 78 years (mean 58.1 years). The average follow-up duration was 13.4 months (range, 8-34 months). We performed debridement and abscess removal after simple laminotomy, and then washed out epidural and disc space using a continuous irrigation system. Broad spectrum antibiotics were administered empirically and changed according to the subsequent culture result. Clinical outcomes were based on the low back outcome scale (LBOS), visual analogue scale (VAS) score, and Frankel grade at the last follow-up. Radiological assessment involved plain radiographs, including functional views. RESULTS: Common predisposing factors included local injection for pain therapy, diabetes mellitus, chronic renal failure, and liver cirrhosis. Causative microorganisms were identified in 22 cases (70.9%) : Staphylococcus aureus and Streptococcus spp. were the main organisms. After surgery, LBOS, VAS score, and Frankel grade showed significant improvement in most patients. Spinal stability was maintained during the follow-up period, making secondary reconstructive surgery unnecessary for all patients, except one. CONCLUSION: Simple laminotomy with continuous irrigation by insertion of a catheter into intervertebral disc space or epidural space was minimally invasive and effective in the treatment of pyogenic spondylitis. This procedure could be a beneficial treatment option in patients with thoracolumbar spondylitis combined with minimal or moderate destructive change of vertebrae.

Interspinous Implant with Unilateral Laminotomy for Bilateral Decompression of Degenerative Lumbar Spinal Stenosis in Elderly Patients

OBJECTIVE: This study assessed the safety and efficacy of one level unilateral laminotomy bilateral decompression (ULBD) with the placement of a device for intervertebral assisted motion (DIAM) compared with one level ULBD only in elderly patients with degenerative lumbar spinal stenosis (DLSS). METHODS: A non randomized prospective analysis was performed on 16 patients who underwent one level ULBD with DIAM (Group A) and 20 patients with one level ULBD only (Group B) between February 2007 and March 2008. Radiographic imaging, visual analog scale (VAS) and MacNab outcome scale were obtained before and after surgery at a mean interval of 21 months (range 17-27 months). RESULTS: The disc height, interpedicular distance, slip distance and segmental lordotic angle were similar between two groups. In the group A, there was no significant difference between the pre- and post-operative imaging in terms of the sagittal balance and disc height. Both groups showed significant improvement in the clinical outcomes. In addition, there was significantly less low-back pain in the group A than in the group B at the last follow up, while the clinical improvement of the leg pain and MacNab outcome scale showed no significant difference in the two groups. There were no major complications or DIAM associated complications. CONCLUSION: ULBD with DIAM is a safe and efficacious treatment for selective elderly patients with DLSS, particularly for relieving low back pain comparing to ULBD. ULBD with DIAM did not alter the disc height or sagittal alignment at the mean 21 months follow-up interval.

Long Term Clinical and Radiographic Results of Lumbar Spinal Stenosis with Grade I Degenerative Spondylolisthesis after Microsurgical Bilateral Decompression via Unilateral Laminotomy

OBJECTIVE: The purpose of this study was to assess long-term clinical outcomes and radiographic changes in patients with lumbar spinal stenosis with grade I degenerative spondylolisthesis who underwent microsurgical bilateral decompression via unilateral laminotomy, as a minimally invasive surgery. Method: Medical records of twenty-five patients who underwent the surgery between 1999 and 2005 were retrospectively evaluated. Clinical outcomes were evaluated through interviews over telephone with standardized questionnaires. Preoperative and postoperative radiographs were taken from all patients in neutral and dynamic lateral views. The mean follow-up period after surgery was 38.5 months(range 9-57 months). RESULTS: Seventy-two percent of patients were either pain free(48%) or doing well with occasional acetaminophens(24 %), and satisfied with the treatment. The most improved preoperative symptom was neurogenic intermittent claudication, which was ameliorated in 94.7% of patients(excellent 84.2%, good 10.5%, fair 5.3%). Postoperative vertebral slippage was also measured and appeared to be slightly increased but this was not statistically significant. Postoperative dynamic angulation did not change significantly compared to the preoperative value. CONCLUSION: Microsurgical bilateral decompression via unilateral laminotomy achieved a satisfactory decompression and symptomatic relief without extensive destruction of the weight-bearing structures and functional mobile segments. This treatment can be an effective modality for patients with lumbar spinal stenosis associated with mild degenerative spondylolisthesis.

Percutaneous Endoscopic Lumbar Discectomy (PELD) Using Interlaminar Approach in Lumbar Disc Herniation: Endoscopic Laminotomy / 대한척추외과학회지

STUDY DESIGN: Retrospective study OBJECTIVES: This study examined the post-operative results of interlaminar percutaneous endoscopic lumbar discectomy (PELD) with or without endoscopic laminotomy in lumbar disc herniation. SUMMARY OF LITERATURE REVIEW: In addition to the technical feasibility, the indications of PELD surgery are usually the same as those for open discectomy. MATERIALS AND METHODS: From January 2005 to August 2006, 62 cases treated with PELD using an interlaminar approach due to lumbar disc herniation were examined. The mean age of the subjects was 40.1 years (18-70) and the mean follow up period was 32.6 months (24-44). Thirty-four and 28 herniated discs were extracted from L4-L5 and L5-S1, respectively. The clinical results were evaluated using MacNab's criteria. RESULTS: The herniated discs were accessible in all cases. Excellent and good results were obtained in 85% (53 cases) of patients but 15% of patients (9 cases) showed unsatisfactory results or needed revision. There were 4 cases of incomplete removal, 2 cases of recurrence and 4 cases of persistent low back pain due to associated degenerative pathologies. Additional surgery was required in 7 cases which were open discectomy in 5 cases (3 cases of 4 incomplete removal and 2 of recurrence). There was one case of PLIF and 1 additional decompression. Cauda equina syndrome occurred in one case who underwent subsequent wide decompression and open discectomy. CONCLUSIONS: interlaminar PELD using endoscopic laminotomy is an effective method for treating lumbar disc herniation with moderate up and down migration. The clinical success rate can be improved by selecting patients with accessible discs and excluding those with an associated pathology.

Spontaneous Spinal Epidural Hematoma in an Infant : A Case Report and Review of the Literature

Spontaneous spinal epidural hematoma (SSEH) is rare in children, especially in infants, in whom only 12 cases have been reported. Because of the nonspecificity of presenting symptoms in children, the diagnosis may be delayed. We report herein a case of SSEH in a 20-month-old girl who initially presented with neck pain, and developed lower extremity motor weakness and symptoms of neurogenic bladder 2 weeks prior to admission. The magnetic resonance imaging showed an epidural mass lesion extending from C7 to T4, and the spinal cord was severely compressed by the mass. After emergency decompressive surgery the neurologic function was improved immediately. Two months after surgery, the neurological status was normal with achievement of spontaneous voiding. We suggest that surgical intervention can provide excellent prognosis in case of SSEH in infants, even if surgery delayed.

Minimally Invasive Lumbar Spinal Decompression: A Comparative Study Between Bilateral Laminotomy and Unilateral Laminotomy for Bilateral Decompression

OBJECTIVE: Bilateral laminotomy and unilateral laminotomy for bilateral decompression are becoming the minimally invasive procedures for lumbar spinal stenosis (LSS). With the aim of less invasiveness and better preservation of spinal stability, these techniques have been developed. But there are no large randomized studies to show the surgical results between these two techniques. The objective of this study was to examine the safety and efficacy of these two minimally invasive techniques. METHODS: A total of 80 patients were included in this study (Group I : bilateral laminotomy, Group II : Unilateral laminotomy for bilateral decompression). Perioperative parameters and complications were analyzed. Symptoms and scores such as visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, and SF-36 scores of prospectively accrued patients were assessed preoperatively and at 1 month and 12 months after surgery. Paired-t test, two-sample student-t tests, and nonparametric tests were used to determine cross-sectional differences between two groups. RESULTS: No major complications such as spinal instability or deaths occurred during follow-up periods. VAS, ODI scores and SF-36 body pain and physical function scores showed statistically significant improvements in both groups (p<0.001). The significant widening of the spinal canal diameter was also noted in both groups. But, in Group II, there were minor postoperative complications such as dural tear (2 cases 5.0%), fracture of ipsilateral inferior facet (1 case 2.5%), and 5 cases of transient leg symptoms of contralateral side. CONCLUSION: Both bilateral laminotomy and unilateral laminotomy for bilateral decompression allow achievement of adequate and long-lasting operative results in patients with LSS. But postoperative complications are more frequent in Group II (unilateral laminotomy and bilateral decompression). These results indicate that bilateral laminotomy is the preferred minimally invasive technique to treat symptomatic LSS.

Minimally Invasive Lumbar Spinal Decompression: A Comparative Study Between Bilateral Laminotomy and Unilateral Laminotomy for Bilateral Decompression

OBJECTIVE: Bilateral laminotomy and unilateral laminotomy for bilateral decompression are becoming the minimally invasive procedures for lumbar spinal stenosis (LSS). With the aim of less invasiveness and better preservation of spinal stability, these techniques have been developed. But there are no large randomized studies to show the surgical results between these two techniques. The objective of this study was to examine the safety and efficacy of these two minimally invasive techniques. METHODS: A total of 80 patients were included in this study (Group I : bilateral laminotomy, Group II : Unilateral laminotomy for bilateral decompression). Perioperative parameters and complications were analyzed. Symptoms and scores such as visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, and SF-36 scores of prospectively accrued patients were assessed preoperatively and at 1 month and 12 months after surgery. Paired-t test, two-sample student-t tests, and nonparametric tests were used to determine cross-sectional differences between two groups. RESULTS: No major complications such as spinal instability or deaths occurred during follow-up periods. VAS, ODI scores and SF-36 body pain and physical function scores showed statistically significant improvements in both groups (p<0.001). The significant widening of the spinal canal diameter was also noted in both groups. But, in Group II, there were minor postoperative complications such as dural tear (2 cases 5.0%), fracture of ipsilateral inferior facet (1 case 2.5%), and 5 cases of transient leg symptoms of contralateral side. CONCLUSION: Both bilateral laminotomy and unilateral laminotomy for bilateral decompression allow achievement of adequate and long-lasting operative results in patients with LSS. But postoperative complications are more frequent in Group II (unilateral laminotomy and bilateral decompression). These results indicate that bilateral laminotomy is the preferred minimally invasive technique to treat symptomatic LSS.

The Effect of Polylactide Resorbable Film on the Epidural Fibrosis After Lumbar Laminotomy / 대한정형외과연구학회지

PURPOSE: The purpose of this study is to evaluate the effect of polylactide resorbable film in preventing epidural fibrosis after lumbar laminotomy. MATERIALS AND METHODS: Thirty-six New Zealand male rabbits about fifteen month old, weighing 3.5 kg in average, were used. Uniform laminotomy windows measuring 7x7 mm were made on the left side of the spine at three lumber locations (L2, L3 and L4). The laminotomy window at second lumbar spine was left untreated and used as control group (Group 1). The lanimotomy window of 3rd lumbar spine was covered with free fat tissue (Group 2), and polylactide ( Surgi-Wrap(R)) resorbable film was inserted on the laminotomy window of 4th lumbar spine (Group 3). Twelve rabbits were euthanized at 4, 8 and 12 weeks each after operation for biochemical analysis of hydroxyproline content and histologic examination. RESULTS: 1. There was considerable reduction in the total collagen, ranging from 40~48% in the Group 2 or the Group 3 compared to the Group 1. There was no statistical difference between the Group 2 and the Group 3. 2. The extent of fibrosis and fibroblast density was significantly lower in the Group 2 or the Group 3 than in the Group 1. However, the extent of fibrosis and fibroblast density did not differ statistically between the Group 2 and the Group 3. 3. No significant statistical differences of the collagen content and the histologic findings in each group was demonstrated during experimental period. CONCLUSION: These results suggest that polylactide (Surgi-Wrap(R)) resorbable film may be a useful method for reduction of epidural fibrosis after lumbar laminotomy.

Comparison of the Results of the Decompression Methods for Degenerative Lumbar Spinal Stenosis: Comparison of Posterior Element Saving Procedures / 대한척추외과학회지

STUDY DESIGN: This is a prospective study. OBJECTIVES: We wanted to analyze the radiographic and clinical results of the three posterior element saving decompression techniques for treating lumbar degenerative spinal stenosis. SUMMARY OF THE LITERATURE REVIEW: Minimal invasive decompression reduces patient morbidity and the hospital stay. MATERIALS AND METHODS: We evaluated 30 patients, who were treated with posterior element saving microscopic decompression for their lumbar spinal stenosis (without instability), during the period from March, 2002 and February, 2004. The procedures were bilateral laminotomy (10 cases), spinous process osteotomy (8 cases) and laminoplasty (12 cases). We evaluated the estimated blood loss, the amount of transfusion, the complications and the radiographic instability at the last follow-up. The clinical results were evaluated with using the Oswestry disability index (ODI) and the visual analogue scale (VAS) for buttock and leg pain both preoperatively and at postoperative 1, 3, 6 and 12 months, respectively. RESULTS: There was no radiographic instability noted for any of the patients at the last follow up. The mean ODI and VAS scores were substantially improved at postoperative 1 month and then they were marginally improved afterwards. However, there were no statistically significant differences among three procedures (p>0.05). The mean blood loss and the amount of transfusion for each spinal level were 290 ml and 0.5 U for bilateral laminotomy, 370 ml and 0.9 U for spinous process osteotomy and 180 ml and 0.1 U for laminoplasty, respectively. CONCLUSION: There were no significant differences in the radiograhic and clinical results among bilateral laminotomy, spinous process osteotomy and laminoplasty. Yet in terms of blood loss and transfusion, laminoplasty was better than the other techniques. We believe that laminoplasty is a useful and safe technique for treating degenerative lumbar spinal stenosis.