|Year : 2019 | Volume
| Issue : 2 | Page : 566-573
Different surgical modalities in the management of lumbar canal stenosis
Mohamed K Eissa1, Adel M Hanafy1, Hesham Y Aborahma1, Ahmed S El Gammal2, Hazem M Negm1
1 Department of Neurosurgical, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of General Surgery, Faculty of Medicine, Menoufia University, Menoufia, Egypt
|Date of Submission||29-Dec-2017|
|Date of Acceptance||19-Feb-2019|
|Date of Web Publication||25-Jun-2019|
Mohamed K Eissa
2 Anwar Al-Sadat Street, Elbatanon, Shebinelkom, Menoufia 32511
Source of Support: None, Conflict of Interest: None
The aim of this study was to evaluate the results of different methods of decompression in lumbar canal stenosis (LCS) with regard to the effectiveness of different techniques in relieving symptoms, duration of surgery, intraoperative blood loss, and decreasing of postoperative complications.
LCS is defined as a narrowing of any part of the lumbar spinal canal. Several surgical techniques for lumbar spine decompression have been described over the last few decades. The aim of surgery for symptomatic LCS is to relieve the symptoms by adequate neural decompression while preserving the anatomy and the biomechanical function of the lumbar spine as much as possible.
Patients and methods
This prospective study was conducted from September 2015 to August 2017 including three groups: group A treated with conventional laminectomy (CL), group B treated with CL with posterolateral fusion, and group C treated with unilateral laminectomy with bilateral decompression. We used Oswestry disability index to assess preoperative and postoperative disabilities and pain.
In this study, statistical results revealed that there was statistical significance in the improvement of claudicating sciatica between the three groups as regards the Oswestry disability index (P < 0.001). There was statistical significance between three groups with regard to blood loss (P < 0.001), length of surgical procedure (P = 0.009), postoperative hospital stays (P < 0.001), and postoperative complication.
On the basis of short-term follow-up, a minimally invasive technique like unilateral laminectomy with bilateral decompression allowed decompression, preserving spine stability with a natural range of motion, with less blood loss, less hospital stay, and decreased intraoperative and postoperative complication rather than CL with or without posterolateral fusion.
Keywords: claudication, conventional laminectomy, lumbar canal stenosis, posterolateral fusion, unilateral laminectomy
|How to cite this article:|
Eissa MK, Hanafy AM, Aborahma HY, El Gammal AS, Negm HM. Different surgical modalities in the management of lumbar canal stenosis. Menoufia Med J 2019;32:566-73
|How to cite this URL:|
Eissa MK, Hanafy AM, Aborahma HY, El Gammal AS, Negm HM. Different surgical modalities in the management of lumbar canal stenosis. Menoufia Med J [serial online] 2019 [cited 2020 Feb 28];32:566-73. Available from: http://www.mmj.eg.net/text.asp?2019/32/2/566/260939
| Introduction|| |
Lumbar canal stenosis (LCS) is defined as a narrowing of any part of the lumbar spinal canal. These narrowing sites exert excessive pressure on both the spinal cord and peripheral nerves resulting in pain, numbness, and/or weakness in the lower extremities. Absolute stenosis has been defined as an anteroposterior lumbar spine diameter of less than 10 mm. Neurogenic claudication is a term used to define intermittent pain or paraesthesia in the lower extremities brought about by walking or standing and relieved by sitting or lying down. Sciatica is a relatively common condition with an incidence varying from 13 to 40%. Patient symptoms comprise unilateral or bilateral low back and leg pain, which slowly develop and persist over several months, or even years. The back pain is localized to the lumbar spine and can radiate towards the gluteal region, groin and legs, frequently displaying a pseudoradicular pattern. In cases of lateral recess stenosis or foraminal stenosis, isolated radiculopathy can occur. The severity of all symptoms present at the time of the visit should be measured using the Oswestry disability index (ODI). The ODI measures symptoms in ten sections, including factors such as pain intensity, personal care, lifting, walking, and sleeping. An accurate patient history and diagnosis are of paramount importance in order to achieve good clinical results. These highly sensitive and specific diagnostic procedures such as MRI lumbosacral spine (LSS), computed tomography LSS, radiography LSS, nerve conduction velocity, and electromyography of both lumbosacral plexus are important as they provide a definitive LCS diagnosis while eliminating possible differential diagnoses such as hip osteoarthritis, trochanteric bursitis, and peripheral neuropathy. Several surgical techniques for lumbar spine decompression have been described over the last few decades. The aim of surgery for symptomatic lumbar spinal stenosis is to relieve the symptoms by adequate neural decompression while preserving the anatomy and the biomechanical function of the lumbar spine as much as possible. Traditional treatment of spinal stenosis involves wide laminectomy and undercutting of the medial facet with foraminotomy as well as spinal fusion. Lumbar laminectomies and partial facetectomies are currently the only surgical techniques supported by class 1 evidence. Frequent surgical failure has been attributed to local tissue trauma and postoperative spinal instability. Although in recent years the rates of fusion have been increasing, a minimally invasive procedure that decompresses and stabilizes the spine still allows for natural range of motion. Fusion and instrumentation procedures represent a growing proportion of all LCS surgeries being performed. Despite this growth, currently, there is no class one evidence to prove that instrumentation (pedicle screws, plates, and cages) or biological agents (bone morphogenetic protein) should be used to enhance osseous fusion in patients without criteria of instability. However, there are many studies that present class 2 evidence levels that demonstrate that fusion is both a safe and satisfactory technique in achieving optimal outcomes in elderly patients and patients with degenerative disk disease,. While this evidence is promising, it should be noted that fusion procedures, especially those involving instrumentation, are associated with increased surgical costs and complications.
The aim of this study was to evaluate the results of different methods of decompression in LCS with regard to the effectiveness of different techniques in relieving symptoms, duration of surgery, intraoperative blood loss, and decreasing of postoperative complications such as spinal instability.
| Patients and Methods|| |
This was a prospective study that included 60 patients suffering from LCS with claudicating sciatica in the period spanning from September 2015 to the end of August 2017. Patients were treated with conventional laminectomy without posterolateral fusion, or conventional laminectomy with posterolateral fusion (CLPF), or unilateral laminectomy with bilateral decompression (ULBD). Patients had at least a follow-up period of 6 months.
All patients were presented to the Neurosurgery Department, Faculty of Medicine, Menoufia University. All patients consented for surgery. An approval from the Ethics Committee of the Faculty of Medicine, Menoufia University was taken.
This study included patients complaining of claudicating sciatica (may be more prominent on one side) with evidence of lumbar spinal stenosis or bilateral disc prolapsed in computed tomography or MRI and not responding to nonsurgical treatment [Figure 1]a,[Figure 1]b,[Figure 1]c,[Figure 1]d.
|Figure 1: A case of a female patient, 57 years old, presenting with right claudicating sciatica for 9 months, (a and b) Sagittal and axial T2WI MRI images are showing L4–5, L5-S1 discogenic with ligamentum stenosis more on right side. (c) Preoperative radiograph A–P and lateral views are normal with no spinal instability. (d) Postoperative axial CT scans show unilateral laminectomy. (e and f) intraoperative images show L5 nerve root on both sides decompressed after ULBD. (g) Tilting the table 15-20 degrees brings the zone of foramen and lateral recess into view.|
Click here to view
This study excluded patients with traumatic lumbar spinal injury or spinal instability, specific or nonspecific spinal infection, vascular claudication and no radiological evidence of nerve root compression in their investigation.
Selection of a different surgical approach was according to surgeon's preference. Data such as age, surgery levels, blood loss, operative time, length of stay, and complications were obtained. Postoperative clinical evaluation was conducted within 4 weeks of surgery and 6 months postoperatively. Postoperative MRI was performed if needed. In this study, all cases selected for unilateral laminectomy surgery had bilateral affection with lateral recess and central stenosis. We began with general anesthesia; thereafter, the patient was placed in the prone position. By using the preincision needle localization film to determine the correct size of exposure, a small incision (∼2 cm) was made in or just off the midline. Bovie-electrocautery could be used for subcutaneous dissection and for accomplishing hemostasis. Monopolar-electrocautery was used to dissect through subcutaneous fat to the lumbodorsal fascia. Dissection should be continued with monopolar cautery to elevate paraspinal muscles subperiosteally; Cobb dissectors can be used with a sweeping motion. Self-retaining hemiretractor or tube retractor was placed as needed. For exposure of neural structures, we removed the lower half of the lamina above and upper third of the lamina below, allowing for complete removal of ligamentum flavum and leaving the central portion of the neural arch preserved. Thus, the interspinous and supraspinous ligaments remained intact, minimizing spinal instability. In order to gain access to the medial aspect of the superior facet, a partial facetectomy of the inferior facet was performed medially. Undercutting of the superior facet was carried out and then performed with the aid of a Kerrison rongeur. The neural foramen was subsequently checked for whether the nerve root had been adequately decompressed. Dealing with the contralateral side started with undermining the spinous process; tilting the table 15–20° brings the zone of the foramen and lateral recess into view [Figure 1]g, affording visualization across the midline beneath the deepest portion of the interspinous ligament. The contralateral portion of the ligamentum flavum was resected sequentially from cephalic to caudal until the contralateral nerve root was seen exiting freely into the foramen; thereafter, the lateral recess was cleaned. Undercutting of the spinous process with a rongeur provided excellent visibility of the contralateral side. Contralateral decompression was performed and then achieved in the same manner. Sufficient decompression of the nerve root was tested by sliding a blunt instrument along its course as in [Figure 1]e and [Figure 1]f. Discectomy was generally required in the treatment of LCS when it was of disc origin or when there was a possibility of a concomitant disc herniation that might compress the root. Free fragment in the canal could be removed with rongeurs if visible; if under the thecal sac, the fragments could often be brought into the field with nerve hooks, and then removed with a rongeur. With bipolar electrocautery, the annulus over the disc space was cauterized; crossing epidural veins are likewise cauterized and divided. The annulus was incised with a no. 11 either making a rectangle or single cut parallel to the nerve root. The nerve hooks helped to free up subligamentous fragments. Disc fragments were removed using a rongeur. Hemostasis with cautery, gel-foam, and gentle pressure with cottonoid were performed as needed. Hemovac was used if hemostasis was a concern. We used 1 Vicryl suture in fascia and 0 Vicryl suture in subcutaneous tissue. The skin was reapproximated and closed with either 2.0 prolene or running 4-0 subcuticular stitches.
In case of conventional laminectomy (CL), we removed the spinous process, supraspinous ligament, interspinous ligament with complete removal to the lamina to allow for complete removal of the underlying hypertrophied ligamentum flavum.
In case of severe bony stenosis, we removed the lateral recess through performing medial facetectomy and checking the neural foramen to ensure that the nerve root has been adequately decompressed through foraminotomy. With the previous laminectomy, we opted for posterolateral fusion through pedicle screw instrumentation in case of CLPF [Figure 2] and [Figure 3].
|Figure 2: A case of a male patient, 65 years old, presenting with neurogenic claudication on both sides for more than one year, (a and b) Sagittal and axial T2WI MRI images are showing multiple level discogenic with ligamentum stenosis. (c) postoperative MRI images are showing left unilateral laminectomy with bilateral decompression for multiple level. (d) Postoperative axial CT scans show unilateral laminectomy to do bilateral decompression. (e) postoperative sagittal CT scan shows intact spinous process. (f) postoperative radiograph A-P shows multiple unilateral laminectomy.|
Click here to view
|Figure 3: A case of a male patient, 55 years old, presenting with neurogenic claudication more on left side for 8 months, (a and b) Sagittal and axial T2WI MRI images are showing multiple level discogenic with ligamentum and bony stenosis. (c and d) Preoperative radiograph A–P and lateral views are normal with no spinal instability. (e) Postoperative radiograph A–P and lateral views show 4 levels conventional laminectomy with posterolateral fusion. |
Click here to view
Data were collected, tabulated, and statistically analyzed using an IBM personal computer with statistical package for the social sciences (SPSS) version 23 (2015; released by SPSS Inc., Chicago, Illinois, USA. IBM SPSS statistics for windows, version 23.0; IBM Corp., Armonk, New York, USA), where the following statistics were applied. Descriptive statistics with quantitative data were presented in the form of mean, SD and range. Qualitative data were presented in the form of numbers and percentages. χ2-Test was used to study the association between two qualitative variables. Wilcoxon's test was used for nonparametric data. Level of significance was set as the P value of less than 0.05.
| Results|| |
This study included 60 patients, with age varying from 30 to 70 years and mean age of 57.7 ± 10.3. A total of 41 (68.3%) patients were male individuals and 19 (31.6%) patients were female individuals. In this study, claudication and sciatica were present in 93% of cases, 6% of cases presented motor deficit, cauda equina or sphincteric disturbance. Twenty patients were subjected to ULBD surgery. Single-level decompression was performed for 11 cases, double-level decompression was performed for seven cases, and triple-level decompression was performed for two cases, and the total levels were 31 levels. Twenty patients were subjected to CL surgery. Single-level decompression was performed for one case, double-level decompression was performed for eight cases, and triple-level decompression was performed for eight cases, quadruple-level decompression was performed for three cases and the total levels were 53 levels. Twenty patients were subjected to CLPF surgery. Single-level decompression was performed for two cases, double-level decompression was performed for seven cases, triple-level decompression was performed for seven cases and quadruple-level decompression was performed for four cases and the total levels were 53 levels. As regards the mean duration of surgery in ULBD, surgery lasted for 3.0 ± 0.59 h for one level, 6.1 ± 1.3 h for two levels, and 6.5 ± 0.0 h for three levels, although in CL surgery, the mean duration of surgery was 1.5 ± 0.0 h for one level, 2.9 ± 0.88 h for two levels, 3.13 ± 0.84 h for 3 levels, and 3.8 ± 1.9 h for four levels, despite the fact that in CLPF mean was 2.0 ± 0.0 h for one level, 3.6 ± 0.49 h for two levels, 3.9 ± 0.35 h for three levels, and 4.0 ± 0.0 h for four levels (P = 0.009) [Figure 4]. The mean ± SD blood loss in ULBD surgery was 100.0 ± 51.3 ml, but in CL it was 852.5 ± 361.8 ml and in CLPF it was 1000.0 ± 295.6 ml. According to the intraoperative blood loss in relation to the number of levels of surgery, mean blood loss in single-level ULBD surgery was 63.3 ml, but, in CL, it became 500 ml and, in CLPF laminectomy was 700 ml. These numbers increased with the number of levels, mean blood loss in three-level ULBD surgery was 150 ml, although in CL it was 943.8 and in CLPF it was 1050 ml (P < 0.001). In this study, twenty patients were subjected to ULBD surgery, intraoperative complications, especially dural tear, occurred in three (15%) patients. The other 20 patients were subjected to CL surgery, dural tear occurred in three (15%) patients, but, in 20 patients with CLPF, dural tear was occurred in two (10%) patients. The incidence of cerebrospinal fluid leak after dural tear was 0% in case of ULBD surgery, but in CL or CLPF, it was 100% of all cases with dural tear (three cases in CL and two cases with CLPF) (P = 0.35). In this study, root injury occurred in one patient of 20 in case of ULBD surgery, in two patients of 20 in CL and in three patients of 20 in CLPF (P = 0.57). One (5%) patient of 20 patients with ULBD surgery developed hematoma collection in the wound, five (25%) patients with CL developed hematoma collection in the wound, but seven (35%) patients with CLPF developed the same complication (P = 0.05). Postoperative wound infection in ULBD surgery occurred in two (10%) of 20 patients, four (20%) patients with CL suffered from wound infection but five (25%) patients with CLPF had wound infection (P = 0.46). In this study, one (5%) of the 20 patients subjected to ULBD surgery had late (1 year later) postoperative spinal instability (spondylolisthesis). Two (10%) of 20 patients subjected to CL surgery had late (1 year later) postoperative spinal instability (spondylolisthesis). Three (15%) of 20 patients subjected to CLPF surgery had late (1 year later) postoperative spinal instability (spondylolisthesis) [Table 1]. In this study, the duration of hospital stay for patients subjected to ULBD surgery was 1 day postoperatively with a mean ± SD of 1.0 ± 0.51 days. The duration of hospital stay for patients subjected to CL surgery was 2.5 days with mean ± SD of 2.5 ± 1.2 days. The duration of hospital stay for patients subjected to CLPF surgery was 2.8 days with mean ± SD of 2.8 ± 1.7 days (P < 0.001). There was a statistically significant difference between preoperative ODI and 1 month postoperative ODI. Moreover, there was a statistically significant difference on comparing preoperative ODI and after 6 months of surgery (P < 0.001). On the contrary, there was no significant differences between ODI immediately postoperatively and after 6 months of surgery either in ULBD or CL or CLPF. Patients subjected to ULBD surgery had the same outcome according to ODI [Table 2].
|Figure 4: Time of operation in hours in relation to levels operated with each approach.|
Click here to view
|Table 2: Preoperative and postoperative (1 month and 6 months) Oswestry disability index for different approaches|
Click here to view
| Discussion|| |
LCS has a large spectrum of potential treatment options, as the disease itself has a wide range of severities. The patient's physical and socioeconomic status should also be taken into account when diagnosing LCS. Today, most LCS patients fall between 50 and 60 years of age, with their condition commonly arising alongside age-associated degeneration of the lumbar and facet joints. However, female individuals, heavy manual laborers, smokers, and individuals with a BMI above 30 had more risk for developing LCS. Traditional treatment of spinal stenosis involves wide laminectomy and undercutting of the medial facet with foraminotomy. The affection of the younger mean age group in this study may be because most patients suffered from discoligamentous stenosis, which occurs in a younger age group than bony stenosis, which occurs in an older age group, as in other studies, and because of lack of exercise and increasing BMI in most of the Egyptian population. Postacchini et al. reported a significantly increased duration of bilateral laminectomy in cases of multiple-level decompression, but not when comparing single-level decompression. Most of the studies reported same operative time for CL with or without posterolateral fusion for the different levels but less time for ULBD,,,,. Most of the studies reported that blood loss was much more in the CL approach with or without fusion rather than ULBD, and it also increased with the number of levels,,,,. Minimal invasive approach such as ULBD had a rapid recovery starting from the first day postoperatively, with less blood loss intraoperatively, thus resulting in less hospital stay, but most of the studies reported long hospital stay for those who underwent CL with or without posterolateral fusion,,. Studies reported that intraoperative and postoperative complications increased with CL, without fusion or with posterolateral fusion, and became more prominent rather than minimal invasive procedure, as in ULBD,,. Most of the studies reported that ODI has significant difference after operation in LCS, with different surgical approaches, whether minimally invasive or conventional surgeries, rather than preoperatively,,. Most of the changes in the ODI occurred between preoperative and early follow-up. Limitations in this study lie in its small sample size and short length of follow-up, because difficulties to work with such a big sample and outcomes may be worse in the long term,. Clear conclusions between group differences in ODI and long-term complication and reoperation rates could not be made. It was hard to perform a different type of fusion (like posterolateral lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), or anterolateral lumbar interbody fusion (ALIF). There was a difficulty of performing minimal invasive ULBD in some patient with evidence of scoliosis or multiple levels (more than 4 levels) and severe bony stenosis. There was a steep learning curve bias in this study, as ULBD took time with different neurosurgeons. The good point in this study was that all patients in different groups significantly improved with the different approaches used.
| Conclusion|| |
On the basis of short-term follow-up, a minimally invasive technique like ULBD allowed decompression, preserving spine stability with a natural range of motion, with less blood loss, less hospital stay and decreased intraoperative and postoperative complication than CL with or without posterolateral fusion.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Zweig T, Enke J, Mannion AF, Sobottke R, Melloh M, Freeman BJ, et al
. Is the duration of pre-operative conservative treatment associated with the clinical outcome following surgical decompression for lumbar spinal stenosis? A study based on the Spine Tango Registry. Eur Spine J 2017; 26
Harrisson SA, Stynes S, Dunn KM, Foster NE, Konstantinou K. Neuropathic pain in low back-related leg pain patients: what is the evidence of prevalence, characteristics, and prognosis in primary care? A systematic review of the literature. J Pain 2017; 2017
Montemarano MA. Thesuccess rates of surgical and non-surgical approaches in the management and treatment of spinal stenosis. Boston University; Boston city, 2015.
Alimi M, Hofstetter CP, Pyo SY, Paulo D, Härtl R. Minimally invasive laminectomy for lumbar spinal stenosis in patients with and without preoperative spondylolisthesis: clinical outcome and reoperation rates. J Neurosurg Spine 2015; 22
Joaquim AF, Sansur CA, Hamilton DK, Shaffrey CI. Degenerative lumbar stenosis: update. Arq Neuropsiquiatr 2009; 67
Hong S-W, Choi KY, Ahn Y, Baek OK, Wang JC, Lee S-H, et al
. A comparison of unilateral and bilateral laminotomies for decompression of L4-L5 spinal stenosis. Spine 2011; 36
Malmivaara A, Slätis P, Heliövaara M, Sainio P, Kinnunen H, Kankare J, et al
. Surgical or nonoperative treatment for lumbar spinal stenosis? A randomized controlled trial. Spine 2007; 32
Ulrich NH, Burgstaller JM, Pichierri G, Wertli MM, Farshad M, Porchet F, et al
. Decompression surgery alone versus decompression plus fusion in symptomatic lumbar spinal stenosis: a Swiss Prospective Multicenter Cohort Study with 3 years of follow-up. Spine 2017; 42
Pavlov PW, Meijers H, van Limbeek J, Jacobs WC, Lemmens JAM, Obradov-Rajic M, et al
. Good outcome and restoration of lordosis after anterior lumbar interbody fusion with additional posterior fixation. Spine 2004; 29
Katz JN, Harris MB. Lumbar spinal stenosis. N Engl J Med 2008; 358
Postacchini F, Cinotti G, Perugia D, Gumina S. The surgical treatment of central lumbar stenosis. Multiple laminotomy compared with total laminectomy. Bone Joint J 1993; 75
Çelik SE, Çelik S, Göksu K, Kara A, Ince I. Microdecompressive laminatomy with a 5-year follow-up period for severe lumbar spinal stenosis. Clin Spine Surg 2010; 23
Thomé C, Zevgaridis D, Leheta O, Bäzner H, Pöckler-Schöniger C, Wöhrle J, et al
. Outcome after less-invasive decompression of lumbar spinal stenosis: a randomized comparison of unilateral laminotomy, bilateral laminotomy, and laminectomy. J Neurosurg Spine 2005; 3
Yagi M, Okada E, Ninomiya K, Kihara M. Postoperative outcome after modified unilateral-approach microendoscopic midline decompression for degenerative spinal stenosis. J Neurosurg Spine 2009; 10
Schöller K, Alimi M, Cong G-T, Christos P, Härtl R. Lumbar spinal stenosis associated with degenerative lumbar spondylolisthesis: a systematic review and meta-analysis of secondary fusion rates following open vs. minimally invasive decompression. Neurosurgery 2017; 80
Overdevest G, Vleggeert-Lankamp C, Jacobs W, Thomé C, Gunzburg R, Peul W. Effectiveness of posterior decompression techniques compared with conventional laminectomy for lumbar stenosis. Eur Spine J 2015; 24
Rahman M, Summers L, Richter B, Mimran R, Jacob R. Comparison of techniques for decompressive lumbar laminectomy: the minimally invasive versus the 'classic' open approach. Minm Invasive Neurosurg 2008; 51
Ghogawala Z, Dziura J, Butler WE, Dai F, Terrin N, Magge SN, et al
. Laminectomy plus fusion versus laminectomy alone for lumbar spondylolisthesis. N Engl J Med 2016; 374
Fu Y-S, Zeng B-F, Xu J-G. Long-term outcomes of two different decompressive techniques for lumbar spinal stenosis. Spine 2008; 33
Liu X, Yuan S, Tian Y. Modified unilateral laminotomy for bilateral decompression for lumbar spinal stenosis. Spine 2013; 38
Austevoll IM, Gjestad R, Brox JI, Solberg TK, Storheim K, Rekeland F, et al
. The effectiveness of decompression alone compared with additional fusion for lumbar spinal stenosis with degenerative spondylolisthesis: a pragmatic comparative non-inferiority observational study from the Norwegian Registry for Spine Surgery. Eur Spine J 2017; 26
Çavuşoǧlu H, Kaya RA, Türkmenoglu ON, Tuncer C, Colak I, Aydın Y. Midterm outcome after unilateral approach for bilateral decompression of lumbar spinal stenosis: 5-year prospective study. Eur Spine J 2007; 16
Mariconda M, Fava R, Gatto A, Longo C, Milano C. Unilateral laminectomy for bilateral decompression of lumbar spinal stenosis: a prospective comparative study with conservatively treated patients. Clin Spine Surg 2002; 15
Tuite GF, Stern JD, Doran SE, Papadopoulos SM, McGillicuddy JE, Oyedijo DI, et al
. Outcome after laminectomy for lumbar spinal stenosis. Part I: clinical correlations. J Neurosurg 1994; 81
[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]