Chimney sublaminar decompression for degenerative lumbar spinal stenosis

Efficacy of Spinous Process Splitting Decompression Compared with Conventional Laminectomy for Degenerative Lumbar Stenosis

BACKGROUND

Spinous process splitting decompression (SPSD) is a minimally invasive surgical technique. We evaluated the clinical and radiological outcomes of SPSD compared with conventional laminectomy for the treatment of degenerative lumbar spinal stenosis.

METHODS

SPSD was performed in 144 patients (group 1) and conventional laminectomy was performed in 132 patients (group 2) for degenerative lumbar spinal stenosis. Operative time, blood loss, hospital stay, and complications were compared between groups. Functional outcome was evaluated 2 years after surgery by Oswestry Disability Index, visual analog scale for back pain and leg pain, and progress in walking capacity. Spinal anteroposterior diameter and cross-sectional area were assessed by magnetic resonance imaging and computed tomography.

RESULTS

Both groups showed significant improvement in mean functional outcome scores of Oswestry Disability Index and mean visual analog scale for back and leg pain after surgery (P < 0.001), although the differences in scores between the groups (P > 0.05) were not statistically significant. Walking capacity was reported as "much better" and "moderately better" in 89% of patients in group 1 and 87.8% of patients in group 2 (P > 0.05). On the basis of radiographic findings, satisfactory neurological decompression was achieved in group 1 (72.2% increase in mean spinal anteroposterior diameter, 102.5% increase in cross-sectional area) and group 2 (80.3% in mean spinal anteroposterior diameter, 108.8% increase in cross-sectional area) (P > 0.05).

CONCLUSIONS

Patients who underwent SPSD for lumbar spinal decompression had comparable functional recovery rates correlated with clinical and radiological improvement to patients who underwent conventional laminectomy.

Sublaminar Decompression: A New Technique for Spinal Canal Decompression in the Treatment of Stenosis in Degenerative Spinal Conditions

STUDY DESIGN

Technical report and case illustration.

OBJECTIVE

To review the rationale and steps for a sublaminar decompression in the setting of adult deformity surgery and in degenerative spondylosis.

SUMMARY OF BACKGROUND DATA

Several variations of lumbar laminotomy and posterior decompressions have been reported, although these are primarily in the setting of isolated lumbar stenosis, and often focus on treatment of central stenosis.

MATERIALS AND METHODS

Our operative technique is illustrated and 1 patient with a 1-year follow-up is presented to further describe this surgical approach.

RESULTS AND SURGICAL TECHNIQUES

The patient underwent a lumbar decompression and fusion procedure. A sublaminar decompression with bilateral foraminotomies was performed at L4-L5, combined with instrumented posterior fusion.

CONCLUSIONS

The presented sublaminar decompression technique allows for adequate decompression of the central canal, lateral recess, and neural foramina while providing maximum bone surface area for posterolateral as well as posterior fusion.

Lumbar Spinous Process-Splitting Laminoplasty: A Novel Technique for Minimally Invasive Lumbar Decompression

Minimally invasive posterior spinous process-splitting laminoplasty preserving the paraspinal musculature has been introduced to treat patients with lumbar spinal stenosis. Despite its theoretical advantage of limiting muscular trauma, additional efforts are required to evaluate patients' clinical and functional results following this procedure. Between 2010 and 2012, 37 patients underwent spinous process-splitting laminoplasty for lumbar stenosis at a mean age of 68 years (range, 36-87 years) and were followed for minimum of 1 year (mean, 1.3 years). There were 22 (59%) men and 15 (41%) women. Mean number of levels treated with a spinous process-splitting laminoplasty was 2.2 (range, 1-6 levels). Patients had statistically significant improvements in their scores for all self-reported outcomes, including visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and Short Form 36 (SF-36) components. Mean VAS significantly decreased by 4.4±3.2 points for back pain and 3.9±3.7 points for leg pain (P<.0001). Mean ODI significantly decreased by 17.5±19.1 points (P<.0001), and mean SF-36 significantly increased by 29±30.4 points (P=.0017) for the physical component and 21.8±25.6 points (P=.0062) for the mental health component. Four (10.8%) patients had a dural tear requiring repair (3 were intraoperative), 3 (8%) had an epidural hematoma requiring evacuation, 1 (2.7%) had an infection requiring irrigation and debridement, and 2 (5%) had additional decompression for symptom recurrence secondary to instability. Lumbar spinous process-splitting laminoplasty is a novel minimally invasive technique that provides adequate decompression for the neuronal elements and may avoid extensive paraspinal muscular damage associated with conventional laminectomy. Patients demonstrated significant improvements in pain and overall heath and function scores at a minimum 1-year follow-up. [Orthopedics.2016; 39(5):e950-e956.].

Iatrogenic spondylolisthesis following laminectomy for degenerative lumbar stenosis: systematic review and current concepts

OBJECT Decompression without fusion for degenerative lumbar stenosis is an effective treatment for both the pain and disability of neurogenic claudication. Iatrogenic instability following decompression may require further intervention to stabilize the spine. The authors review the incidence of postsurgical instability following lumbar decompression, and assess the impact of surgical technique as well as study design on the incidence of instability. METHODS A comprehensive literature search was performed to identify surgical cohorts of patients with degenerative lumbar stenosis, with and without preexisting spondylolisthesis, who were treated with laminectomy or minimally invasive decompression without fusion. Data on patient characteristics, surgical indications and techniques, clinical and radiographic outcomes, and reoperation rates were collected and analyzed. RESULTS A systematic review of 24 studies involving 2496 patients was performed, assessing both open laminectomy and minimally invasive bilateral canal enlargement. Postoperative pain and functional outcomes were similar across the various studies, and postoperative radiographie instability was seen in 5.5% of patients. Instability was seen more frequently in patients with preexisting spondylolisthesis (12.6%) and in those treated with open laminectomy (12%). Reoperation for instability was required in 1.8% of all patients, and was higher for patients with preoperative spondylolisthesis (9.3%) and for those treated with open laminectomy (4.1%). CONCLUSIONS Instability following lumbar decompression is a common occurrence. This is particularly true if decompression alone is selected as a surgical approach in patients with established spondylolisthesis. This complication may occur less commonly with the use of minimally invasive techniques; however, larger prospective cohort studies are necessary to more thoroughly explore these findings.

Clinical outcomes following sublaminar decompression and instrumented fusion for lumbar degenerative spinal pathology

Traditional treatment for lumbar stenosis with instability is laminectomy and posterolateral arthrodesis, with or without interbody fusion. However, laminectomies remove the posterior elements and decrease the available surface area for fusion. Therefore, a sublaminar decompression may be a preferred approach for adequate decompression while preserving bone surface area for fusion. A retrospective review of 71 patients who underwent sublaminar decompression in conjunction with instrumented fusion for degenerative spinal disorders at a single institution was performed. Data collected included demographics, preoperative symptoms, operative data, and radiographical measurements of the central canal, lateral recesses, and neural foramina, and fusion outcomes. Paired t-tests were used to test significance of the outcomes. Thirty-one males and 40 females with a median age 60years underwent sublaminar decompression and fusion. A median of two levels were fused. The mean Visual Analog Scale pain score improved from 6.7 preoperatively to 2.9 at last follow-up. The fusion rate was 88%, and the median time to fusion was 11months. Preoperative and postoperative mean thecal sac cross-sectional area, right lateral recess height, left lateral recess height, right foraminal diameter, and left foraminal diameter were 153 and 209mm(2) (p<0.001), 5.9 and 5.9mm (p=0.43), 5.8 and 6.3mm (p=0.027), 4.6 and 5.2mm (p=0.008), and 4.2 and 5.2mm (p<0.001), respectively. Sublaminar decompression provided adequate decompression, with significant increases in thecal sac cross-sectional area and bilateral foraminal diameter. It may be an effective alternative to laminectomy in treating central and foraminal stenosis in conjunction with instrumented fusion.

A novel surgical approach to the lumbar spine involving hemilateral split-off of the spinous process to preserve the multifidus muscle: technical note

In the conventional posterior approach to the lumbar spine, the lamina is exposed by stripping the paravertebral muscles from the spinous process, and the resulting paravertebral muscle damage can produce muscle atrophy and decreased muscle strength. The author developed a novel surgical approach to the lumbar spine in which the attachment of the paravertebral muscles to the spinous process is preserved. In the novel approach, the spinous process is split on the midline without stripping the attached muscles, and a hemilateral half of the spinous process is then resected at the base, exposing only the ipsilateral lamina. Before closing, the resected half is sutured and reattached to the remaining half of the spinous process. Thirty-eight patients with lumbar spinal canal stenosis (LSCS) undergoing unilateral partial laminectomy and bilateral decompression using this novel approach were analyzed. Postoperative changes in the multifidus muscle were evaluated by T2 signal intensity on MR images. MRI performed 1 year after the operation revealed no significant difference in the T2 signal intensity of the multifidus muscle between the approach and nonapproach sides. This result indicated that postoperative changes of the multifidus muscle on the approach side were slight. The clinical outcomes of unilateral partial laminectomy and bilateral decompression using this approach for LSCS were satisfactory. The novel approach can be a useful alternative to the conventional posterior lumbar approach.

Spinous Process splitting Laminectomy: Clinical outcome and Radiological analysis of extent of decompression

INTRODUCTION

Spinous process splitting laminectomy (SPSL) is a useful technique in achieving adequate decompression for lumbar canal stenosis, has the advantage of simultaneously decompressing multiple levels and minimising injury to the paraspinal muscles. Some concern has been expressed over the efficacy of this technique in decompressing lateral recesses. This study was undertaken to assess the clinical outcome of SPSL technique and radiologically assess the extent of decompression.

PATIENTS AND METHODS

Thirty-nine consecutive patients treated by SPSL for degenerative lumbar spinal stenosis were methodically assessed for demographic data, clinical findings, Pre- and post-op VAS, JOA scores and spinal canal dimensions on imaging. Surgical technique for SPSL is described.

RESULTS

The mean age of the patients was 66.9 yrs. The mean follow-up was 7.3 months. The mean pre- and post-operative VAS scores were 7.8 and 3.7, respectively. The mean pre- and post-operative JOA scores were 6.3 and 11.2, respectively. The mean JOA recovery rate was 57.3%. 77% of the patients were in the 'good' or 'excellent' McNab's grades at follow-up. Radiologic results were assessed separately at the 118 levels decompressed by the SPSL technique. The ratio increase for the spinal canal dimensions on post-operative images were as follows - Interfacet distance-116.6%; Effective AP distance-67.6%; Right lateral recess depth-165.1%; Right lateral recess angle-145.5%; Left lateral recess depth-149.3%; Left lateral recess angle-133.6%; Cross-sectional spinal canal area-163.8%. There was no worsening of pre-existing degenerative listhesis or scoliosis in any case.

CONCLUSION

SPSL achieves effective central and lateral recess decompression, at the same time minimising injury to the paraspinal muscles thus reducing post-operative pain and aiding in quicker mobilisation and recovery. It is an effective tool to treat multiple level spinal stenosis, especially in elderly patients who have pre-existing spinal deformities which can precipitate into frank instability after conventional procedures.

Central decompressive laminoplasty for treatment of lumbar spinal stenosis : technique and early surgical results

OBJECTIVE

Lumbar spinal stenosis is a common degenerative spine disease that requires surgical intervention. Currently, there is interest in minimally invasive surgery and various technical modifications of decompressive lumbar laminectomy without fusion. The purpose of this study was to present the author's surgical technique and results for decompression of spinal stenosis.

METHODS

The author performed surgery in 57 patients with lumbar spinal stenosis between 2006 and 2010. Data were gathered retrospectively via outpatient interviews and telephone questionnaires. The operation used in this study was named central decompressive laminoplasty (CDL), which allows thorough decompression of the lumbar spinal canal and proximal two foraminal nerve roots by undercutting the lamina and facet joint. Kyphotic prone positioning on elevated curvature of the frame or occasional use of an interlaminar spreader enables sufficient interlaminar working space. Pain was measured with a visual analogue scale (VAS). Surgical outcome was analyzed with the Oswestry Disability Index (ODI). Data were analyzed preoperatively and six months postoperatively.

RESULTS

The interlaminar window provided by this technique allowed for unhindered access to the central canal, lateral recess, and upper/lower foraminal zone, with near-total sparing of the facet joint. The VAS scores and ODI were significantly improved at six-month follow-up compared to preoperative levels (p<0.001, respectively). Excellent pain relief (>75% of initial VAS score) of back/buttock and leg was observed in 75.0% and 76.2% of patients, respectively.

CONCLUSION

CDL is easily applied, allows good field visualization and decompression, maintains stability by sparing ligament and bony structures, and shows excellent early surgical results.

Lumbar spinous process splitting decompression provides equivalent outcomes to conventional midline decompression in degenerative lumbar canal stenosis: a prospective, randomized controlled study of 51 patients

STUDY DESIGN

Prospective, randomized controlled study.

OBJECTIVE

To compare the functional outcomes and extent of paraspinal muscle damage between 2 decompressive techniques for lumbar canal stenosis.

SUMMARY OF BACKGROUND DATA

Lumbar spinous process splitting decompression (LSPSD) preserves the muscular and liga-mentous attachments of the posterior elements of the spine. It can potentially avoid problems such as paraspinal muscle atrophy and trunk extensor weakness that can occur after conventional midline decompression. However, large series prospective randomized controlled studies are lacking.

METHODS

Patients with lumbar canal stenosis were randomly allocated into 2 groups: LSPSD (28 patients) and conventional midline decompression (23 patients). The differences in operative time, blood loss, time to comfortable mobilization, and hospital stay were studied. Paraspinal muscle damage was assessed by postoperative rise in creatine phosphokinase and C-reactive protein levels. Functional outcome was evaluated at 1 year by Japanese Orthopaedic Association score, neurogenic claudication outcome score, and visual analogue scale for back pain and neurogenic claudication.

RESULTS

Fifty-one patients of mean age 56 years were followed-up for a mean 14.2 ± 2.9 months. There were no significant differences in the operative time, blood loss, and hospital stay. Both the groups showed significant improvement in the functional outcome scores at 1 year. Between the 2 groups, the Japanese Orthopaedic Association score, neurogenic claudication outcome score improvement, visual analogue scale for back pain, neurogenic claudication visual analogue scale, and the postoperative changes in serum C-reactive protein and creatine phosphokinase levels did not show any statistically significant difference. On the basis of the Japanese Orthopaedic Association recovery rate, it was found that 73.9% of conventional midline decompression group had good outcomes compared with only 60.7% after LSPSD.

CONCLUSION

The functional outcome scores, back pain, and claudication pain in the immediate period and at the end of 1 year are similar in both the techniques. More patients had better functional outcomes after conventional decompression than the LSPSD technique. On the basis of this study, the superiority of one technique compared with the other is not established, mandating the need for further long-term studies.

LEVEL OF EVIDENCE

2.

Results after lumbar decompression with and without discectomy: comparison of the transspinous and conventional approaches

OBJECTIVE

To evaluate the efficacy of the transspinous approach compared with the conventional approach in single-level lumbar laminotomies with and without discectomies.

METHODS

Forty consecutive patients underwent single-level lumbar decompression with or without a discectomy. The first 20 patients underwent surgery by the conventional approach (11 with discectomy and 9 without), and the transspinous approach was used in the remaining 20 patients (11 with discectomy and 9 without). Results between the groups were assessed by comparing the following measures: length of inpatient hospital stay, postoperative pain and analgesia use, estimated blood loss, rate of postoperative disability and complications, and incision length.

RESULTS

The groups did not differ significantly with respect to age, level of pathology, insurance status, or type of analgesia used. The primary outcome was physical disability, measured using the Roland-Morris Disability Questionnaire. The secondary outcome was pain intensity, measured using the Brief Pain Inventory. Patients who underwent the transspinous approach had better outcomes across all measures with significance appreciated in those who underwent transspinous decompression with discectomies. Other statistically significant differences were identified in incision length and postoperative analgesia use at the end of 1 week. No statistically significant differences were identified in the rates of complications, estimated blood loss, inpatient narcotic analgesia use, or length of inpatient hospital stay.

CONCLUSION

Patients who underwent single-level lumbar decompression with or without discectomy had similar outcomes as those who underwent the conventional approach. Although of modest clinical significance, the transspinous approach may afford early mobilization and reduced postoperative pain while providing a satisfactory neurological and functional outcome.

Clinical outcomes of microendoscopic decompressive laminotomy for degenerative lumbar spinal stenosis

The goal of surgical treatment for degenerative lumbar spinal stenosis (LSS) is to effectively relieve the neural structures by various decompressive techniques. Microendoscopic decompressive laminotomy (MEDL) is an attractive option because of its minimally invasive nature. The aim of prospective study was to investigate the effectiveness of MEDL by evaluating the clinical outcomes with patient-oriented scoring systems. Sixty consecutive patients receiving MEDL between December 2005 and April 2007 were enrolled. The indications of surgery were moderate to severe stenosis, persistent neurological symptoms, and failure of conservative treatment. The patients with mechanical back pain, more than grade I spondylolisthesis, or radiographic signs of instability were not included. A total of 53 patients (36 women and 17 men, mean age 62.0) were included. Forty-five patients (84.9%) were satisfied with the treatment result after a follow-up period of 15.7 months (12-24). The clinical outcomes were evaluated with the Oswestry disability index (ODI) and the Japanese Orthopedic Association (JOA) score. Of the 50 patients providing sufficient data for analysis, the ODI improved from 64.3 +/- 20.0 to 16.7 +/- 20.0. The JOA score improved from 9.4 +/- 6.1 to 24.2 +/- 6.0. The improvement rate was 73.9 +/- 30.7% and 40 patients (80%) had good or excellent results. There were 11 surgical complications: dural tear in 5, wrong level operation in 2, and transient neuralgia in 4 patients. No wound-related complication was noted. Although the prevalence of pre-operative comorbidities was very high (69.8%), there was no serious medical complication. There was no post-operative instability at the operated segment as evaluated with dynamic radiographs at final follow-up. We concluded that MEDL is a safe and very effective minimally invasive technique for degenerative LSS. With an appropriate patient selection, the risk of post-operative instability is minimal.

Unilateral multilevel interlaminar fenestration instead of laminectomy or hemilaminectomy: an alternative surgical approach to intraspinal space-occupying lesions

✓Laminectomy is the most conventional dorsal approach to intraspinal space-occupying lesions and may result in gradually increasing instability or deformity of the vertebral column. Less invasive procedures such as hemilaminectomy and osteoplastic laminotomy have been described by other authors, but an approach that interferes with spinal stability to an even lesser extent seems desirable.

In an attempt to further reduce the need for bone removal, the authors used interlaminar fenestration (mostly unilateral) at one or more spinal levels to remove intramedullary, extramedullary, or extradural lesions, and even some lesions that extended over several spine segments. The authors present their experiences with this surgical approach in 78 patients harboring different intraspinal lesions. Up to 16 segments were fenestrated in one patient. Complete removal of the lesion was possible in most patients, and no postoperative spinal instabilities were observed in up to 8 years of follow up. Multilevel interlaminar fenestration, also called “multiple spinal keyhole surgery,” is a feasible, safe, and effective approach to intraspinal lesions.

Split-spinous process laminotomy and discectomy for degenerative lumbar spinal stenosis: a preliminary report

OBJECT

The authors evaluated a new minimally invasive spinal surgery technique to correct degenerative lumbar spinal stenosis involving a split-spinous process laminotomy and discectomy (also known as the "Marmot operation").

METHODS

This prospective study randomized 70 patients with lumbar stenosis to undergo either a Marmot operation (40 patients), or a conventional laminectomy (30 patients), with or without discectomy. Spinal anteroposterior diameter, cross-sectional area, lateral recess distance, spinal stability, postoperative back pain, functional outcomes, and muscular trauma were evaluated. The follow up ranged from 10 to 18 months, with a mean of 15.1 months for the Marmot operation group and 14.8 months for the conventional laminectomy group. Compared with patients in the conventional laminectomy group, patients who received a Marmot operation had a shorter mean postoperative duration until ambulation without assistance, a reduced mean duration of hospital stay, a lower mean creatine phosphokinase-muscular-type isoenzyme level, a lower visual analog scale score for back pain at 1-year follow up, and a better recovery rate. These patients also had a longer mean duration of operative time and a greater mean blood loss compared with the conventional group. Satisfactory neurological decompression and symptom relief were achieved in 93% of these patients. Most of the patients (66%) in this group needed discectomy for decompression. The postoperative mean lateral recess width, spinal anteroposterior diameter, and cross-sectional area were all significantly increased. There was no evidence of spinal instability in any patient. One patient with insufficient lateral recess decompression and recurrent disc herniation needed additional conventional laminectomy and discectomy, and one patient with mild superficial wound infection was successfully treated with antibiotics and frequent dressing changes.

CONCLUSIONS

A Marmot operation may provide effective spinal decompression. Although this method requires more operative time than a conventional method, it may involve only minimal muscular trauma, spinal stability maintenance, and early mobilization; shorten the duration of hospital stay; reduce postoperative back pain; and provide satisfactory neurological and functional outcomes.