Outcome after laminectomy for lumbar spinal stenosis. Part I: Clinical correlations

Minimally Invasive Decompression With Noninstrumented Facet Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion for Stenosis Associated With Grade 1 Lumbar Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective matched cohort study.

SUMMARY OF BACKGROUND DATA

With a growing interest in minimally invasive spine surgery (MIS), the question of which technique is the most advantageous for patients with low-grade degenerative lumbar spondylolisthesis (DLS) still remains unclear.

OBJECTIVE

To compare patient-reported outcomes, perioperative morbidity, and rates of reoperation between MIS decompression with either unilateral noninstrumented facet fusion (MIS-F) or with transforaminal interbody fusion (MIS-T) for grade 1 DLS.

METHODS

Twenty patients who underwent MIS-T and 20 patients with MIS-F were matched based on age, sex, and preoperative ODI, VAS back, and VAS leg. All patients had DLS with at least 4 millimeters of translation on standing radiographs. Exclusion criteria included prior level surgery, multilevel instability, disk impinging on the exiting nerve root, spondylolisthesis from significant facet arthropathy, or foraminal compromise from disk collapse. ODI, VAS back, VAS leg, and patient satisfaction measured by the North American Spine Society questionnaire were tracked at 3, 6, 12, and 24 months postoperatively. Minimum clinically important differences and substantial clinical benefits were calculated.

RESULTS

MIS-F and MIS-T resulted in decreased ODI at 3, 6, and 12 months following the index procedure. Sixty percent of MIS-F and 83% of MIS-T patients reached minimum clinically important difference at 1 year postoperatively; however, using the threshold of 30% ODI reduction from baseline, 67% of MIS-F and 83% MIS-T ( P = 0.25) achieved this goal. Forty-three percent of MIS-F and 59% of MIS-T patients met substantial clinical benefits. Satisfaction at 1 year, measured by a score of 1 or 2 on the North American Spine Society questionnaire, was 64% for MIS-F and 83% for MIS-T.

CONCLUSIONS

MIS-F and MIS-T are effective treatment options for spinal stenosis associated with low-grade DLS. Both techniques result in comparable patient-reported outcomes and satisfaction up to 2 years and have similar long-term reoperation rates. More evidence is required to delineate optimal selection characteristics for MIS-F versus MIS-T.

A transfacet approach to the lumbar nerve root canal: technical note

BACKGROUND

Intraforaminal and extraforaminal nerve root compressions caused by disk herniation or stenosis are relatively common causes of lumbar radiculopathy. Currently, the two available surgical treatment methods are decompression from the spinal canal or lateral decompression via the Wiltse approach.

OBJECTIVE

To describe a novel transosseous approach to the lumbar nerve root canal.

METHODS

Transfacet foraminotomy was performed in 11 patients with intraforaminal or extraforaminal disk herniation. The outcome was measured using the Patient Satisfaction Index (PSI), need for reoperation, radiographic criteria, and finite element analysis.

RESULTS

We noted that at the time of dismissal, PSI scores of 1 and 3 were reported by 10 and one patients, respectively. At the last follow-up, 10 patients reported a PSI score of 1 or 2. Two patients required reoperation because of recurrent disk herniation. Two patients underwent computed tomography (CT) postoperatively, which showed the transfacet approach. Intriguingly, a second postoperative CT after one month showed that the hole through the facet joint had shrunk significantly.

CONCLUSION

A posterior-anterior transfacet approach for intraforaminal or extraforaminal disk herniations using an ellipsoid facetectomy is safe and allows for fast and comfortable decompression of the nerve root without compromising the long-term strength of the facet joint.

Microscopic Unilateral Approach for Bilateral Decompression of Lumbar Spinal Stenosis

BACKGROUND

This is a study based on single-surgeon data on spinal stenosis surgery via microscopic approach. The aim is to evaluate the effectiveness of the unilateral approach to bilateral decompression and the usage of Taylor retractors and brain spatula in patients with spinal stenosis.

METHODS

This is a retrospective study on bilateral decompression for lumbar spinal stenosis using a microscopic unilateral approach by a single surgeon, between April 2015 and March 2018. In total, 50 patients were operated due to single level lumbar spinal stenosis. All patients were evaluated by preoperative and postoperative plain radiographs and magnetic resonance (MR) images. Walking distance (WD), visual analog scale (VAS) for pain and Odom's criteria were evaluated for follow-up.

RESULTS

One level of the lumbar spine was surgically decompressed in all patients. The median age of patients was 64.6 (51- 82). Of the patients, 72% (36) were women, and 28% (14) were men. Most patients had refractory low back pain (96%) after conservative treatment. The stenotic levels of the cases were as follows: L3-4, 23(46%); L4-5, 24(48%); and L5-S1, 3 (6%). VAS scores decreased in all patients after surgery. According to Odom's criteria, an excellent or good score was found in 43 patients at the 12th follow-up examination. WDs increased up to 1000 meters for 41 patients.

CONCLUSION

The microscopic unilateral approach to bilateral decompression is an effective method for decompression in spinal stenosis. Via this approach, surgical trauma is reduced and surgically induced instability is avoided as much as possible.

Are There Differences Between Patients with Extreme Stenosis and Non-extreme Stenosis in Terms of Pain, Function or Complications After Spinal Decompression Using a Tubular Retractor System?

BACKGROUND

Micro-tubular decompression in extreme lumbar spinal stenosis is challenging because it is technically difficult to achieve adequate decompression. Whether the results of micro-tubular decompression related to pain, function, and complications in lumbar spinal stenosis of the extreme and non-extreme varieties are different has not yet been conclusively established.

QUESTIONS/PURPOSES

Are there differences between patients with extreme stenosis and non-extreme stenosis in terms of (1) VAS back or leg pain, (2) Oswestry Disability Index (ODI), or (3) complications when they were treated with spinal decompression using a tubular retractor system?

METHODS

Between January 2007 and January 2017, one surgeon performed 325 single-level lumbar micro-tubular decompressions without fusion. Of those, 43% (140 of 325) had extreme stenosis (defined as the absence of cerebrospinal fluid signal and a grey homogeneous dural sac with unrecognizable rootlets and posterior epidural fat in T2 weighted axial MRI image) and the rest had non-extreme stenosis. During this time, we used tubular retractors for these procedures in patients with simple lumbar spinal stenosis who had persistent symptoms despite conservative treatment for neurogenic claudication. No alternate form of decompression was performed in the study period. Patients with complex lumbar spinal stenosis associated with a deformity or instability who were treated with instrumented fusion were excluded. A total of 14% (20 of 140) patients in the extreme stenosis group and 15% (28 of 185) patients in the non-extreme stenosis group were lost to follow-up before 2 years; the remaining 120 patients with extreme stenosis and 157 patients with non-extreme stenosis were analyzed at a mean follow-up of 33 ± 5 months in this retrospective, comparative study. The groups were not different at baseline in terms of preoperative VAS score for back pain, age, gender, BMI or the percentage who had diabetes or who smoked. However, patients with extreme stenosis had higher preoperative ODI scores and higher preoperative VAS score for leg pain compared with the non-extreme group. There was a higher proportion of men in the non-extreme stenosis group (56% [104 of 185] versus 50% [71 of 140]; p = 0.324). Study endpoints were VAS score for leg and back pain, ODI, and complications, all of which were ascertained by chart review. With the numbers available, we could detect with 80% power at p < 0.05 a difference of 0.93 cm of 10 cm on a 10-cm VAS scale for VAS leg pain; a difference of 1.00 cm of 10 cm on a 10-cm VAS scale for VAS back pain and a difference of 2.12 cm of 100 cm on a 100-cm ODI scale.

RESULTS

In terms of pain, both groups improved after surgery, but there was no between-group difference in terms of the VAS scores at the most recent follow-up. VAS back pain improved from a mean of 3 ± 1 to 2 ± 1 in the extreme stenosis group and from 3 ± 1 to 1 ± 1 in the non-extreme stenosis group (p = 0.904); VAS leg pain improved from 7 ± 1 to 1 ± 1 versus 6 ± 1 to 1 ± 1, respectively (p = 0.537). ODI scores likewise improved in both groups, with no between-group difference in the ODI scores at latest follow-up (66 ± 7 to 19 ± 2 in the extreme stenosis group versus 59 ± 5 to 19 ± 2 in the non-extreme stenosis group (p = 0.237). Complications in the group with extreme stenosis occurred in six patients (incidental dural tears in two patients, urinary retention in three patients, and Syndrome of Inappropriate Anti Diuretic Hormone secretion (SIADH) in one patient); complications in the non-extreme stenosis occurred in two patients (incidental dural tears in two patients).

CONCLUSIONS

The results in terms of improvement in VAS for leg and back pain and ODI scores were not different between patients with extreme and non-extreme stenosis. Micro-tubular decompression can be thus considered an alternative for patients with extreme stenosis. Future studies, ideally multicentre, comparative trials, are needed to confirm our preliminary results.

LEVEL OF EVIDENCE LEVEL

III, therapeutic study.

Patient Satisfaction in Spine Surgery: A Systematic Review of the Literature

Patient satisfaction reflects the patients' perception of the outcome of care and is being considered for use in future reimbursement schemes. No consensus exists regarding the best instrument to measure patient satisfaction in the field of spine surgery. This systematic review aimed to determine how patient satisfaction for spine surgery has been measured previously and whether a disease-specific, comprehensive instrument to measure patient satisfaction has been established; we also aimed to define the dimensions of care that determine patient satisfaction in spine surgery. A systematic search of three online databases, unpublished sources, and citations was undertaken to identify 156 empirical studies that reported on patient satisfaction in the field of spine surgery. Manuscripts were reviewed in terms of the patient satisfaction instrument used, and the instruments were categorized as per content and method axes. Taxonomy of patient satisfaction with spine surgery identified the major characteristics of providers and medical care that influenced patient satisfaction and acted as a structure to categorically define the dimensions of patient satisfaction in spine surgery. The reviewed studies predominantly used global (108/156) rather than multidimensional (46/156), instruments. Most studies (96.2%) reported satisfaction with outcome rather than with care, and only 18.5% of the studies (29/156) utilized a disease-specific instrument. The following seven dimensions of patient status, outcome, and care experience that affected patient satisfaction were identified: pain, function, patient expectations/preference, specific patient health characteristics, caregiver interpersonal manner, efficacy/clinical outcomes, and postoperative care/therapy. Currently, no disease-specific instrument that includes all dimensions of patient satisfaction in spine surgery has been developed. Such a patient satisfaction instrument should be designed, tested for reliability and validity, and widely implemented.

Effect of spinal decompression on back pain in lumbar spinal stenosis: a Canadian Spine Outcomes Research Network (CSORN) study

BACKGROUND CONTEXT

Surgical decompression is usually offered for improvement of neurogenic claudication in patients with symptomatic lumbar canal stenosis. These patients often have associated low back pain (LBP) and little is known about the effect of decompression on this symptom.

PURPOSE

The goal of the present study is to specifically quantify the improvement in LBP following surgical decompression for lumbar canal stenosis and to identify factors associated with changes in LBP in this population.

STUDY DESIGN

This is a multicenter, retrospective review of consecutive spine surgery patients enrolled by the Canadian Spine Outcomes and Research Network.

PATIENT SAMPLE

Consecutive patients who underwent surgical treatment for symptomatic lumbar spine stenosis without instability between 2014 and 2017.

OUTCOME MEASURES

Change in LBP on the Numeric Rating Scale (NRS).

METHODS

Patient-reported outcomes were collected at baseline and at 3, 12, and 24 months after surgery. The primary outcome was change in LBP on the NRS. Multivariable logistic regression was used to model the relationship between the outcome and potential factors associated with achieving minimal clinical important difference in back pain using a backward selection procedure.

RESULTS

In all, 1,221 patients were included in the analysis. Mean age was 64 years and 58% were males. Baseline back pain scores were available in 1,133 patients and follow-up evaluations were available in 968/1,133 (85%) patients at 3 months, 649/903 (72%) patients at 12 months, and 331/454 (73%) at 24 months. LBP significantly improved 3 months after surgery and the improvement was sustained at 24 months (p<.001). We found that 74% of patients reached the minimal clinical important difference in back pain. Predictive factors for sustained improvement (12 and 24 months) in LBP after surgical intervention were absence of narcotic usage or compensation claims and increased severity of LBP before surgery (high NRS).

CONCLUSIONS

Alleviation of clinically significant LBP was observed at 3 months after lumbar decompression surgery for neurogenic claudication and was maintained at 12 and 24 months after surgery in the majority of patients.

Application of an interspinous process device after minimally invasive lumbar decompression could lead to stress redistribution at the pars interarticularis: a finite element analysis

Background

An interspinous process device, the Device for Intervertebral Assisted Motion (DIAM™) designed to treat lumbar neurogenic disease secondary to the lumbar spinal stenosis, it provides dynamic stabilization after minimally invasive (MI) lumbar decompression. The current study was conducted using an experimentally validated L1-L5 spinal finite element model (FEM) to evaluate the limited decompression on range of motion (ROM) and stress distribution on a neural arch implanted with the DIAM.

Methods

The study simulated bilateral laminotomies with partial discectomy at L3-L4, as well as unilateral and bilateral laminotomies with partial discectomy combined with implementation of the DIAM at L3-L4. The ROM and maximum von Mises stresses in flexion, extension, lateral bending, and axial torsion were analyzed in response to the hybrid protocol in comparison with the intact model.

Results

The investigation revealed that decreased ROM, intradiscal stress, and facet joint force at the implant level, but considerably increased stress at the pars interarticularis were found during flexion and torsion at the L4, as well as during extension, lateral bending, and torsion at the L3, when the DIAM was implanted compared with the defect model.

Conclusion

The results demonstrate that the DIAM may be beneficial in reducing the symptoms of stress-induced low back pain. Nevertheless, the results also suggest that a surgeon should be cognizant of the stress redistribution at the pars interarticularis results from MI decompression plus the application of the interspinous process device.

Bone-Preserving Decompression Procedures Have a Minor Effect on the Flexibility of the Lumbar Spine

Objective

To mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation.

Methods

A universal spine tester was used to measure the flexibility of six L2–L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3–L4; 2) on three specimens, the unilateral laminotomy was extended to L4–L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3–L4 in the first three specimens and at L4–L5 in the rest); and 4) pedicle screw fixation at the involved levels.

Results

Unilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases.

Conclusion

In vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

Lumbar Spinal Stenosis Associated With Degenerative Lumbar Spondylolisthesis: A Systematic Review and Meta-analysis of Secondary Fusion Rates Following Open vs Minimally Invasive Decompression

Background

Decompression without fusion is a treatment option in patients with lumbar spinal stenosis (LSS) associated with stable low-grade degenerative spondylolisthesis (DS). A minimally invasive unilateral laminotomy (MIL) for "over the top" decompression might be a less destabilizing alternative to traditional open laminectomy (OL).

Objective

To review secondary fusion rates after open vs minimally invasive decompression surgery.

Methods

We performed a literature search in Pubmed/MEDLINE using the keywords "lumbar spondylolisthesis" and "decompression surgery." All studies that separately reported the outcome of patients with LSS+DS that were treated by OL or MIL (transmuscular or subperiosteal route) were included in our systematic review and meta-analysis. The primary end point was secondary fusion rate. Secondary end points were total reoperation rate, postoperative progression of listhetic slip, and patient satisfaction.

Results

We identified 37 studies (19 with OL, 18 with MIL), with a total of 1156 patients, that were published between 1983 and 2015. The studies' evidence was mostly level 3 or 4. Secondary fusion rates were 12.8% after OL and 3.3% after MIL; the total reoperation rates were 16.3% after OL and 5.8% after MIL. In the OL cohort, 72% of the studies reported a slip progression compared to 0% in the MIL cohort, respectively. After OL, satisfactory outcome was 62.7% compared to 76% after MIL.

Conclusion

In patients with LSS and DS, minimally invasive decompression is associated with lower reoperation and fusion rates, less slip progression, and greater patient satisfaction than open surgery.

Perioperative Results and Complications after Posterior Lumbar Interbody Fusion for Spinal Stenosis in Geriatric Patients over than 70 Years Old

Objective

As increasing the size of the geriatric population, the number of elderly patients, who need the surgery for painful degenerative spinal stenosis has been increasing. The geriatric population may be relatively high complications, because of age and age-associated medical conditions. However, there is a lack of studies addressing the perioperative complications and outcomes in elderly patients with posterior lumbar inter body fusion with screw augmentation (PLIF).

Methods

We retrospectively reviewed the medical records and radiographic studies of geriatric patients who had spine surgery of PLIF due to spinal stenosis for 11 years. We divided into 2 groups (A; 70–75 years, B; over then 76 years) according to the age. Surgical level of each groups, hospital day and postoperative day, co-morbidities, complications, clinical outcomes were analyzed. Operative reports, hospital and outpatient clinic charts, and radiographic studies were reviewed.

Results

Group A was composed of 80 patients, their mean age was 72.21 and female dominant (n=46), and their mean surgically fused level was 1.52 level. Group B was 36 patients, their mean age was 78.83 and female dominant (n=20), and their mean surgically fused level was 1.36 level. Comparing between two groups, complications, postoperative hospital stay were slightly increase in group B and co-morbidity was statistically high in group B, however clinical outcomes were similar between two groups.

Conclusion

Increasing age might be an important risk factor for complications in patients undergoing PLIF, however, we would like to recommend that if the situation of spine of extreme geriatric patients need PLIF, it should be in the surgeon’s consideration after careful selection and clinical judgement.

Assessment of Paraspinal Muscle Cross-sectional Area After Lumbar Decompression: Minimally Invasive Versus Open Approaches

STUDY DESIGN

A retrospective, blinded analysis of imaging studies.

SUMMARY OF BACKGROUND DATA

To evaluate changes in paraspinal muscle cross-sectional area (CSA) after surgical treatment for lumbar stenosis and to compare these changes between minimally invasive and standard open approaches. The open approach to lumbar stenosis is effective, but it involves retraction and resection of muscle from the spinous process, which can result in ischemia and denervation of paraspinal musculature and may lead to muscle atrophy and pain.

OBJECTIVE

It is hypothesized that the microendoscopic decompression of stenosis (MEDS) technique will better preserve the paraspinal muscles compared with the open procedure.

MATERIALS AND METHODS

A total of 18 patients underwent a 1-level posterior decompression for lumbar stenosis, (9 open, 9 MEDS). Lumbar magnetic resonance imaging was obtained before surgery and after surgery (open approach average 16.3 mo; MEDS average 16.6 mo). CSA of paraspinal muscles were averaged over the distance of the surgical site.

RESULTS

The mean age of patients treated with the open and MEDS approaches were 55.2 and 66.4 years, respectively (P=0.07). Paraspinal muscle CSA decreased by an average of 5.4% (SD=10.6%; range, -24.5% to +7.7%) in patients treated with the open approach and increased by an average of 9.9% (SD=14.4%; range, -9.8% to +33.1%) in patients treated with MEDS (P=0.02). For the open approach, changes in CSA did not differ significantly between the left and right sides for erector spinae (P=0.35) or multifidus muscles (P=0.90). After the MEDS approach there were no significant differences between the dilated and contralateral sides with regard to change in CSA for erector spinae (P=0.85) or multifidus muscles (P=0.95).

CONCLUSIONS

Compared with the open approach for lumbar stenosis, MEDS had significantly less negative impact on the paraspinal muscle CSA. Previous reports have documented negative effects of paraspinal muscle injury, including weakness, disability, and pain. Collectively, these data suggest that the MEDS approach for lumbar decompression is less destructive to the paraspinous muscles than the open approach and may facilitate better clinical outcomes.

Microsurgical unilateral laminotomy for decompression of lumbar spinal stenosis: long-term results and predictive factors

BACKGROUND

The microsurgical unilateral laminotomy (MUL) technique for bilateral decompression of lumbar spinal stenosis (LSS) is a less destabilizing alternative to laminectomy and leads to good short-term outcomes. However, little is known about the long-term results including predictive factors.

METHODS

Medical records of patients who underwent MUL for LSS decompression between 2005 and 2010 were reviewed, and a questionnaire was distributed to complement the long-term outcome data. The study population consisted of 176 patients including 17 patients with stable grade I spondylolisthesis. Complications and reoperations were meticulously analyzed. Clinical outcome was measured using a modified Prolo scale and was further dichotomized in good vs. poor outcome. Predictive factors were obtained from uni- and multivariate analyses.

RESULTS

The median age of the cohort was 70.0 years and the follow-up 71.7 months. Complications occurred in 5.1 % of the patients. The overall reoperation rate was 17.0 %, including surgery, which was exclusively performed at other levels in 4.0 %. The reoperation rate for fusion was 4.5 %. Good neurogenic claudication outcome faded from 98.3 % at hospital discharge to 47.2 % at 6 years. Multivariate analysis identified previous lumbar operation as a potential independent predictor of a reoperation; potential independent predictors of poor long-term claudication outcome were older age, female gender, higher body mass index (BMI) and tobacco smoking.

CONCLUSIONS

In our experience, the long-term reoperation rate after MUL for LSS is not negligible and higher in previously operated patients. It seems like the good initial clinical results after MUL may fade over time, and several patient-related predictive factors including potentially modifiable obesity and tobacco smoking seem to play an important role.

Preoperative retrolisthesis as a risk factor of postdecompression lumbar disc herniation

OBJECT

In this study, the authors aimed to identify specific risk factors for postdecompression lumbar disc herniation (PDLDH) in patients who have not undergone discectomy and/or fusion.

METHODS

Between 2007 and 2012, 493 patients with lumbar spinal stenosis underwent bilateral partial laminectomy without discectomy and/or fusion in a single hospital. Eighteen patients (herniation group [H group]: 15 men, 3 women; mean age 65.1 years) developed acute sciatica as a result of PDLDH within 2 years after surgery. Ninety patients who did not develop postoperative acute sciatica were selected as a control group (C group: 75 men, 15 women; mean age 65.4 years). Patients in the C group were age and sex matched with those in the H group. The patients in the groups were also matched for decompression level, number of decompression levels, and surgery date. The radiographic variables measured included percentage of slippage, intervertebral angle, range of motion, lumbar lordosis, disc height, facet angle, extent of facet removal, facet degeneration, disc degeneration, and vertebral endplate degeneration. The threshold for PDLDH risk factors was evaluated using a continuous numerical variable and receiver operating characteristic curve analysis. The area under the curve was used to determine the diagnostic performance, and values greater than 0.75 were considered to represent good performance.

RESULTS

Multivariate analysis revealed that preoperative retrolisthesis during extension was the sole significant independent risk factor for PDLDH. The area under the curve for preoperative retrolisthesis during extension was 0.849; the cutoff value was estimated to be a retrolisthesis of 7.2% during extension.

CONCLUSIONS

The authors observed that bilateral partial laminectomy, performed along with the removal of the posterior support ligament, may not be suitable for lumbar spinal stenosis patients with preoperative retrolisthesis greater than 7.2% during extension.

Screening for neuropathic characteristics in failed back surgery syndromes: challenges for guiding treatment

OBJECTIVE

Neuropathic pain screening tools have shown promise in identifying common neuropathic pain characteristics that derive from diverse etiologies (e.g., diabetic peripheral neuropathy, postherpetic neuralgia). However, no prior studies have specifically assessed whether these tools are capable of discerning the underlying pain mechanisms in the vast, heterogeneous group of patients diagnosed with failed back surgery syndrome (FBSS).

DESIGN

In this clinical observational study, two tests for neuropathic pain characteristics, the Douleur Neuropathique en 4 (DN4) and Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) questionnaires, were performed on 43 subjects with FBSS. Subjects underwent physical or neurosensory exam components of the DN4 and LANSS in the region of most severe pain (e.g., axial low back or lower extremities). DN4 and LANSS scores were correlated with clinical history and neurologic exam, pain-related quality of life questionnaires, and compared to an independent assessment of pain distribution.

RESULTS

The presence of neuropathic characteristics, determined by the DN4 (62% sensitivity, 44% specificity), LANSS (38% sensitivity, 75% specificity; cut-offs of 4 and 12, respectively), or their combination (20% sensitivity, 58% specificity) was associated with higher pain intensity as measured by the visual analog scale (DN4 > 4, P = 0.001; LANSS ≥ 12, P = 0.042), modified Brief Pain Inventory-Short Form (DN4 > 4, P = 0.001; LANSS ≥ 12, P = 0.082), and Neuropathic Pain Symptom Inventory (DN4 > 4, P = 0.001; LANSS ≥ 12, P = 0.001), and greater pain-related functional impairment as measured by the Roland-Morris Disability Questionnaire (DN4 > 4, P = 0.006; LANSS ≥ 12, P = 0.018). The percentage of subjects characterized as neuropathic by the DN4 and LANSS lacked concordance (67.4 vs. 25.6), and the distribution of most severe symptoms (i.e., axial vs radicular) did not correlate with subjects determined to have neuropathic pain.

CONCLUSIONS

Unlike other neuropathic syndromes, the neuropathic component of FBSS is less reliably identified by the LANSS and DN4.

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.

Outcomes after decompressive laminectomy for lumbar spinal stenosis: comparison between minimally invasive unilateral laminectomy for bilateral decompression and open laminectomy: clinical article

OBJECT

The development of minimally invasive surgical techniques is driven by the quest for better patient outcomes. There is some evidence for the use of minimally invasive surgery for degenerative lumbar spine stenosis (LSS), but there are currently no studies comparing outcomes with matched controls. The object of this study was to compare outcomes following minimally invasive unilateral laminectomy for bilateral decompression (ULBD) to a standard "open" laminectomy for LSS.

METHODS

The authors conducted a prospective, 1:1 randomized trial comparing ULBD to open laminectomy for degenerative LSS. The study enrolled 79 patients between 2007 and 2009, and adequate data for analysis were available in 54 patients (27 in each arm of the study). Patient demographic characteristics and clinical characteristics were recorded and clinical outcomes were obtained using pre- and postoperative Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores for leg pain, patient satisfaction index scores, and postoperative 12-Item Short Form Health Survey (SF-12) scores.

RESULTS

Significant improvements were observed in ODI and VAS scores for both open and ULBD interventions (p < 0.001 for both groups using either score). In addition, the ULBD-treated patients had a significantly better mean improvement in the VAS scores (p = 0.013) but not the ODI scores (p = 0.055) compared with patients in the open-surgery group. ULBD-treated patients had a significantly shorter length of postoperative hospital stay (55.1 vs. 100.8 hours, p = 0.0041) and time to mobilization (15.6 vs. 33.3 hours, p < 0.001) and were more likely to not use opioids for postoperative pain (51.9% vs. 15.4%, p = 0.046).

CONCLUSIONS

Based on short-term follow-up, microscopic ULBD is as effective as open decompression in improving function (ODI score), with the additional benefits of a significantly greater decrease in pain (VAS score), postoperative recovery time, time to mobilization, and opioid use.

Degenerative spondylolisthesis does not affect the outcome of unilateral laminotomy with bilateral decompression in patients with lumbar stenosis

STUDY DESIGN

Prospective subcohort study.

OBJECTIVE

To determine whether preoperative presence of degenerative spondylolisthesis worsens the outcome of patients undergoing unilateral laminotomy with bilateral decompression for lumbar stenosis.

SUMMARY OF BACKGROUND DATA

The standard surgical treatment for degenerative spondylolisthesis with lumbar stenosis is lumbar fusion after standard laminectomy. Although this strategy is widely adopted, it is not supported by class I evidence. This strategy assumes that degenerative spondylolisthesis worsens the outcome of laminectomy by causing postoperative instability. However, instability may be reduced or prevented by the use of less invasive decompression techniques.

METHODS

To test the hypothesis that preoperative degenerative spondylolisthesis worsens the outcome of less invasive lumbar decompression, we performed a prospective cohort study of 165 consecutive patients who underwent unilateral laminotomy with bilateral decompression at our institution. The patients were prospectively followed with a standardized questionnaire, 36-Item Short Form Health Survey, and standing lumbar radiographs for a maximum follow-up period of 5 years. According to the presence or absence of degenerative spondylolisthesis, the patients were divided into 2 groups: an olisthesis group and a nonolisthesis group.

RESULTS

The average 36-Item Short Form Health Survey physical score and bodily pain score improved substantially immediately after surgery. This improvement was maintained up to 5 years postoperatively. Progression of slippage was uncommon in both groups, with an overall incidence of 8% at 5 years of follow-up. There was no significant difference in the average physical score, the bodily pain score, or the rate of progression of slippage between the olisthesis and nonolisthesis groups.

CONCLUSION

Our study thus indicates that preoperative degenerative spondylolisthesis does not worsen the outcome of patients with lumbar stenosis undergoing unilateral laminotomy with bilateral decompression. These results suggest that lumbar fusion is often unnecessary in patients with degenerative spondylolisthesis and lumbar stenosis if the posterior decompression technique is unilateral laminotomy with bilateral decompression.

LEVEL OF EVIDENCE

2.

Long-term clinical and radiological postoperative outcomes after an interspinous microdecompression of degenerative lumbar spinal stenosis

STUDY DESIGN

A retrospective study to evaluate the clinical outcome and the risk of postoperative instability 5 years after microsurgical management of lumbar spinal stenosis using the interspinous approach.

OBJECTIVE

To evaluate the long-term outcome and the risk of postoperative instability after the microsurgical interspinous decompression of lumbar spinal stenosis.

SUMMARY OF BACKGROUND DATA

The interspinous approach involves partial resection of the supraspinous ligament followed by resection of the interspinous ligament, partial resection of the caudal aspect of the superior spinous process and resection of the ligamentum flavum, producing a central fenestration through which the decompression of the cauda equina and the nerve roots can be effected with an undercutting technique, with tailored partial resection of the lamina and the medial aspects of the facet joints. In this article, we investigated the long-term clinical outcome and the long-term risk for instability after using this approach.

METHODS

One hundred and 6 patients undergoing decompressive surgery for lumbar spinal stenosis using the interspinous approach, including cases with spondylolisthesis without instability, were included in this study. The long-term outcome was evaluated in a follow-up study, 5 years after surgery. The clinical long-term outcome was evaluated retrospectively using self-rating questionnaires: the Oswestry Disability Index, visual analogue scale (0-10), walking capacity (1-5), progress in walking capacity and global activity, and level of satisfaction. The risk of postoperative instability was evaluated on the basis of dynamic radiographs of the lumbar spine.

RESULTS

The Oswestry Disability Index showed a mean improvement in symptoms from 58.20% to 21.61%, and the visual analogue scale showed that the intensity of leg and back pain decreased from 8.62 and 8.69 points to 2.33 and 3.48 points, respectively. Walking capacity increased from 3.37 (severely restricted) to 1.81 (slightly restricted), and 93.23% of cases indicated that they were moderately satisfied or very satisfied. Dynamic radiographs revealed no postoperative instability after decompression using the interspinous approach.

CONCLUSION

The clinical outcome 5 years postoperatively after using the interspinous approach for lumbar spinal stenosis showed a favorable maintenance of improvement in symptoms. Radiological data showed that this approach does not alter the stability of the spine.

LEVEL OF EVIDENCE

4.

Does the presence of the nerve root sedimentation sign on MRI correlate with the operative level in patients undergoing posterior lumbar decompression for lumbar stenosis?

BACKGROUND CONTEXT

Recent research describes the use of a nerve root sedimentation sign to diagnose lumbar spinal stenosis (LSS). The lack of sedimentation of the nerve roots (positive sedimentation sign) to the dorsal part of the dural sac is the characteristic feature of this new radiological parameter.

PURPOSE

To demonstrate how the nerve root sedimentation sign compares with other more traditional radiological parameters in patients who have been operated for LSS.

STUDY DESIGN/SETTING

A retrospective chart and image review.

PATIENT SAMPLE

Preoperative magnetic resonance images (MRIs) were reviewed from 71 consecutive operative patients who presented with LSS and received spinal decompression surgery from 2006 to 2010.

OUTCOME MEASURES

Preoperative T2-weighted MRIs were reviewed for each patient.

METHODS

One hundred thirty-four vertebral levels from L1 to L5 were measured for: sedimentation sign, cross-sectional area (CSA) and anterior/posterior (A/P) diameter of the dural sac, thickness of the ligamentum flavum, and Fujiwara grade of facet hypertrophy. Radiological measurements were made using Surgimap 1.1.2.169 software (Nemaris, Inc., New York, NY, USA). Statistical analyses were performed using the SPSS 17.0 statistical software (SPSS Inc., Chicago, IL, USA). Significance was demonstrated using unpaired t tests and chi-squared tests. Study funding was departmental. There were no study-specific conflicts of interest-associated biases.

RESULTS

A positive sedimentation sign was determined in 120 operated levels (89.5%), whereas 14 levels (10.5%) had no sign (negative sedimentation sign). The mean CSA and A/P diameter were 140.62 mm(2) (standard deviation [SD]=53) and 11.76 mm (SD=3), respectively, for the no-sign group; the mean CSA and A/P diameter were 81.87 mm(2) (SD=35) and 8.76 mm (SD=2.2), respectively, for the sedimentation sign group (p<.001). We found that 60% of levels with Fujiwara Grade A facet hypertrophy did not have a sedimentation sign, whereas 86.3% of levels with Grade B, 93.2% of levels with Grade C, and 100.0% of levels with Grade D did have a sedimentation sign (p<.001).

CONCLUSIONS

The sedimentation sign is a new measurement tool that can enable physicians to objectively assess and quantify spinal stenosis. The sign is most often present in patients who have clinically significant lumbar stenosis and require surgery.

An evidence-based clinical guideline for the diagnosis and treatment of degenerative lumbar spinal stenosis (update)

BACKGROUND CONTEXT

The evidence-based clinical guideline on the diagnosis and treatment of degenerative lumbar spinal stenosis by the North American Spine Society (NASS) provides evidence-based recommendations to address key clinical questions surrounding the diagnosis and treatment of degenerative lumbar spinal stenosis. The guideline is intended to reflect contemporary treatment concepts for symptomatic degenerative lumbar spinal stenosis as reflected in the highest quality clinical literature available on this subject as of July 2010. The goals of the guideline recommendations are to assist in delivering optimum efficacious treatment and functional recovery from this spinal disorder.

PURPOSE

Provide an evidence-based educational tool to assist spine care providers in improving quality and efficiency of care delivered to patients with degenerative lumbar spinal stenosis.

STUDY DESIGN

Systematic review and evidence-based clinical guideline.

METHODS

This report is from the Degenerative Lumbar Spinal Stenosis Work Group of the NASS's Evidence-Based Clinical Guideline Development Committee. The work group consisted of multidisciplinary spine care specialists trained in the principles of evidence-based analysis. The original guideline, published in 2006, was carefully reviewed. A literature search addressing each question and using a specific search protocol was performed on English language references found in MEDLINE, EMBASE (Drugs and Pharmacology), and four additional, evidence-based, databases to identify articles published since the search performed for the original guideline. The relevant literature was then independently rated by a minimum of three physician reviewers using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final recommendations to answer each clinical question were arrived at via work group discussion, and grades were assigned to the recommendations using standardized grades of recommendation. In the absence of Levels I to IV evidence, work group consensus statements have been developed using a modified nominal group technique, and these statements are clearly identified as such in the guideline.

RESULTS

Sixteen key clinical questions were assessed, addressing issues of natural history, diagnosis, and treatment of degenerative lumbar spinal stenosis. The answers are summarized in this document. The respective recommendations were graded by the strength of the supporting literature that was stratified by levels of evidence.

CONCLUSIONS

A clinical guideline for degenerative lumbar spinal stenosis has been updated using the techniques of evidence-based medicine and using the best available clinical evidence to aid both practitioners and patients involved with the care of this condition. The entire guideline document, including the evidentiary tables, suggestions for future research, and all references, will be available electronically at the NASS Web site (www.spine.org) and will remain updated on a timely schedule.

Facet-sparing lumbar decompression with a minimally invasive flexible MicroBlade Shaver® versus traditional decompression: quantitative radiographic assessment

Background

Laminectomy/laminotomy and foraminotomy are well established surgical techniques for treatment of symptomatic lumbar spinal stenosis. However, these procedures have significant limitations, including limited access to lateral and foraminal compression and postoperative instability. The purpose of this cadaver study was to compare bone, ligament, and soft tissue morphology following lumbar decompression using a minimally invasive MicroBlade Shaver^® instrument versus hemilaminotomy with foraminotomy (HL).

Methods

The iO-Flex^® system utilizes a flexible over-the-wire MicroBlade Shaver instrument designed for facet-sparing, minimally invasive “inside-out” decompression of the lumbar spine. Unilateral decompression was performed at 36 levels in nine human cadaver specimens, six with age-appropriate degenerative changes and three with radiographically confirmed multilevel stenosis. The iO-Flex system was utilized on alternating sides from L2/3 to L5/S1, and HL was performed on the opposite side at each level by the same investigator. Spinal canal, facet joint, lateral recess, and foraminal morphology were assessed using computed tomography.

Results

Similar increases in soft tissue canal area and decreases in ligamentum flavum area were noted in nondiseased specimens, although HL required removal of 83% more laminar area (P < 0.01) and 95% more bone resection, including the pars interarticularis and facet joints (P < 0.001), compared with the iO-Flex system. Similar increases in lateral recess diameter were noted in nondiseased specimens using each procedure. In stenotic specimens, the increase in lateral recess diameter was significantly (P = 0.02) greater following use of the iO-Flex system (43%) versus HL (7%). The iO-Flex system resulted in greater facet joint preservation in nondiseased and stenotic specimens. In stenotic specimens, the iO-Flex system resulted in a significantly greater increase in foraminal width compared with HL (24% versus 4%, P = 0.01), with facet joint preservation.

Conclusion

The iO-Flex system resulted in significantly better decompression of the lateral recess and foraminal areas compared with HL, while preserving posterior spinal elements, including the facet joint.

Midterm outcome after a microsurgical unilateral approach for bilateral decompression of lumbar degenerative spondylolisthesis

Object

The aim of this study was to evaluate the results and effectiveness of bilateral decompression via a unilateral approach in the treatment of lumbar degenerative spondylolisthesis (DS).

Methods

Operations were performed in 84 selected patients (mean age 62.1 ± 10 years) with lumbar DS between the years 2001 and 2008. The selection criteria included lower back pain with or without sciatica, neurogenic claudication that had not improved after at least 6 months of conservative treatment, and a radiological diagnosis of Grade I DS and lumbar stenosis. Decompression was performed at 3 levels in 15.5%, 2 levels in 54.8%, and 1 level in 29.7% of the patients with 1 level of spondylolisthesis. All patients were followed up for at least 24 months. For clinical evaluations, a visual analog scale, Oswestry Disability Index (ODI), and Neurogenic Claudication Outcome Score (NCOS) were used. Spinal canal size and (neutral and dynamic) slip percentages were measured both pre- and postoperatively.

Results

Neutral and dynamic slip percentages did not significantly change after surgery (p = 0.67 and p = 0.63, respectively). Spinal canal size increased from 50.6 ± 5.9 to 102.8 ± 9.5 mm2 (p < 0.001). The ODI decreased significantly in both the early and late follow-up evaluations, and good or excellent results were obtained in 64 cases (80%). The NCOS demonstrated significant improvement in the late follow-up results (p < 0.001). One patient (1.2%) required secondary fusion during the follow-up period.

Conclusions

Postoperative clinical improvement and radiological findings clearly demonstrated that the unilateral approach for treating 1-level and multilevel lumbar spinal stenosis with DS is a safe, effective, and minimally invasive method in terms of reducing the need for stabilization.

De novo spine surgery as a predictor of additional spine surgery at the same or distant spine regions

INTRODUCTION

Degenerative spine disorders are steadily increasing parallel to the aging of the population with considerable impact on cost and productivity. In this paper we study the prevalence and risk factors for multiple spine surgery and its impact on cost.

METHODS

Data on 1,153 spine surgery inpatients operated between October 2005 and September 2008 (index spine surgery) in regard to the number of previous spine surgeries and location of surgeries (cervical or lumbar) were retrospectively collected. Additionally, prospective follow-up over a period of 2-5 years was conducted.

RESULTS

Retrospectively, 365 (31.7%) patients were recurrent spine surgery patients while 788 (68.3%) were de novo spine surgery patients.Nearly half of those with previous spine surgery (51.5%) were on different regions of the spine. There were no significant differences in length of stay or hospital charges except in lumbar decompression and fusion (LDF) patients with multiple interventions on the same region of the spine. Significant differences (P<.05) in length of stay (5.4 days vs. 7.4 days) and hospital charges ($55,477 vs. $74,878) between LDF patients with one previous spine versus those with ≥3 previous spine surgeries on the same region were noted.Prospectively, the overall reoperation rate was 10.4%. The risk of additional spine surgery increased from 8.0% in patients with one previous spine surgery (index surgery) to 25.6% in patients with ≥4 previous spine surgeries on different regions of the spine (including index surgery).After excluding patients with previous spine surgeries on different regions of the spine, 17.2% of reoperated patients had additional spine surgery on a different spine region. The percentage of additional spine surgery on a distant spine region increased from 14.0% in patients with one spine surgery to 33.0% in patients with two spine surgeries on the same region. However, in patients with three or more spine surgeries on the same spine region there were no interventions on a distant spine region during the follow-up period.

CONCLUSION

De novo spine surgery is associated with an increased incidence of additional spine surgery at the same or distant spine regions. Large prospective studies with extended follow-up periods and multifaceted cost-outcome analysis are needed to refine the appropriateness of spine surgery.

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.

Outcome after surgical treatment for lumbar spinal stenosis: the lumbar extension test is not a predictive factor

STUDY DESIGN

A prospective clinical study.

OBJECTIVES

To investigate the predictive value of the lumbar extension test for outcome after surgical treatment of lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

Studies have indicated that aggravation of the symptoms from LSS by extension of the lumbar spine has predictive value for the outcome after decompression. The aim of this study was to investigate this theory in a larger group of patients.

METHODS

One hundred forty-six consecutive patients surgically treated for LSS were included in the study. The clinical condition was recorded before surgery and at 3, 6, 12, and 24 months after surgery using 3 different scoring systems: Swiss Spinal Stenosis Questionnaire, Neurogenic Claudication Outcome Score, and Oswestry Disability Index. The group of patients with preoperative aggravation of the symptoms by the lumbar extension test, (positive extension test), was compared with the group of patients without aggravation by the test, (negative extension test).

RESULTS

Before surgery, patients with a positive extension test scored significantly worse on all disability scoring systems than patients with a negative test. However, the extension test itself had no prognostic value for the overall outcome after lumbar decompression. Using regression models with the 2-year Oswestry Disability Index as dependent variable, only before surgery self-reported health and age were found to have prognostic significance.

CONCLUSION

The lumbar extension test has no predictive value for the outcome after surgical treatment of LSS.

The efficacy of physical therapy and physical therapy plus calcitonin in the treatment of lumbar spinal stenosis

PURPOSE

The aim of our study was to compare the efficacy of physical therapy alone and in combination with calcitonin in patients with neurogenic claudication (NC).

MATERIALS AND METHODS

In this single blind, and randomized study, patients with lumbar spinal canal stenosis who were diagnosed by clinical findings and MRI and having NC were included. Patients were observed for 8 weeks and evaluated before and after treatment. Patients were randomized between the salmon calcitonin 200 U/day + physical therapy (n = 23) (Group 1) and paracetamol 1,500 mg/day + physical therapy (n = 22) (Group 2) treatment groups. Both groups received the same physical therapy (interferential current + hot pack + short wave diathermy) and exercise protocol. The association of various clinical and functional parameters was assessed statistically by using paired and unpaired t test, chi square test and McNemar's test. p < 0.05 indicated statistical significant.

RESULTS

Mean age of the patients in Group 1 was 57.6 +/- 11.2 and in Group 2 54.5 +/- 10.6 years. Before treatment, there were no significant differences between groups with respect to age, body mass index, spinal axial diameter, Visual Analogue Scale (VAS), spinal mobility, functional status and walking distance (p > 0.05). After 8 weeks of treatment, both groups benefited significantly with respect to VAS, functional status and walking distance (p < 0.001). There was no statistically significant difference between groups (p > 0.05).

CONCLUSION

In 45 patients with lumbar spinal stenosis who received 8 weeks of treatment, concomitant use of calcitonin with physical therapy and exercise did not have any benefical effect on the patient's pain, functional status, lumbar mobility and walking distance.

Minimally invasive decompression for lumbar stenosis and disc herniation

For decades, lumbar disc herniation and lumbar stenosis have been treated surgically via traditional open techniques. With recent emphasis on minimally invasive approaches in spine surgery, a number of new techniques has been introduced that are aimed at treating these 2 common pathological conditions. Currently the most widely used and efficacious minimally invasive technique for treating these disorders is direct decompression with minimally invasive surgery. Due to the scarcity of large randomized studies, however, it is difficult to compare the effectiveness and possible superiority of this technique with traditional decompression. Further studies are needed to evaluate this issue.

A biomechanical evaluation of graded posterior element removal for treatment of lumbar stenosis: comparison of a minimally invasive approach with two standard laminectomy techniques

STUDY DESIGN

A validated finite element model of the intact lumbar spine (L1-S1) was modified to study the biomechanical changes as a result of surgical alteration for treatment of stenosis at L3-L4 and L4-L5 using 2 established techniques and 1 new minimally invasive technique.

OBJECTIVE

To investigate the impact of graded posterior element removal associated with new surgical techniques on postoperative segmental motion and loading in the annulus.

SUMMARY OF BACKGROUND DATA

Several studies have shown that laminectomy increases and produces segmental instability unless fusion is performed. However, no data exist comparing the biomechanical impact of completely preserving the contralateral anatomy and what effect this has compared to traditional approaches.

METHODS

The effect of graded removal of posterior elements because of iatrogenic change associated with the 3 approaches was investigated using an 800 N compressive preload using the follower load technique and application of 8 Nm flexion, 6 Nm extension, 4 Nm torsion, and 6 Nm lateral bending moments.

RESULTS

This study shows that removal of posterior elements for treatment of stenosis at L3-L4 and L4-L5 results in increased flexion-extension and axial rotation at the surgical site. This study also shows that the segmental motion following a traditional laminectomy is greater than the minimally invasive approach in flexion, extension, left and right axial rotation. Moderate preservation of the posterior elements which occurs in the intralaminar approach generates greater segmental motion that the minimally invasive approach in extension, left and right axial rotation.

CONCLUSION

Minimization of bone and ligament removal associated with minimally invasive procedures results in greater preservation of the normal motion of the lumbar spine after surgery. This study suggests that preservation of the posterior spinal elements associated with minimally invasive surgery could minimize the risk of developing de novo postoperative changes in spinal alignment and/or acceleration of facet and disc degeneration.

Degenerative lumbar spinal stenosis: analysis of results in a series of 374 patients treated with unilateral laminotomy for bilateral microdecompression

Object

Surgical decompression is the recommended treatment in patients with moderate to severe degenerative lumbar spinal stenosis (DLSS) in whom symptoms do not respond to conservative therapy. Multilevel disease, poor patient health, and advanced age are generally considered predictors of a poor outcome after surgery, essentially because of a surgical technique that has always been considered invasive and prone to causing postoperative instability. The authors present a minimally invasive surgical technique performed using a unilateral approach for lumbar decompression.

Methods

A retrospective study was conducted of data obtained in a consecutive series of 473 patients treated with unilateral microdecompression for DLSS over a 5-year period (2000–2004). Clinical outcome was measured using the Prolo Economic and Functional Scale and the visual analog scale (VAS). Radiological follow-up included dynamic x-ray films of the lumbar spine and, in some cases, computed tomography scans.

Results

Follow-up was completed in 374 (79.1%) of 473 patients—183 men and 191 women. A total of 520 levels were decompressed: 285 patients (76.2%) presented with single-level stenosis, 86 (22.9%) with two-level stenosis, and three (0.9%) with three-level stenosis.

Three hundred twenty-nine patients (87.9%) experienced a clinical benefit, which was defined as neurological improvement in VAS and Prolo Scale scores. Only three patients (0.8%) reported suffering segmental instability at a treated level, but none required surgical stabilization, and all were successfully treated conservatively.

Conclusions

Evaluation of the results indicates that unilateral microdecompression of the lumbar spine offers a significant improvement for patients with DLSS, with a lower rate of complications.

A comparison of the degree of lateral recess and foraminal enlargement with facet preservation in the treatment of lumbar stenosis with standard surgical tools versus a novel powered filing instrument: a cadaver study

BACKGROUND

The SurgiFile (SurgiFile, Inc., Carlsbad, California) is a specialized tool designed for the treatment of lateral recess and foraminal stenosis that allows surgeons to internally expand and decompress the entire length of the neural foramen while preserving the integrity of the overlying facet complex.

METHODS

We used two cadaveric specimens in this study. After they removed the lamina and spinous processes of L2, L3, L4, and L5 from the dorsal spine, fellowship-trained spinal surgeons used the standard tools and the SurgiFile to the best of their experience and ability on alternating sides of each level to decompress the lateral recess and neural foramen while still preserving at least 50% of the dorsal facet complex. Using preoperative and postoperative fine-cut CT scans with axial and sagittal reconstructions, we evaluated the degree of decompression and the amount of preserved facet complex using analytical tests and recording the measurements.

RESULTS

The difference between the proximal recess and lateral foramen of the groups was statistically significant in the axial CT images. On sagittal reconstruction CT images, the difference between the two groups was significant (P < 0.05, Wilcoxon) only for the lateral foramen. Although a strong trend toward better area change was evident for the proximal recess measurements in the experimental tool sides, this did not achieve statistical significance. Macroscopic and CT scans measurements showed that the amount of facetectomy for adequate decompression with the SurgiFile was less than the amount achieved with the standard tools.

CONCLUSIONS

For the treatment of spinal stenosis, this novel powered-file instrument provides surgeons with a new means of decompressing the lateral recess and neural foramina. In this cadaveric study, procedures performed with the SurgiFile tool showed a statistically superior degree of decompression as compared with the standard surgical instruments and techniques.

Midterm outcome after unilateral approach for bilateral decompression of lumbar spinal stenosis: 5-year prospective study

The aim of our study is to evaluate the results and effectiveness of bilateral decompression via a unilateral approach in the treatment of degenerative lumbar spinal stenosis. We have conducted a prospective study to compare the midterm outcome of unilateral laminotomy with unilateral laminectomy. One hundred patients with 269 levels of lumbar stenosis without instability were randomized to two treatment groups: unilateral laminectomy (Group 1), and laminotomy (Group 2). Clinical outcomes were assessed with the Oswestry Disability Index (ODI) and Short Form-36 Health Survey (SF-36). Spinal canal size was measured pre- and postoperatively. The spinal canal was increased to 4-6.1-fold (mean 5.1 +/- SD 0.8-fold) the preoperative size in Group 1, and 3.3-5.9-fold (mean 4.7 +/- SD 1.1-fold) the preoperative size in Group 2. The mean follow-up time was 5.4 years (range 4-7 years). The ODI scores decreased significantly in both early and late follow-up evaluations and the SF-36 scores demonstrated significant improvement in late follow-up results in our series. Analysis of clinical outcome showed no statistical differences between two groups. For degenerative lumbar spinal stenosis unilateral approaches allowed sufficient and safe decompression of the neural structures and adequate preservation of vertebral stability, resulted in a highly significant reduction of symptoms and disability, and improved health-related quality of life.

Minimally invasive operative management for lumbar spinal stenosis: overview of early and long-term outcomes

Standard open posterior decompression is well established and familiar to virtually all spine surgeons. However, this traditional surgical treatment of lumbar spinal stenosis (LSS) is often associated with significant postoperative pain, disability, and dysfunction. This article reviews the use of a minimally invasive microendoscopic approach for bilateral decompression of lumbar stenosis by way of a unilateral approach. This technique has been shown to provide symptomatic relief equivalent to that of open discectomy, with significant reductions in operative blood loss, postoperative pain, hospital stay, and narcotic usage. Furthermore, the article explains the rationale, indications, and surgical techniques for minimally-invasive LSS surgery and presents the authors' 4-year outcomes data.

LONG-TERM RESULTS OF MICROSURGICAL TREATMENT OF LUMBAR SPINAL STENOSIS BY UNILATERAL LAMINOTOMY FOR BILATERAL DECOMPRESSION

OBJECTIVE

Laminectomy and bilateral laminotomy are the standard procedures for decompression of lumbar spinal stenosis (LSS). With the aim of less invasiveness and better preservation of spinal stability, the technique of unilateral laminotomy for bilateral decompression (ULBD) was developed. However, limited follow-up data exist to determine the efficiency and outcome of ULBD. Therefore, the authors present their 10-year experience with ULBD and postoperative long-term results.

METHODS

One hundred thirty-three consecutive patients (73 men and 60 women; mean age, 63 yr) meeting clinical and radiographic criteria for LSS who underwent first-time ULBD between 1994 and 1999 entered the study. The study parameters were set to ensure a follow-up period of at least 4 years. All patients were available for short-term follow-up re-evaluation within 3 months, and 102 (77%) of the 133 patients were available for long-term examination after a mean duration of 5.6 years. The scale of Finneson and Cooper was used for evaluation of the clinical results.

RESULTS

One hundred thirty patients (97.7%) improved immediately after surgery. Ninety-four (92.2%) of the 102 patients available for long-term follow-up examination remained improved, and 85.3% had an excellent-to-fair operative result. The incidence of complications was 9.8%. Resurgery for complication was necessary in three patients, for restenosis in seven patients, and for spinal instability in two patients, accounting for a reoperation rate of 11.8%.

CONCLUSION

ULBD allows achievement of good and long-lasting operative results in patients with LSS. Postoperative deterioration, recurrences, and spinal instability are infrequent. For the authors, ULBD is the preferred technique to treat symptomatic LSS.

Five-year outcomes of surgical treatment for degenerative lumbar spinal stenosis: a prospective observational study of symptom severity at standard intervals after surgery

STUDY DESIGN

A prospective observational study of patients undergoing surgery for degenerative lumbar spinal stenosis.

OBJECTIVE

To determine whether the long-term outcomes differ as a function of age and gender.

SUMMARY OF BACKGROUND DATA

The long-term results of surgery for lumbar spinal stenosis are not well understood, and the patient characteristics that predispose patients to worse outcomes are unknown.

METHODS

Seventy patients who underwent decompressive laminotomy with or without arthrodesis for degenerative lumbar spinal stenosis were prospectively studied at standard intervals after surgery with respect to symptom severity rated on a visual analog scale (VAS).

RESULTS

The VAS scores for younger patients improved steadily for 3 or 6 months, after which the improvement was maintained until 60 months. The VAS scores for older patients showed a similar time course until 36 months, after which the VAS scores were worse compared with those for younger patients. The VAS scores for females were worse than those for males, in three symptoms queried, at one or more of the evaluation time points.

CONCLUSION

In patients undergoing surgery for degenerative lumbar spinal stenosis, older age predicts a greater risk of late recurrence of symptoms, and women have higher VAS scores than men after surgery.

Chimney sublaminar decompression for degenerative lumbar spinal stenosis

Object

The authors evaluated the efficacy and safety of so-called chimney sublaminar decompression, a new technique to decompress the degenerative stenotic lumbar spinal canal without stripping of the paravertebral muscles.

Methods

Eighteen patients (nine men and nine women whose mean age was 67 years) with symptoms of claudication were selected to undergo chimney sublaminar decompression. The duration of symptoms was greater than 6 months in 17 patients. Two lumbar segments were involved in seven patients, three in eight, and four in the remaining three patients. Central canal stenosis was present in 13 patients, and lateral recess stenosis in five patients. Mild spondylolisthesis was noted in seven patients. All the patients underwent chimney sublaminar decompression.

After surgery, mild wound pain developed in 14 patients, moderate wound pain in two, and severe wound pain in two. The postoperative hospital stay was 4 days or fewer in 14 patients. At follow-up examination, excellent, good, and fair outcomes were achieved in 11, five, and two patients, respectively. No patient required a body brace, and no worsening of preexisting spondylolisthesis was detected. The spinal canal was increased to two- to 6.8-fold (mean 4.2-fold) the preoperative size.

Conclusions

Compared with laminectomy or endoscopic surgery, the aforementioned chimney sublaminar decompression technique was an equally effective and less invasive technique in the treatment of degenerative lumbar canal stenosis.

Outcome after less-invasive decompression of lumbar spinal stenosis: a randomized comparison of unilateral laminotomy, bilateral laminotomy, and laminectomy

OBJECT

Recently, limited decompression procedures have been proposed in the treatment of lumbar stenosis. The authors undertook a prospective study to compare the safety and outcome of unilateral and bilateral laminotomy with laminectomy.

METHODS

One hundred twenty consecutive patients with 207 levels of lumbar stenosis without herniated discs or instability were randomized to three treatment groups (bilateral laminotomy [Group 1], unilateral laminotomy [Group 2], and laminectomy [Group 3]). Perioperative parameters and complications were documented. Symptoms and scores, such as visual analog scale (VAS), Roland-Morris Scale, Short Form-36 (SF-36), and patient satisfaction were assessed preoperatively and at 3, 6, and 12 months after surgery. Adequate decompression was achieved in all patients. The overall complication rate was lowest in patients who had undergone bilateral laminotomy (Group 1). The minimum follow up of 12 months was obtained in 94% of patients. Residual pain was lowest in Group 1 (VAS score 2.3 +/- 2.4 and 4 +/- 1 in Group 3; p < 0.05 and 3.6 +/- 2.7 in Group 2; p < 0.05). The Roland-Morris Scale score improved from 17 +/- 4.3 before surgery to 8.1 +/- 7, 8.5 +/- 7.3, and 10.9 +/- 7.5 (Groups 1-3, respectively; p < 0.001 compared with preoperative) corresponding to a dramatic increase in walking distance. Examination of SF-36 scores demonstrated marked improvement, most pronounced in Group 1. The number of repeated operations did not differ among groups. Patient satisfaction was significantly superior in Group 1, with 3, 27, and 26% of patients unsatisfied (in Groups 1, 2, and 3, respectively; p < 0.01).

CONCLUSIONS

Bilateral and unilateral laminotomy allowed adequate and safe decompression of lumbar stenosis, resulted in a highly significant reduction of symptoms and disability, and improved health-related quality of life. Outcome after unilateral laminotomy was comparable with that after laminectomy. In most outcome parameters, bilateral laminotomy was associated with a significant benefit and thus constitutes a promising treatment alternative.

Correlation of patient satisfaction with symptom severity and walking ability after surgical treatment for degenerative lumbar spinal stenosis

STUDY DESIGN

Prospective follow-up of 83 patients who had decompressive laminotomy with or without fusion for degenerative lumbar spinal stenosis between September 1992 and September 1998.

OBJECTIVE

To evaluate the significance of the correlation between patient satisfaction and both the severity of postoperative symptoms and walking ability.

SUMMARY OF BACKGROUND DATA

In clinical studies of surgery for degenerative lumbar spinal stenosis, patient satisfaction often is an item in the outcome questionnaire. However, little is known about the relationship of patient satisfaction to postoperative symptoms or functioning.

METHODS

Patients completed standardized preoperative and follow-up questionnaires about symptom severity, walking ability, and their satisfaction with the results of surgical treatment. The significance of the correlation of patient satisfaction with the severity of postoperative symptoms and walking ability was evaluated.

RESULTS

The mean length of follow-up was 39 months (range 12-84 months). The final questionnaire of a series was answered by 77 patients (93% of the cohort). By univariate analysis, the correlations of patient satisfaction with postoperative back pain, leg pain, numbness, subjective difficulty in walking, and walking ability were statistically significant (Spearman rank-order correlation coefficient: 0.58, 0.57, 0.53, 0.64, and 0.43, respectively). Postoperative walking ability was a weaker correlate of patient satisfaction than the severity of postoperative symptoms. By multivariate regression analysis, the only independent correlate was subjective difficulty in walking.

CONCLUSIONS

In the evaluation of patient satisfaction as an outcome in patients operated on for degenerative lumbar spinal stenosis, we should keep in mind that postoperative functioning is a weak correlate of satisfaction.

Nonsurgical management of patients with lumbar spinal stenosis: a literature review and a case series of three patients managed with physical therapy

This article critically reviews the available literature regarding nonsurgical management for lumbar spinal stenosis (LSS) and presents a case series of three patients managed with manual physical therapy. This case series uses a well-defined, impairment-based, noninvasive, outpatient treatment program for patients with LSS and provides patient-centered, long-term outcome information. The outpatient treatment program focuses on patients' individualized, prioritized impairments identified on initial examination, and emphasizes manual physical therapy techniques targeting each patient's impairments, specific exercises to either reinforce the manual physical therapy treatment or strengthen specific muscles, and a walking program. The results demonstrate that patients with LSS can make significant gains in disability, symptoms, and function in relatively short periods of time and that these gains can be maintained for up to 18 months. Under this physical therapy program, patients experienced significant improvements, and the potential adverse effects of invasive therapies or pharmacologic management strategies, which often are included in other "nonsurgical" treatment programs, were avoided.

Microendoscopic Decompressive Laminotomy for the Treatment of Lumbar Stenosis

OBJECTIVE

By modifying existing microendoscopic discectomy techniques, we previously developed a novel surgical treatment of lumbar stenosis and validated its ability to achieve a thorough decompression in a cadaveric study. We now describe our clinical experience with this new, minimally invasive microendoscopic decompressive laminotomy (MEDL) technique.

METHODS

A MEDL was performed in 25 patients with classic features of lumbar stenosis. By use of a fluoroscopically guided percutaneous technique, the working portal was docked on the lamina with minimal soft-tissue injury. With the angle of the endoscope combined with an oblique entry, a bilateral bony and ligamentous decompression was achieved under the midline, thereby preserving the supraspinous–interspinous ligaments and contralateral musculature. A second group of 25 patients treated with open decompression was used for comparison.

RESULTS

Effective circumferential decompression was achieved in the majority of patients. The results for the MEDL group were as follows: operative time, 109 minutes per single level; blood loss, 68 ml; and postoperative stay, 42 hours. The results for the open-surgery group were as follows: operative time, 88 minutes; blood loss, 193 ml; and postoperative stay, 94 hours. The MEDL group needed significantly less narcotic medication after surgery. Overall, 16% of the MEDL patients reported resolution of their back pain, 68% improved symptomatically, and 16% remained unchanged. The outcome of the open group was very similar.

CONCLUSION

Compared with an equivalent open technique, MEDL appears to offer a similar short-term clinical outcome with a significant reduction in operative blood loss, postoperative stay, and use of narcotics. This lower surgical stress, decreased tissue trauma, and quicker recovery are particularly important in this elderly population of patients.

Minimally Invasive Percutaneous Posterior Lumbar Interbody Fusion

OBJECTIVE

The wide exposure required for a standard posterior lumbar interbody fusion (PLIF) can cause unnecessary trauma to the lumbar musculoligamentous complex. By combining existing microendoscopic, percutaneous instrumentation and interbody technologies, a novel, minimally invasive, percutaneous PLIF technique was developed to minimize such iatrogenic tissue injury (MIP-PLIF).

METHODS

The MIP-PLIF technique was validated in three cadaveric torsos with six motion segments decompressed and fused. Preoperative variables measured from imaging included interpedicular distance, pedicular height and width, interspinous distance, lordosis, intervertebral height, Cobb angle, and foraminal height and volume. Using the METRx and MD spinal access systems (Medtronic Sofamor Danek, Memphis, TN), bilateral laminotomies were performed using a hybrid of microsurgical and microendoscopic techniques. The intervertebral disc spaces were then distracted and prepared with the Tangent (Medtronic Sofamor Danek) interbody instruments. Either a 10 or 12 by 22 mm interbody graft was then placed. Using the Sextant (Medtronic Sofamor Danek) system, percutaneous pedicle screw-rod fixation of the motion segment was completed. We then applied MIP-PLIF in three patients.

RESULTS

For segments with preoperative intervertebral/foraminal height loss, MIP-PLIF was effective in restoring both heights in all cases. The amount of improvement (9.7 to 38% disc height increase; 7.7 to 29.9% foraminal height increase) varied directly with the size of the graft used and the original degree of disc and foraminal height loss. Segmental lordosis improved by 29% on average. Graft and screw placement was accurate in the cadavers, except for a single Grade 1 screw violation of one pedicle. The average operative time was 3.5 hours per level. In our three clinical cases, the MIP-PLIF procedure required a mean of 5.4 hours, estimated blood loss was 185 ml, and inpatient stay was 2.8 days, with no intravenous narcotic use after 2 days in any of the patients. All screw and graft placements were confirmed.

CONCLUSION

A complete PLIF procedure can be safely and effectively performed using minimally invasive techniques, thereby potentially reducing the pain and morbidity associated with standard open surgery. Prospective, randomized outcome studies will be required to validate the efficacy of this exciting new surgical technique.

The natural history of lumbar degenerative spinal stenosis

The purpose of this review is to present current information on the natural course of lumbar spinal stenosis. As the population becomes older this condition is encountered more frequently. The diagnosis accuracy has improved and the number of cases detected is increasing intemationally. Because of the relative unpredictability of surgical treatment, good knowledge of natural evolution and of the predictive factors influencing the course of the disease is crucial. Unfortunately, and in contrast with numerous surgical series few studies have dealt with natural evolution. In addition to anecdotal reports, a few non randomized studies will be reviewed. Only one randomized study has compared shortand long term results of medical versus surgical treatment. Most of these studies are retrospective, with methodological flaws and are difficult to compare. At the present time no scientifically based recommandations can be made to LSS. patients at diagnosis. Similarly predictors of success of medical and surgical treatment still need to be identified. However results of the studies analyzed in this review suggest that a substantial proportion of patients do not automatically deteriorate and will remain unchanged or even improved by medical means. They also suggest that patients with severe baseline symptoms, block stenosis and degenerative spondylolisthesis tend to require surgical decompression. Randomized studies with the necessary ethical precautions are needed to obtain clear-cut conclusions.

Functional outcome study of patients after surgical decompression for lumbar spinal stenosis: effects of concomitant pathology

The aim of this study is to identify factors associated with poor outcome in the medium (2-5 years) postoperative period following lumbar stenosis surgery. Fifty-six consecutive patients who underwent decompression for lumbar spinal stenosis were retrospectively analyzed using chart and radiologic review, questionnaire using American Association of Orthopaedic Surgeon's MODEM questionnaire containing disability, symptoms, and illness rating, as well as Short Form-36 questionnaires. Postoperatively, there was 98% partial or total relief in leg pain, 85% had partial or total relief in back pain, and 69% had partial or total recovery of neurologic deficit. Functional outcome according to the Short Form-36 was comparable with the age-adjusted population when other comorbidities were taken into account. We found a direct relationship between poor outcome and coexisting medical conditions (p <0.001). Accompanying comorbid conditions have a significant impact on outcome after surgical decompression for lumbar spinal stenosis.

Electrophysiology of radiculopathies

The anatomy, pathophysiology, and clinical evaluation of radiculopathies are discussed. Defining whether root injury is present and which roots are involved can be difficult but critical for patient management. In conjunction with clinical and radiological information, studies that establish physiological abnormalities of roots should be helpful and important. Clinical neurophysiological studies for radiculopathies are performed frequently but have yet to achieve a universally accepted role in the evaluation of these patients. Electrophysiological techniques for the evaluation of radiculopathies are reviewed. Needle electromyography is the best established of these procedures but has the disadvantage of requiring injury to motor fibers of both a certain degree and distribution. Nerve conduction studies may rarely be abnormal in radiculopathies but are needed to be certain other conditions that may produce similar symptoms and signs are not present. H reflexes and F waves probably have roles in the evaluation of radiculopathies but published reports about F waves in radiculopathies have been marred by inadequate methodology. There is evidence based on large series of patients that somatosensory evoked potentials can be helpful for evaluating patients with multilevel injury such as spinal stenosis, patients where electrophysiological studies may have their greatest clinical utility. Further work using either electrical stimulation with needles or magnetic stimulation of roots seems warranted. The demonstration of meaningful electrophysiological changes with activities that reproduce radicular symptoms may be a promising experimental approach. Available information does not necessarily answer critical questions about the role of electrophysiology in patients with radiculopathies. This cannot be done using analyses based on current ideas about evidence based medicine given the absence of a 'gold standard' for defining radiculopathies as well the absence of blinded studies. The available information provides strong arguments for further investigations evaluating different clinical neurophysiological techniques in the same patient, and for evaluating the value of these techniques by concentrating on their clinical import.

A minimally invasive technique for decompression of the lumbar spine

STUDY DESIGN

The technical feasibility of percutaneous microendoscopic bilateral decompression of lumbar stenosis via a unilateral approach was evaluated in a human cadaver model.

OBJECTIVES

The purpose of this study was to determine the feasibility of using a microendoscopic laminotomy technique to treat spinal stenosis.

SUMMARY AND BACKGROUND DATA

Minimally invasive surgery is an important means of reducing tissue trauma and patient morbidity. This may prove to be essential in improving pain and in reducing postoperative stress responses and delayed sequelae that can lead to unfortunate complications after otherwise uneventful procedures. To date, minimally invasive lumbar endoscopic techniques have not been used to decompress the lumbar spinal canal.

METHODS

In each of four cadavers, the laminae of L1 through L4 were subjected to one of four procedures consisting of unilateral microendoscopic laminotomy, bilateral microendoscopic laminotomy, unilateral open laminotomy, and bilateral open laminotomy. Every procedure was performed once at all levels. Computed tomography was performed before and after laminotomy to establish the extent of decompression of the spinal canal, and measurements of the midsagittal, interpedicular, and decompression diameters were taken.

RESULTS

The four procedures were successfully performed at every level. Satisfactory decompression of the spinal canal was achieved regardless of the approach used. The exiting nerve roots were well visualized when any one of these techniques was used. Complications, including dural tears and facet complex instability, were independent of the procedure performed.

CONCLUSION

Microendoscopic laminotomy can be used to decompress the spinal canal as effectively as an open laminotomy and may prove to be beneficial in decreasing the complications and morbidity of standard treatments for lumbar stenosis.

The reliability of the Shuttle Walking Test, the Swiss Spinal Stenosis Questionnaire, the Oxford Spinal Stenosis Score, and the Oswestry Disability Index in the assessment of patients with lumbar spinal stenosis

STUDY DESIGN

The Shuttle Walking Test (SWT), the Swiss Spinal Stenosis (SSS) Questionnaire, the Oxford Claudication Score (OCS), and the Oswestry Disability Index (ODI) were administered to patients with lumbar spinal stenosis and neurogenic claudication.

OBJECTIVE

To determine reliability of the SWT, the SSS (Q1-12), the OCS, and the ODI in lumbar spinal stenosis assessment.

SUMMARY OF BACKGROUND DATA

Reliability data for exercise tests in lumbar spinal stenosis are lacking.

METHODS

To determine reliability, 32 clinic patients with lumbar spinal stenosis were assessed twice, with 1 week between assessments. Retrospective data from 17 patients assessed before surgery and 18 months after surgery for lumbar spinal stenosis were used to investigate the use of reliability in a clinical setting.

RESULTS

Test-retest reliability in terms of the intraclass correlation coefficient (ICC) was 0.92 for the SWT, 0.92 for the SSS, 0.83 for the OCS and 0.89 for the ODI. The mean percentage scores were 51 for the SSS, 45 for the OCS, and 40 for the ODI. To achieve 95% certainty of change between assessments for a single patient, the SSS would need to change by 15, the OCS by 20, and the ODI by 16. The mean SWT was 150 m, with a change of 76 m required for 95% confidence. Cronbach's alpha was 0.91 for the SSS, 0.90 for the OCS, and 0.89 for the ODI. The change in ODI correlated most strongly with patient satisfaction after surgery (rho = 0.80; P < 0.001).

CONCLUSIONS

Fluctuations in a patient's symptoms result in wide individual confidence intervals. Performance on the SSS, OCS, and ODI questionnaires are broadly similar, the most precise being the condition-specific SSS. The SWT gives a snapshot of physical function, which is acceptable for group analysis. Use of the SWT for individual assessment after surgery is feasible.