The validity of ankle-brachial index for the differential diagnosis of peripheral arterial disease and lumbar spinal stenosis in patients with atypical claudication

Purpose

Claudication is a typical symptom of peripheral arterial disease (PAD) and lumbar spinal stenosis (LSS). Differential diagnosis of PAD and LSS is often difficult due to the subjective natures of symptoms and atypical signs. The authors aimed to determine the usefulness of ankle-brachial index (ABI) measurement for the differential diagnosis of PAD and LSS when the etiology of claudication is uncertain.

Methods

Forty-two consecutive patients who had been referred by spine surgeons to a lower extremity vascular surgeon for atypical claudication were retrospectively analyzed. Atypical claudication was defined as claudication not caused by PAD, as determined by clinical manifestations, or by LSS, as determined by MR imaging. A final diagnosis of PAD was established by CT angiography (CTA) and of LSS by excluding PAD. Diagnostic validity of ABI for PAD in atypical presentation was assessed.

Results

Sixty-two legs of 42 atypical claudication patients were analyzed. Mean patient age was 65.8 ± 8.2 years (38–85) and 29 (69.0%) had diabetes mellitus. Mean ABI was 0.73 ± 0.14 (0.53–0.94) in the PAD group and 0.92 ± 0.18 (0.52–1.10) in the LSS group (P < 0.001). Of the 33 legs with a low ABI (ABI < 0.9), 29 legs were diagnosed as true positives for PAD by CTA and 4 were false positives, and of the 29 legs with a high ABI, 5 were false negatives and 24 were true negatives. The sensitivity and specificity of ABI for the diagnosis of PAD in patients with atypical claudication were 85.3 and 85.7%, respectively, and its positive and negative predictive values were 87.9 and 82.8%.

Conclusions

ABI is a recommended screening test for the differential diagnosis of lower leg claudication when clinical symptoms are atypical.     

Kinetic magnetic resonance imaging analysis of lumbar segmental mobility in patients without significant spondylosis

Purpose

The purpose of this study was to examine lumbar segmental mobility using kinetic magnetic resonance imaging (MRI) in patients with minimal lumbar spondylosis.

Methods

Mid-sagittal images of patients who underwent weight-bearing, multi-position kinetic MRI for symptomatic low back pain or radiculopathy were reviewed. Only patients with a Pfirrmann grade of I or II, indicating minimal disc disease, in all lumbar discs from L1–2 to L5–S1 were included for further analysis. Translational and angular motion was measured at each motion segment.

Results

The mean translational motion of the lumbar spine at each level was 1.38 mm at L1–L2, 1.41 mm at L2–L3, 1.14 mm at L3–L4, 1.10 mm at L4–L5 and 1.01 mm at L5–S1. Translational motion at L1–L2 and L2–L3 was significantly greater than L3–4, L4–L5 and L5–S1 levels (P < 0.007). The mean angular motion at each level was 7.34° at L1–L2, 8.56° at L2–L3, 8.34° at L3–L4, 8.87° at L4–L5, and 5.87° at L5–S1. The L5–S1 segment had significantly less angular motion when compared to all other levels (P < 0.006). The mean percentage contribution of each level to the total angular mobility of the lumbar spine was highest at L2–L3 (22.45 %) and least at L5/S1 (14.71 %) (P < 0.001).

Conclusion

In the current study, we evaluated lumbar segmental mobility in patients without significant degenerative disc disease and found that translational motion was greatest in the proximal lumbar levels whereas angular motion was similar in the mid-lumbar levels but decreased at L1–L2 and L5–S1.     

Bilateral decompression using a unilateral pedicle construct for lumbar stenosis

Purpose

To determine the effectiveness of bilateral decompression via a unilateral approach using unilateral pedicle screw fixation for two-level lumbar stenosis with instability.

Methods

Between October 2006 and October 2010, 98 patients (61 men and 37 women) who had reached the three-year follow-up interval were treated with unilateral pedicle screw fixation at the authors’ institution. All patients underwent two-level transforaminal lumbar interbody fusion (TLIF), and the mean age was 59.6 years (range, 40–72). Visual analog scale (VAS) scores and Oswestry Disability Index (ODI) were used to assess the pre-operative and postoperative clinical results. Fusion status, the disc space height, and the whole lumbar lordotic angle were analysed for the radiological evaluation.

Results

The ODI scores decreased significantly in both early and late follow-up evaluations and the visual analog scale (VAS) score demonstrated significant improvement in late follow-up (P < 0.01). The disc space height (P < 0.05) and the whole lumbar lordotic angle (P < 0.05) were increased at the final follow-up. Successful fusion was achieved in all patients.

Conclusion

Bilateral decompression via a unilateral approach using unilateral pedicle screw fixation for two-level lumbar stenosis with instability, which can maintain the lumbar lordosis and the disc space height, is an effective and less invasive method than with bilateral constructs.     

Morphometric analysis of the lumbar intervertebral foramen in patients with degenerative lumbar scoliosis by multidetector-row computed tomography

Purpose

How the lumbar neural foramina are affected by segmental deformities in patients in whom degenerative lumbar scoliosis (DLS) is unknown. Here, we used multidetector-row computed tomography (MDCT) to measure the morphology of the foramina in three dimensions, which allowed us to elucidate the relationships between foraminal morphology and segmental deformities in DLS.

Methods

In 77 DLS patients (mean age, 69.4) and 19 controls (mean age, 69), the foraminal height (FH), foraminal width (FW), posterior disc height (PDH), interval between the pedicle and superior articular process (P-SAP), and cross-sectional foraminal area (FA) were measured on reconstructed MDCT data, using image-editing software, at the entrance, minimum-area point, and exit of each foramen. The parameters of segmental deformity included the intervertebral wedging angle and anteroposterior and lateral translation rate, measured on radiographs, and the vertebral rotation angle, measured using reconstructed MDCT images.

Results

The FH, PDH, P-SAP, and FA were smaller at lower lumbar levels and on the concave side of intervertebral wedging (p < 0.05). In the DLS patients, the FH, P-SAP, and FA were significantly smaller than for the control group at all three foraminal locations and every lumbar level (p < 0.05). Intervertebral wedging strongly decreased the FA of the concave side (p < 0.05). Anteroposterior translation caused the greatest reduction in P-SAP (p < 0.05). Vertebral rotation decreased the P-SAP and FA at the minimum-area point on the same side as the rotation (p < 0.05).

Conclusion

The new analysis method proposed here is useful for understanding the pathomechanisms of foraminal stenosis in DLS patients.     

Prediction of long-term clinical outcome in patients with lumbar spinal stenosis

Purpose

The natural course of lumbar spinal stenosis (LSS) fluctuates and is not necessarily progressive. The aim of this study was to explore the predictors of clinical outcome in patients with LSS that might eventually help to optimise the therapeutic choices.

Methods

A group of 56 patients (27 men, 29 women, median age 55; range 31–72 years) with clinically symptomatic mild-to-moderate LSS were re-examined after a median period of 88 months and their clinical outcomes classified as satisfactory (34 patients, 60.7 % with stable or improved clinical status) or unsatisfactory (22 patients, 39.3 % for whom clinical status deteriorated). A wide range of demographical, clinical, imaging and electrophysiological entry parameters were evaluated as possible predictors of clinical outcome.

Results

Unlike the demographical, clinical and imaging variables, certain electrophysiological parameters were significantly associated with unsatisfactory outcomes. There was a significantly higher prevalence of pluriradicular involvement detected by EMG in patients with unsatisfactory outcome than those with satisfactory outcome (68.2 vs. 32.3 %; p = 0.035). Patients with unsatisfactory outcome had more frequent bilateral abnormalities of the soleus H-reflex (50.0 vs. 14.7 %; p = 0.015) and lower mean H-reflex amplitude. Multivariate logistic regression proposed two variables as mutually independent predictors of unsatisfactory outcome: EMG signs of pluriradicular involvement (OR = 3.72) and averaged soleus H-reflex amplitude ≤2.8 mV (OR = 2.87).

Conclusions

Satisfactory outcomes were disclosed in about 61 % of the patients with mild-to-moderate LSS in a 7-year follow-up. Electrophysiological abnormalities, namely the presence of pluriradicular involvement and abnormalities of the soleus H-reflex, were predictive of deterioration of clinical status in these patients.     

High-intensity zone (HIZ) of lumbar intervertebral disc on T2-weighted magnetic resonance images: spatial distribution, and correlation of distribution with low back pain (LBP)

Objectives

To analyze the three-dimensional distribution of high-intensity zone (HIZ) in lumbar disks and to assess the correlation between low back pain (LBP) and spatial distribution of HIZs.

Methods

Clinical records and lumbar MRIs of 623 patients (337 males and 286 females, age 50.10 ± 15.38 years) were selected and reviewed. Baseline characteristics and 3D localization were performed and recorded by two radiologists in a blind fashion.

Results

Among the 623 patients, 200 exhibited an HIZ in at least one disk. HIZs were more frequently seen in the inferior part of annulus fibrosus (superior–middle–inferior ratio 39:59:140, P < 0.001). One hundred and eighty-one HIZs (76.1%) occurred at L4/5 and/or L5/S1. The prevalence of multi-segmental HIZ was 16.5%. Among the 33 patients with multi-segmental HIZs, 24 exhibited HIZs in adjacent disks. The LBP rate of HIZ patients was significantly higher than that of patients who exhibited no HIZ (57.5 vs. 47.8%, P < 0.05). There was no evidence for a correlation between LBP and spatial distribution of HIZ in disk (P > 0.05). The incidence of LBP was slightly higher when the HIZ disk level was lower or when there were HIZs exhibited in more disks; however, the difference was statistically insignificant (P > 0.05).

Conclusions

High-intensity zones occurred frequently at lower segments, inferior part of annulus fibrosus, and single disk.     

Comparative study of spinopelvic sagittal alignment between patients with and without degenerative spondylolisthesis

Introduction

To date, few studies have focused on spinopelvic sagittal alignment as a predisposing factor for the development of degenerative spondylolisthesis (DS). The objectives of this study were to compare differences in spinopelvic sagittal alignment between patients with or without DS and to elucidate factors related to spinopelvic sagittal alignment.

Materials and methods

A total of 100 patients with or without DS who underwent surgery for lumbar spinal canal stenosis were assessed in this study. Fifty patients with DS (DS group) and 50 age- and gender-matched patients without DS (non-DS group) were enrolled. Spinopelvic parameters including pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L4 slope, L5 slope, thoracic kyphosis (TK), lumbar lordosis (LL) and sagittal balance were compared between the two groups. In the DS group, the percentage of vertebral slip (% slip) was also measured.

Results

Several spinopelvic parameters, PI, SS, L4 slope, L5 slope, TK and LL, in the DS group were significantly greater than those in the non-DS group, and PI had positive correlation with % slip (r = 0.35, p < 0.05). Degrees of correlations among spinopelvic parameters differed between the two groups. In the DS group, PI was more strongly correlated with SS (r = 0.82, p < 0.001) than with PT (r = 0.41, p < 0.01). In the non-DS group, PI was more strongly correlated with PT (r = 0.73, p < 0.001) than with SS (r = 0.38, p < 0.01).

Conclusions

Greater PI may lead to the development and the progression of vertebral slip. Different compensatory mechanisms may contribute to the maintenance of spinopelvic sagittal alignment in DS and non-DS patients.     

Comparison of minimally invasive versus open transforaminal lumbar interbody fusion in two-level degenerative lumbar disease

Purpose

The purpose of this study was to compare the clinical and radiological outcomes of minimally invasive versus open transforaminal lumbar interbody fusion in two-level degenerative lumbar disease.

Methods

We conducted a prospective cohort study of 82 patients, who underwent two-level minimally invasive or open transforaminal lumbar interbody fusion (TLIF) from March 2010 to December 2011. Forty-four patients underwent minimally invasive transforaminal lumbar interbody fusion (MITLIF) (group A) and 38 patients underwent the traditional open TLIF (group B). Demographic data and clinical characteristics were comparable between the two groups before surgery (p > 0.05). Peri-operative data, clinical and radiological outcomes between the two groups were compared.

Results

The mean follow-up period was 20.6 ± 4.5 months for group A and 20.0 ± 3.3 months for group B (p > 0.05). No significant difference existed in operating time between the two group (p > 0.05). X-ray exposure time was significantly longer for MITLIF compared to open cases. Intra-operative blood loss and duration of postoperatively hospital stay of group A were significantly superior to those of group B (p < 0.05). On postoperative day three, MITLIF patients had significantly less pain compared to patients with the open procedure. No statistical difference existed in pre-operative and latest VAS value of back pain (VAS-BP) and leg pain (VAS-LP), pre-operative and latest ODI between the two groups. The fusion rate of the two groups was similar (p < 0.05). Complications included small dural tear, superficial wound infection and overlong screws. When comparing the total complications, no significant difference existed between the groups (p > 0.05).

Conclusions

MITLIF offers several potential advantages including postoperative back pain and leg pain, intra-operative blood loss, transfusion and duration of hospital stay postoperatively in treating two-level lumbar degenerative disease. However, it required much more radiation exposure.     

The lumbar lordosis index: a new ratio to detect spinal malalignment with a therapeutic impact for sagittal balance correction decisions in adult scoliosis surgery

Purpose

Sagittal malalignment is frequently observed in adult scoliosis. C7 plumb line, lumbar lordosis and pelvic tilt are the main factors to evaluate sagittal balance and the need of a vertebral osteotomy to correct it. We described a ratio: the lumbar lordosis index (ratio lumbar lordosis/pelvic incidence) (LLI) and analyzed its relationships with spinal malalignment and vertebral osteotomies.

Methods

53 consecutive patients with a surgical adult scoliosis had preoperative and postoperative full spine EOS radiographies to measure spino-pelvic parameters and LLI. The lack of lordosis was calculated after prediction of theoretical lumbar lordosis. Correlation analysis between the different parameters was performed.

Results

All parameters were correlated with spinal malalignment but LLI is the most correlated parameter (r = −0.978). It is also the best parameter in this study to predict the need of a spinal osteotomy (r = 1 if LLI <0.5).

Conclusion

LLI is a statistically validated parameter for sagittal malalignment analysis. It can be used as a mathematical tool to detect spinal malalignment in adult scoliosis and guides the surgeon decision of realizing a vertebral osteotomy for adult scoliosis sagittal correction. It can be used as well for the interpretation of clinical series in adult scoliosis.     

Establishment of parameters for congenital stenosis of the cervical spine: an anatomic descriptive analysis of 1066 cadaveric specimens

Purpose

Congenital cervical stenosis (CCS) occurs when the bony anatomy of the cervical canal is smaller than expected in the general population predisposing an individual to symptomatic neural compression. No studies have defined CCS based on the normal population. The diagnosis is currently made based on clinical impression from radiographic studies. The aim of this study is to establish parameters that are associated with CCS, based on anatomic measurements on a large sample of skeletal specimens.

Methods

From the Hamann-Todd collection at the Cleveland Museum of Natural History, 1,066 skeletal specimens were selected. Digital calipers were used to measure the sagittal canal diameter (SCD), interpedicular distance (IPD), and pedicle length. Canal area at each level was calculated using a geometric formula. A standard distribution was created and values that were 2 SD below mean were considered as congenitally stenotic. An analysis of deviance was performed to identify parameters that were associated with CCS. Regression analysis was used to determine odds ratios (OR) for CCS using these parameters.

Results

CCS was defined at each level as: C3/4 = 1.82 cm², C4/5 = 1.80 cm², C5/6 = 1.84 cm², C6/7 = 1.89 cm², C7/T1 = 1.88 cm². Values of SCD < 13 mm and IPD < 22.5 mm were associated with CCS and yielded sensitivities and specificities of 88–100 % at each level. Logistic regression demonstrated a significant association between these parameters and presence of CCS with OR > 18 at each level.

Conclusions

Based on our study of a large population of adult skeletal specimens, we have defined CCS at each level. Values of SCD < 13 mm and IPD < 23 mm are strongly associated with the presence of CCS at all levels.     

Driving reaction time before and after surgery for lumbar disc herniation in patients with radiculopathy

Purpose

Although patients scheduled to undergo lumbar disc surgery often ask when they are allowed to drive a motor vehicle again, there are no published recommendations on this subject.

Methods

We conducted a prospective study in 46 consecutive patients (mean age 48.9 years) to determine driving reaction time (DRT) before and after surgery in patients with lumbar disc herniation. Of the patients 23 had left-side radiculopathy and 23 right-side radiculopathy. Driving reaction time as well as back and leg pain were evaluated preoperatively, on the day of discharge from hospital and at the 5-week follow-up examination (FU). 31 healthy subjects were tested as controls.

Results

Significant improvement in DRT was seen for both patient samples (p < 0.05). For patients with a right-side radiculopathy preoperative DRT was 664 ms (median, IQR: 241), which was reduced to 605 ms (median, IQR: 189) immediately postoperatively and to 593 ms (median, IQR: 115) at FU. For patients with a left-side radiculopathy DRT was 675 ms (median, IQR: 247) preoperatively, 638 ms (median, IQR: 242) postoperatively and 619 ms (median, IQR: 162) at FU. Pain was moderately correlated to DRT. Control subjects had a driving reaction time of 487 (median, IQR: 116), which differed significantly from patients at all three testing times (p < 0.001).

Conclusion

Our data indicate a positive effect of the surgery on driving ability. Therefore, we would suggest that for both patient samples it is safe to continue driving after hospital discharge. However, patients have to be informed about increased DRT caused by radiculopathy already before surgery.     

Full-endoscopic cervical arcocristectomy for the treatment of spinal stenosis: results of a cadaver study

Purpose

Cervical spondylotic myelopathy is a multifactorial disease that is directly correlated by the degree of spinal stenosis. Surgery remains the best therapy. A posterior approach is often recommended in patients with multilevel dorsal cervical compression. Aim of the present experimental study was to evaluate the feasibility of a full-endoscopic arcocristectomy in a cadaver study.

Methods

We performed full-endoscopic arcocristectomy on ten formalin-fixed human cervical specimens. Before and after decompression we obtained high-resolution computerized tomography (CT) data to evaluate the diameter of the cervical spinal canal.

Results

Overall, surgery was possible on 55 segments in ten cadaver specimens. A mean increase of 4.1 mm (±1.2 mm) in the sagittal diameter of the cervical spinal canal could be achieved (p < 0.05, t test).

Conclusions

The full-endoscopic arcrocristectomy is feasible and achieves a sufficient decompression. This minimal invasive technique protects most of the dorsal structures and therefore probably preserves biomechanical functions, which has to be proven in future studies.     

A morphometric cadaver study of the anterior lumbar epidural space

Introduction

Free disc fragments end often up in the concavity of the anterior epidural space. This space consists of two compartments. The discrepancy between the impressive magnetic resonance imaging findings, clinical symptoms in patients and the problem of treatment options led us to the anatomical determination of anterior epidural space volumes.

Materials and methods

For the first time, the left and right anterior epidural volume between the peridural membrane and the posterior concavity of the lumbar vertebral bodies L3–S1 were determined for each segment. A CT scan and a polyester resin injection were used for the in vitro measurements.

Results

The volumes determined in human cadavers using this method ranged from 0.23 ccm for L3 to 0.34 ccm for L5. The CT concavity volume determination showed this increase in volume from cranial to caudal, as well.

Conclusion

This volume is large enough to hold average-sized slipped discs without causing neurological deficits. A better understanding of the anterior epidural space may allow a better distinction of patient treatment options.     

The effect of timing of rehabilitation on physical performance after lumbar spinal fusion: a randomized clinical study

Background

The number of patients undergoing lumbar spinal fusion procedures (LSF) has risen in recent years, but only few studies have examined different rehabilitation strategies for this patient group.

Purpose

To evaluate the impact of initiating rehabilitation either 6 or 12 weeks after a LSF based on the patients’ physical performance using the 6-min walking test (6MWT) and the Åstrand Fitness test (AF-test) as measurement.

Methods

A multicentre RCT including 82 patients with degenerative disc diseases undergoing LSF randomly assigned to initiate rehabilitation either 6 or 12 weeks after surgery. Both groups received the same group-based rehabilitation. The main outcome measures were the 6MWT and the AF-test, secondarily questionnaire-based measures. Follow-up at baseline as well as at 3, 6 and 12 months after surgery.

Results

Comparing the two groups no statistically significant difference was found in walking distance or fitness over time. In both groups, the patients achieved an overall increase in walking distance (p < 0.01), but no improvement in fitness. The 6MWT showed significant correlation (−0.37 to −0.59) with the questionnaire-based outcome measures (p < 0.01). The AF-test did not correlate to either the 6MWT or any of the questionnaire-based outcome measures.

Conclusion

No difference was found in the effect of initiating rehabilitation either 6 or 12 weeks after LSF on the patients’ physical performance in terms of fitness and walking distance. The 6MWT showed fair to moderate correlation to the questionnaire-based outcome measures. The AF-test showed no significant independent value, and we question its use in LSF patients.     

Lumbar spine fusion surgery and stroke: a national cohort study

Purpose

To investigate the incidence and risk of stroke after lumbar spinal fusion surgery.

Method

Study subjects were identified from a nationwide cohort of 1 million people from 2000 to 2005 and were divided into the lumbar spinal fusion group (n = 2,015), who received posterior lumbar spinal fusion surgery, and the comparison group (n = 16,120) composed of age-, sex-, and propensity score-matched control subjects. The matching process was intended to adjust for demographics, comorbidities, and other immeasurable covariates to minimize selection bias. All subjects were followed up for 3 years for stroke, including hemorrhagic and ischemic strokes. Kaplan–Meier and Cox regression analyses were performed.

Results

The overall incidence rate of stroke in the cohort was 9.99 per 1,000 person-year. The lumbar spinal fusion group was less likely to have any stroke (adjusted hazard ratio (HR) = 0.83, p = 0.293), hemorrhagic stroke (adjusted HR = 0.74, p = 0.739) and ischemic stroke (adjusted HR = 0.81, p = 0.250) than the comparison group, but without significance.

Conclusions

Three years post-operatively, patients who received lumbar spinal fusion had stroke incidence rates similar to those without surgery. Posterior lumbar spinal fusion surgery is not associated with increased risks for any kind of stroke.     

Proinflammatory cytokines in the cerebrospinal fluid of patients with lumbar radiculopathy

In pathologic radicular pain of lumbar spinal stenosis, cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukins (ILs) play a crucial role in the pathogenesis of nerve degeneration and pain. We investigated TNF-α and IL-6 levels in the cerebrospinal fluid (CSF) of patients with radicular pain caused by lumbar spinal stenosis (LSS). A total of 30 LSS patients and 10 age-matched controls were examined. CSF samples were obtained adjacent to the level of stenosis in 30 LSS patients, and at the L4–L5 level in the 10 control patients. TNF-α and IL-6 levels in the samples were analyzed using enzyme-linked immunosorbent assays (ELISA). We compared the amounts of TNF-α and IL-6 with severity of pain (low back and leg pain), walking ability, and severity of stenosis (cross-sectional area of dural space). The concentration of IL-6 was significantly higher in LSS patients than in controls, but TNF-α levels were beneath the limit of detection. There was no correlation between IL-6 levels and severity of pain or walking ability (p > 0.05). However, there was a significant correlation between IL-6 levels and severity of stenosis (p < 0.05). The current study showed that the increased CSF IL-6 levels in LSS patients with radicular pain were not correlated with pain severity; although not proven in this study, the increase in CSF IL-6 concentration could indicate pathological nerve damage or degeneration of lumbar radiculopathy represented by the severity of stenosis.     

Posterior lumbar spinal fusion and instrumentation in morbidly obese patients using the Synframe retractor system: technical note

Purpose

Lumbar spine surgery in morbidly obese patients is a challenge to the operating surgeon. The aim of the study was to evaluate the surgical experience in this group of patients using the Synframe retractor system (Synthes, Paoli, PA, USA) as a tool for improved surgical access.

Methods

An Institutional Review Board approved retrospective study was conducted on 43 morbidly obese patients undergoing posterior lumbar decompression instrumentation and fusion. Patient selection was based on a BMI of >40. Information acquired included BMI, set up time, procedure time, ASA, intraoperative blood loss and the number of preoperative co-morbidities of each patient. Postoperative complications, length of stay, and pre-operative and postoperative Oswestry disability index (ODI) and visual analogue scale (VAS) were recorded at each postoperative visit. They were compared to 45 age matched controls from our spine database.

Results

The average set-up time (73.5 min), amount of blood loss (average 1,040 mL), length of incision (10.3–14.5 cm) and length of hospital stay (5.4 days) were recorded. The average surgical time was dependent on the procedure and number of levels fused and ranged from 164 to 245 min. These parameters were compared with normal weight patients and noted to be higher.

Conclusion

The surgical experience determined that the Synframe retractor system provided a stable and well-illuminated operative field. It minimized the number of personnel required for assistance and improved surgical access. As may be expected, all the above recorded parameters were greater in the morbidly obese group.     

Effect of a prototype lumbar spinal stenosis belt versus a lumbar support on walking capacity in lumbar spinal stenosis: a randomized controlled trial

BACKGROUND CONTEXT

Lumbar spinal stenosis (LSS) can impair blood flow to the spinal nerves giving rise to neurogenic claudication and limited walking ability. Reducing lumbar lordosis can increases the volume of the spinal canal and reduce neuroischemia. We developed a prototype LSS belt aimed at reducing lumbar lordosis while walking.

Analysis of lumbar pedicle morphology in degenerative spines using multiplanar reconstruction computed tomography: what can be the reliable index for optimal pedicle screw diameter?

Purpose

The measurement of transverse pedicle width is still recommended for selecting a screw diameter despite being weakly correlated with the minimum pedicle diameter, except in the upper lumbar spine. The purpose of this study was to reveal the difference between the minimum pedicle diameter and conventional transverse or sagittal pedicle width in degenerative lumbar spines.

Methods

A total of 50 patients with degenerative lumbar disorders without spondylolysis or lumbar scoliosis of >10° who preoperatively underwent helical CT scans were included. The DICOM data of the scans were reconstructed by imaging software, and the transverse pedicle width (TPW), sagittal pedicle width (SPW), minimum pedicle diameter (MPD), and the cephalocaudal inclination of the pedicles were measured.

Results

The mean TPW/SPW/MPD values were 5.46/11.89/5.09 mm at L1, 5.76/10.44/5.39 mm at L2, 7.25/10.23/6.52 mm at L3, 9.01/9.36/6.83 mm at L4, and 12.86/8.95/7.36 mm at L5. There were significant differences between the TPW and MPD at L3, L4, and L5 (p < 0.01) and between the SPW and MPD at all levels (p < 0.01).

Conclusions

The MPD was significantly smaller than the TPW and SPW at L3, L4, and L5. The actual measurements of the TPW were not appropriate for use as a direct index for the optimal pedicle screw diameter at these levels. Surgeons should be careful in determining pedicle screw diameter based on plain CT scans especially in the lower lumbar spine.     

Reoperation after lumbar disc surgery in two hundred and seven patients

Purpose

The purpose of this study was to compare the causes and characteristics of reoperations after different primary operations for lumbar disc herniation (LDH).

Methods

Out of a series of 5,280 patients who underwent operations for LDH between 2001 and 2012, 207 patients (135 male and 72 female, mean age 47.7 years) underwent primary and revision operations, which were included in this study. The following clinical parameters were retrospectively assessed: the primary surgical methods, the intervals between primary and revision operations, and surgical findings in the revisions.

Results

In total, 232 lumbar discs underwent reoperations. One hundred and nineteen reoperations were performed after microendoscopic discectomy (MED group), 68 after percutaneous endoscopic lumbar discectomy (PELD group) and 45 after open disc surgery (open group). The locations of revision operations had priority over those of primary surgery, with a moderate correlation (kappa coefficient = 0.533). A total of 46.6 % of reoperations were performed within 0.5 years after primary surgery, and 35.3 % were performed between one and five years. Real recurrent herniation (homolateral herniations at the same level) was significantly more common than other reoperative surgical findings (70.6 % in PELD group, 47.1 % in MED group, 37.8 % in open group). The overall mean interval until revision surgery was 18.9 months (8.1 months in the PELD group vs. 19.7 months in the MED group vs. 33.1 months in the open group, p < 0.01).

Conclusions

For LDH, real recurrent herniation was the most common cause of reoperations, and more reoperations for real recurrent herniations and shorter intervals were found after minimally invasive endoscopic discectomy than after open disc surgery.