Contrast enrichment of spinal cord MR imaging using a ratio of T1-weighted and T2-weighted signals.

By London Spine
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Contrast enrichment of spinal cord MR imaging using a ratio of T1-weighted and T2-weighted signals.

J Magn Reson Imaging. 2014 Nov;40(5):1199-207

Authors: Teraguchi M, Yamada H, Yoshida M, Nakayama Y, Kondo T, Ito H, Terada M, Kaneoke Y

Abstract
PURPOSE: We aimed to assess if the T1-weighted (T1w)/T2-weighted (T2w) signal ratio could be used to improve image contrast in MR spinal cord imaging.
MATERIALS AND METHODS: T1w and T2w cervical spinal cord MR images were acquired from 23 normal subjects using 3 Tesla (T) MR scanner. In addition, a multiple sclerosis patient, and a cervical spondylotic myelopathy patient were evaluated. White matter (WM) and gray matter (GM) signal intensities were measured for each image (T1w, T2w, and T1w/T2w) for seven cervical segments in each subject to calculate the contrast. Age-related changes in signal intensity were assessed at each location (lateral column, anterior column, dorsal column, and GM) for each image. Additionally, the imaging results of two subjects with spinal diseases and the controls were numerically compared.
RESULTS: The contrast between the WM and GM in the T1w/T2w ratio image was approximately twice as much as that in the T1w and T2w images (mean ± SD = 1.8 ± 0.4). The signal intensity ratio was related to age. For both clinical patients, the signal intensities were significantly lower in the lesion areas in the ratio images.
CONCLUSION: The T1w/T2w ratio images demonstrated increased image contrast compared with T1w and T2w images alone and, reduced inter-individual signal intensity differences.

PMID: 24395471 [PubMed – indexed for MEDLINE]

Vertebral Compression Fractures after Lumbar Instrumentation.

By London Spine

Vertebral Compression Fractures after Lumbar Instrumentation.

Cureus. 2017 Sep 29;9(9):e1729

Authors: Granville M, Berti A, Jacobson RE

Abstract
Lumbar spinal stenosis (LSS) is primarily found in an older population. This is a similar demographic group that develops both osteoporosis and vertebral compression fractures (VCF). This report reviewed a series of patients treated for VCF that had previous lumbar surgery for symptomatic spinal stenosis. Patients that only underwent laminectomy or fusion without instrumentation had a similar distribution of VCF as the non-surgical population in the mid-thoracic, or lower thoracic and upper lumbar spine. However, in the patients that had previous short-segment spinal instrumentation, fractures were found to be located more commonly in the mid-lumbar spine or sacrum adjacent to or within one or two spinal segments of the spinal instrumentation. Adjacent-level fractures that occur due to vertebral osteoporosis after long spinal segment instrumentation has been discussed in the literature. The purpose of this report is to highlight the previously unreported finding of frequent lumbar and sacral osteoporotic fractures in post-lumbar instrumentation surgery patients. Important additional factors found were lack of preventative medical treatment for osteoporosis, and secondary effects related to inactivity, especially during the first year after surgery.

PMID: 29201578 [PubMed]

Percutaneous minimally invasive instrumentation for traumatic thoracic and lumbar fractures: a prospective analysis.

By London Spine
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Percutaneous minimally invasive instrumentation for traumatic thoracic and lumbar fractures: a prospective analysis.

Acta Orthop Belg. 2012 Jun;78(3):376-81

Authors: Krüger A, Rammler K, Ziring E, Zettl R, Ruchholtz S, Frangen TM

Abstract
Open posterior instrumentation is still the standard procedure for unstable traumatic thoracic and lumbar fractures. There is a general tendency towards minimally invasive approaches in various surgical disciplines. The Sextant II Rod Insertion system is one of these. The authors prospectively studied this system in 51 patients with thoracic and lumbar fractures, between October 2007 and January 2011. Most fractures (31/51) were situated at the lumbar level. In 7 older patients the technique was combined with kyphoplasty and/or cement augmentation of the pedicle screws. The median operative time was 61 minutes (range: 26-130). The median fluoroscopy time was 132 seconds (range: 24-414). Most pedicle screws were correctly placed: 197 out of 204 screws. All fractures showed bony union after 6 weeks, but the multiaxial pedicle screws were not able to conserve the slight correction obtained peroperatively via positioning and longitudinal traction. Percutaneous minimally invasive stabilization of the spine needs further improvement.

PMID: 22822580 [PubMed – indexed for MEDLINE]

Uni- and bi-lateral Instrumented Posterolateral Fusion of the Lumbar Spine with Local Bone Grafting: a Prospective Study with a 2-Year Follow-Up.

By London Spine

Uni- and bi-lateral Instrumented Posterolateral Fusion of the Lumbar Spine with Local Bone Grafting: a Prospective Study with a 2-Year Follow-Up.

Spine (Phila Pa 1976). 2011 May 3;

Authors: Ohtori S, Koshi T, Suzuki M, Takaso M, Yamashita M, Yamauchi K, Inoue G, Orita S, Eguchi Y, Ochiai N, Kishida S, Kuniyoshi K, Aoki Y, Nakamura J, Ishikawa T, Arai G, Miyagi M, Kamoda H, Suzuki M, Furuya T, Toyone T, Takahashi K

ABSTRACT: Study Design. Prospective trial.Objective. To examine the bone union and clinical results after unilateral or bilateral instrumented posterolateral fusion surgery using a local bone graft.Summary of Background Data. The iliac crest bone graft technique for lumbar posterolateral fusion surgery is widely used; however, donor site problems such as pain and sensory disturbance have been reported. Local bone has been used for bilateral multi-segment fusion surgery; however, outcomes have been poor because of insufficient amounts of local bone used. The current study evaluated unilateral and bilateral posterolateral fusion at 3 levels using a local bone graft.Methods. Sixty-two patients diagnosed with degenerated spondylolisthesis at 3 levels were divided into 2 groups. All underwent decompression and bilateral instrumented posterolateral fusion. However, a unilateral local bone graft was used in 32 patients and bilateral local bone graft was used in 30 patients. The amount of bone grafting, proportion of patients with bone union, duration of bone union, visual analog scale (VAS) score, Japanese Orthopedic Association (JOA) score, and Oswestry Disability Index (ODI) were evaluated before and 2 years after surgery.Results. VAS score, JOA score, and ODI were not significantly different between the 2 groups before and after surgery (P > 0.05). The amount of local bone graft used for each segment was significantly less in the bilateral group (P < 0.05). The proportions of patients with, or rates of bone union and instability were 86% and 9% respectively in the unilateral group, but significantly poorer at 60% and 34% in the bilateral group.Conclusion. If multi-segment fusion (3 level fusion) is performed, bilateral local bone grafting results in a poor rate of bone union because of an insufficiency of local bone. Unilateral bone grafting is recommended because better rates of bone union and stability are achieved.

PMID: 21544013 [PubMed – as supplied by publisher]

Altering Conventional to High Density Spinal Cord Stimulation: An Energy Dose-Response Relationship in Neuropathic Pain Therapy.

By Kamruz Zaman
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Altering Conventional to High Density Spinal Cord Stimulation: An Energy Dose-Response Relationship in Neuropathic Pain Therapy.

Neuromodulation. 2016 Oct 24;:

Authors: Wille F, Breel JS, Bakker EW, Hollmann MW

Abstract
OBJECTIVES: To examine whether converting from conventional Spinal Cord Stimulation (SCS) to High Density (HD) SCS reduces neuropathic pain over a period of 12 months in patients with failed SCS therapy.
METHODS: Retrospective, open label, single center, consecutive case series of 30 neuropathic pain patients (Failed Back Surgery Syndrome [FBSS], Complex Regional Pain Syndrome [CRPS], and polyneuropathy [NP]). Patients with an initial adequate response to conventional SCS, but in whom pain increased over time, were included (Numeric Rating Scales [NRS] >6). These patients were stimulated with HD-SCS parameters and followed-up for 12 months. We report pain intensity, measured with NRS, before SCS implantation, 1 and 3 months after starting SCS with conventional stimulation, and after 1, 6, and 12 months of HD SCS.
RESULTS: Pain reduction with conventional stimulation was initially adequate (NRS mean 8.6 to 5.3 at three months postimplant) but increased over time to a mean NRS of 7.7 at the time of reprogramming. NRS scores decreased significantly to 4.3 (p = 0.015) after reprogramming from conventional SCS (30 Hz, 300 µsec, 3.0 V) to HD SCS (409 Hz, range 130-1000 Hz, 409 µsec, 2.4V) in the patients still using HD-SCS at 12 months. In the nonresponders (patients who stopped HD-SCS for any reason), 76% had a diagnosis of FBSS. Almost half of the patients aborting HD-SCS preferred to feel paresthesias despite better pain relief. There was a significant difference between nonresponders and responders regarding the amount of electrical energy delivered to the spinal cord.
CONCLUSION: Neuropathic pain suppression is significantly enhanced after converting from failed conventional SCS to HD SCS in patients with FBSS, CRPS, and NP over a measured period of 12 months. There appears to be a dose-related response between the amount of energy delivered to the spinal cord and clinical effect.

PMID: 27778413 [PubMed – as supplied by publisher]