Analysis of quantitative magnetic resonance imaging and biomechanical parameters on human discs with different grades of degeneration.

Analysis of quantitative magnetic resonance imaging and biomechanical parameters on human discs with different grades of degeneration.

J Magn Reson Imaging. 2013 Apr 30;

Authors: Antoniou J, Epure LM, Michalek AJ, Grant MP, Iatridis JC, Mwale F

Abstract
PURPOSE: To establish relationships between quantitative MRI (qMRI) and biomechanical parameters in order to help inform and interpret alterations of human intervertebral discs (IVD) with different grades of degeneration. MATERIALS AND METHODS: The properties of the nucleus pulposus (NP) and annulus fibrosus (AF) of each IVD of 10 lumbar spines (range, 32-77 years) were analyzed by qMRI (relaxation times T1 and T2, magnetization transfer ratio [MTR], and apparent diffusion coefficient [ADC]), and tested in confined compression and dynamic shear. RESULTS: T1 and T2 significantly decreased in both the NP and AF with increasing degeneration grades while the MTR increased significantly with grade 4. In contrast to the other qMRI parameters, the ADC had a tendency to decrease with increasing grade. Disc degeneration caused a decrease in the aggregate modulus, hydraulic permeability and shear modulus magnitude along with an increase in phase angle in the AF. In contrast, disc degeneration of NPs demonstrated decreases in shear modulus and phase angle. CONCLUSION: Our studies indicate that qMRI can be used as a noninvasive diagnostic tool in the detection of IVD properties with the potential to help interpret and detect early, middle, and late stages of degeneration. QMRI of human IVD can therefore become a very important diagnostic assessment tool in determining the functional state of the disc. J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.

PMID: 23633131 [PubMed – as supplied by publisher]

Mechanism of parathyroid hormone-mediated suppression of calcification markers in human intervertebral disc cells.

Mechanism of parathyroid hormone-mediated suppression of calcification markers in human intervertebral disc cells.

Eur Cell Mater. 2013;25:268-83

Authors: Madiraju P, Gawri R, Wang H, Antoniou J, Mwale F

Abstract
In degenerative intervertebral discs (IVD), type X collagen (COL X) expression (associated with hypertrophic differentiation) and calcification has been demonstrated. Suppression of COL X expression and calcification during disc degeneration can be therapeutic. In the present study we investigated the potential of human parathyroid hormone 1-34 (PTH) in suppressing indicators of calcification potential (alkaline phosphatase (ALP), Ca2+, inorganic phosphate (Pi)), and COL X expression. Further, we sought to elucidate the mechanism of PTH action in annulus fibrosus (AF) and nucleus pulposus (NP) cells from human lumbar IVDs with moderate to advanced degeneration. Mitogen activated protein kinase (MAPK) signalling and alterations in the markers of calcification potential were analysed. PTH increased type II collagen (COL II) expression in AF (~200 %) and NP cells (~163 %) and decreased COL X levels both in AF and NP cells (~75 %). These changes in the expression of collagens were preceded by MAPK phosphorylation, which was increased in both AF and NP cells by PTH after 30 min. MAPK signalling inhibitor U0126 and protein kinase-A inhibitor H-89 DCH attenuated PTH stimulated COL II expression in both cell types. PTH decreased ALP activity and increased Ca2+ release only in NP cells. The present study demonstrates that PTH can potentially retard IVD degeneration by stimulating matrix synthesis and suppressing markers of calcification potential in degenerated disc cells via both MAPK and PKA signalling pathways. Inhibition of further mineral deposition may therefore be a viable therapeutic option for improving the status of degenerating discs.

PMID: 23636951 [PubMed – in process]

Dynamic and static overloading induce early degenerative processes in caprine lumbar intervertebral discs.

Dynamic and static overloading induce early degenerative processes in caprine lumbar intervertebral discs.

PLoS One. 2013;8(4):e62411

Authors: Paul CP, Schoorl T, Zuiderbaan HA, Zandieh Doulabi B, van der Veen AJ, van de Ven PM, Smit TH, van Royen BJ, Helder MN, Mullender MG

Abstract
Mechanical overloading of the spine is associated with low back pain and intervertebral disc (IVD) degeneration. How excessive loading elicits degenerative changes in the IVD is poorly understood. Comprehensive knowledge of the interaction between mechanical loading, cell responses and changes in the extracellular matrix of the disc is needed in order to successfully intervene in this process. The purpose of the current study was to investigate whether dynamic and static overloading affect caprine lumbar discs differently and what mechanisms lead to mechanically induced IVD degeneration. Lumbar caprine IVDs (n = 175) were cultured 7, 14 and 21 days under simulated-physiological loading (control), high dynamic or high static loading. Axial deformation and stiffness were continuously measured. Cell viability, cell density, and gene expression were assessed in the nucleus, inner- and outer annulus. The extracellular matrix (ECM) was analyzed for water, glycosaminoglycan and collagen content. IVD height loss and changes in axial deformation were gradual with dynamic and acute with static overloading. Dynamic overloading caused cell death in all IVD regions, whereas static overloading mostly affected the outer annulus. IVDs expression of catabolic and inflammation-related genes was up-regulated directly, whereas loss of water and glycosaminoglycan were significant only after 21 days. Static and dynamic overloading both induced pathological changes to caprine lumbar IVDs within 21 days. The mechanism by which they inflict biomechanical, cellular, and extracellular changes to the nucleus and annulus differed. The described cascades provide leads for the development of new pharmacological and rehabilitative therapies to halt the progression of DDD.

PMID: 23638074 [PubMed – in process]

Blood loss in spinal tumour surgery and surgery for metastatic spinal disease: A meta-analysis.

Blood loss in spinal tumour surgery and surgery for metastatic spinal disease: A meta-analysis.

Bone Joint J. 2013 May;95-B(5):683-8

Authors: Chen Y, Tai BC, Nayak D, Kumar N, Chua KH, Lim JW, Goy RW, Wong HK

Abstract
There is currently no consensus about the mean volume of blood lost during spinal tumour surgery and surgery for metastatic spinal disease. We conducted a systematic review of papers published in the English language between 31 January 1992 and 31 January 2012. Only papers that clearly presented blood loss data in spinal surgery for metastatic disease were included. The random effects model was used to obtain the pooled estimate of mean blood loss. We selected 18 papers, including six case series, ten retrospective reviews and two prospective studies. Altogether, there were 760 patients who had undergone spinal tumour surgery and surgery for metastatic spinal disease. The pooled estimate of peri-operative blood loss was 2180 ml (95% confidence interval 1805 to 2554) with catastrophic blood loss as high as 5000 ml, which is rare. Aside from two studies that reported large amounts of mean blood loss (> 5500 ml), the resulting funnel plot suggested an absence of publication bias. This was confirmed by Egger’s test, which did not show any small-study effects (p = 0.119). However, there was strong evidence of heterogeneity between studies (I(2) = 90%; p < 0.001). Spinal surgery for metastatic disease is associated with significant blood loss and the possibility of catastrophic blood loss. There is a need to establish standardised methods of calculating and reporting this blood loss. Analysis should include assessment by area of the spine, primary pathology and nature of surgery so that the amount of blood loss can be predicted. Consideration should be given to autotransfusion in these patients. Cite this article: Bone Joint J 2013;95-B:683-8.

PMID: 23632682 [PubMed – in process]

Long-term outcomes of 2 cervical laminoplasty methods: midline splitting versus unilateral single door.

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Long-term outcomes of 2 cervical laminoplasty methods: midline splitting versus unilateral single door.

J Spinal Disord Tech. 2012 Dec;25(8):E224-9

Authors: Park JH, Roh SW, Rhim SC, Jeon SR

Abstract
BACKGROUND: Two major current methods are midline splitting laminoplasty (MSL) and unilateral single-door laminoplasty (USDL). Few studies have compared the 2 techniques.
METHODS: We retrospectively analyzed the outcomes of 100 consecutive myelopathy patients who underwent decompressive laminoplasty between January 2004 and June 2008. The mean follow-up duration was 48.2 months.
RESULTS: The mean Japanese Orthopedic Association scores changed from 6.9 to 11.9 in the MSL group and from 6.2 to 12.4 in the USDL group, resulting in mean calculated recovery rates of 55.5% and 63.0%, respectively (P = 0.14). Mean cervical lordosis declined from 12.0 to 10.2 degrees in the MSL group and from 10.3 to 8.5 degrees in the USDL group (P = 0.24). Mean cervical range of motion declined from 27.8 to 25.6 degrees in the MSL group, and from 23.4 to 16.0 degrees in the USDL group (P = 0.38). Bony spinal canal dimension increased from 201.2 to 280.8 mm in the MSL group and from 204.3 to 331.7 mm in the USDL group (P < 0.001). In the USDL group, 6 patients experienced postoperative neck pain, 7 experienced C5 palsy, and 2 experienced cerebrospinal fluid leakage. No such complications occurred in the MSL group (P ≥ 0.05 for both complications).
CONCLUSIONS: MSL and USDL patients had similar long-term clinical and radiologic outcomes, except that bony canal expansion was greater in the latter. We believe that removal of the ligamentum flavum and drilling of the internal bony edge were factors in the favorable clinical outcomes and low rate of complications in the MSL group.

PMID: 23160272 [PubMed – indexed for MEDLINE]

Systematic review of caudal epidural injections in the management of chronic back pain.

Systematic review of caudal epidural injections in the management of chronic back pain.

R I Med J (2013). 2013;96(1):12-6

Authors: Friedman JH, Dighe G

Abstract
Epidural steroids recently attracted world attention due to medication contamination resulting in many cases of fungal meningitis. What was rarely noted in these reports is that there is little data to support use of this treatment. This article reviews the literature on epidural steroids for various types of back pain and concludes that further testing should be performed to determine if and in what situations this intervention is useful before wide-spread use is resumed.

PMID: 23638452 [PubMed – in process]