The rate of subsidence for lumbar fusion surgery is variable from 7- 89%. Subsidance can affect the outcome of surgery by compramising alignment, foraminal height and stability. Modic changes have been shown to affect the stiffness and strength of the vertebral end plate and shown to affect both fusion rates and clinical outcome. Ongoing laboratory investigations into the material properties of the degenerate lumbar spine show modic changes affect the end plate and trabecular bone mechanics. This study aims to bridge this basic science research into clinical practice. A retrospective analysis of all patients in two tertiary spinal centres who have undergone lumbar interbody fusion with the implantation of a ‘cage’ over the past 6 years were analysed by two independent spinal surgeons. Pre-operative MRI findings were correlated with post-operative interbody cage subsidence after 1 year.Background
Methods
This study aims to establish the micro-structure of the vertebral endplate and its interface with the adjacent bone and disc in fresh, unstained tissue so that the structure can be related to normal and pathological function. The endplate is key in both the mechanics, anchoring and nutrition of the disc. Understanding the detailed structure of the normal and pathological endplate is important for understanding how it achieves its functions. Advancements in imaging technology continually allow for greater understanding of biological structures. The development of two-photon fluorescence (TPF) combined with second harmonic generation (SHG), allows for the imaging of relatively thick, fresh samples without the need for staining.Purpose of study
Background
To study the relationship between Zygoapophysial Joint Tropism and pathologic fractures affecting lumbar and thoracic vertebrae in elderly patients. The sagittal plane orientation of the Zygoapophysial joints (facets or ZAJ) of 324 vertebrae of 63 patients were measured on MRI scans, stratified into lumbar and thoracic, fractured and non-fractured, and then classified according to the presence of tropism. The correlation between tropism and fractures, demographics pertaining to age, spinal level, and morbidity were studied.Purpose
Methods
Lumbar spine foraminal stenosis has previously been defined by the foraminal and posterior disc height. We performed a study to determine whether residual clinically significant foraminal stenosis correlates with foraminal dimensions and peri-neural fat signal loss in a group of patients with leg pain undergoing surgery for lateral recess stenosis. We retrospectively studied the pre-operative para-sagittal MRI slices of 57 patients undergoing lumbar decompression and measured pre- and post-operative VAS as a primary outcome measure to evaluate surgical success. We performed a linear regression analysis comparing change in VAS score, 1 year VAS and percentage change in VAS with foraminal height and width and found no significant correlation (R2 <0.2 for all correlations). We identified a sub-group of 16 patients with absent perineural foraminal fat signal with a significantly increased probability of post-operative VAS>2 compared to patients with present fat signal (p=0.0001) who all had foraminal height <10mm. In conclusion, we were unable to define dimensional foraminal parameters for clinically significant foraminal stenosis on para-sagittal MRI. Obliteration of perineural fat was associated with worse outcome and post-operative leg pain. The aetiology of foraminal stenosis is multi-factorial and more detailed imaging of the foramen is required. We recommend that coronal and fine para-sagittal MRI slices are analysed to evaluate patients with central and lateral recess stenosis for co-existing foraminal stenosis.
To assess the effectiveness of dynamic stabilisation as a treatment for discogenic pain compared to standard treatment of interbody fusion. All patients were referred for a 2 year back-pain management programme. Patients with continued pain following conservative treatment underwent discography & MRI. Patients with painful degenerate discs on the above investigations were selected. Patients underwent interbody fusion (PLIF/TLIF) or dynamic stabilisation. Mean follow-up was 24 months with a minimum follow-up of 12 months. All patients had pre-operative ODI and VAS scores. Patients were then sent further questionnaires at 6 month intervals. The mean improvement in ODI following dynamic stabilisation was 20% (-20% → 56%), the mean improvement in the pain score was 2.4 (0→8). The mean improvement in ODI following interbody fusion was 11% (-14%→48%), the mean improvement in the pain score was 2.6 (-4→9). 10 patients in the dynamic stabilisation group had a greater than 20% improvement in ODI, 7 patients in the interbody fusion group had similar results. The above results demonstrate that dynamic stabilisation is at least as effective at treating discogenic pain as interbody fusion. The results however do question the validity of either interbody fusion (PLIF/TLIF) or dynamic stabilisation in the management of discogenic pain.
To assess the effectiveness of dynamic stabilisation as a treatment for discogenic pain compared to standard treatment of interbody fusion. Study Design & Subjects All patients were referred for a 2 year back-pain management programme. Patients with continued pain following conservative treatment underwent discography & MRI. Patients with painful degenerate discs on the above investigations were selected. Patients underwent interbody fusion (PLIF/TLIF) or dynamic stabilisation. Mean follow-up was 24 months with a minimum follow-up of 12 months. All patients had pre-operative ODI and VAS scores. Patients were then sent further questionnaires at 6 month intervals.Objective
Outcome Measures
