Qualitative grading of disc degeneration by magnetic resonance in the lumbar and cervical spine: lack of correlation with histology in surgical cases.

BACKGROUND: Clinically, magnetic resonance (MR) imaging is the most effective non-invasive tool for assessing IVD degeneration. Histological examination of the IVD provides a more detailed assessment of the pathological changes at a tissue level. However, very few reports have studied the relationship between these techniques. Identifying a relationship may allow more detailed staging of IVD degeneration, of importance in targeting future regenerative therapies. OBJECTIVES: To investigate the relationship between MR and histological grading of IVD degeneration in the cervical and lumbar spine in patients undergoing discectomy. METHODS: Lumbar (N = 99) and cervical (N = 106) IVD samples were obtained from adult patients undergoing discectomy surgery for symptomatic IVD herniation and graded to ascertain a histological grade of degeneration. The pre-operative MR images from these patients were graded for the degree of IVD (MR grade) and vertebral end-plate degeneration (Modic Changes, MC). The relationship between histological and MR grades of degeneration were studied. RESULTS: In lumbar and cervical IVD the majority of samples (93%) exhibited moderate levels of degeneration (ie MR grades 3-4) on pre-operative MR scans. Histologically, most specimens displayed moderate to severe grades of degeneration in lumbar (99%) and cervical spine (93%). MR grade was weakly correlated with patient age in lumbar and cervical study groups. MR and histological grades of IVD degeneration did not correlate in lumbar or cervical study groups. MC were more common in the lumbar than cervical spine (e.g. 39 versus 20% grade 2 changes; p < 0.05), but failed to correlate with MR or histological grades for degeneration. CONCLUSIONS: In this surgical series, the resected IVD tissue displayed moderate to severe degeneration, but there is no correlation between MR and histological grades using a qualitative classification system. There remains a need for a quantitative, non-invasive, pre-clinical measure of IVD degeneration that correlates with histological changes seen in the IVD.

Angiogenic cell therapy for critical limb ischemia: an update on concepts and trials.

Therapeutic neovascularization is a novel approach used to salvage critically ischemic limbs that are not amenable to conventional treatments. Initial efforts were based on single injections of angiogenic factors but there is now a realization that delivering angiogenic cells is more likely to achieve effective revascularization. Clinical studies to date have mostly used mixtures of mononuclear cells harvested from the bone marrow or peripheral blood. The modest results achieved with these cells, only a proportion of which are angiogenic, has stimulated a search for more potent cell types. Preclinical studies have identified several candidates, including adipose derived, embryonic and induced pluripotent stem cells. This review provides an update on the current status of angiogenic cell therapy for the ischemic limb and outlines efforts aimed at enhancing the clinical efficacy of treatments.