Previous studies have stated that presence of concomitant back pain has a negative effect on the outcome of lumbar decompression/microdiscectomy but none have actually defined what level of back pain should be considered as significant. This is a study of consecutive patients who underwent a primary single level lumbar micro decompression /microdiscectomy performed by thirty nine surgeons at a single tertiary spinal centre between August 2011 and December 2014. The aim was to determine the differential effect of the intensity of back pain and leg pain as a predictor of outcome. Data was prospectively collected using SpineTango COMI questionnaires pre-operatively and at 3 months postoperatively. 995 patients who had a complete dataset were included in the analysis. Multivariate regression analysis and ROC curves were used to evaluate factors associated with poor outcome. At 3 months follow up 72.16% of patients were satisfied with the outcome of surgery. The VAS for low back pain was a significant predictor of poor outcome. Of patients with a VAS of 6 or more 34% had a poor outcome following surgery while of patients with a VAS of less than 6, 17% had a poor outcome at three months.Back ground:
Method and Result:
Increasing numbers of young people receive metal on metal (CoCr on CoCr) total hip replacements. These implants generate nano-particles and ions of Co and Cr. Previous studies have shown that micro-particles, nano-particles and ions of CoCr cause DNA damage and chromosomal abberrations in human fibroblasts in tissue culture, and in lymphocytes and bone marrow cells in patients with implants. Several surgeons have used these implants in women of child-bearing age who have subsequently had children. Significantly elevated levels of cobalt and cromium ions have been measured in cord blood of pregnant women with CoCr hip implants. The MHRA (Medicines and Healthcare products Regulatory Agency) subsequently stated that there is a need to determine whether exposure to cobalt and chromium represents a health risk during pregnancy. In an attempt to investigate this risk, we used a well established in vitro model of the placental barrier comprised of BeWo cells (3 cells in thickness) derived from the chorion and exposed this barrier to nanometer (29nm) and micron (3.4μm) sized CoCr particles, as well as ions of Co2+ and Cr6+ individually or in combination. We monitored DNA damage in BJ fibroblasts beneath the barrier with the alkaline gel electrophoresis comet assay and with γH2AX staining. The results showed evidence of DNA damage after all types of exposure. The indirect damage (through the barrier) was equal to the direct damage at the concentrations tested. The integrity of the barriers was checked with measurements of electrical resistance (TEER values) and permeability to sodium fluorescein (376Da) and found to be intact. In light of these results and with the knowledge that BeWo cells express the transmembrane protein Connexin 43, we tested the theory that a damaging signal was being relayed via gap junctions or hemi channels in the BeWo cells to the underlying fibroblasts. We used the connexin mimetic peptides Gap19 and Gap26 (known to selectively block hemichannels and gap junctions respectively) and 18α-glycyrrhetinic acid (non-selective gap junction blocker). All of these compounds completely obliterated the indirect damaging effect seen in our previous experiments. We conclude that CoCr particles can cause DNA damage through a seemingly intact barrier, and that this damage occurs via a bystander mechanism. It would be of interest to test whether this is simply a tissue culture effect or could be seen in vivo.
