Abstract. Objective. Spinal cord surgery is a technically challenging endeavour with potentially devastating complications for patients and surgeons. Intra-operative neurophysiological monitoring(IONM), or spinal cord monitoring (SCM), is one method of preventing and identifying damage to the spinal cord. At present, indications for its use are based more on individual surgeon preference and for medico legal purposes. Our study aimed to determine IONM's utility as a clinical tool. Methods. This is a retrospective case series of 169 patients who underwent spinal surgery with IONM at two institutions between 2013 and 2018. Signal changes detected were recorded as well as the surgeon's response to these changes. Patients were followed up to one-year post-surgery using our institution's EVOLVE system. The main outcome measure in this study was new post-operative neurological signs and/or symptoms and what effect, if any, IONM and subsequent surgeon intervention had on these complications. Result. Indications for IONM included cervical stenosis, cervical disc prolapse, unstable fractures and bony metastases. Signal changes were observed in 33% (n=55) of cases. 24 of these patients responded to re-positioning. There were 7 total complications with full resolution by 12 months. False negative rate was 2.4% (n=4). There was one true positive. The largest cohort of patients included those who experienced no signal changes and subsequently no post-operative deficits (n=124). Conclusion. IONM is a non-invasive clinical tool that may be utilised for medicolegal reasons. Its use as a clinical tool is questionable given its relatively high false negative rate and low false positive rate. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Background. Post-operative acute kidney injury is significant complication following surgery. Patients who develop AKI have an increased risk for progression into chronic kidney disease, end-stage renal failure and increased mortality risk. The patient outcomes following total knee replacement (TKR), who develop AKI has been a topic of interest in recent years as it may have patient and medicolegal implications. Nevertheless, there are no studies looking at the incidence, risk factors and outcomes of AKI following bilateral TKRs at the same sitting. Objectives. To determine the incidence, risk factors and outcomes of post-operative AKI following bilateral TKRs surgery at the same sitting. Methods. This was a retrospective single-centre study performed at the Princess Royal Hospital, which performed a total of 25 BTKR. The incidence, Surgical and patient risk factors were recorded and analysed. Results. The incidence of AKI as defined by NICE guidelines following bilateral TKRs was 20%. 16% (4 patients) had stage 1 and 4% (1 patient) had stage 2 AKI. The mean change in Creatinine between pre- and post-operative blood tests was +19μmol/L. There was a strong significant correlation between CKD and AKI (r=0.75, P<0.05). Furthermore, a moderate correlation was found between higher BMI and pre-operative Charlson index and AKI. AKI did not have an effect on the length of inpatient stay with the mean inpatient length of stay for patients who had an AKI of 10 days compared to 11days for those who did not. All AKIs were resolved within 72 hours. There were no associated mortalities with AKI. Conclusion. The incidence of AKI following bilateral TKR was 20%. Pre-operative chronic kidney disease as well as having a higher BMI were identified as risk factors for developing AKI. Pre-operative CKD optimisation and careful adequate hydration intra-operatively should be considered in these patients. AKI was not associated with an increased length of stay or mortality in our study

Over the past two decades much has been written regarding pain and disability following whiplash injury. Several authors have reported on the relationship between insurance claims and whiplash-associated disorders. Our own experience of over 10-years suggests that fracture may be protective of whiplash injury following road traffic accident (RTA). We exported all ‘medical legal’ cases due to RTA from our EMR system and combined this with patient-reported outcome measures. 1,482 (57%) of all medicolegal cases are due to RTA: 26% ‘head-on’, 34% ‘side-impact’ and 40% ‘rear-ended’. Over half of the vehicles involved are subsequently written-off. While the mean BMI is 27.1, ¼ of this cohort has a BMI over 30 (obese). 163 (11%) patients report a fracture occurring as a result of RTA. Type of impact is significant for fracture (p < 0.05). 47% of RTA which result in fracture are due to ‘head-on’ collision; conversely only 21% are due to ‘rear-ended’ impacts. In 1,324 (89%) of RTA without fracture, patients are twice as likely to report whiplash injury as one of their top-3 sources of pain (p < 0.01). Gender is statistically significant for age (M 44.4, F 38.6, p < 0.05). While the BMI of this cohort is alarming, it is consistent with Irish obesity statistics. Type of impact, in particular ‘head-on’ collision (high kinetic energy event), is significant for fracture. Finally, we report that fracture is significantly protective (p < 0.01) of whiplash injury following RTA

Introduction. Herniated disc tissue removed at surgery usually appears degenerated, and MRI often reveals degenerative changes in adjacent discs and vertebrae. This has fostered the belief that a disc must be degenerated before it can herniate, which has medicolegal significance. We hypothesise that degenerative changes in herniated disc tissues differ from those found in tissues that have degenerated in-situ, and are consistent with being consequences rather than causes of herniation. Methods. Surgically-removed discs were examined using histology, immunohistochemistry and confocal microscopy. 21 samples of herniated tissues were compared with age-matched tissues excised from 11 patients whose discs had reached a similar Pfirrman grade of degeneration but without herniating. Degenerative changes were assessed separately in three tissue types (where present): nucleus, inner annulus, and outer annulus. Mann-Whitney U tests were used to compare ‘herniated’ vs ‘in-situ’ tissues. Results. Herniated tissues showed significantly greater cellularity (annulus), greater proteoglycan loss (outer annulus), greater neovascularisation (annulus), greater innervation (annulus) as judged by PGP 9.5 staining, greater expression of matrix-degrading enzymes MMP1 and MMP3 (inner annulus), but less cell clustering (outer annulus). Some similar but non-significant differences were seen in nucleus tissues. Interpretation. Herniated tissues that escape the pressurised confines of the disc are free to swell, lose proteoglycans and come into contact with blood cells. These events could explain most of the differences between herniated tissues and those that degenerated ‘in situ’. Results support our hypothesis, and warn against assuming that degenerative changes always precede (or cause) disc herniation. No conflicts of interest. No funding obtained. This abstract has not been previously published in whole or in part; nor has it been presented previously at a national meeting