A SYSTEMATIC PROCESS USING INTRA-OPERATIVE X-RAY IN PREVENTING WRONG LEVEL SURGERY FOR LUMBAR MICRODISCECTOMY

To review the accuracy of our systematic process in preventing wrong level lumbar microdiscectomy. X-ray is used to identify the correct level for the skin incision to be made, x-ray is again used if the surgeon is in doubt prior performing the flavotomy. Following a lumbar microdiscectomy a Watson Chane is inserted into the empty disc space and an intra-operative x-ray is taken to confirm the level the discectomy has occurred. Observers A and B independently reviewed intra-operative x-ray in patients undergoing lumbar microdiscectomies and correlated the accuracy of the x-ray in determining correct level surgery against the pre-operative MRI scan and the preposed level of surgery. 123 patients, 66 males and 57 females underwent 127 lumbar microdiscectomy procedures between 2007 and 2009. The levels where surgery occurred are;- L2/3 -1 patient, L3/4–8 patients, L4/5–53 patients and L5/S1-65 patients. Kappa coefficient was used to determine inter-observer and Pearson Correlation coefficient was used to determine the X-ray and MRI relationship Percentage of patients who required a pre-flavotomy x-ray level check are:- L2/3–100%, L3/4-63%, L4/5–45%, and L5/S1–40%. Pearson9s correlation in confirming the level lumbar microdiscectomy was performed using final x-ray and the pre-operative MRI scan was 1. Kappa coefficient between observer A and B was 1. This process of using intra-operative x-ray in determining the exact level where lumbar microdiscectomy was performed is 100% accurate. This is our standard process in preventing wrong level surgery for lumbar microdiscectomy.