Follow-up Study Of The Curative Effect Of Microendoscopic Discectomy-assisted For Protrusion Of The Lumbar Intervertebral Disc Herniation

Objective: To explore the short-time, middle-time and long-term clinical efficacy of the mono-segment Lumbar Intervertebral Disc Herniation(LDH) with the treatment of Microendoscopic Discectomy(MED) and the length of the study curve, by using different evaluation parameters, evaluate the safety and minimally invasive of MED, efficacy stability and improve the level of the clinical application of MED technology.Methods: 80 cases with low mono-segment LDH were analyzed from January 2011 to June 2012, among them, 40 cases operated with MED and 40 cases operated with Open Discectomy(OD), named MED group and OD group respectively. By comparing the length of surgical incision, blood loss, operating time, the average temperature for three consecutive days after surgery, preoperative and postoperative low back pain and leg pain Faces Pain Scale-Revised(FPS-R), the short-term clinical effect of MED for mono-segment LDH were evaluated. By comparing Japanese orthopaedic association low back pain(JOA) score a month after surgery and Oswestry Disability Index a month, 3 months and 6 months after surgery, and excellent rate calculated by the rate of improved JOA score, the middle-term clinical effect of MED for mono-segment LDH were evaluated. The datas of follow up of cases with mono-segment LDH from January 2011 to December 2014 were collected and the long-term clinical effect of MED for mono-segment LDH were evaluated, by comparing the changes of intervertebral height of preoperative and postoperative lesions in MED group between followed up for over 24 months and 36 months. The datas of operation record with mono-segment LDH operated by MED from January 2011 to December 2014 were collected and the operation time was summarized and these cases were divided into four groups, like A(2011 year), B(2012 year), C(2013 year), D(2014 year), and the mean operative time of each group of patients was calculated. The learning curve of MED for mono-segment LDH was explored and concluded, by comparing the mean operative time of these four groups.Results: Significant differences could be observed in the length of surgical incision and blood loss between MED group and OD group, with statistical significance, showing MED group was superior to OD group(t=32.573, R=0.000 and t=34.275, P=0.000). There were also significant differences in the mean operative time between MED group and OD group, with statistical significance, showing OD group was superior to MED group(t=11.236, P=0.000). There were no significant differences in the mean body temperature 3 days after surgery between two groups, without statistical significance(t=1.726, P=0.088). The low back pain FPS-R score during the same period after operation in the MED group was significantly lower than the OD group with statistical significance(F=155.637, P=0.000) while without statistical significance(F=0.001, P=0.975) for the differences of leg pain FPS-R score during the same period. The rate of excellent and good 6 outcomes one month after surgery was 95% in MED group, and 97.5% in OD group, according to the JOA score, without statistical significance(2c =1.233, P=0.267 and t=0.523, P=0.602), and the same with JOA score one month after surgery, ODI score 1 month after surgery, 3 months after surgery and 6 months after surgery(F=0.235, P=0.629). In addition, there was no statistical significance(t=0.218, P=0.828 and t=0.476, P=0.636) of the differences among preoperative and postoperative(24 months and 36 months) intervertebral height. The average operation time presented a decreasing trend in the A(2011 year), B(2012 year), C(2013 year), D(2014 year) group successively divided by annual, with the operation time in B, C, D group flattening and obviously lower than A group.Conclusion: MED had the advantages of less trauma, less blood loss, fast pain relief, significant short-term surgery effect, compared to OD. MED had no significant difference in the middle-term surgery effect, with exact effect, compared to OD. postoperative(24 months to 36 months) intervertebral height with MED didn?t have a significant decrease, having long-term stable efficacy and therefore, MED was the preferred choice for LDH. The learning curve of MED technology varies with different learners with a slight difference and generally dozens of cases surgery are enough for entering the plateau, and once mastering the technique, surgical safety and stability are high. The learning curve would not affect the curative effect of the patients initially treated by MED technology.