Change of Pain Score for One Month after Endoscopic Lumbar Discectomy in Patients Who Showed Substantial Improvement of Pain and Who Did Not at Postoperative One Day

Objective: After endoscopic disectomy (ED), some patients may get substantial improvement just after the operation or may not.If we could expect short-term change of pain status, it would be helpful for consultation with patients.The object of this study was to present change of pain score for one month after ED in patients who showed substantial improvement of pain and who did not at postoperative one day.Methods: From Jan 2007 to Dec 2008, 116 patients (M:F=114:2; Age, 22.4±5.3)were operated on endoscopic discectomy (ED) due to lumbar herniated intervertebral disc (HIVD).The operated levels were L4-5 in 90 cases and L5-S1 in 26 cases.At 30 days postoperative, outcome was assessed by Macnab's criteria.All patients were followed-up for at least one month.Results: At one month postoperative, outcome was assessed (excellent, 94/116, 81%; good, 6/116, 5%; fair, 14/116, 12%, and poor, 2/116, 2%).The outcome was divided into favorable (n=100, excellent and good outcome) and unfavorable (n=16, fair and poor outcome) group.There was no difference in age, preoperative VAS on trunk and leg between groups (p>0.05).The change of pain score started to differ from the postoperative one day between groups.The VAS was reduced 61% on the trunk and 84% on the leg in a favorable group comparing preoperative score at postoperative one day.On the contrary, the pain was improved 22% on the trunk and 42% on the leg in an unfavorable group.Conclusions: If patients did not show substantial improvement at postoperative one day after endoscopic lumbar discectomy, the pain may persist for at least one month.