Incidence of Low Back Pain After Lumbar Discectomy for Herniated Disc and Its Effect on Patient-reported Outcomes.

Abstract

Long-term postdiscectomy degenerative disc disease and low back pain is a well-recognized disorder; however, its patient-centered characterization and quantification are lacking. We performed a systematic literature review and prospective longitudinal study to determine the frequency of recurrent back pain after discectomy and quantify its effect on patient-reported outcomes (PROs). A MEDLINE search was performed to identify studies reporting on the frequency of recurrent back pain, same-level recurrent disc herniation, and reoperation after primary lumbar discectomy. After excluding studies that did not report the percentage of patients with persistent back or leg pain more than 6months after discectomy or did not report the rate of same level recurrent herniation, 90 studies, which in aggregate had evaluated 21,180 patients, were included in the systematic review portion of this study. For the longitudinal study, all patients undergoing primary lumbar discectomy between October 2010 and March 2013 were enrolled into our prospective spine registry. One hundred fifteen patients were more than 12months out from surgery, 103 (90%) of whom were available for 1-year outcomes assessment. PROs were prospectively assessed at baseline, 3months, 1year, and 2years. The threshold of deterioration used to classify recurrent back pain was the minimum clinically important difference in back pain (Numeric Rating Scale Back Pain [NRS-BP]) or Disability (Oswestry Disability Index [ODI]), which were 2.5 of 10 points and 20 of 100 points, respectively. The proportion of patients reporting short-term (6-24months) and long-term (>24months) recurrent back pain ranged from 3% to 34% and 5% to 36%, respectively. The 2-year incidence of recurrent disc herniation ranged from 0% to 23% and the frequency of reoperation ranged from 0% to 13%. At 1-year and 2-year followup, 22% and 26% patients reported worsening of low back pain (NRS: 5.3±2.5 versus 2.7±2.8, p<0.001) or disability (ODI%: 32±18 versus 21±18, p<0.001) compared with 3months. In a systematic literature review and prospective outcomes study, the frequency of same-level disc herniation requiring reoperation was 6%. Two-year recurrent low back pain may occur in 15% to 25% of patients depending on the level of recurrent pain considered clinically important, and this leads to worse PROs at 1 and 2years postoperatively.