Association between peridural scar and activity-related pain after lumbar discectomy

The purpose of this study was to investigate the correlation between activi ty-related pain six months after first surgery for herniated lumbar disc, a nd the extent of lumbar epidural fibrosis present at the surgical site, ass essed by magnetic resonance imaging. The 298 patients who underwent surgery for lumbar disc herniation were studied in a randomized, controlled, doubl e-blind multicenter clinical trial to test the effectiveness of the scar-in hibiting device ADCON(R)-L. Clinical assessments were conducted preoperativ ely and at 1, 3, and 6 month intervals post-operatively, and included wound examination, magnetic resonance imaging scar assessment, and the Johns Hop kins activity-related pain questionnaire. In addition, a longer-term follow -up assessment was conducted at 12 months post-operatively. The association between the presence of epidural scar and activity-related pain was analyz ed at the 6-month interval, when successful surgical excision of protruding disc material should have eliminated chronic pain. Logistic regression ana lysis demonstrated a significant association (p = 0.02, odds ratio = 0.7) w hereby the odds of extensive scar decreased by 30% for every 31 % decrease in activity-related pain score. In addition, those patients receiving ADCON (R)-L at surgery developed significantly less scar in the months following operation (p = 0.01, 6 and 12 months post-operatively). Repeated measures a nalysis demonstrated that patients who received treatment with ADCON(R)-L a t the time of surgery experienced less activity-related pain through the 12 -month assessment (p = 0.05). A significant association between extensive e pidural scar and activity-related pain is demonstrated. Patients with less scar had less activity related pain, confirming the finding that the use of the scar inhibitor ADCON(R)-L has a positive effect on surgical outcome.