Results of applying ADCON-L gel after lumbar discectomy: the German ADCON-L study

Object. Failed-back syndrome is still an unsolved problem. Use of ADCON-L g el, already commercially available, has been proven to reduce postoperative scarring in animal experiments. The authors of two controlled clinical stu dies have also shown positive results when applying the gel. They did not, however, establish patient-oriented endpoints. The authors report a study o f ADCON-L in which they focus on patient-oriented endpoints. Methods. Patients with lumbar disc herniation were randomized to an ADCON-L -treated or control group. Therapeutic success was evaluated using the vali dated Hannover Questionnaire on Activities of Daily Living (FFbH) 6 months after surgery. The study took place between November 14, 1996, and April 20 , 1998, in eight neurosurgical centers in Germany. A total of 398 patients was recruited; 41 patients dropped out during follow up. The mean functional FFbH score (100 points = all activities are possible wi thout problem; 0 points = no activity is possible) was 78.5 points in the A DCON-L-treated group compared with 80 points in the control group. Furtherm ore, in terms of secondary outcome variables, the ADCON-L group did not hav e an advantage over the control group. Only the mean magnetic resonance ima ging score showed a slight advantage of ADCON-L over the control group. Conclusions. The authors found no positive effect of treatment with ADCON-L gel in patients in whom one-level lumbar microdiscectomy was performed. Be cause of its rather large sample size and its homogeneity, the study had su fficient power to detect even small differences between the two groups.