Correlation of the amount of disc removed in a lumbar microdiscectomy with long-term outcome

The authors conducted a prospective clinical study. The objectives of this study were to investigate the relationship, if any, of the amount of removed disc in a standard first-time lumbar microdiscectomy and long-term outcome as well as recurrence and postoperative instability rates. There is lack of data on the amount of disc that needs to be removed during a lumbar microdiscectomy. Anecdotal data and dogmatic recommendations make the subject even more controversial. A total of 106 patients underwent a standard first-time lumbar microdiscectomy for medically refractory sciatica resulting from a herniated disc. The removed disc material was weighted. All patients were clinically followed for at least 2 years and outcome was evaluated by using pain intensity, presence of physical signs, functional capacity, return to work, and patients' opinion regarding their outcome. The mean amount of disc removed was calculated at 2.1 +/- 0.9 g. Ninety-one patients had an excellent outcome and returned to their preoperative work. Fifteen patients had persistent symptomatology and underwent extensive radiographic workup, which revealed a disc recurrence at the same level in 8 patients and first-degree instability in 3 patients. In the remaining 4 patients, no clinical or radiographic abnormality was proven and the patients were treated conservatively, whereas all of them had applied for disability. No relationship was proven between the amount of the removed disc and the intraoperative blood loss or the intraoperative complication rate. Our statistical analysis showed no correlation between the amount of the removed disc and the long- term outcome, recurrence rate, or postoperative instability. The degree of disc removal did not influence the outcome or complication rate in our clinical series.