With lumbar discectomy for disc herniation, surgeons must choose between limited nucleus removal associated with higher reherniation risk or more aggressive nucleus removal associated with increased back pain and disc degeneration. This trade-off is particularly challenging in patients with large anular defects, which carry the highest risk of reherniation. We examined the effect of an anular closure device on reherniation and clinical outcomes.
Seventy-five primary discectomy patients had a limited discectomy followed by implantation of an anular closure device and were followed-up to 2 years. Anular defect size and volume of removed nucleus was recorded at surgery. Reherniations were reported, pain and function were monitored throughout, and imaging was performed at annual visits.
The overall symptomatic reherniation rate was 1.4%, and the asymptomatic reherniation rate was 1.5% at 12 months and 5.1% at 24 months. Both rates compare favorably with literature reports which include symptomatic rates ranging between 2 and 18% (up to 27% for patients with large anular defects) and an asymptomatic rate of 13%.
The low reherniation rate in patients at high-risk of reherniation based on anular defect size, despite discectomy being only limited, suggests that an anular closure device may reduce reherniation risk. Clinical outcomes for pain and function at 1 and 2 years post-operatively compared favorably with literature reports. Further study in a randomized controlled trial is required to confirm these results.