Annular closure device for disc herniation: meta-analysis of clinical outcome and complications

Lumbar intervertebral disc herniation is a common cause of lower back and leg pain, with surgical intervention (e.g. discectomy to remove the herniated disc) recommended after an appropriate period of conservative management, however the existing or increased breach of the annulus fibrosus persists with the potential of reherniation. Several prosthesis and techniques to reduce re-herniation have been proposed including implantation of an annular closure device (ACD) - Barricaid™ and an annular tissue repair system (AR) - Anulex-Xclose™. The aim of this meta-analysis is to assist surgeons determine a potential approach to reduce incidences of recurrent lumbar disc herniation and assess the current devices regarding their outcomes and complications.Four electronic full-text databases were systematically searched through September 2017. Data including outcomes of annular closure device/annular repair were extracted. All results were pooled utilising meta-analysis with weighted mean difference and odds ratio as summary statistics.Four studies met inclusion criteria. Three studies reported the use of Barricaid (ACD) while one study reported the use of Anulex (AR). A total of 24 symptomatic reherniation were reported among 811 discectomies with ACD/AR as compared to 51 out of 645 in the control group (OR: 0.34; 95% CI: 0.20,0.56; I2 = 0%; P < 0.0001). Durotomies were lower among the ACD/AR patients with only 3 reported cases compared to 7 in the control group (OR: 0.54; 95% CI: 0.13, 2.23; I2 = 11%; P = 0.39). Similar outcomes for post-operative Oswestry Disability Index and visual analogue scale were obtained when both groups were compared.Early results showed the use of Barricaid and Anulex devices are beneficial for short term outcomes demonstrating reduction in symptomatic disc reherniation with low post-operative complication rates. Long-term studies are required to further investigate the efficacy of such devices.