Insertion of an annular disc implant at lumbar discectomy

5.1 Incidental durotomy (potentially causing cerebrospinal fluid leakage and complications such as headache) occurring during disc fragment removal was reported in 1 patient treated by discectomy plus annular disc implantation and in 1 patient treated by discectomy only in a non‑randomised comparative study of 102 patients (30 patients treated by discectomy plus annular disc implant and 72 patients treated by discectomy only; level of significance not stated). Incidental durotomy was reported in 1 patient treated by discectomy plus annular disc implantation and in 1 patient treated by discectomy only in a non‑randomised comparative cohort study of 76 patients (30 patients from the same implant cohort as in the previous study and 46 patients treated by discectomy only; level of significance not stated).

5.2 Suspected discitis 56 days after surgery was reported in 1 patient treated by discectomy plus annular disc implantation and in none of the patients treated by discectomy only in the non‑randomised comparative cohort study of 76 patients (level of significance not stated). The infection was successfully treated by intravenous antibiotics.

5.3 Reoperations were reported in 3 patients treated by annular disc implantation after discectomy in a case series of 45 patients: 1 was a symptomatic reherniation 4 months after surgery because the device was implanted too deep into the disc space, 1 was a contralateral herniation 3 weeks after surgery possibly caused by the implant, and 1 was for excessive scar tissue 5 months after surgery.

5.4 The specialist advisers listed additional theoretical adverse events as haematoma, cauda equina damage, implant displacement causing nerve root damage, pain, numbness, weakness and neurological compression.