Minimally invasive cervical foraminotomy and diskectomy for laterally located soft disk herniation

The posterior cervical foraminotomy and diskectomy (PCD) is a traditional surgical technique for patients with laterally located soft-disk herniation. Recently, tubular retractor-assisted posterior foraminotomy and diskectomy (MTPF) and posterior percutaneous endoscopic cervical foraminotomy and diskectomy (P-PECD) have been introduced, but a comparative study has not yet been performed.

Patients with foraminal soft-disk herniation and a follow-up period of >2 years were retrospectively reviewed; 22 patients underwent a MTPF and 22 patients underwent a P-PECD. The primary end-point was an improvement of arm pain more than 4.3. The clinical parameters (age, sex, disability index, neck and arm pain), radiological parameters (cervical curvature, segmental angle, anterior-/posterior-disk height and amount of facet joint removal) preoperatively and at postoperative month 24 and the surgical methods were considered as co-variates.

Successful outcome was achieved in 19/22 (87%) of the patients after both MTPF and a P-PECD. Preoperative SA showed trend (P = 0.08; OR 1.2; 95% CI 0.98-1.4) and the cut-off SA was 1.45° (sensitivity 80%, specificity 73%). The length of the facet joint's removal was 0.02-2.49 mm (0.1-15.2%) with no difference between the MTPF and P-PECD. The surgical method was not a significant factor.

For patients with foraminal soft-disk herniation, either MTPF or P-PECD, may be regarded as an alternative options to open surgery. Preoperative kyphotic SA (cut-off value 1.45°) seemed to be associated with poor outcome and this may be considered in selecting surgical methods.