The key hole augmentation with demineralized bone matrix in anterior cervical trans-corporeal discectomy – Preliminary result of a novel technique

Objective: The objective of this study was to evaluate the benefit of key hole augmentation with demineralized bone matrix (DBM) when performing the anteriortrans-corporeal discectomy (ACTD) for the treatment of cervical disc herniation. Methods: Of the 44 patients diagnosed with symptomatic cervical disc herniation, 22 patients were surgically treated by ACTD-alone, and the remaining 22were treated using ACTD with keyhole augmentation using DBM. Clinical outcomes were assessed using a visual analog scale (VAS). Plain radiographs were periodically checked during and up to 1 year postoperatively. The changes in the cervical lordosis angle, functional spinal unit angle, disc height, and anterior/posterior body height were serially measured and compared between the two groups. Results: In the ACTD-alone group, the disc height, anterior body height, and posterior body height gradually decreased during 1 year postoperatively, from 6.1 ± 1.00 mm to 4.3 ± 0.94 mm, 14.6 ± 1.60 mm to 12.7 ± 2.19 mm, and 14.6 ± 1.72 mm to 13.1 ± 2.23 mm, respectively; in the ACTD with keyhole augmentation group, these values were relatively stable (6.4 ± 1.02 mm to 4.6 ± 0.93 mm, 15.3 ± 1.27 mm to 13.9 ± 1.32 mm, and 15.8 ± 1.30 mm to 14.5 ± 1.32 mm, respectively). Most significant changes occurred 6 months postoperatively (p < 0.05). Conclusions: This preliminary result of comparative study suggested that key hole augmentation with DBM could be an effective technique to prevent early height loss of the vertebral body and disc after ACTD and provide better biomechanical stability.