Incremental cost-effectiveness ratio between titanium plate and hydroxyapatite block spacers in cervical laminoplasty for degenerative cervical myelopathy.

Introduction: Laminoplasty is a widely used surgical procedure to decompress the cervical spinal cord. Recently, titanium plates (TPs) have been used instead of conventional hydroxyapatite block (HA) spacers to prevent laminar reclosure. However, no study has compared the cost-effectiveness of TP and HA. Therefore, this study aimed to compare the cost-effectiveness and postoperative outcomes of laminoplasty using TP or HA.

Methods: A total of 167 patients who underwent cervical laminoplasty at our institution were included in this study. Patients with cervical spinal cord injury, epidural hematoma, or follow-up of <1 year were excluded. Of the 167 patients, 69 underwent laminoplasty using TP (the TP group), and 98 underwent laminoplasty using HA (the HA group). The surgical costs and incremental cost-effectiveness ratio (ICER) were compared between the two groups. Additionally, the operation time, complications, Japanese Orthopaedic Association score, Hirabayashi recovery rate, and pre and postoperative cervical alignment on X-ray images were investigated.

Results: The surgical costs were significantly higher in the TP group than in the HA group (HA, 7255 ± 1504 USD vs. TP, 11,642 ± 2492 USD, p < 0.01). The ICER was 21,935 USD per quality-adjusted life year in the TP group. The operation time was shorter in the TP group than in the HA group (HA, 70.0 ± 22.5 min vs. TP, 63.6 ± 19.3 min, p = 0.06). The Hirabayashi recovery rate and radiographic parameters were similar between the two groups. Implant displacements were significantly more common in the HA group than in the TP group (HA, 11.2 % vs. TP, 0 %, p < 0.01).

Conclusions: The surgical costs and ICER with TPs were higher than those with HA spacers. However, no difference in the Hirabayashi recovery rate and postoperative radiological parameters was observed between the two groups, although the HA group had more implant displacements.