A novel height-adjustable nano hydroxyapatite/polyamide-66 vertebral body for reconstruction of thoracolumbar structural stability after spinal tumor resection.

BACKGROUND: Reconstruction of thoracolumbar structural stability is a formidable challenge for spine surgeons after vertebral body tumor resection. Various disadvantages of the currently used expandable or non-expandable cages have limited their clinical applications.

OBJECTIVE: To develop a novel prosthesis for clinical use and assess its preliminary clinical outcome in reconstruction of thoracolumbar structural stability after spinal tumor resection.

METHODS: Based on the data obtained from a retrospective analysis of the morphological characteristics of the thoracolumbar vertebrae and endplates in previously published articles, we modified the nano hydroxyapatite/polyamide-66 (n-HA/PA66) strut into a novel height adjustable vertebral body. A retrospective study was performed to include 7 patients who underwent reconstruction of thoracolumbar structural stability with this novel prosthesis from August 2016 to January 2017.

RESULTS: A novel height adjustable vertebral body (AHVB) made of (n-HA/PA66) with two separate components with a 163-degree contact surface at each end was manufactured. The height adjustable range was 28mm to 37mm. No significant implant-related complications were observed in the process of operation. All patients had a significant reduction in pain with the VAS score decreasing from 7.9 to 4.0, and neurological improvement was assessed by the Frankel grading system after surgery. Postoperative radiographs and CT/MRI indicated that the operated segment was stability, the outcome of kyphosis correction was good, and no prosthesis subsidence or dislocation was observed.

CONCLUSION: This novel prosthesis has many advantages in reconstruction of height, lordosis, and alignment after thoracolumbar spinal tumor resection and has a favorable prospect for clinical application.