Cervical Open-Door Laminoplasty by Hydroxyapatite Implant Insertion Without Suturing

Abstract

Objective: To assess the efficacy of cervical open-door laminoplasty by hydroxyapatite implant insertion between the lamina and the lateral mass without suturing.

Methods: All patients who underwent cervical open-door laminoplasty with C2/C7 undermining and insertion of hydroxyapatite implants from C3 to C6 were retrospectively evaluated for surgical time and neurological outcomes according to the Japanese Orthopaedic Association (JOA) score. To assess the alignment of the cervical spine and postoperative cervical pain, the C2-7 angle and a visual analogue scale score were used, respectively.

Results: The population consisted of 102 women and 222 men ranging in age from 32 to 90 years. The average surgical time was 86 minutes. Fourteen of 1,296 hydroxyapatite implants were kept in place with sutures due to a weak restoration force of the hinge during surgery. No hydroxyapatite implant dislocation was detected on cervical computed tomography at 1 year after surgery. The average JOA score was 10.2±2.5 before surgery and 14.6±2.8 at 1 year after surgery. The average recovery rate was 61.8%. The average C2-7 angle at the neutral position was 7.1°±6.2° before surgery and 6.5°±6.3° at 1 year after surgery.

Conclusion: This method enabled us to achieve minimal exposure of the lateral mass, prevention of lateral mass injury and dural injury, and a shorter surgical time while maintaining acceptable surgical outcomes. The idea that firm suture fixation is needed to prevent spacer deviation during cervical open-door laminoplasty may need to be revisited.

Keywords: Cervical laminoplasty; Insertion implants without suturing; Surgical outcomes.

Fig. 1.

Diagrams showing hydroxyapatite implants (Olympus, Tokyo, Japan) designed for this study. The implant has 2 holes for suturing and 2 notches for capturing bony edges. The changes in the anterior-posterior diameter of the cervical spinal canal that were caused by L3-157-VM-327-7.5, L3-157-VM-327-9.5, and L3-157-VM-327-11.5 were found to be 4.2 ± 0.4 mm, 7.1 ± 0.3 mm, and 9.8 ± 0.5 mm, respectively

Fig. 2.

Cervical laminoplasty by hydroxyapatite implant insertion between the lamina and lateral mass without suturing. (A) A midline skin incision (3–4 cm in length) was made at the level of the spinous process from C3 to C6. (B) A hydroxyapatite implant was inserted from the inferior side into the space between the left lamina and the left articular process by elevating the laminae with the penfield. (C) The laminae fell automatically when the penfield was removed, leading to strong fixation of the hydroxyapatite implant.