Effect of Titanium Miniplate Fixation on Hinge Fracture and Hinge Fracture Displacement Following Cervical Open-Door Laminoplasty

Safety and Efficacy of Combined Imbrication Axle Reconstruction and Z-Type Titanium Plate Fixation for Hinge Fracture Displacement During Open-Door Laminoplasty

BACKGROUND

 Open-door laminoplasty is a classical decompression method used to treat cervical spondylotic myelopathy. However, hinge fracture displacement (HFD) is a common occurrence during this procedure. The current study aimed to investigate the safety and efficacy of a combined imbrication axle reconstruction and Z-type titanium plate fixation method for HFD during open-door laminoplasty.

METHODS

 In total, 617 patients with cervical spondylotic myelopathy who underwent C3-C7 open-door laminoplasty from March 2015 to October 2018 were included in this retrospective study. Overall, 73 patients developed HFD during surgery. Of these, 43 underwent combined imbrication axle reconstruction and Z-type titanium plate fixation (IRZF group) and 30 underwent traditional titanium plate fixation (TF group). Data such as the operative time, intraoperative blood loss volume, and distribution of fractured hinges were recorded. Both groups were compared in terms of improvement in neurologic function, cervical curvature index, hinge fusion rate, incidence of C5 palsy, severity of axial symptoms, and development of complications.

RESULTS

 The operative time and intraoperative blood loss were slightly higher in the IRZF group than in the TF group; however, the differences were not significant (p > 0.05). Furthermore, there was no significant difference between the groups in terms of the number of fractured segments and the distribution of fractured hinges (p > 0.05). The cervical curvature index did not decline in the two groups (p > 0.05). The IRZF group had a higher hinge fusion rate than the TF group at 3 (79.6 vs. 57.1%) and 12 (93.9 vs. 74.3%) months postoperatively (p < 0.05). There was no significant difference in the incidence of C5 palsy between the two groups (9.3 vs. 6.7%; p > 0.05). However, the TF group had more severe axial symptoms than the IRZF group (p < 0.05). The neurologic function of the two groups increased postoperatively as per the Japanese Orthopaedic Association scoring system (p < 0.05). Nevertheless, there was no significant difference in terms of neurologic function at any observational time point (p > 0.05). One patient in the TF group with hinge nonunion underwent laminectomy due to lamina displacement into the spinal canal and nerve root compression.

CONCLUSION

 In patients with HFD, IRZF facilitates a more intimate contact between the lamina and the lateral mass and, therefore, achieves fractured hinge fusion without additional surgical trauma. This technical improvement can significantly promote neurologic recovery, decrease the severity of axial symptoms, and prevent the development of spinal cord or nerve root recompression.

Laminoplasty in Motion: Evolving Techniques and Complications

Cervical laminoplasty is an increasingly popular surgical option for the treatment of cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). Over the past few decades, there have been substantial developments in both surgical technique and hardware options. As the field of cervical surgery rapidly evolves, there is a timely need to reassess the evolving complications associated with newer techniques. This review aims to synthesize the available literature on cervical laminoplasty and associated mechanical complications pertaining to different laminoplasty hinge fixation options.

Biomechanics optimisation of the laminoplasty groove size and position: A numerical study

BACKGROUND

This study is focused on the opening technique of the cervical vertebrae during laminoplasty which serves to substantially reduce the most severe adverse effects of the simple resection of posterior vertebral elements. This computational study aims to clarify by an optimisation approach what shape and position upon the lamina the groove should have.

METHODS

The computational model was developed in the computational software COMSOL Multiphysics 5.6a based on a computer tomography data obtained from the C4 vertebra. For finding the optimal minimum or maximum of a function (surface), optimisation algorithms are developed following the Nelder-Mead algorithm.

RESULTS

The reaction-opening force increases with a decreasing groove radius and an increasing position from the vertebra body. The created area increases with a decreasing groove radius and a decreasing position. As the opening happens mostly only above the groove, the opening area increases only in this location. Moreover, the von Mises stress peak value is almost twice as large as in the case of maximization of the opening area, which might result in breaking of the lamina as the thickness of the lamina would be reduced to its minimum.

CONCLUSION

The groove radius and position can affect the opening force and the opening area in case of double door laminoplasty. The opening force is highly influenced by the groove position and radius. The best position for placing the groove is in the middle of the lamina and the radius of the groove should be as large as possible.

Case Report: Bilateral Biportal Endoscopic Open-Door Laminoplasty With the Use of Suture Anchors: A Technical Report and Literature Review

Background

Unilateral biportal endoscopy (UBE) is a newly developed technique for spine surgery. Owing to the convenience of nerve decompression and compatibility with open surgical instruments under endoscopic guidance, this technique has seen widespread global use. In this study, we first used modified UBE with suture anchor fixation for cervical laminoplasty in a 65-year-old female patient with good clinical outcomes.

Methods

We used bilateral biportal endoscopy (BBE) for cervical laminoplasty with suture anchor fixation in a patient with cervical stenosis. Under endoscopic guidance, a bilateral approach was used to make the gutter and lift the lamina door. After the lamina doors were opened, sutures were tied tightly using facia cannula and knot pusher. After confirming the solidarity of the open-door status, the drainage tube was inserted and the incisions were closed. The patient’s pre- and postoperative radiological and clinical results were evaluated.

Results

Postoperative Japanese Orthopaedic Association (JOA) and Neck Disability Index (NDI) scores were improved clinically, and cervical canal was decompressed radiologically.

Conclusions

BBE laminoplasty combined with suture anchor fixation showed a favorable clinical and radiological result and appears to be a safe and effective technique for cervical stenosis.

Influence of fixed titanium plate position on the effectiveness of open-door laminoplasty for cervical spondylotic myelopathy

BACKGROUND

During open-door laminoplasty, the position of the bone gutter is not fixed, and when the gutter migrates inward, the outer end of the titanium plate must be fixed on the lamina edge. It is unclear whether this will affect the clinical efficacy. This study aimed to observe the influence of the titanium plate fixation position on the effectiveness of open-door laminoplasty for cervical spondylotic myelopathy (CSM).

METHODS

A total of 98 patients with CSM who underwent open-door laminoplasty from August 2016 to October 2019 were included in this retrospective study. Fifty-five patients had the titanium plate fixed on the lateral mass (lateral mass group), and 43 patients had the titanium plate fixed on the lamina edge (lamina group). The opening angle, opening width, occurrence of hinge fracture, spinal cord drift distance, cervical curvature index (CCI), neurological function recovery (JOA score), neck function (NDI), C5 palsy and severity of axial symptoms were observed and compared between the two groups.

RESULTS

The opening angle in the lamina group was significantly larger than that in the lateral mass group, while the opening width and the spinal cord drift distance were significantly smaller than those in the lateral mass group (P < 0.05). The occurrence of hinge fracture in the lamina group was significantly higher than that in the lateral group (25.6% and 9.1%, respectively) (P < 0.05). The CCI was maintained well in both groups (P > 0.05), and there was no significant difference between the groups (P > 0.05). After surgery, the JOA score significantly increased in both groups (P < 0.05), and the neurological recovery rates were similar between the two groups (62.6% vs. 64.5%). The NDI score significantly decreased in both groups (P < 0.05), but the lateral mass group recovered to a greater degree than the lamina group (P < 0.05). The occurrence of C5 palsy was 2.3% in the lamina group and 14.5% in the lateral mass group, and there was a significant difference between the groups (P < 0.05). Postoperative axial symptom severity was significantly worse in the lamina group than in the lateral mass group (P < 0.05).

CONCLUSIONS

In open-door laminoplasty, it is feasible to fix the titanium plate on the lateral mass or to the lamina due to the same neurological function recovery. However, fixing it to the lamina will increase the opening angle and decrease the opening width, making the hinge prone to fracture and increasing the severity of postoperative axial symptoms.