Biomechanical study of the stability of posterior cervical expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation: a finite element analysis.

BACKGROUND: Posterior cervical expansive open-door laminoplasty (EODL) may cause postoperative C5 palsy, and it can be avoided by EODL with bilateral C4/5 foraminotomy. However, prophylactic C4/5 foraminotomy can compromise cervical spine stability. To prevent postoperative C5 palsy and boost cervical stability, We propose a new operation method: EODL combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation. However, there are no studies on the biomechanical properties of this surgery. PURPOSE: Evaluating the biomechanical characteristics of EODL combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation and other three classic surgery. METHODS: An original model (A) and four surgical models (B-E) of the C2-T1 vertebrae of a female patient were constructed. (B) EODL; (C) EODL combined with bilateral C4/5 foraminotomy; (D) C3-6 expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation; (E) C3-6 expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and C3-6 lateral mass screw system. To compare the biomechanical properties of cervical posterior internal fixation; (E) C3-6 expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and C3-6 lateral mass screw system. To compare the biomechanical properties of cervical posterior internal fixation methods, six physiological motion states were simulated for the five models using a 100N load force and 1.5Nm torque. The biomechanical advantages of the four internal fixation systems were evaluated by comparing the ranges of motion (ROMs) and maximum stresses. RESULTS: The overall ROM of Model C outperformed the other four models, reaching a maximum ROM in the extension state of 10.59°±0.04°. Model C showed a significantly higher ROMs of C4/5 segment than other four models. Model D showed a significantly lower ROM of C4/5 segment than both Model B and Model C. Model E showed a significantly lower ROM of C4/5 segment than Model D. The stress in the four surgical models were mainly concentrated on the internal fixation systems. CONCLUSION: EODL combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation can maintain the stability of the spine and has minimal effects on the patient's cervical spine ROMs in the extension and flexion state. As a result, it may be a promising treatment option for cervical spondylotic myelopathy (CSM) to prevention of postoperative C5 palsy.

Comparison of Postoperative Pain and Surgical Outcomes Between Three Types of Modified Muscle-Sparing Laminoplasty and Conventional Laminoplasty for Multilevel Degenerative Cervical Myelopathy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: This study aimed to compare postoperative pain and surgical outcomes of open-door laminoplasty (LP) and three types of muscle-sparing laminoplasties, namely unilateral muscle-preservation laminoplasty (UL), spinous process splitting double-door laminoplasty (DL) and intermuscular "raising roof" laminoplasty (RL) for multilevel degenerative cervical myelopathy (MDCM). METHODS: Consecutive MDCM patients underwent LP or modified laminoplasties (UL, DL, RL) in 2022 were enrolled. Patients' preoperative baseline data and surgical characteristics were collected. Postoperative transient pain (TP), the axial pain and Japanese Orthopedic Association (JOA) score and neck disability index (NDI) at 6-month and 12-month follow-up were documented. RESULTS: A total of 154 MDCM patients were included and a 12-month follow-up was completed for 148 patients (LP: 36, UL:39, DL: 37, RL:36). No significant difference was observed in the baseline data. Four groups presented favorable and comparable surgical outcome. The RL group reported significantly the least severe TP on the first three days following surgery. However, no significant difference was found in the axial pain and axial symptoms at both follow-ups. After regression analysis, RL group exhibited significantly better efficacy in alleviating Day-1 TP (P = 0.047) and 6-month axial pain (P = 0.040). However, this superiority was not observed at 12-month follow-up. CONCLUSION: All the three muscle-sparing laminoplasty procedures showed similar short-term surgical outcomes compared to LP. The RL procedure demonstrated superiority in alleviating TP and 6-month axial pain compared to LP. The RL and DL groups showed less C5 palsy compared to LP.

Comparison of Surgical Outcomes After Posterior Decompression by Junior or Senior Surgeons for Patients With Cervical Ossification of the Posterior Longitudinal Ligament: Results From Retrospective Multicenter Cohort Study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate surgical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL) when performed by board-certified spine (BCS) or non-BCS (NBCS) surgeons. METHODS: We included 203 patients with cervical OPLL who were followed for a minimum of 1 year after surgery. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed preoperatively and at the final follow-up using the Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) for the neck. We compared outcomes between BCS surgeons, who must meet several requirements, including experience in more than 300 spinal surgeries, and NBCS surgeons. RESULTS: BCS surgeons performed 124 out of 203 cases, while NBCS surgeons were primary in 79 cases, with 73.4% were directly supervised by a BCS surgeon. There was no statistically significant difference in surgical duration, estimated blood loss, and perioperative complication rates between the BCS and NBCS groups. Moreover, no statistically significant group differences were observed in each position of the C2-7 angle and cervical range of motion at preoperation and the final follow-up. Preoperative and final follow-up JOA scores, VAS for the neck, and JOA score recovery rate were comparable between the two groups. CONCLUSIONS: Surgical outcomes, including functional recovery, complication rates, and cervical dynamics, were comparable between the BCS and NBCS groups. Consequently, posterior decompression for cervical OPLL is considered safe and effective when conducted by junior surgeons who have undergone training and supervision by experienced spine surgeons.

Two-level Anterior Cervical Corpectomy and Fusion versus Posterior Open-door Laminoplasty for the Treatment of Cervical Ossification of Posterior Longitudinal Ligament: A Comparison of the Clinical Impact on the Occipito-Atlantoaxial Complex.

OBJECTIVE: Both two-level anterior cervical corpectomy and fusion (t-ACCF) and posterior open-door laminoplasty (ODLP) are effective surgical procedures for the treatment of ossification of the posterior longitudinal ligament (OPLL). Previous studies have identified different effects of different surgical procedures on the upper and subaxial cervical spine (UCS, SCS), however, there are no studies on the effects of t-ACCF and ODLP on the occipito-atlantoaxial complex. Therefore, the purpose of this study is to compare the changes in sagittal parameters and range of motion (ROM) of the occipito-atlantoaxial complex in OPLL patients treated with t-ACCF and ODLP. METHODS: This was a retrospective study that included 74 patients who underwent t-ACCF or ODLP for the treatment of OPLL from January 2012 to August 2022 at our institution. Preoperative, 3-month, and 1-year postoperative cervical neutral, flexion-extension, and lateral flexion radiographs were taken. Sagittal parameters including Cobb angle of C2-7, C0-2, C0-1, C1-2, C2 slope, and the ROM were measured. The clinical outcome was assessed using the JOA, VAS, and NDI scores preoperatively and at 3 and 12 months postoperatively. Multiple linear regression was employed to identify factors influencing changes in UCS. RESULTS: In the ODLP group, the SCS (C2-7) Cobb angle was significantly reduced (12.85 ± 10.0 to 7.68 ± 11.27; p < 0.05), and the UCS (C0-2) Cobb angle was significantly compensated for at 1 year postoperatively compared with the t-ACCF group (3.05 ± 4.09 vs 0.79 ± 2.62; p < 0.01). The SCS and lateral flexion ROM of the ODLP group was better maintained than t-ACCF (14.51 ± 6.00 vs 10.72 ± 3.79; 6.87 ± 4.56 vs 3.81 ± 1.67; p < 0.01). The compensatory increase in C0-2, C0-1, and C1-2 ROM was pronounced in both groups, especially in the ODLP group. The results of multiple linear regression showed that only the surgical procedure was a significant factor influencing UCS. CONCLUSION: The loss of the SCS Cobb angle was more pronounced in ODLP relative to t-ACCF, resulting in a significant compensatory increase in UCS and atlantoaxial Cobb angle. The ROM of the UCS, atlantooccipital, and atlantoaxial joints was significantly increased in both groups, this may accelerate degenerative changes in the occipital-atlantoaxial complex, may leading to poorer outcomes in the long-term; of these, ODLP should receive more attention. In contrast, t-ACCF better maintains normal curvature of the SCS and occipito-atlantoaxial complex but loses more ROM.

Plate-only open-door laminoplasty is associated with durable, significantly improved clinical outcomes and a very low reoperation rate for progressive spondylosis or adjacent segment disease: average 8-year follow-up.

BACKGROUND CONTEXT: Multilevel cervical myelopathy is a common cause of spinal cord dysfunction in adults. Surgical intervention via laminoplasty can provide satisfactory clinical outcomes by expansive decompression of the spinal cord. Traditional suture or bone graft techniques have been associated with insufficient fixation, leading to premature closure and subsequent neurological deterioration. In contrast, plated laminoplasty has been shown to provide stable fixation to maintain canal enlargement, but longer-term outcomes are lacking. PURPOSE: To evaluate longer-term clinical outcomes and reoperations associated with plate-only open-door laminoplasty. STUDY DESIGN: Retrospective review of prospectively collected data. PATIENT SAMPLE: Postoperative patients who underwent plate-only open door laminoplasty with minimum 5-year follow up. OUTCOME MEASURES: modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and 12-item Short Form Health Survey (SF-12). METHODS: All patients at a single academic institution who underwent plate-only open-door cervical laminoplasty from 9/1/2006 to 9/1/2016 were identified to ensure minimum 5 year follow up. Clinical outcomes included the modified Japanese Orthopaedic Association (mJOA) score, the Neck Disability Index (NDI), and the 12-item Short Form Health Survey (SF-12). The occurrence of any repeat operations on the cervical spine was evaluated, as well as its cause. The study team attempted to contact all eligible patients to achieve at least 5 years postoperative follow-up. Pairwise t tests were performed to compare clinical outcomes at preoperative, 6 months, 1-year, and final postoperative follow-up with an α level of 0.05. RESULTS: A total of 774 met the initial inclusion criteria, of which 157 were included in the study (20.3%). Most common reasons for exclusion included inability to reach after 3 attempts (49.48%), inactive phone numbers (20.28%), and patient declining (3.49%). Included patients had an average age of 60.66±10.63 and an average follow-up time of 8.37±2.57 years (minimum 5 years). mJOA scores (preoperative 11.59±2.16) improved significantly at 6-months (14.57±2.07, p<.001), 1-year (15.19±1.95, p<.001), and final follow-up (14.59±2.63, p<.001). NDI (preoperative 33.89±18.54) improved significantly at 6 months (27.89±19.72, p=.03), 1-year (25.96±19.79, p=.01) and final follow-up (17.88±17.17, p<.001). SF-12 MCS (preoperative 44.73) improved significantly at 6 months (52.01, p=.001), 1-year (51.62, p=.008), and final follow-up (52.32, p<.001). No patient underwent reoperations for plate failure or canal closure with recurrent stenosis. Reoperations for progressive spondylosis during the follow up period were rare and occurred in only three patients for new onset radiculopathy (1.9%) and two patients for myelopathy (1.3%) at an average of 3.2 years postoperative. There were no reoperations performed for adjacent segment disease. CONCLUSIONS: At a minimum of 5 years and an average of more than 8 years postoperative, laminoplasty was associated with significant and sustained improvements in mJOA, NDI, and SF-12 MCS. Importantly, no patients underwent revision surgery for plate failure or recurrent canal closure. Reoperations for new onset radiculopathy and myelopathy were also very rare over the 8-year average follow-up period, with no reoperations for adjacent segment disease. Plate-only laminoplasty is a durable means of treating multilevel myelopathy with excellent longer-term outcomes and a very low risk of reoperation, either for premature closure or the inevitable spondylotic changes that occur over time in patients with similar baseline characteristics to the study population.

Computerized Three-Dimensional Analysis: A Novel Method to Assess the Effect of Open-Door Laminoplasty.

INTRODUCTION: The three-dimensional elaboration of morphological data derived from computed tomography (CT) and magnetic resonance imaging (MRI) scans generates virtual anatomical reconstructions. Here, we propose a novel protocol to analyze the postoperative results of open-door laminoplasty to evaluate differences in the volume of the spinal canal. The protocol uses geometric models in patients with cervical degenerative myelopathy before versus after cervical laminoplasty. MATERIALS AND METHODS: Mimics and 3-Matic software (Materialise, Leuven, BE) programs were used to segment anatomical structures and create polygon meshes of spines. Patients with cervical spondylotic myelopathy were enrolled. The models obtained before and after laminoplasty were superimposed by using a global registration function. The magnitude of divergence was quantified by using the root-mean-square error (RMSE). RESULTS: Using this novel protocol, we were able to map the differences in the volume of the spinal canal before laminoplasty and after laminoplasty and to quantify its magnitude and calculate the volumes. DISCUSSION AND CONCLUSIONS: The development of a procedure to measure the space within the cervical bone walls using geometric parameters represents a new, powerful method to verify the results obtained by cervical laminoplasty. Further research horizons may include the routine use of virtual models in surgical planning for this procedure.

Clinical outcomes of modified versus traditional expansive open-door laminoplasty for cervical spondylotic myelopathy: A single-institution experience.

PURPOSE: To compare the surgical outcomes of modified expansive open-door laminoplasty (EOL) (C4-C6) and traditional EOL (C3-C7) in patients with cervical spondylotic myelopathy (CSM). METHODS: One hundred and two CSM patients were retrospectively recruited from Fujian Medical University Union Hospital between March 2012 and December 2019. Seventy-one patients with CSM underwent modified EOL, and 31 patients underwent traditional EOL. The primary endpoint was axial symptoms. RESULTS: Patients who underwent modified EOL had a significantly lower incidence of axial symptoms (odds ratio: 0.273; 95% confidence interval: 0.184-0.691; p = .002). The length of hospital stay (p = .263), and intraoperative blood loss (p = .402) were not significantly different between the groups. Significantly more postoperative drainage was observed in patients who underwent modified EOL (p < .001), while the cost of hospitalization in patients treated with traditional EOL was higher (p = .011). There were significant differences between modified and traditional EOL for the changes in range of motion (p < .001), modified Japanese Orthopaedic Association score (p = .001), and the Nurick grade (p = .014), while the changes of visual analogue scale (p = .250), and the neck disability index (p = .134) were not significantly different between the groups. CONCLUSION: This study found modified EOL may decrease the incidence of axial symptoms in patients with CSM compared to traditional EOL.

Optimal Treatment of C3 Lamina in Cervical Laminoplasty.

STUDY DESIGN: Results of C4-C6 laminoplasty with C3 laminectomy and C3-C6 laminoplasty were compared retrospectively. OBJECTIVES: To clarify the difference between C3 laminectomy and C3 laminoplasty in cervical laminoplasty. SUMMARY OF BACKGROUND DATA: Intraoperative damage to the semispinalis cervicis has been shown to lead to postoperative axial symptoms and reduced range of motion (ROM). To prevent this event, C3 laminectomy in cervical laminoplasty is considered superior to C3 laminoplasty. METHODS: A total of 36 patients were included in this study: 20 patients (GroupA) of C3 laminectomy, C4-C6 laminoplasty compared with 16 patients (GroupB) of C3-C6 laminoplasty. We collected patient's background data, operative time, Japanese Orthopaedic Association (JOA) score, VAS score, and radiologic findings such as C2-C7 Cobb angle, ROM, C2 inter-spinous angle, and use of postoperative PRN medication were compared. RESULTS: There was no statistically significant difference in the C2-C7 Cobb angles between the 2 groups before and after surgery (P = 0.315). In ROM, there was a 17.7% decrease from 31.5 preoperatively to 25.9 postoperatively in Group A, and a 6.1% decrease from 29.3 preoperatively to 27.5 postoperatively in Group B. There was no statistically significant difference in ROM (P = 0.683). Postoperative neck pain (VAS) was significantly lower in Group A than in Group B both at 1 week (P = 0.015) and 1 month (P = 0.035) after surgery. The C2 inter-spinous angle was statistically significantly smaller in Group A than in Group B (P = 0.004). Clinical outcomes and surgical outcomes did not differ significantly between groups. CONCLUSIONS: If the C2 interspinous angle is wide and intraoperative semispinalis capitis damage can be minimized, it is worth trying C3 laminoplasty, but if the C2 inter-spinous angle is narrow, C3 laminectomy is recommended from the beginning.

[Progress on the impact of adjacent vertebral arch after single open door laminoplasty].

Single-door laminoplasty has been widely used in the treatment of multisegment cervical myelopathy, with the clinical advantages of decompression of the spinal cord, relieving preoperative neurological symptoms or signs, and maintaining cervical mobility. However, in clinical work, patients with limited cervical spine activity after single open door laminoplasty are often encountered, and the direct contact with the adjacent vertebral arch can be observed in the postoperative X-ray of the anterior and lateral cervical spine, which is called the adjacent vertebral arch bone impact, which is one of the important causes of the limited cervical spine movement. In recent years, there have been many reports on the prevention of bone impact, although the short-term clinical effect is significant, but long-term clinical efficacy to be further study, and the cause and the pathogenesis of bone impact is no consensus, this paper on the surgery of adjacent vertebral arch impact epidemiology, biomechanics, clinical performance, surgical effect and improvement.

Clinical Outcomes of Open-Door Laminoplasty Combined with Bilateral Lateral Mass Screw Fixation for Multi-Level Cervical Spinal Stenosis with Traumatic Cervical Instability and Spinal Cord Injury: A Retrospective Study.

OBJECTIVES: The prevalence of multi-level cervical spinal stenosis complicated with traumatic cervical instability and spinal cord injury (MCSS-TCISCI) is low, and the optimal surgical approach remains unclear. Open-door laminoplasty combined with bilateral lateral mass screw fixation (ODL-BLMSF) is a relatively new surgical technique; however, its clinical effectiveness in managing MCSS-TCISCI has not been well-established. This study aims to assess the clinical value of ODL-BLMSF against MCSS-TCISCI. METHODS: We retrospectively analyzed 20 cases of MCSS-TCISCI treated with ODL-BLMSF from July 2016 to June 2020. Radiographic alterations of all included patients were measured using plain radiographs, CT scans, and MRI scans. Cervical lordosis was evaluated using C2-C7 Cobb angle and cervical curvature index (CCI) on lateral radiographs, and Pavlov ratio at the C5 level. Neurological functional recovery was assessed using Japanese Orthopaedic Association (JOA) scores and Nurick grade, while neck and axial symptoms were assessed using the neck disability index (NDI) and the visual analog scale (VAS). The paired t-test was utilized for statistical analysis. RESULTS: All included patients were followed up for an average period of 26.5 months (range: 24-30 months) after ODL-BLMSF. The average Pavlov ratio at the C5 level significantly improved from 0.57 ± 0.1 preoperatively to 1.13 ± 0.1 and 1.12 ± 0.04 at 6 months postoperatively and at the last follow-up (t = 16.347, 16.536, p < 0.001). Importantly, this approach significantly increased the JOA score from 5.0 ± 2.6 before surgery to 11.65 ± 4.3 and 12.1 ± 4.3 at 6 months postoperatively and at the last follow-up (t = 9.6, -9.600, p < 0.001), with an average JOA recovery rate of 59.1%; and the average Nurick disability score decreased from 3.0 ± 1.3 (preoperative) to 1.65 ± 1.22 and 1.5 ± 1.2 (6 months postoperatively and at last follow-up) (t = 5.111, 1.831, p < 0.001). Meanwhile, the NDI score decreased from 30.3 ± 4.3 preoperatively to 13.2 ± 9.2 at 6 months (t = 12.305, p < 0.001), and to 12.45 ± 8.6 at the final follow-up (t = 13.968, p < 0.001), while the VAS score decreased from 4.0 ± 1.5 preoperatively to 1.5 ± 0.7 at 6 months (t = 9.575, p < 0.001), and to 1.15 ± 0.7 at the final follow-up (t = 10.356, p < 0.001). CONCLUSION: ODL-BLMSF can effectively dilate the stenotic spinal canal to decompress the spinal cord, maintain good cervical alignment and stability, and improve the recovery of neurological function and neck function. This technique is suitable for treating selected cases of MCSS-TCISCI.