Cervical laminoplasty

K-Line Tilt May Influence the Short-Term Surgical Outcomes After Laminoplasty in Patients With Degenerative Cervical Myelopathy

Study DesignA retrospective study.ObjectivesTo explore the relationship between K-line tilt and short-term surgical outcomes following laminoplasty in patients with multilevel degenerative cervical myelopathy (DCM), and to evaluate the potential of K-line tilt as a reliable preoperative predictor.MethodsA retrospective analysis was performed for 125 consecutive patients who underwent laminoplasty for multilevel DCM. The radiographic parameters utilized in this study encompassed T1 slope (T1S), C2-C7 lordosis (CL), C2-C7 sagittal vertical axis (cSVA), T1 slope minus C2-C7 lordosis (T1S-CL), C2-C7 range of motion (ROM), and K-line tilt. The neurological recovery was evaluated using the Japanese Orthopaedic Association (JOA) score. Pearson correlation coefficients were calculated to assess the relationship between K-line tilt and other classical cervical parameters. Logistic regression analysis was employed to examine the association between K-line tilt and surgical outcomes.ResultsOf the 125 patients, 89 were men. The mean age of the patients was 61.74 ± 11.31 years. The results indicated a correlation between the K-line tilt and the cSVA (r = 0.628, P < 0.001), T1S (r = 0.259, P = 0.004), and T1S-CL (r = 0.307, P < 0.001). The K-line tilt showed an association with the failure of the JOA recovery rate (RR) to reach the minimal clinically important difference (MCID) and the occurrence of postoperative kyphotic deformity. We identified cutoff values for the K-line tilt which predict the failure of the JOA RR to reach the MCID and postoperative kyphotic deformity as 10.13° and 9.93°, respectively.ConclusionsThe K-line tilt is an independent preoperative risk factor associated with both the failure of the JOA RR to reach the MCID and the occurrence of postoperative kyphotic deformity in patients with multilevel DCM after laminoplasty.

Evaluating the Educational Impact of 3D-Printed Models in Cervical Laminoplasty Training: A Survey-Based Study

Background and objective The complexities of spinal surgery, particularly the intricacies of cervical pathology, demand precision and expertise in surgical interventions. Cervical laminoplasty is a procedure that requires meticulous execution and a profound understanding of delicate anatomical structures. Recognizing the limitations of traditional training methods, this study highlights the transformative impact of integrating 3D modeling and printing technologies into medical education. These technologies provide an immersive, interactive, and highly detailed training platform, enabling aspiring surgeons to visualize, dissect, and practice procedures in a risk-free environment. Beyond education, 3D models enhance patient-doctor communication, enable precise preoperative planning, facilitate custom implant design, and support a personalized approach to spinal surgery. Collectively, these advancements hold the promise of reducing surgical errors and improving outcomes. Materials and methods Thirty-eight participants, including neurosurgeons, residents, and medical doctors, were enrolled in this study. High-resolution CT scans, obtained with informed consent to ensure confidentiality and ethical compliance, were used to create the 3D models. These models, printed with polylactic acid (PLA) filament and refined through post-processing, achieved high anatomical accuracy and quality. The training program combined lectures, live demonstrations, and hands-on sessions with 3D models. Participants' experiences and perceptions were evaluated through a survey, focusing on the models' utility and realism in advancing surgical skills. Results The participants overwhelmingly praised the 3D models for their utility in helping to understand cervical laminoplasty concepts and enhancing their learning compared to traditional methods. The models were particularly valued for their accurate representation of anatomical structures and improved visualization of surgical steps. Notably, 81.6% of participants found the models extremely beneficial in planning surgical approaches. The survey results unanimously highlighted the transformative potential of 3D models in medical education. Participants strongly recommended their integration into training programs and preoperative planning processes, emphasizing their ability to elevate the learning experience and improve surgical preparedness. Conclusions Our findings show that 3D modeling significantly enhances training in cervical laminoplasty by providing superior learning tools and improving anatomical visualization compared to conventional methods. The unanimous endorsement from participants underscores the adaptability and precision of 3D models in medical education and preoperative planning. As an indispensable resource in modern medical training, these models represent a pivotal advancement in preparing surgeons for the complexities of spinal surgery.

Accuracy of Realigned K-line for Predicting Surgical Outcomes After Laminoplasty in Patients With Degenerative Cervical Myelopathy

STUDY DESIGN

A prospective cohort study.

OBJECTIVES

To report a new index, the realigned K-line, for predicting surgical outcomes after laminoplasty in patients with degenerative cervical myelopathy (DCM).

METHODS

One hundred twenty-eight patients with DCM undergoing laminoplasty were enrolled from January 2018 to April 2021 in our department. A realigned K-line was defined as the line connecting the midpoints of the spinal cord between C2 and C7 on realigned T1-weighted magnetic resonance imaging. The minimum interval between the anterior compression factors of the spinal cord and the realigned K-line (INTrea), and the modified K-line (INTmod) were measured. A logistic regression analysis was performed to identify factors associated with unsatisfactory surgical outcomes. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) was applied to evaluate the reliability of the multivariate logistic regression model.

RESULTS

Univariate analysis showed that the score for the bladder function section of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire, numeric rating scale scores for arm pain, and INTrea might be related to the Japanese Orthopaedic Association (JOA) recovery rate (RR) not achieving the minimal clinically important difference (MCID) (P < .05). Only INTrea (odds ratio = .744, P < .05) was an independent preoperative factor related to the JOA RR not achieving the MCID (area under the curve, .743). A cutoff of 5.0 mm for INTrea had an accuracy of 71.9% and specificity of 80.3% for predicting the JOA RR not achieving the MCID.

CONCLUSIONS

INTrea is an independent preoperative risk factor related to the JOA RR not achieving the MCID in patients with DCM. A cutoff point of 5.0 mm is most appropriate for alerting spine surgeons to a high likelihood of the JOA RR not achieving the MCID.

Impact of wedge-shaped resection of the posterior bony arch on postoperative outcomes after open door laminoplasty in the cervical spine: a 2-year follow-up study

BACKGROUND CONTEXT

Open door laminoplasty (ODLP) can also lead to significant postoperative motion restriction that further increases over time, for which one of the possible factors is the bony impingement between neighboring posterior bony arches. Previously, we reported this phenomenon and modified technique of ODLP, wedge-shaped resection of the posterior bony arch that produced greater range of motion (ROM) of the cervical spine and less posterior neck pain compared with conventional ODLP (cODLP) in 1-year follow-up time, but no longer follow-up outcomes of the surgical technique has been reported.

PURPOSE

The study aimed to thoroughly evaluate the impact of posterior bony impingement following ODLP on postoperative cervical motion and related outcomes, and to compare postoperative outcomes of conventional ODLP (cODLP with those of modified ODLP (mODLP) in 2-year follow-up times.

STUDY DESIGN

This is a retrospective comparative study.

PATIENT SAMPLE

A total of 145 patients who underwent cODLP or mODLP and were followed up for at least 2 years were classified into two groups: Group A (cODLP, 79 patients) and Group B (mODLP, 66 patients).

OUTCOME MEASURES

The primary outcome measure was ROM of the cervical spine. Secondary outcome measures included (1) patient satisfaction, (2) radiological outcomes, including the rate of bony impingement and spontaneous fusion, and bone regrowth of the resection site, (3) clinical outcomes based on pain intensity and scores on the 12-item short-form health survey (SF-12) and neck disability index (NDI), (4) surgical outcomes, and (5) surgery-related complications.

METHODS

We compared baseline data in both groups. To evaluate the impact of our surgical modification on postoperative outcome after ODLP, we compared the outcome measures in 2-year follow-up times. No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.

RESULTS

The ROM of the cervical spine was significantly greater in Group B 2 years after surgery than in Group A (p=.001). Patient satisfaction (p=.02) at 2 years after surgery and pain intensity of the posterior neck at 1 (p=.01) and 2 years (p<.01) after surgery were better in Group B than in Group A. Radiological evidence of posterior bony impingement and spontaneous fusion between ODLPsegments were definitely fewer less in Group B than in Group A (p<.001 and<0.001, respectively). The mean value of bone regrowth was 1.2 mm (range, 0-3 mm). The NDI and SF-12 scores did not differ significantly between groups. Surgical outcomes and postoperative complications were similar between groups.

CONCLUSIONS

These results indicate that posterior bony impingement can be a factor in ROM restriction after cODLP surgery and that wedge-shaped resection during ODLP can be a reliable option for preserving cervical ROM and improving postoperative clinical and radiological outcomes.

Wedge-Shaped Resection of the Posterior Bony Arch During Open Door Laminoplasty to Prevent Postoperative Motion Limitation

STUDY DESIGN

Prospective randomized double-arm noninferiority study.

OBJECTIVE

To evaluate an additional surgical procedure (wedge-shaped resection of the cranial portion of the posterior bony arch) during open-door laminoplasty (ODLP), and to compare the outcomes with those of conventional ODLP surgery.

SUMMARY OF BACKGROUND DATA

In clinical practice, spine surgeons sometimes encounter patients who show bony impingement on lateral radiographs after ODLP; bony impingement may lead to reduced motion of the cervical spine and posterior neck pain. However, this problem has not been well studied, and no methods have been developed to prevent it.

METHODS

Of total 79 patients, 75 were enrolled and randomly assigned to either group A (additional procedure in ODLP, n = 38) or group B (ODLP alone, n = 37). The primary outcome measure was range of motion (ROM) of the cervical spine. Secondary endpoints included clinical outcomes based on pain intensity, 12-item short form health survey (SF-12), and modified Japanese Orthopedic Association scale; presence of bony impingement on dynamic lateral radiographs; surgical outcomes; and surgery-related complications.

RESULTS

ROM of the cervical spine was significantly greater at 6 months (P = 0.04) and 1 year (P = 0.02) postoperative in group A than in group B. Pain intensity at the posterior neck was significantly lower 1 year after surgery in group A than in group B (P = 0.03). In lateral radiographs 1 year after surgery, the presence of posterior bony impingement was 0% in group A and 32.4% in group B (P <0.01). Clinical outcomes and surgery-related complications were similar between groups.

CONCLUSION

Performing wedge-shaped resection of the cranial portion of the posterior bony arch in ODLP surgery can lead to better outcomes than ODLP alone in terms of preservation of cervical ROM, prevention of posterior bony impingement, and amelioration of posterior neck pain.

LEVEL OF EVIDENCE

2.