How to Avoid Postoperative Remaining Ossification Mass in Anterior Controllable Antedisplacement and Fusion Surgery

Comparison of Anterior Controllable Antedisplacement and Fusion Versus Laminoplasty in the Treatment of Multisegment Ossification of Cervical Posterior Longitudinal Ligament: A Meta-Analysis of Clinical

OBJECTIVE

This study aims to provide a comprehensive summary of the existing literature and conduct a systematic evaluation of the clinical outcomes associated with anterior controllable antedisplacement and fusion (ACAF) and posterior laminoplasty (LP) for the treatment of multisegment ossification of the cervical posterior longitudinal ligament (OPLL).

METHODS

We conducted an electronic search of databases, including PubMed, Embase, Cochrane Library, and CNKI, from the inception of the initial database to March 2023. We analyzed various parameters, including demographic data, operation time, intraoperative blood loss, cervical curvature, Japanese Orthopaedic Association (JOA) scores, Visual Analog Scale (VAS) scores, and postoperative complications. Two independent reviewers screened the literature, extracted data, and assessed the risk of bias in the included studies. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

Our evaluation encompassed 7 studies involving a total of 467 patients. The patient cohort was divided into 2 groups: Group A (ACAF) comprised 226 patients, while Group B (LP) comprised 241 patients. Overall, our statistical analysis revealed significant differences between the 2 groups (P < 0.05) in terms of intraoperative blood loss, operative time, JOA score, JOA score improvement rate, postoperative VAS score, postoperative cervical curvature, and the incidence of certain postoperative complications (C5 nerve root paralysis, dysphagia, and axial symptoms). However, there was no statistically significant difference in the incidence of postoperative cerebrospinal fluid leakage and postoperative total complications between the 2 groups (P > 0.05).

CONCLUSIONS

The findings of this study suggest that, in the treatment of multilevel cervical OPLL, ACAF yields superior outcomes compared to LP. Specifically, ACAF improves postoperative neurologic function, reduces postoperative pain, lowers intraoperative blood loss, improves postoperative cervical curvature, and decreases the incidence of C5 nerve root paralysis and postoperative axial symptoms. Nonetheless, ACAF is associated with longer operative times and a higher incidence of postoperative dysphagia, though the overall incidence of postoperative complications is similar. It is important to note that these conclusions should be interpreted cautiously due to the limited sample size and the variable quality of the included studies. Further research involving larger, high-quality studies is warranted to validate these findings.

Anterior controllable antedisplacement and fusion: quantitative analysis of a single surgeon's learning experience

BACKGROUND CONTEXT

Anterior controllable antedisplacement and fusion (ACAF) is a novel surgical technique for the treatment of ossification of the posterior longitudinal ligament (OPLL) but the surgical learning curve for this technique has not been previously characterized.

PURPOSE

The aim of this study was to quantify a surgeon's learning curve for ACAF and the effect of surgeon experience on postoperative outcomes.

STUDY DESIGN

Prospective study of a single institution and single surgeon experience with ACAF surgery.

PATIENT SAMPLE

A total of 70 consecutive patients with OPLL undergoing ACAF surgery by a single, non-ACAF trained surgeon between 2017 and 2020 were analyzed.

OUTCOME MEASURES

Intraoperative and postoperative outcomes (blood loss, operative time, errors of surgical procedure, length of hospital stay, Japanese Orthopedic Association (JOA) scoring system, and surgical complications) were assessed.

METHODS

We prospectively reviewed the first 70 ACAF procedures between 2017 and 2020 performed by a single, non-ACAF trained surgeon. The function relationship between the operative time and case number was fitted using a locally weighted scatterplot smoothing (LOESS) plot. Spearman's correlation analysis was performed to determine factors affecting the operative time. The operative time-related learning curve for ACAF was established and difficulty of each procedure was assessed using a cumulative sum (CUSUM) model. The association between the specific errors of surgical procedures and surgeon experience was further analyzed. A modified CUSUM model was also used to establish the surgical procedure-related learning curve, and thus whether these two learning curves matched with each other was observed. Postoperative outcomes in relation to surgeon experience was compared using a Wilcoxon rank sum test and Chi-squared test.

RESULTS

Operative time presented a specific pattern of fewer patient-dependent changes as the case number increased. Spearman's correlation analysis showed the operative time was more affected by the case number (r=-0.73) than the complexity of condition and number of levels hoisted. The operative time-related CUSUM model identified the early (first 29 cases) and late phase (late 41 cases) of the learning process, which was also confirmed by a modified CUSUM model based on surgical procedure. The critical point of the CUSUM model for bilateral osteotomies was at case number 29, and time reduction after the early phase was approximately 34 minutes. Length of hospital stay and blood loss were less during the late phase than during the early phase (p<.05). Although no significant difference was observed in postoperative JOA scores between two phases, patients in the late phase obtained higher recovery rates of neurologic function than those in the early phase (p<.01). There was significant difference in the number of specific errors between the two phases (p=.02). There were no significant differences in overall complication rates between two phases, but a higher incidence of certain complications caused by specific errors was observed in the early phase (p=.02), including CSF leakage, C5 palsy and incomplete decompression.

CONCLUSIONS

We described, for the first time, a detailed learning curve for ACAF surgery. About 29 cases were needed to achieve mastery of ACAF. Once mastered, the surgeon could deal with various OPLL presentations in a universal way regardless of condition complexity and number of surgical levels. Bilateral osteotomies were the most difficult part of ACAF and produced the greatest reduction in time after mastery. We found a close association between specific errors of surgical procedure for ACAF and surgeon experience. Furthermore, certain complications caused by these errors should be on the alert during the early phase of learning ACAF, including CSF leakage, C5 palsy and incomplete decompression.

Computer-Based 3D Simulations to Formulate Preoperative Planning of Bridge Crane Technique for Thoracic Ossification of the Ligamentum Flavum

Background

The bridge crane technique is a novel surgical technique for the treatment of thoracic ossification of the ligamentum flavum (TOLF), but its preoperative planning has not been studied well, which limits the safety and efficacy of surgery to some extent. The purpose of this study was to investigate the method of application and effect of computer-aided preoperative planning (CAPP) on the bridge crane technique for TOLF.

Material/Methods

This retrospective multi-center included 40 patients with TOLF who underwent the bridge crane technique from 2016 to 2018. According to the utilization of CAPP, patients were divided into Group A (with CAPP, n=21) and Group B (without CAPP, n=19). Comparisons of clinical and radiological outcomes were carried out between the 2 groups.

Results

The patients in Group A had higher post-mJOA scores and IR of neurological function than those in Group B (p<0.05). Group A had shorter surgery time, fewer fluoroscopic images, and lower incidence of complications than Group B. In Group A, there was a high consistency of all the anatomical parameters between preoperative simulation and postoperative CT (p>0.05). In Group B, there were significant differences in 3 anatomical parameters between postoperative simulation and postoperative CT (p<0.05). In Group B, the patients with no complications had higher post-SVOR and lower SVRR and height of posterior suspension of LOC in postoperative CT than those in postoperative simulation (p<0.05).

Conclusions

CAPP can enable surgeons to control the decompression effect accurately and reduce the risk of related complications, which improves the safety and efficacy of surgery.