Surgical Options in Treating Ossification of the Posterior Longitudinal Ligament: Single-Center Experience

Instrumented fusion versus instrumented non-fusion following expansive open-door laminoplasty for multilevel cervical ossification of the posterior longitudinal ligament

PURPOSE

To compare the outcomes of expansive open-door laminoplasty with instrumented fusion (ELIF) and expansive open-door laminoplasty with instrumented non-fusion (ELINF) for multilevel cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

Patients who underwent ELIF or ELINF due to multilevel cervical OPLL from June 2013 to June 2019 were identified. Clinical and radiological outcomes were compared between the two groups.

RESULTS

A total of 78 patients were enrolled in this study with a minimum follow-up of 24 months, including 42 patients in the ELIF group and 36 patients in the ELINF group. At the final follow-up, sagittal vertical axis (SVA) and C2-C7 Cobb angle in the ELIF group were significantly better than those in the ELINF group, and cervical range of movement (ROM) in the ELIF group decreased significantly than that in the ELINF group. The incidence of OPLL progression at the final follow-up was 4.76% (2/42) in the ELIF group and 27.78% (10/36) in the ELINF group. Postoperative Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), and visual analog scale (VAS) score improved significantly in each group, but JOA score and recovery rate (RR) in the ELIF group were significantly better than those in the ELINF group at the final follow-up. When K-line was positive, the difference in the final JOA score between the two groups was not significant, but the RR in the ELIF group was significantly better than that in the ELINF group. When K-line was negative, the final JOA score and RR in the ELIF group were significant higher than those in the ELINF group.

CONCLUSIONS

ELIF and ELINF were two effective surgical procedures for treating multilevel cervical OPLL. However, ELIF was superior to ELINF due to better postoperative JOA score and RR, significant improvement of C2-C7 Cobb angle and maintenance of SVA, and suppressant effect on OPLL progression, especially for patients with K-line ( - ) OPLL.

Use of a smartphone leveling application to optimize cervical thoracic alignment prior to posterior instrumentation

OBJECTIVE

Posterior cervical decompression and instrumentation (PCDI) is often associated with increase in sagittal balance and loss of lordosis. Here we propose a simple method of surgical positioning utilizing a readily available smartphone application to optimize cervical thoracic alignment in PCDI. The intent of this optimization is to minimize losses in lordosis and increases in sagittal balance.

METHODS

For patients since 2019, the position of the head was adjusted so that the occiput to thoracic spine was aligned and the chin brow angle was parallel to the rails of the surgical table utilizing a leveling smart application (RIDGID Level). Patients before 2019 who were not optimized were compared.

RESULTS

There were 13 patients in the nonoptimized cohort (NOC) and 20 in the optimized cohort (OC). In the NOC, the change in lordosis was -7° (p=0.016) and change in C2-SVA was 7 mm (p<0.001) from preoperative to postoperative values. In the OC, the change in lordosis was 2° (p=0.104) and change in C2-SVA was 2 mm (p=0.592) from preoperative to postoperative values. Between the NOC and OC cohorts, the changes in lordosis and sagittal balance between cohorts were significant (p=0.002 and p=0.001 respectively). There was no significant difference in clinical outcomes as measured by JOA or complication rates.

CONCLUSION

Positioning of the patient in preparation for PCDI can influence post-operative lordosis and sagittal balance. Using the leveling application on the smart phone (RIDGID Level), is a rapid and free alternative for the maintenance of lordosis and sagittal balance during instrumentation in the operating room.

Cervical alignment in the obese population following posterior cervical fusion for cervical myelopathy

STUDY DESIGN

Retrospective cohort study OBJECTIVE: The aim of this study was to investigate the effect of body mass index (BMI) on the reoperation rate and cervical sagittal alignment of patients who underwent posterior cervical decompression and fusion for cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Cervical sagittal balance has been correlated with postoperative clinical outcomes. Previous studies have shown worse postoperative sagittal alignment and higher reoperation rates in patients with high BMI undergoing anterior decompression and fusion. Similar evidence for the impact of obesity in postoperative sagittal alignment for patients with (CSM) undergoing posterior cervical decompression and fusion (PCF) is lacking.

METHODS

A retrospective analysis of 198 patients who underwent PCF for cervical myelopathy due to degenerative spine disease was performed. Demographics, need for reoperation, and perioperative radiographic parameters were collected. Cervical lordosis (CL), C2-7 sagittal vertical axis (SVA), and T1 slope (T1S) was measured on standing lateral radiographs. Comparative analysis of the patient cohort was performed by stratifying the sample population into three BMI categories (<25, 25-30, ≥30).

RESULT

Of the 198 patients that met inclusion criteria, 53 had BMI normal (<25), 65 were overweight (25-30), and 80 were obese (≥30). Mean SVA increased postoperatively in all groups, 4 mm in the normal group, 13 mm in the overweight group, and 13 mm in the obese group (p = 0.003). There was no significant difference in the postoperative change of cervical lordosis or T1 slope between the groups. Multivariate analysis demonstrated fusions involving the cervicothoracic junction and those involving 5 or more levels significantly affected alignment parameters. There were 27 complications requiring reoperation (14%) with no significant differences among the groups stratified by BMI (p = 0.386).

CONCLUSIONS

Overweight patients (BMI>25) with CSM undergoing PCF had a greater increase in SVA than normal weight patients while reoperation rates were similar. In addition, preoperative CL increased with increasing BMI, although this trend was not Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation significant and there was not found to be a significant difference between the change in CL from baseline to post-fusion between BMI cohorts. This study further highlights the importance of considering BMI when attempting to optimize sagittal alignment in patients undergoing PCF.

Comparison of Interventions for Cervical Ossification of Posterior Longitudinal Ligament: A Systematic Review and Network Meta-Analysis

OBJECTIVE

To summarize the literature and systematically evaluate outcomes for ossification of posterior longitudinal ligament interventions including anterior cervical corpectomy and fusion (ACCF), anterior controllable antedisplacement and fusion (ACAF), laminoplasty (LP), and laminectomy with fusion (LF).

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library from January 1990 to March 2021. Patient demographic data, Japanese Orthopaedic Association score, cervical lordosis and overall complications were analyzed.

RESULTS

We evaluated 30 studies involving 2038 patients. Patients undergoing ACCF had improved Japanese Orthopaedic Association scores compared with patients undergoing LP (weighted mean difference [WMD] 1.17, 95% confidence interval [CI] 0.49-1.85) and LF (WMD 1.21, 95% CI 0.17-2.24). Patients with ACAF had better cervical lordosis compared with patients with ACCF (WMD 7.00, 95% CI 0.72-13.27), LP (WMD 10.27, 95% CI 4.64-15.90), and LF (WMD 8.98, 95% CI 2.48-15.47). Additionally, ACAF (odds ratio 0.24, 95% CI 0.07-0.84) and LP (odds ratio 0.50, 95% CI 0.28-0.90) had a lower incidence of complications compared with ACCF.

CONCLUSIONS

Japanese Orthopaedic Association score outcomes indicated that ACCF was superior to LP and LF. ACAF had the largest cervical lordosis among all procedures. ACCF showed a higher incidence of overall complications compared with ACAF and LP.