Adverse effect of trauma on neurologic recovery for patients with cervical ossification of the posterior longitudinal ligament

Progression of Ossification of Posterior Longitudinal Ligament After Anterior Cervical Discectomy and Fusion in Military Patients Exposed to Minor Trauma

Objective

Ossification of the posterior longitudinal ligament (OPLL) can progress even after cervical spine surgery and may cause neurological injury as a result of minor trauma. The purpose of this study was to investigate the preventive factors associated with OPLL progression after anterior cervical discectomy and fusion (ACDF), a procedure commonly performed in clinical practice.

Methods

We retrospectively investigated 295 male soldiers who underwent ACDF surgery between 2012 and 2017. Patients who were followed up for >12 months using dynamic radiography and computed tomography (CT) were included in the study. Radiological parameters investigated included OPLL progression, C2-C7 angles on dynamic radiography, segmental angles, C2-C7 cervical sagittal vertical axis (C2-C7 SVA), and the T1 slope. These parameters were measured preoperatively and 1 year postoperatively.

Results

A total of 49 patients were enrolled, and 10 patients were confirmed to have OPLL progression. Comparison between the OPLL progression and non-progression groups showed no statistically significant differences in pre- and postoperative cervical range of motion. However, statistically significant differences were observed in the postoperative neutral C2-C7 angle (progression -3.9°±6.4° vs. non-progression -13.4°±7.9°, p=0.001) and the SVA change (progression 5.8±7.9 mm vs. non-progression -3.7±6.3 mm, p=0.00). The cutoff values were -8.01° for the postoperative neutral C2-C7 angle and 1.4 mm for SVA changes.

Conclusion

Increased SVA (>1.4 mm) and a small postoperative neutral C2-C7 angle (>-8.01°) 1 year after ACDF were associated with OPLL progression. It is important to be mindful of these factors during follow-up after ACDF, because additional surgical treatment may be necessary for OPLL progression due to neurological injury caused by minor trauma.

Does surgical treatment increase the progression of spinal cord injury in patients with ossification of posterior longitudinal ligament of cervical spine? A systematic review and meta-analysis

PURPOSE

The purpose of this study is to explore if the surgical treatment will accelerate the progression of spinal cord injury (SCI) in patients with cervical Ossification of the posterior longitudinal ligament (OPLL) and if surgery will have better curative effect than conservative treatment.

METHODS

An extensive search of literature was implemented in PubMed, EMBASE, and other online databases. The quality of the included articles was evaluated according to the Newcastle-Ottawa Quality Assessment Scale, as recommended by the Cochrane manual, and meta-analysis was performed using the review manage5.3 software.

RESULTS

No obvious statistical difference was observed in the rate of SCI progression (P > 0.05, OR 1.15 [0.66, 2.00]), cervical range of motion, (P > 0.05, weighted mean difference (WMD) 4.52 [-5.75, 14.79]), and Japanese Orthopedic Association scores before surgery (P > 0.05, WMD -2.78 [-7.87, 2.32]) between the surgical group and conservative treatment group. However the surgical group illustrated obviously higher neurofunctional recovery rate (P < 0.05, OR 6.07 [1.55, 23.78]) and postoperative JOA score of the surgery group (P < 0.05, WMD -0.77 [-1.21, -0.33]) than conservative group.

CONCLUSIONS

Based on this meta-analysis, there is not enough evidence to indicate that surgery will accelerate the progress of SCI with OPLL. However, the superiority of surgical efficacy can be observed over conservative treatment in terms of relieving neurological symptoms.

A Systematic Review of Classification Systems for Cervical Ossification of the Posterior Longitudinal Ligament

DESIGN

Systematic review.

OBJECTIVE

To conduct a systematic review to (1) summarize various classification systems used to describe cervical ossification of the posterior longitudinal ligament (OPLL) and (2) evaluate the diagnostic accuracy of various imaging modalities and the reliability of these classification systems.

METHODS

A search was performed to identify studies that used a classification system to categorize patients with OPLL. Furthermore, studies were included if they reported the diagnostic accuracy of various imaging modalities or the reliability of a classification system.

RESULTS

A total of 167 studies were deemed relevant. Five classification systems were developed based on X-ray: the 9-classification system (0.60%); continuous, segmental, mixed, localized or focal, circumscribed and others (92.81%); hook, staple, bridge, and total types (2.40%); distribution of OPLL (2.40%); and K-line classification (4.19%). Six methods were based on computed tomography scans: free-type, contiguous-type, and broken sign (0.60%); hill-, plateau-, square-, mushroom-, irregular-, or round-shaped (5.99%); rectangular, oval, triangular, or pedunculate (1.20%); centralized or laterally deviated (1.80%); plank-, spindle-, or rod-shaped (0.60%); and rule of nine (0.60%). Classification systems based on 3-dimensional computed tomography were bridging and nonbridging (1.20%) and flat, irregular, and localized (0.60%). A single classification system was based on magnetic resonance imaging: triangular, teardrop, or boomerang. Finally, a variation of methods was used to classify OPLL associated with the dura mater (4.19%).

CONCLUSIONS

The most common method of classification was that proposed by the Japanese Ministry of Health, Labour and Welfare. Other important methods include K-line (+/-), signs of dural ossification, and patterns of distribution.

Clinical and Imaging Predictors of Surgical Outcome in Multilevel Cervical Ossification of Posterior Longitudinal Ligament: An Analysis of 184 Patients

OBJECTIVE

To investigate the clinical and imaging predictors of surgical outcomes in patients with ossification of the posterior longitudinal ligament (OPLL).

MATERIALS AND METHODS

From May 2010 to April 2012, a total of 200 consecutive patients with cervical OPLL were recruited for this study. Of them, 184 patients (130 men and 54 women) who could be tracked for more than 24 months after surgery were finally included for analysis. Their demographic, clinical and radiological data were collected preoperatively. The recovery ratio in terms of JOA score was used to assess the outcome of the patients preoperatively and at 2 years postoperatively. A JOA recovery rate less than 50% was considered a poor outcome.

RESULTS

Compared with good outcome group, an older mean age at operation, a longer mean duration of symptoms, a lower mean pre-operativer JOA score, and a higher proportion of diabetics were observed in poor outcome group. Patients in poor outcome group were more likely to present kyphotic cervical alignment, smaller mean transverse area of the spinal cord, and intramedullary signal abnormalities. The result of multivariate stepwise logistic regression showed that a longer duration of symptoms and the presence of T1 hypo-intensity intramedullary changes on MRI were significant risk factors of lower JOA recovery ratios.

CONCLUSION

A longer duration of symptom, T1 hypointensity on MRI and a history of minor trauma were highly predictive of a poor outcome for patients undergoing surgical treatment of OPLL. Age at operation, the history of diabetes, the preoperative JOA score, the transverse area of the spinal cord and T2 hyper-intensity on MRI were also associated with the prognosis of OPLL.

Posterior indirect reduction and pedicle screw fixation without laminectomy for Denis type B thoracolumbar burst fractures with incomplete neurologic deficit

Purpose

The aim of this study is to evaluate the efficacy of posterior indirect reduction and pedicle screw fixation without laminectomy for the treatment of Denis type B thoracolumbar burst fractures with incomplete neurologic deficit.

Methods

From March 2008 to May 2012, 36 consecutive patients of Denis type B thoracolumbar burst with incomplete neurologic deficit were enrolled. All of the patients accepted the treatments of posterior indirect reduction and pedicle screw fixation without laminectomy. Clinical and radiologic outcomes were assessed preoperatively and postoperatively.

Results

Operations were performed in a relatively short time without massive hemorrhage. Their neurologic functions were improved by at least one Frankel grade. The average score of American Spinal Injury Association (ASIA) motor increased from 25.4 ± 10.8 to 42.1 ± 10.5, and the recovery rate of the ASIA score was also increased. The pain level was relieved for all the patients. The local kyphosis angle was reduced from 25.9° ± 3.4° to 6.9° ± 2.2° (P <0.05) and remained 7.9° ± 2.0° (P > 0.05) at the latest follow-up. After the operation, the mean vertebral canal diameter increased from 5.5 ± 1.3 to 11.1 ± 2.2 mm (P < 0.05) and the mean canal stenosis index increased from 32.9 ± 7.8 to 84.8 ± 7.3 % (P < 0.05). There were no serious complications and fixation failures during follow-up.

Conclusion

Denis type B thoracolumbar burst fractures with incomplete neurologic deficit can be effectively treated by posterior indirect reduction and pedicle screw fixation without laminectomy.