Intervertebral foramen narrowing during vertical dynamic loading

Morphological changes after open lumbar microdiscectomy at 2-year follow-up

BACKGROUND

It is known that a possible decrease in disc height (DH) and foraminal size after open lumbar microdiscectomy (OLM) may cause pain in the long term. However, there is still insufficient information about the short- or long-term pathoanatomical and morphological effects of microdiscectomy. For example, the exact temporal course of the change in DH is not well known.

OBJECTIVE

The purpose of this study was to examine morphological changes in DH and foramen dimensions after OLM.

METHODS

In patients who underwent OLM for single-level lumbar disc herniation, MRI scans were obtained before surgery, and at an average of two years after surgery. In addition to DH measurements, foraminal area (FA), foraminal height (FH), superior foraminal width (SFW), and inferior foraminal width (IFW), were measured bilaterally.

RESULTS

A postoperative increase in DH was observed at all vertebral levels, with an average of 5.5%. The mean right FHs were 15.3 mm and 15.7 mm before and after surgery, respectively (p= 0.062), while the left FHs were 14.8 mm and 15.8 mm before and after surgery (p= 0.271). The mean right SFW was 5.4 mm before surgery and 5.7 mm after surgery, while the mean right IFW ranged from 3.6 mm to 3.9 mm. The mean left SFW was 4.8 mm before surgery and 5.2 mm after surgery, while the mean left IFW ranged from 3.5 mm to 3.9 mm. Before surgery, the FAs were, on average, 77.1 mm2 and 75.6 mm2 on the right and left sides, respectively. At the 2-year follow-up, the mean FAs were 84.0 mm2 and 80.2 mm2 on the right and left sides, respectively.

CONCLUSIONS

Contrary to prevalent belief, in patients who underwent single-level unilateral OLM, we observed that there may be an increase rather than a decrease in DH or foramen size at the 2-year follow-up. Our findings need to be confirmed by studies with larger sample sizes and longer follow-ups.

Full-endoscopic spine surgery treatment of lumbar foraminal stenosis after osteoporotic vertebral compression fractures: A case report

BACKGROUND

Few reports have described lumbar foraminal stenosis-induced radiculopathy after treatment by full-endoscopic spine surgery (FESS) combined with percutaneous vertebroplasty (PVP) in patients with vertebral compression fractures. We herein report such a case, including the patient’s treatment process and doctor’s surgical experience.

CASE SUMMARY

A 79-year-old man presented with symptoms of radiculopathy after sustaining L4 vertebral compression fractures. Imaging and physical examination revealed L4 vertebral compression fractures combined with L3/4 Lumbar foraminal stenosis (LFS). The patient’s symptoms were low back pain with pain in the lateral left leg. Although many reports have described radiculopathy induced by osteoporotic vertebral compression fractures, the use of FESS combined with PVP has rarely been reported. This case report indicates that the combination of FESS and PVP is a safe and effective approach for the treatment of LFS-induced radiculopathy after vertebral compression fractures. This minimally invasive technique has great potential to replace traditional lumbar fixation and decompression surgery. Thus, we suggest the continued accumulation of similar cases to discuss the wider application of FESS.

CONCLUSION

For patients with osteoporotic vertebral compression fracture (OVCF) and LFS, PVP and FESS can be used to restore the vertebral height and reduce the pressure around the intervertebral foramen. Additionally, the combination of FESS and PVP can treat the pain or numbness of the low back and lower limbs and allow for recovery in a short time with excellent postoperative effects. In general, FESS is a good treatment for radiculopathy caused by foraminal stenosis after OVCF.

Importance of neural foraminal narrowing in lumbar spine fractures of low AIS severity

OBJECTIVE

In recent years, based on injuries predicted using machine learning, there have been efforts to reduce imaging performed on trauma patients. While useful, such efforts do not incorporate results from studies investigating the pathophysiology of traumatic events. The objective of this study was to identify potentially symptomatic vertebral foramen narrowing in the presence of minor to moderate (AIS ≤ 2 levels of severity) thoracolumbar fractures sustained in motor vehicle crashes (MVCs).

METHODS

Hospital records and images of patients admitted to a Level One trauma center between the years 2014 and 2018 with the diagnosis of thoracolumbar fracture were reviewed. Spinal injuries were scored using the AIS v2015. In addition, the geometry of the neural foramina, particularly the height of the foramina and intervertebral disk at the posterior region, were measured using reconstructed sagittal computed tomography (CT) images. The criteria for foraminal narrowing were associated with <15 mm for the foraminal height and <4 mm for the height of the posterior disk.

RESULTS

24 patients with MVCs associated thoracolumbar fractures, who met both the clinical and imaging criteria for radiculopathy and foraminal narrowing without spinal cord injury, were considered for the present clinical study. 54% of the total lumbar fracture cases reported were rated as AIS 2 injuries. AIS ≥ 3 cases reported 50% narrowing of foramen, which was expected. However, it was surprising to note that the AIS 2 cases also sustained foraminal stenosis, narrowing ranging from 13% to 20%.

CONCLUSIONS

Low severity (AIS ≤ 2) injuries were often found to be associated with foraminal narrowing leading to clinical complaints. While the present clinical study cannot determine if narrowing existed prior to the trauma, they were certainly asymptomatic prior to the trauma. The present findings emphasize the need for detailed imaging in all instances of thoracolumbar trauma, as clinically significant nerve compression may occur even with modest vertebral body injury.