Pedicle paradox: Duplicate vertebral pedicles creating a rare “pseudo foramen” with symptomatic foraminal stenosis

TL;DR

A rare case of duplicated vertebral pedicles caused a pseudo foramen and symptoms of nerve compression in the lumbar spine.

Contribution

This is the first reported case linking pedicle duplication to clinically significant foraminal stenosis.

Findings

Duplication of a vertebral pedicle can create a pseudo foramen leading to neuroforaminal stenosis.

Symptoms of radiculopathy were confirmed to be associated with the pseudo foramen at L2 via imaging and steroid injection.

This case is the first to report clinical significance of stenosis within a pseudo foramen.

Abstract

Duplication of a vertebral pedicle is a rare congenital anatomic variant with limited representation in the medical literature. Such anomalies are thought to arise during intrauterine or early postnatal phases of osseous development. Aberrant pedicle duplication can result in the creation of a “pseudo foramen,” with potential clinical implications that are not well characterized.

A patient presented with symptoms of painful burning sensations and paresthesias within the right groin and anterior thigh, consistent with upper lumbar radiculopathy. Advanced imaging of the lumbar spine revealed neuroforaminal stenosis associated with a “pseudo foramen” at L2, created by pedicle duplication. Together with clinical suspicion, results of a transforaminal epidural steroid injection supported the conclusion that the neuroforaminal stenosis at this level contributed to the patient's symptoms. This report examines the embryological origins and imaging findings of pedicle formation, considers the spectrum of pedicle duplication and semi-segmented hemivertebra, and reviews relevant imaging findings.

This case highlights the importance of carefully reviewing lumbar imaging modalities. Not only is there observation of a rare duplication of vertebral pedicles, but also a thorough review of available literature suggests that this is the first case to specifically report on clinically significant stenosis occurring within a “pseudo foramen.”

Figures