Forestier disease associated with a retroodontoid mass causing cervicomedullary compression

Area of Science:

• Spine surgery
• Neurology
• Rheumatology

Background:

• Forestier Disease (FD), also known as diffuse idiopathic skeletal hyperostosis (DISH), is a progressive skeletal disorder.
• FD is characterized by extensive calcification of the anterior longitudinal ligament in the thoracic and cervical spine.
• Retroodontoid masses associated with FD have not been previously described.

Purpose of the Study:

• To describe retroodontoid masses in patients with Forestier Disease.
• To evaluate the clinical presentation and surgical management of these masses.
• To understand the underlying pathophysiology of CMJ compression in FD.

Main Methods:

• A retrospective review of five patients with FD and subaxial cervical fusion treated for retroodontoid masses and CMJ compression.
• Surgical procedures included transoral resection followed by occipitocervical fusion or posterior decompression and occipitocervical fusion.
• Histopathological examination of the resected masses.

Main Results:

• All five patients presented with progressive neurological symptoms due to CMJ compression.
• Four patients underwent combined transoral resection and occipitocervical fusion; one had posterior decompression and fusion.
• Postoperative neurological improvement was observed in four patients; one patient died from pulmonary complications.
• Histopathology revealed hypertrophic degenerative fibrocartilage.

Conclusions:

• Altered biomechanics from FD-associated cervical spine fusion can lead to stress-induced ligamentous hypertrophy at the craniovertebral junction.
• This hypertrophy can cause CMJ compression and neurological deficits, a previously undescribed entity in FD/DISH.
• Surgical decompression and fusion are effective treatments for symptomatic retroodontoid masses in FD/DISH patients.