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Updated: Oct 10, 2025
Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum TOLF Using Ultrasonic and Conventional Osteotomes
Published on: April 21, 2023
Preoperative Magnetic Resonance Imaging Signal Intensity Classification Is Associated With Clinical Presentation and
Chao Zhang1, Shengdong Yang1, Lin Wang1
1Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Study Design:
Retrospective Cohort Study.
Objectives:
To explore whether classification of the increased signal intensity (ISI) on magnetic resonance imaging (MRI) correlates with clinical presentations and outcomes in symptomatic thoracic ossification of ligamentum flavum (T-OLF) patients.
Methods:
All patients with symptomatic T-OLF who underwent laminectomy at four institutions were reviewed. The ISI on preoperative T2-weighted MRI was divided into 3 groups, Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). Neurological function before surgery and at follow-up was evaluated by the revised Japanese Orthopedic Association (JOA) score. Patients' demographics, clinical manifestations, and surgical outcomes were compared.
Results:
A total of 94 patients were involved. Preoperative MRI showed 32 patients in Grade 0, 39 patients in Grade 1, and 23 patients in Grade 2. Low extremities numbness, weakness, and clinical signs were less frequent in Grade 0 patients. The grade of ISI was correlated with the duration of symptoms and cord compression. Grade 0 patients had a better preoperative JOA score than those with ISI changes, while Grade 2 patients showed worse neurological recovery, longer duration of operation, more intraoperative blood loss, and a higher incidence of perioperative complications.
Conclusion:
The classification of ISI is an effective parameter for preoperatively assessing cord compression, clinical severity, and surgical outcomes in T-OLF patients. Grade 0 patients have relatively mild neurological impairment but are more likely to be misdiagnosed. Grade 2 indicates the worst clinical impairment and neurological recovery, and implies a risky and challenging surgery.
