A Scoring System for Anterior Longitudinal Ligament Ossification of the Lumbar Spine in Diffuse Idiopathic Skeletal Hyperostosis: Relationship Between the Extent of Ligament Ossification and the Range of Motion

Abstract

Study Design: Retrospective observational study. Objective: To investigate the relationship between the extent of ligament ossification and the range of motion (ROM) of the lumbar spine and develop a new scoring system. Methods: Forty-three patients (30 men and 13 women) with lumbar spinal canal stenosis who underwent decompression from January to December 2018. Ligament ossification at L1/2 to L5/S was assessed on plain X-ray (Xp) and computed tomography (CT) using a modified Mata scoring system (0 point: no ossification, 1 point: ossification of less than half of the intervertebral disc height, 2 points: ossification of half or more of the intervertebral disc height, 3 points: complete bridging), and the intra-rater and inter-rater reliability of the scoring was assessed. The relationship of the scores with postoperative lumbar ROM was investigated. Result: Intra-rater reliability was high (Cronbach’s α was 0.74 for L5/S on Xp but 0.8 or above for other sections), as was inter-rater reliability (Cronbach’s α was 0.8 or above for all the segments). ROM significantly decreased as the score increased (scores 1 to 2, and 2 to 3). A significant moderate negative correlation was found between the sum of the scores at L1/2-L5/S and the ROM at L1-S (ρ = − 0.4493, P = 0.025). Conclusion: Our scoring system reflects lumbar mobility and is reproducible. It is effective for assessing DISH in fractures and spinal conditions, and monitoring effects on treatment outcomes and changes over time.

Imaging Features of Early Diffuse Idiopathic Skeletal Hyperostosis (pre-DISH): Analysis of Progression of Ligament Ossification over 5 Years by Computed Tomography

“…Thus, attention should be focused not only on imaging findings but also on age, but we could not clarify predictive factors such as age, metabolic disease, and so on in this study. Murakami et al 6) quantified ligament ossification in the lumbar spine and found a correlation between the total score and the range of motion of the lumbar spine. They reported that the range of motion decreased with an increasing score.…”

“…DISH was diagnosed when three diagnostic criteria developed by Resnick and Niwayama 1) were met: (1) the presence of osseous bridging of four contiguous vertebral bodies on the anterior or lateral aspect, (2) the presence of relatively preserved intervertebral disc spaces, and (3) the absence of the rigid sacroiliac joint. Subsequently, the extent of the progression of ligament ossification in each intervertebral space was evaluated using the modified Mata scoring system 6) . Scores were assigned as follows: 0 point, no ligament ossification; 1 point, ligament ossification of less than half of the intervertebral disc height; 2 points, ligament ossification of half or more of the intervertebral disc height but incomplete fusion; and 3 points, complete bridging (Fig.…”

“…For example, patients with bridging of two contiguous intervertebral spaces and patients with three or more contiguous intervertebral spaces almost bridged (2 points on the Mata scoring system) were noted. Considering that one report shows that the mobility of intervertebral discs decreases with ossification progression despite the absence of completely bridged intervertebral spaces 6) , treatment of other spinal diseases even in patients with pre-DISH should be undertaken cautiously, similar to that in patients with DISH. However, there are no clearly defined diagnostic criteria for pre-DISH.…”