Dimensions of the spinous process and interspinous space: a morphometric study.
PURPOSE
To measure the morphological dimensions of the spinous process (SP) and interspinous space, and provide a basis for the development of interspinous devices for the Korean or East Asian populations.


METHODS
We retrospectively analyzed the anatomical parameters of 120 patients. The parameters included height, length, and width of SP, interspinous distance (supine, standing, and dynamic), cortical thickness of SP, and spino-laminar (S-L) angle. Correlations between measurements, age, and gender were investigated.


RESULTS
The largest height, length, and cortical thickness and S-L angle were noted at L3. The largest width was observed at S1. The interspinous distance decreased significantly from L2-3 to L5-S1 and was significantly larger in the supine than in standing posture for L5-S1. Cortical thickness was gradually tapered from the anterior to the posterior position. The S-L angle at L2 and L3 was similar and significantly decreased from L3 to S1. An increased trend in width with aging and a decreased trend in distance (supine) were noted. A significant increase in height, length, and distance in males compared with females was also observed.


CONCLUSIONS
The interspinous space is wider at the anterior, and the cortex is thicker anteriorly. Accordingly, it appears that the optimized implant position lies in the interspinous space anteriorly. The varying interspinous space with different postures and gradually narrowing with age suggest the need for caution when sizing the device. Gender differences also need to be considered when designing implantable devices.
['Lin|Guang-Xun|GX|', 'Suen|Tsz-King|TK|', 'Quillo-Olvera|Javier|J|', 'Akbary|Kutbuddin|K|', 'Hur|Jung-Woo|JW|', 'Kim|Eun|E|', 'Park|Eun-Jin|EJ|', 'Kim|Jin-Sung|JS|']
D000328:Adult D000368:Aged D063405:Anatomic Variation D044466:Asians D004867:Equipment Design D005260:Female D006801:Humans D008159:Lumbar Vertebrae D008297:Male D008875:Middle Aged D019736:Prostheses and Implants D011857:Radiographic Image Interpretation, Computer-Assisted D012189:Retrospective Studies D013130:Spinal Stenosis D014057:Tomography, X-Ray Computed
Spinous process Interspinous space Cortical thickness Morphometry Spino-laminar angle