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Spine, 1998
A study was performed to measure the vertebral body depths in different locations from C2 to C7. ... more A study was performed to measure the vertebral body depths in different locations from C2 to C7. To measure the vertebral body depths in 10 linear dimension from C2 to C7. Anterior plate-screw fixation of the cervical spine has been the common surgical procedure for management of multilevel degenerative disc disease and fracture dislocation. However, injury to the spinal cord during drill or screw placement is the most feared complication of this procedure. It is beneficial for one to have a knowledge of the vertebral body depths in different locations of the vertebral body before anterior cervical plating. Twenty-seven cervical spines from C2 to C7 were evaluated directly for this study. Anatomic evaluation of the vertebral body included the anteroposterior midline sagittal depth and the anteroposterior parasagittal depth 5 mm lateral to midline on the superior and inferior endplates, as well as on the middle body. Measurements also were made of anteroposterior parasagittal vertebral depth with both medial and lateral inclination of 10 degrees, with respect to the parasagittal plane of the vertebral body. In general, the measurements of male specimens were larger than those of female specimens. Significant differences were noted at 21 measurements over C3 through C7. The mean depths of the superior endplate for all male and female specimens increased consistently from C3 to C7. The mean depths of the inferior endplate varied but generally increased from C2 to C6, then decreased to C7. The mean sagittal and parasagittal middle vertebral body depths were both 14 mm. This information, in conjunction with preoperative computed tomographic evaluation, may be helpful in determining proper screw length during anterior plating of the cervical spine.
Spine, 2001
This is an anatomic and radiologic study on the lateral mass of the C2 vertebra. To define the lo... more This is an anatomic and radiologic study on the lateral mass of the C2 vertebra. To define the location of the pedicle and pars interarticularis in the C2 vertebra. Transpedicular screw fixation of the C2 has been addressed in the literature. However, the use of the anatomic terminology of the pedicle or pars interarticularis (isthmus) in C2 is confusing in most of orthopaedic and neurosurgical literature since C2 is considered a transitional vertebra. Twenty dry C2 vertebrae were obtained for observation of the external anatomy of the C2 from superior, lateral, and inferior views. Six C2 vertebrae were harvested from cadavers and sectioned in the sagittal, horizontal, and coronal planes to observe the internal structures of the lateral mass using high resolution radiographs. Based on observation, the pedicle of the C2 vertebra is defined as the portion beneath the superior facet and anteromedial to the transverse foramen. The pars interarticularis or isthmus is defined as the narrower portion between the superior and inferior facets. No remarkable difference in bone density and trabecular bone orientation between the pedicle and pars interarticularis was noted. It is still more appropriate to call this procedure "transpedicular screw fixation" in the C2 to avoid confusion, although this technique requires placing a screw from the posterior aspect of the inferior articular process through the isthmus and pedicle into the vertebral body.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2004
Purpose: Management of articular sided partial-thickness rotator cuff tears is controversial. Mos... more Purpose: Management of articular sided partial-thickness rotator cuff tears is controversial. Most management decisions rest on determining the thickness of tendon loss and location of tendon involvement, without any clear guidelines offered on how to make this determination. This study attempts to confirm the normal cuff thickness at its humeral head attachment and correlate the amount of exposed bone at the "footprint" attachment of the supraspinatus as an accurate measurement of the amount of tendon loss. Type of Study: Anatomic study. Methods: Forty-eight cadaver shoulders with an average age of 71.5 years were examined. Specimens with full-or partial-thickness rotator cuff tears were not measured, leaving 17 specimens with an average age of 70 for analysis. The anterior to posterior width of the supraspinatus was measured with a caliper, as well as the medial to lateral width at the rotator interval, at midtendon, and at the posterior limit determined by the spine of the scapula raphe. The distance from the articular cartilage margin to the supraspinatus tendon insertion was also measured. Results: The mean anteroposterior dimension of the supraspinatus insertion was 25 mm. The mean superior to inferior tendon thickness at the rotator interval was 11.6 mm, 12.1 mm at midtendon, and 12 mm at the posterior edge. The distance from the articular cartilage margin to the bony tendon insertion was 1.5 to 1.9 mm, with a mean of 1.7 mm. Conclusions: Articular partial-thickness tears with Ͼ 7 mm of exposed bone lateral to the articular margin should be considered significant tears approximating 50% of the tendon substance. Arthroscopic measurement of the exposed bone between the articular margin and the supraspinatus tendon insertion (footprint) is an accurate way to estimate tear depth and provide a rational, reproducible guideline for treatment.
Spine, 1998
A study was performed to measure the vertebral body depths in different locations from C2 to C7. ... more A study was performed to measure the vertebral body depths in different locations from C2 to C7. To measure the vertebral body depths in 10 linear dimension from C2 to C7. Anterior plate-screw fixation of the cervical spine has been the common surgical procedure for management of multilevel degenerative disc disease and fracture dislocation. However, injury to the spinal cord during drill or screw placement is the most feared complication of this procedure. It is beneficial for one to have a knowledge of the vertebral body depths in different locations of the vertebral body before anterior cervical plating. Twenty-seven cervical spines from C2 to C7 were evaluated directly for this study. Anatomic evaluation of the vertebral body included the anteroposterior midline sagittal depth and the anteroposterior parasagittal depth 5 mm lateral to midline on the superior and inferior endplates, as well as on the middle body. Measurements also were made of anteroposterior parasagittal vertebral depth with both medial and lateral inclination of 10 degrees, with respect to the parasagittal plane of the vertebral body. In general, the measurements of male specimens were larger than those of female specimens. Significant differences were noted at 21 measurements over C3 through C7. The mean depths of the superior endplate for all male and female specimens increased consistently from C3 to C7. The mean depths of the inferior endplate varied but generally increased from C2 to C6, then decreased to C7. The mean sagittal and parasagittal middle vertebral body depths were both 14 mm. This information, in conjunction with preoperative computed tomographic evaluation, may be helpful in determining proper screw length during anterior plating of the cervical spine.
Spine, 2001
This is an anatomic and radiologic study on the lateral mass of the C2 vertebra. To define the lo... more This is an anatomic and radiologic study on the lateral mass of the C2 vertebra. To define the location of the pedicle and pars interarticularis in the C2 vertebra. Transpedicular screw fixation of the C2 has been addressed in the literature. However, the use of the anatomic terminology of the pedicle or pars interarticularis (isthmus) in C2 is confusing in most of orthopaedic and neurosurgical literature since C2 is considered a transitional vertebra. Twenty dry C2 vertebrae were obtained for observation of the external anatomy of the C2 from superior, lateral, and inferior views. Six C2 vertebrae were harvested from cadavers and sectioned in the sagittal, horizontal, and coronal planes to observe the internal structures of the lateral mass using high resolution radiographs. Based on observation, the pedicle of the C2 vertebra is defined as the portion beneath the superior facet and anteromedial to the transverse foramen. The pars interarticularis or isthmus is defined as the narrower portion between the superior and inferior facets. No remarkable difference in bone density and trabecular bone orientation between the pedicle and pars interarticularis was noted. It is still more appropriate to call this procedure "transpedicular screw fixation" in the C2 to avoid confusion, although this technique requires placing a screw from the posterior aspect of the inferior articular process through the isthmus and pedicle into the vertebral body.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2004
Purpose: Management of articular sided partial-thickness rotator cuff tears is controversial. Mos... more Purpose: Management of articular sided partial-thickness rotator cuff tears is controversial. Most management decisions rest on determining the thickness of tendon loss and location of tendon involvement, without any clear guidelines offered on how to make this determination. This study attempts to confirm the normal cuff thickness at its humeral head attachment and correlate the amount of exposed bone at the "footprint" attachment of the supraspinatus as an accurate measurement of the amount of tendon loss. Type of Study: Anatomic study. Methods: Forty-eight cadaver shoulders with an average age of 71.5 years were examined. Specimens with full-or partial-thickness rotator cuff tears were not measured, leaving 17 specimens with an average age of 70 for analysis. The anterior to posterior width of the supraspinatus was measured with a caliper, as well as the medial to lateral width at the rotator interval, at midtendon, and at the posterior limit determined by the spine of the scapula raphe. The distance from the articular cartilage margin to the supraspinatus tendon insertion was also measured. Results: The mean anteroposterior dimension of the supraspinatus insertion was 25 mm. The mean superior to inferior tendon thickness at the rotator interval was 11.6 mm, 12.1 mm at midtendon, and 12 mm at the posterior edge. The distance from the articular cartilage margin to the bony tendon insertion was 1.5 to 1.9 mm, with a mean of 1.7 mm. Conclusions: Articular partial-thickness tears with Ͼ 7 mm of exposed bone lateral to the articular margin should be considered significant tears approximating 50% of the tendon substance. Arthroscopic measurement of the exposed bone between the articular margin and the supraspinatus tendon insertion (footprint) is an accurate way to estimate tear depth and provide a rational, reproducible guideline for treatment.