ABSTRACT
<p><b>OBJECTIVE</b>To investigate the meaning of pedicle exposure technique for screw fixation on atlas with the vertebral groove height less than 4 mm by using reconstructive computed tomography.</p><p><b>METHODS</b>From April 2015 to June 2015, 84 pedicles of 51 patients with groove heights less than 4 mm were studied by digital reconstruction respectively. Parameters of atlas pedicle screw fixation were measured.</p><p><b>RESULTS</b>Among the 51 cases, the vertebral groove height was (3.28±0.51) mm. Lateral mass heights, lateral mass widths and the transition area heights between lateral mass and posterior arch were fit for 3.5 mm screw implanting. Ideal pedicle screw trajectory lengths from 0° to 15° (0°, 5°, 10°, 15°) were (27.36±1.81), (27.01±1.68), (27.07±1.75), (27.48±1.72) mm, exposed trajectory lengths from 0° to 15°(0°, 5°, 10°, 15°) were(23.44±1.79), (23.87±1.84), (24.58±1.89), (25.56±2.01) mm, trajectory length of lateral mass was (20.78±2.05) mm. The mean CT values on 5 sections through pedicle trajectory and lateral mass trajectory were (701.89±141.48) HU and (599.11±137.33) HU, respectively. There were no significant differences between ideal pedicle trajectory lengths from 0° to 15°(>0.05). Exposed trajectory lengths was significantly increased accompanying with medial angles increasing (<0.05), and was longer than trajectory lengths of lateral mass (<0.05). CT value of pedicle screws was higher than CT value of lateral mass screws significantly (<0.01).</p><p><b>CONCLUSIONS</b>Screws can be implanted in atlas with vertebral groove height less than 4 mm by using pedicle exposure technique. Few trajectory lengths will be sacrificed with favorable pull out strength due to adequate bone mass purchased.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinical effects and operative options for the treatment of Forestier disease.</p><p><b>METHODS</b>From June 2005 to May 2012, 8 patients with progressive dysphagia due to Forestier disease were treated through anterior approach, their clinical data were retrospective analyzed. There were 6 males and 2 females, aged from 65 to 83 years old with an average of 73 years. Among the patients, osteophytes removal was performed in 3 cases, osteophytes removal with discectomy and fusion was performed in 2 cases, osteophytes removal with corpectomy and fusion was performed in 3 cases. According to Bazaz dysphagia score to assess the improvement of the patients' symptoms before and after operation.</p><p><b>RESULTS</b>All patients were followed up from 12 to 40 months with the mean of 18.5 months. Seven cases were asymptomatic and 1 case had mild symptom in the last follow-up. Radiographs showed the space enlargement between vertebral body and trachea.</p><p><b>CONCLUSION</b>It is effective to treat patients with progressive dysphagia due to Forestier disease through surgical method. And the operative options depend on the stability of cervical spine and the neurological symptoms of the patients.</p>