Upper Lumbar Pedicle Screw Insertion Using Three-Dimensional Fluoroscopy Navigation:Assessment of Clinical Accuracy

We used a navigation system to insert 128 pedicle screws into 69 vertebrae (L1 to L3) of 49 consecutive patients. We assessed the pedicle isthmic width and the permission angle for pedicle screw insertion. The permission angle is the angle defined by the greatest medial and lateral trajectories allowable when placing the screw through the center of the pedicle. The rate of narrow-width pedicles (isthmic width less than 5mm) was 5 of 60 pedicles (8%) at L1, 4 of 60 pedicles (7%) at L2, and none (0%) at L3, L4 and L5. The rate of narrow-angle pedicles (a permission angle less than 15 degrees) was 21 of 60 pedicles (35%) at L1, 7 of 60 (12%) at L2, 3 of 60 (5%) at L3, and none (0%) at L4 and L5. Of 128 pedicle screws inserted into 69 vertebrae from L1 to L3, 125 (97.7%) were classified as Grade 1 (no pedicle perforation). In general, the upper lumbar vertebrae have more narrow-width and -angle pedicles. However, we could reduce the rate of pedicle screw misplacement in upper lumbar vertebra using a three-dimensional fluoroscopy and navigation system

Clinical Accuracy of Three-Dimensional Fluoroscopy (IsoC-3D)-Assisted Upper Thoracic Pedicle Screw Insertion

Correct screw placement is especially difficult in the upper thoracic vertebrae. At the cervicothoracic junction (C7-T2), problems can arise because of the narrowness of the pedicle and the difficulty of using a lateral image intensifier there. Other upper thoracic vertebrae (T3-6) pose a problem for screw insertion also because of the narrower pedicle. We inserted 154 pedicle screws into 78 vertebrae (C7 to T6) in 38 patients. Screws were placed using intraoperative data acquisition by an isocentric C-arm fluoroscope (Siremobile Iso-C3D) and computer navigation. Out of 90 pedicle screws inserted into 45 vertebrae between C7 and T2, 87 of the 90 (96.7%) screws were classified as grade 1 (no perforation). Of 64 pedicle screws inserted into 33 vertebrae between T3 and T6, 61 of 64 (95.3%) screws were classified as grade 1. In this study, we reduced pedicle screw misplacement at the level of the C7 and upper thoracic (T1-6) vertebrae using the three-dimensional fluoroscopy navigation system

Recovery of Motor Function in Patients with Subaxial Cervical Spine Injury Relevant to the Fracture Pattern

In this study, we studied the relationship between fracture patterns and motor function recovery in 70 consecutive patients with cervical spinal cord injury. Fractures were categorized into 6 fracture types and subdivided into stages according to the Allen-Ferguson classification system:compressive flexion (CF), distractive flexion (DF), compressive extension (CE), distractive extension (DE), vertical compression (VC) and lateral flexion (LF). Paralysis was evaluated using the American Spinal Injury Association (ASIA) impairment scale at the time of injury and 3 months afterwards. The residual rate of complete motor palsy (ASIA grade A or B) at the final examination was higher in those patients with DE fractures than those with CF, DF or CE. The final outcomes were as follows. Of the 14 patients who were classified with CF fractures, residual palsy was frequently seen in patients who had stage 5 injury. Of the 27 patients with DF fractures, residual palsy occurred in about half of the patients who had stage 4 or 5 injury. Of the 18 patients with CE fractures, residual palsy occurred in half of the patients with stage 3 injury or higher. Finally, of the 7 patients with DE fractures, the rate of residual palsy was high even for the stage 1 and 2 cases;indeed, all DE patients who had complete motor palsy at the first examination had residual palsy at the final examination. Accordingly, we conclude that motor recovery may be related to fracture pattern

向精神薬服用患者の突然死症例におけるカリウムイオンチャネルに関する分子生物学的解析：QT延長症候群関連遺伝子の多型が危険因子となり得るか？

Psychotropic drugs can pose the risk of acquired long QT syndrome (LQTS). Unexpected autopsy-negative sudden death in patients taking psychotropic drugs may be associated with prolonged QT intervals and life-threatening arrhythmias. We analyzed genes that encode for cardiac ion channels and potentially associated with LQTS, examining specifically the potassium channel genes KCNQ1 and KCNH2 in 10 cases of sudden death involving patients administered psychotropic medication in which autopsy findings identified no clear cause of death. We amplified and sequenced all exons of KCNQ1 and KCNH2, identifying G643S, missense polymorphism in KCNQ1, in 6 of the 10 cases. A study analysis indicated that only 11% of 381 healthy Japanese individuals carry this polymorphism. Reports of previous functional analyses indicate that the G643S polymorphism in the KCNQ1 potassium channel protein causes mild IKs channel dysfunction. Our present study suggests that administering psychotropic drug therapy to individuals carrying the G643S polymorphism may heighten the risk of prolonged QT intervals and life-threatening arrhythmias. Thus, screening for the G643S polymorphism before prescribing psychotropic drugs may help reduce the risk of unexpected sudden death2013博士（歯学）松本歯科大