変形性胸椎症による胸髄症に対し，直接的前方除圧を行わず後方固定術のみで対処した1例

Treatment of Thoracic Myelopathy Secondary to Spondyloarthrosis by Posterior Fusion without Direct Decompression. Case report

　症例は，変形性胸椎症に伴うTh7/8レベル椎体後方骨棘による胸髄症症例である．骨棘は軽微なものであり，胸髄変性の重症度との間に解離があり，病態の確定診断に難渋した．治療においては，これまで筆者らは胸椎後縦靱帯骨化症に対して後方矯正除圧固定術のみを行い良好な結果を得てきたことを踏まえ，本症例をbeak-typeの胸椎後縦靭帯骨化症に準ずる病態であるとの判断に基づき同様の術式で対処し，良好な結果を得たので報告する．

　Thoracic myelopathy caused by anterior compression of the spinal cord, such as by ossification of the posterior longitudinal ligament (OPLL), has been difficult to treat surgically because of the presence of kyphosis in the thoracic region, and the choice of method of surgical treatment is still a matter of controversy.　We report a case of thoracic myelopathy caused by vertebral body osteophytes at the Th7/8 level that was treated by posterior fusion alone, without laminectomy.　A 64-year-old male complained of weakness in his legs, a difficulty walking, and urinary incontinence.　MRI revealed the presence of small osteophytes secondary to thoracic spondylosis at the Th7/8 level, and we treated the patient by performing Th5-11 posterior fusion by pedicle screw fixation without laminectomy.　This procedure achieved immobilization, and the slight reduction in kyphosis in the thoracic region was successful in achieving indirect decompression of the spinal cord and improving the patient's neurological status.　The results suggest the effectiveness of immobilization and indirect decompression by reduction of kyphosis without direct decompression for the treatment of anterior compression of the spinal cord in the thoracic region.