腰部椎間板ヘルニアの,術前・術後のミエログラムに関する臨床的並に基礎的研究

So far the author performed lumbar disc removal in a series of 38 patients, among whom quite satisfactory immediate postoperative results were obtained with 20 cases. These results can well be considered as belonging to the classification“complete”according to Simon's criteria of the results of disc surgery. Findings of the preoperative myelogramm of these 20 patients were obviously morbid and classified as the following 4 types.<BR>1) Complete block type 3 cases<BR>2) Hour-glass defect type 6<BR>3) Lateral defect type 10<BR>4) Nerve root defect type 1 case This classification is done according to the criteria once advocated in literature by Key, Ford, DePalma, Kondo, Mori and others.<BR>The second myelogramm on these patient was later performed at an average time interval of 15.9 days following surgery and the investigation was made as to whether or not the second myelogramm could show evidence of postoperative relief of clinical symptoms.<BR>In other words, the author made a comparative study between the pre and postoperative myelogramms on 20 lumbar disc patients with whom quite satisfactory postoperative relief was obtained.<BR>And in this clinical series, the results were obtained as follows.<BR>Among postoperative myelogramms on 20 patients,“improvement”was seen only in 2 patients (obviously improved in 1, slightly improved in 1) while with the rest of 18 patients“unchanged”was seen in 12,“worsened”in 6 (obviously worsened in 3. slightly worsened in 3).<BR>From these results it becomes evident that such morbid findings in myelogramm characteristic to the lumbar disc herniation can not be salvaged even in the cases of best operative results.<BR>The author, therefore, wishing to clarify the cause of such contradictory findings between these excellent operative results on one hand and very poor myelographic findings after surgery on the other hand, did a model experiment using 5 healthy rabbits in the following manner:<BR>At first a series of myelography was done with 5 rabbits. Then osteoclastic laminectomy was performed on the level of 4th and 5th lumbar interspaces and the disc was injured by inserting a small drill.<BR>A series of second myelography was later performed at an average postoperative interval of 13 days with the same animals.<BR>The results show that preoperative myelogramm is normal in every instance whereas following surgery various types of findings from constriction to adhesion are found in every myelogramm on the level of 4 th to 5 th lumbar interspace. From these findings the author concludes that pathological findings suggestive of protruded herniation or periclural adhesion formation can always be found in the second myelography on the level of the lowest two lumbar interspaces in the patient who had once received lumbar disc removal and at the same time enjoyed very excellent postoperative results.