コスモフィックス Ⓡで下顎骨切除後の硬性再建を行った5例

Five Cases of Mandibular Reconstruction with a Cosmofix Ⓡ Internal Fixation Plate

はじめに

　悪性腫瘍手術に伴う下顎骨切除後の硬性再建は，遊離腓骨皮弁をはじめとする血管柄付き骨移植（vascularized bone graft：以下，VBG）が第一選択である。しかし，患者の全身状態などの理由でVBGによる即時再建が困難な場合は，下顎再建プレート（mandibular reconstruction plate：以下，MRP）で硬性再建が行われることがある。従来用いられてきたMRP（以下，従来型MRP）は術中のベンディングの煩雑さや破折などの術後合併症が問題とされる。そこで，術中の加工を必要とせず，術後の合併症発生率を低減し得るカスタムメイド患者適合型体内固定用プレートが開発・使用されるようになった 1）。

　今回，当院で硬性再建した5症例にカスタムメイド患者適合型体内固定用プレートであるコスモフィックス Ⓡ（大阪冶金興業社：以下，本プレート）を使用したので，その有用性を検討して報告する。

　After a mandibulectomy has been performed, vascularized bone grafting (VBG) is the primary choice for rigid reconstruction, although mandibular reconstruction plates (MRPs) are sometimes used for various reasons. Fully custom-made mandibular reconstruction plates have emerged to address drawbacks of conventional MRPs. Cosmofix Ⓡ is a patient-adapted internal fixation plate made in Japan that has been in use since 2022. We report five patientsʼ cases in which a Cosmofix Ⓡ was used for rigid reconstruction of the mandible after a resection of malignant tumor. Compared to conventional MRPs, the use of the Cosmofix Ⓡ plate does not require intraoperative modifications, and the placement of the plate can be easily determined. This simplified the operation by omitting parts that required the surgeonʼs experience. Postoperative facial morphology and occlusion were also favorable in all five patients. However, postoperative infection and exposure of the plate occurred in two cases. A Cosmofix Ⓡ plate may be a useful option when VBG cannot be used. However, when a Cosmofix Ⓡ plate is used in conjunction with VBG, careful consideration should be given to the modification of the grafted bone and the design of the plate. It is also important to note the uncertainties regarding postoperative oral function and long-term prognosis.