頭蓋顔面外科領域におけるTM HAKEN Plateの応用

The Use of TM HAKEN Plate in Craniofacial Surgery

I．はじめに

　頭蓋顔面外科領域におけるミニ・マイクロプレートの利用は，強固な固定と確実な骨形態の再構築を主目的とし，優れた固定材料として，現在広く臨床に用いられている．しかしこれら使用にあたっては，単に大きさや固定力ばかりでなく，操作性，生体親和性，偽害作用などを考慮したプレートの選択が必須となる．

　われわれはこれら観点から，チタンおよびチタン合金からなるミニ・マイクロプレートを開発し臨床に用いてきた．そしてさらに，固定手技の簡略化，手術時間の短縮をはかる目的で，プレート端に鋭鉤のついたTM HAKEN plateを考案し臨床に応用，満足すべき成績を得ている．本プレートの概要に，頭蓋顔面外科領域への応用例を供覧し報告する．

Rigid internal fixation using mini/micro plate has be-come a frequent application in cranio-maxillo-facial surgery. In order to make plate fixation easier and re-duce operative time, the TM HAKEN plate, a kind of micro plate, was devised which has a thorny HAKEN like an ice pick and applied to cranio-facial surgery. The plate is made of titanium, and the HAKEN and screw are made of titanium alloy. These allow con-toured engagement in all three dimensions due to the flexibility of titanium, and firm fixation due to the physical strength of titanium alloy, resulting in mini-mized artifact on CT scan and MRI images. The fixa-tion is accomplished by just driving in the plate with a hammer, and using screws. In the case of wide opera-tive field, the plate is driven in directly, while in the case of small field, the plate is driven in with an im-pactor.

TM HAKEN plate has been used for osteosynthesis in 39 cases of craniofacial surgery at the Department of Plastic and Reconstructive Surgery of Toho University Hospital between September 1992 and September 1994. Of the 39 cases, 19 were cranioplasty using frozen pre-served auto-carvarial bone, 9 were midface fractures, 6 were fixation of free bone grafting, and 5 were fixation of artificial bone (hydroxyapatite-tricalcium phosphate composite ceramics) grafting. Satisfactory results were obtained in all cases without any difficult complications such as infection, exposure or migration. In addition, reliable post-operative evaluations and follow-ups were possible with reduced artifact on CT scan and MRI images.

Advantages and indications of this plate are virtually the same as those of micro plates of other types. Three dimensional bending capability provides positive fixa-tion to the thinner bone, and minimal interference with the overlying soft tissue. It also permits positive fixa-tion of the artificial bone firmly without causing dam-age. Clear post-operative evaluations and follow-ups were possible due to the reduced artifact on CT scan and MRI images. It is expected that the TM HAKEN plate will serve as an excellent material for cranio-facial surgery.