Christodoulou N, Moussas T h, Karaindros C, Poyatzis C, Vretos C
Service d'Orthopédie, Hôpital, Général de Karpenissi, Grèce.
Rev Chir Orthop Reparatrice Appar Mot. 1996;82(4):331-5.
The authors present technique and results of a new external fixator, the < < goniometric > > external fixator CH-N for osteosynthesis of high tibial osteotomy for arthritic varus knee deformity on 86 kness (75 patients).
86 knees in varus deformity with degenerative arthritis of the medial compartment (56 females and 16 males - age 63 +/-8 years) were treated for 5 years (1989-1993) by high tibial osteotomy stabilized by a < < goniometric > > external fixator CH-N.
Clinical results were 65,9 per cent excellent, 17, 1 per cent good, 11,8 per cent fair and 5,2 per cent poor 1 year after osteotomy (86 cases analyzed), changing in 60 per cent excellent, 22,3 per cent good, 9, 1 per cent fair and 8,5 per cent at 3 years follow-up (61 cases). Radiological results were: - The preoperative mechanical axis of 13 degrees +/- 5 degrees in varus transformed to 4 degrees +/- 2 degrees in valgus at consolidation and to 2,5 degrees +/- 3 degrees in valgus at one year follow-up. At 3 years follow-up we founded a new loss of correction of 1 degree (mean) in 22 per cent of cases (61 cases). - Subchondral density decreased in 91 per cent of cases (86 cases) one year after and in 82 per cent of cases, 3 years after the osteotomy (61 cases). - In 12 per cent of cases we found a decrease of the overcorrectional angle of the varus deformity 1 year after, and in 22 per cent of cases 3 years after. Two cases needed total knee arthroplasty 4 years after ostcotomy. - Postoperatively, in 86 per cent of cases we did not found increase in both clinical and radiological (pathological) findings of the patellofemoral joint one year after, and in 75 per cent of cases 3 years after.
The principle of this special < < goniometri > > external fixator is based on the < < goniometric > > central joint in the frontal plane, this allows to guide the screws during osteotomy in the predesigned position and to control the correction during and after the procedure, in contrary to the others current system either internal or external. Any faulty correction can be modified. With its distal screwing axis, it allows axial dynamization. There are only some but not serious incoveniences due to the application of pins (temporary neuromuscular problems and pin-track infections.
作者介绍了一种新型外固定器——< < 角度测量型 > > CH-N 外固定器用于膝内翻畸形关节炎性膝高胫骨截骨术的技术及结果，共治疗 86 膝（75 例患者）。
1989 年至 1993 年，对 86 例内侧间室退行性关节炎的膝内翻畸形患者（56 例女性，16 例男性，年龄 63±8 岁）进行了 5 年随访，采用< < 角度测量型 > > CH-N 外固定器固定高胫骨截骨术。
截骨术后 1 年（分析 86 例）临床结果为：优 65.9%，良 17.1%，可 11.8%，差 5.2%；3 年随访时（61 例），优 60%，良 22.3%，可 9.1%，差 8.5%。影像学结果为：- 术前内翻平均机械轴为 13°±5°，愈合时变为外翻 4°±2°，1 年随访时变为外翻 2.5°±3°。在 3 年随访时，我们发现 22%的病例（61 例）平均有 1°的新的矫正丢失。- 截骨术后 1 年，91%的病例（86 例）软骨下骨密度降低；3 年时，82%的病例（61 例）软骨下骨密度降低。- 12%的病例在截骨术后 1 年发现内翻畸形过度矫正角度减小，22%的病例在 3 年时发现过度矫正角度减小。2 例患者在截骨术后 4 年需要行全膝关节置换术。- 术后 1 年，86%的病例未发现髌股关节临床及影像学（病理）表现增加；3 年时，75%的病例未发现髌股关节临床及影像学（病理）表现增加。
这种特殊的< < 角度测量型 > > 外固定器的原理基于额状面的< < 角度测量型 > > 中央关节，这使得在截骨过程中能够将螺钉引导至预先设计的位置，并在手术过程中和术后控制矫正，这与目前其他的内固定或外固定系统不同。任何错误的矫正都可以修改。通过其远端螺钉轴，它允许轴向动力化。由于应用钢针存在一些不便，但并不严重（暂时性神经肌肉问题和针道感染）。
