Objective: To evaluate the effectiveness of precise orthormorphia of tibial angulation deformity and shortening deformity by using digital technology combined with external fixator.
Methods: Twenty-six cases of tibial angulation deformity combined with shortening deformity were treated between June 2012 and August 2016, including 12 males and 14 females aged from 1 to 19 years with an average age of 16.5 years. There were 6 cases of congenital patella pseudoarthrosis, 1 case of fibrous dysplasia of femur and tibia, 3 cases of limb shortening deformity caused by infantile paralysis, 16 cases of fracture malunion. Limb shortening was 1.5-9.5 cm (mean, 6.2 cm) before operation. The deformity from three-dimensional perspective was analysed by digital technology, the surgical procedures of lengthening and osteotomy was simulated, the navigation templates were completed with computer aided design (CAD) and three-dimensional printing, and the external fixator was used to assist the lengthening of the tibia. X-ray films were regularly reviewed after operation to observe the new bone remolding, limb lengthening, load bearing line of lower limb, and recurrences of angulation.
Results: All the patients were followed up 14-48 months (mean, 18.8 months). There was only 1 case of superficial pin site infection which was cured with oral antibiotics and pin site care with mild disinfectants, and no complication such as bone nonunion, equines deformity, or vascular nerve injury occurred. The deformity of tibia and load bearing line of lower limb had been completely recovered according to postoperative X-ray films at 1 week. All the cases achieved perfect limb length as with preoperative design. The bone mineralization time was 12-20 weeks (mean, 11.6 weeks), the external fixator removal time was 18-26 weeks (mean, 14.9 weeks), and the healing index was 21-78 d/cm (mean, 63.4 d/cm). The postoperative flexion range of the injured limb was 15° less than the unaffected extremity in 1 case, and the situation was improved significantly after some physical manipulation and exercise, who completed the limb lengthening and achieved the expected effectiveness finally.
Conclusion: Precise orthormorphia of tibial deformity by using digital technology, and limb lengthening with the aid of external fixator can achieve good effectiveness with good reliability, invasiveness, and precision.
目的: 探讨三维数字化骨科技术和 Ilizarov 环形外固定架辅助胫骨成角短缩畸形精准矫形的效果。.
方法: 2012 年 6 月—2016 年 8 月收治胫骨成角伴短缩畸形患者 26 例，其中男 12 例，女 14 例；年龄 1～19 岁，平均 16.5 岁。先天性胫骨假关节患者 6 例，胫骨、股骨纤维结构不良 1 例，小儿麻痹后遗症导致肢体短缩畸形 3 例，骨折畸形愈合 16 例。术前患侧肢体短缩 1.5～9.5 cm，平均 6.2 cm。采取数字化骨科技术分析患肢三维空间存在的畸形，模拟截骨矫形和延长的手术过程，计算机辅助设计（computer aided design，CAD）、3D 打印个性化辅助截骨矫形导航模板，借助外固定架辅助胫骨延长。术后定期复查 X 线片，随访观察新生骨塑形情况、肢体延长长度、下肢力线、成角畸形有无复发。.
结果: 术后患者均获随访，随访时间 14～48 个月，平均 18.8 个月。1 例发生针孔浅表感染，经清洁换药和口服抗生素治疗后愈合。无骨不连、足部马蹄状畸形、血管神经损伤等并发症发生。术后 1 周复查 X 线片示胫骨畸形完全矫正，下肢负重力线恢复正常。所有患者按照术前计划完成骨延长长度，牵移骨痂矿化时间为 12～20 周，平均 11.6 周；外固定架拆除时间为 18～26 周，平均 14.9 周；愈合指数为 21～78 d/cm，平均 63.4 d/cm。延长过程中 1 例患儿膝关节屈曲活动较健侧减少 15°，经理疗锻炼后好转，并完成肢体延长达到预期矫正效果。.
结论: 采用三维数字化技术辅助胫骨畸形实施精准矫形，借助外固定架辅助矫形术后肢体延长，可获得较好疗效，保证了手术的安全性、微创性和精准性。.
Keywords: Ilizarov circular external fixator; bone lengthening; digital technology; precisely orthormorphia; tibial deformity.