BACKGROUND Re-fracture is the most serious complication in congenital pseudarthrosis of the tibia (CPT). There are reports that children with small cross-sectional areas in the sections of the pseudarthrosis are more prone to re-fracture. Presently, preventing complications is a challenge. Increasing the cross-sectional area in healed segments may reduce the incidence of re-fracture. PURPOSE To elucidate the indications, surgical technique, and outcomes of combined surgery and 3-in-1 osteosynthesis in CPT with intact fibula. METHODS We retrospectively assessed 17 patients with Crawford Type IV CPT with intact fibula (Type A) who were treated with combined surgical technique and 3-in-1 osteosynthesis between March 2014 and August 2015. The average age of the patients at the time of surgery was 3 years. Incidence of re-fracture, ankle valgus, proximal tibial valgus, and limb length discrepancy (LLD) were investigated over an average follow-up time of 47 months. RESULTS Primary union was achieved in all patients. The average time for primary union was 4.9 months. Fifteen (88%) cases showed LLD with an average limb length of 1.6 cm; 6 (35%) cases exhibited tibial valgus with an average tibial valgus deformity of 7.8°; 2 cases had ankle valgus, wherein the ankle valgus deformity was 12° in one and 17° in another; and the cross-sectional area of the bone graft was enlarged to 1.74 times that of the tibia shaft. No case had re-fracture during the follow-up period. Movement of the ankle joint was restored in 16 patients with an average dorsiflexion of 22° and an average plantar flexion of 41°; the function of the ankle joint was normal. One patient had plantar flexion of 20° but did not have dorsiflexion. CONCLUSION Combined surgical technique with 3-in-1 osteosynthesis, which is primarily considered for bone union with a large cross-sectional area, results in a high primary union rate. This can provide satisfactory results in short-term follow-up when treating CPT with intact fibula (Type A).

中文翻译：

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胫骨先天性假性骨完整伴腓骨三联症的三合一手术。

背景技术再骨折是先天性胫骨假关节（CPT）中最严重的并发症。有报道说，假关节的横截面面积较小的儿童更容易再次骨折。目前，预防并发症是一个挑战。增大愈合段的横截面积可减少再次骨折的发生率。目的阐明CPT与完整腓骨的联合手术和3合1骨合成的适应症，手术技术和结果。方法我们回顾性评估了2014年3月至2015年8月间接受手术治疗和3合1骨合成术治疗的17例患有完整腓骨的Crawford IV型CPT患者（A型）。手术时患者的平均年龄是3年。再骨折，踝外翻，在平均47个月的随访时间内，研究了胫骨近端外翻和四肢长度差异（LLD）。结果所有患者均达到原发性愈合。初次结婚的平均时间为4.9个月。15例（88％）LLD患者平均肢体长度为1.6 cm；6例（35％）患胫外翻，平均胫外翻畸形为7.8°；踝外翻畸形2例，其中踝外翻畸形为12°，另一侧为17°。骨移植物的截面积扩大到胫骨干的截面积的1.74倍。在随访期间没有病例再骨折。16例患者的踝关节运动恢复，平均背屈22°，平均足底屈41°。踝关节功能正常。一名患者的plant屈为20°，但没有背屈。结论结合外科手术技术和三合一骨合成技术（主要用于具有较大横截面积的骨结合）被认为具有较高的初次结合率。当用完整腓骨（A型）治疗CPT时，这可以在短期随访中提供令人满意的结果。