Abstract：
Ulna distraction by monolateral external fixator (MEFix) is a good option for the treatment of Masada type I and IIb deformities in children with hereditary multiple exostoses (HMEs). However, there is no consensus regarding where to perform ulnar osteotomy. Our hypothesis is that osteotomy at the proximal third of the ulna and progressive distraction with MEFix can simultaneously correct elbow and wrist deformities in patients with HME.
We retrospectively reviewed patients with HME who underwent ulna distraction osteogenesis from June 2014 to March 2019. The carrying angle (CA), radial articular angle (RAA), ulnar variance (UV), radial variance (RV) and range of motion (ROM) of the affected forearm and elbow were clinically assessed before lengthening and at the last follow-up visit. The total ulna lengthening distance (LD) and radiographic outcome were also recorded.
Nineteen patients (20 forearms) with HME aged 9.1 ± 2.4 years at the time of surgery were retrospectively reviewed. The mean follow-up period was 26.1 ± 5.6 months. There were 11 patients (12 forearms) with Masada type I deformities and eight patients (8 forearms) with Masada type IIb deformities. Patients with type IIb deformity had higher RV, lower CA values, less elbow flexion and forearm pronosupination than those with type I deformity (p < 0.05); RV was an independent risk factor for radial head dislocation, with the cut off at RV > 15.5 mm. The mean LDs in patients with type I and type IIb deformities were 33.6 ± 6.6 mm and 41.4 ± 5.4 mm, respectively. The mean CA, UV, RV, forearm pronation and ulna deviation at the wrist improved significantly following surgery in all patients. In particular, five of eight patients (62.5%) with type IIb deformities had concentric reduction of the radiocapitellar joint, while no radial head subluxation was detected in patients with type I deformities at the last follow-up. Three complications were recorded: two pin-track infections and one delayed union.
Distraction osteogenesis at the proximal third of the ulna provides satisfactory clinical and radiological outcomes in patients with Masada type I and IIb deformities. Early treatment of Masada type I deformities is indicated before progression to more complex type IIb deformities.
We retrospectively reviewed patients with HME who underwent ulna distraction osteogenesis from June 2014 to March 2019. The carrying angle (CA), radial articular angle (RAA), ulnar variance (UV), radial variance (RV) and range of motion (ROM) of the affected forearm and elbow were clinically assessed before lengthening and at the last follow-up visit. The total ulna lengthening distance (LD) and radiographic outcome were also recorded.
Nineteen patients (20 forearms) with HME aged 9.1 ± 2.4 years at the time of surgery were retrospectively reviewed. The mean follow-up period was 26.1 ± 5.6 months. There were 11 patients (12 forearms) with Masada type I deformities and eight patients (8 forearms) with Masada type IIb deformities. Patients with type IIb deformity had higher RV, lower CA values, less elbow flexion and forearm pronosupination than those with type I deformity (p < 0.05); RV was an independent risk factor for radial head dislocation, with the cut off at RV > 15.5 mm. The mean LDs in patients with type I and type IIb deformities were 33.6 ± 6.6 mm and 41.4 ± 5.4 mm, respectively. The mean CA, UV, RV, forearm pronation and ulna deviation at the wrist improved significantly following surgery in all patients. In particular, five of eight patients (62.5%) with type IIb deformities had concentric reduction of the radiocapitellar joint, while no radial head subluxation was detected in patients with type I deformities at the last follow-up. Three complications were recorded: two pin-track infections and one delayed union.
Distraction osteogenesis at the proximal third of the ulna provides satisfactory clinical and radiological outcomes in patients with Masada type I and IIb deformities. Early treatment of Masada type I deformities is indicated before progression to more complex type IIb deformities.
摘要：
通过单外侧外固定器（MEFix）牵张尺骨是治疗遗传性多发性外生性骨外生病（HME）儿童MasadaI和IIb型畸形的良好选择。然而,关于在哪里进行尺骨截骨术尚无共识。我们的假设是，尺骨近端三分之一的截骨术和MEFix的渐进性牵引可以同时纠正HME患者的肘部和腕部畸形。
我们回顾性分析了2014年6月至2019年3月接受尺骨牵张成骨的HME患者。承载角（CA），桡骨关节角(RAA),尺骨方差(UV)，在延长之前和最后一次随访时，对受影响的前臂和肘部的径向方差（RV）和活动范围（ROM）进行了临床评估。还记录了总尺骨延长距离（LD）和影像学结果。
回顾性分析了19例（20个前臂）手术时年龄为9.1±2.4岁的HME患者。平均随访时间为26.1±5.6个月。MasadaI型畸形患者11例（前臂12例），MasadaIIb型畸形患者8例（前臂8例）。IIb型畸形患者的RV较高，较低的CA值，肘关节屈曲和前臂前位少于Ⅰ型畸形(p<0.05);RV是桡骨头脱位的独立危险因素,与切断在RV>15.5毫米。I型和IIb型畸形患者的平均LDs分别为33.6±6.6mm和41.4±5.4mm，分别。平均CA，UV,RV,所有患者手术后，前臂内旋和腕部尺骨偏斜均得到显着改善。特别是,8例IIb型畸形患者中有5例(62.5%)表现为放射状关节同心复位,而在最后一次随访中，I型畸形患者未发现桡骨头半脱位。记录了三种并发症：两种针迹感染和一种延迟愈合。
对于MasadaI型和IIb型畸形患者，尺骨近端三分之一处的牵张成骨可提供令人满意的临床和放射学结果。在发展为更复杂的IIb型畸形之前，需要对MasadaI型畸形进行早期治疗。
我们回顾性分析了2014年6月至2019年3月接受尺骨牵张成骨的HME患者。承载角（CA），桡骨关节角(RAA),尺骨方差(UV)，在延长之前和最后一次随访时，对受影响的前臂和肘部的径向方差（RV）和活动范围（ROM）进行了临床评估。还记录了总尺骨延长距离（LD）和影像学结果。
回顾性分析了19例（20个前臂）手术时年龄为9.1±2.4岁的HME患者。平均随访时间为26.1±5.6个月。MasadaI型畸形患者11例（前臂12例），MasadaIIb型畸形患者8例（前臂8例）。IIb型畸形患者的RV较高，较低的CA值，肘关节屈曲和前臂前位少于Ⅰ型畸形(p<0.05);RV是桡骨头脱位的独立危险因素,与切断在RV>15.5毫米。I型和IIb型畸形患者的平均LDs分别为33.6±6.6mm和41.4±5.4mm，分别。平均CA，UV,RV,所有患者手术后，前臂内旋和腕部尺骨偏斜均得到显着改善。特别是,8例IIb型畸形患者中有5例(62.5%)表现为放射状关节同心复位,而在最后一次随访中，I型畸形患者未发现桡骨头半脱位。记录了三种并发症：两种针迹感染和一种延迟愈合。
对于MasadaI型和IIb型畸形患者，尺骨近端三分之一处的牵张成骨可提供令人满意的临床和放射学结果。在发展为更复杂的IIb型畸形之前，需要对MasadaI型畸形进行早期治疗。
