中文摘要：

目的遗传性多发性骨软骨瘤是一种与EXT基因突变有关的常染色体显性遗传性疾病，约45％～54％的患儿存在踝关节外翻畸形，本文主要分析和探讨多发性骨软骨瘤患儿产生踝关节外翻的相关因素并介绍其治疗方法。方法本研究回顾了2008年至2013年我院诊治的62例患儿，其中胫腓骨远端肿瘤累及的患儿有37例，利用PCR及MLPA技术发现有35例（男27例，女8例）有EXT突变基因。这35例中除6例为单侧外，其余均累及双侧，共64个踝关节（左右各32个）。根据肿瘤是否累及胫骨骨骺分为两组，第一组骨骺组31例，第二组干骺组33例，再根据肿瘤是否累及腓骨分为2个亚组，A组肿瘤仅累及胫骨，B组肿瘤同时累及胫腓骨。采用胫骨远端外侧角（lateral distal tibial angle, LDTA）及Malhotra分级来评估踝关节外翻的程度并利用SPSS19．0进行统计学分析肿瘤位置、性别、年龄以及EXT基因与踝关节外翻的关系。结果骨骺组患儿LDTA明显小于干骺组（P〈0．001），骨骺组内亚组问差异明显（P〈0．05），骨骺组和干骺组病例Malhotra分型有显著性差异（P〈0．001）。EXT基因突变类型与肿瘤位置分布无明显差异（P=0．11）。回归分析显示性别、EXT基因与LDTA均无相关性（P〉0．05），而在骨骺组，年龄与LDTA轻度相关（R^2=0．185，P=0．019）。结论遗传性多发性骨软骨瘤患儿踝关节外翻畸形主要与肿瘤生长的部位有关，而与性别以及突变的基因类型无明显相关。胫骨远端外侧骨骺受累是导致踝关节外翻的主要因素，并且这一畸形随着年龄增长而改变。

英文摘要：

Objective To analyze the factors related to ankle valgus in HME and explore its treatments. Methods A total of 62 HME patients treated at our hospital from 2008 to 2013 were recruited. And 37 of them with distal tibia and fibular involvement received genotyping by polymerase chain reaction （PCR） or multiple ligation-dependent probe amplification （MPLA）. EXT gene mutation was found in 35 patients （27 boys, 8 girls）. Six were unilateral and 29 bilateral. A total of 64 ankles were examined （32 left ankles, 32 right ankles）. Two groups were assigned. There were 31 ankles in group I with exostose only involving epiphysis and 33 ankles in group 1I with exostoses at metaphyseal. Each group was further divided into two subgroups. Subgroup A with exostoses involved only tibia and subgroup B involved both. Lateral distal tibial angle （LDTA） and Malhotra classification were evaluated. And the relationship between location, gender, age, genotype and LDTA were analyzed by SPSS 19. 0. Results LDTA in group I was significantly smaller than that in group Ⅱ （P〈0. 001） and significant difference existed between subgroups of group Ⅰ. The Malhotra classification of ankles had a significant inter-group difference （P〈0. 001）. EXT genotype and location of exostoses had no significant correlation （P = 0. 11）. Regression analysis showed only a weak negative correlation between age and LDTA in group Ⅰ （R^2 = 0. 185, P = 0. 019）. Gender and EXT genotype were not correlated with LDTA in neither group （P 〈0. 05）. Conclusions The location of lesion is a major determinant of valgus deformity of ankle in HME patient. Neither genotype nor gender seems to be correlated with this age progressive deformity. The lateral side of distal epiphysis of tibia is often involved.