目的  研究 β- 羟基 -β 甲基丁酸钠（β-hydroxyl-β methylbutyrate， HMB）对下肢骨折手术后营养不良患者应用效果。 方法  选取 2016 年 2 月 ~2017 年 8 月河北工程大学附属医院收治的下肢骨折手术后营养不良患者 84 例为研究对象，将其以 随机数字表法均分为研究组和对照组。对照组术后参照 2013 版中国居民年膳食营养素参考摄入量予以饮食指导，研究组则 在对照组的基础上予以 HMB（1 包 / 次，2 次 /d，每日总量为 20g）干预 3 个月，比较两组患者干预前后血清 TP、Hb 以及 ALB 等营养指标水平，应用 Inbody 720 肌肉诊断仪检测并比较干预前后两组患者四肢肌肉量，术后并发症发生情况以及满 意度。结果  干预前两组患者营养指标水平差异无统计学意义（P ＞ 0.05）。干预后研究组 TP、Hb 以及 ALB 水平分别 为（65.12±4.90）g/L、（ 114.30±8.29）g/L、（ 31.59±3.17）g/L，均明显高于对照组的（50.39±6.24）g/L、（ 106.26±7.15） g/L、（26.15±3.47）g/L，组间对比差异有统计学意义（P均＜0.05）。两组干预前四肢肌肉组织水平差异无统计学意义（P ＞ 0.05），干预后研究组为（24.39±2.76）kg，显著高于干预前的（20.87±2.50）kg，对照组干预后为（24.39±2.76）kg， 与干预前的（20.76±2.51）kg差异无统计学意义（P＞0.05），治疗后研究组显著高于对照组，差异有统计学意义（P＜0.05）。 研究组术后肺部感染、骨折愈合不良、肌无力、肌肉萎缩发生率分别为2.38%（1/42）、2.38%（1/42）、0.00%（0/42）、0.00% （0/42），均明显低于对照组的19.05%（8/42）、16.67%（7/42）、11.90%（5/42）、9.52%（4/42），组间对比差异有 统计学意义（P ＜ 0.05）。研究组满意度为95.24%（40/42），明显高于对照组的80.95%（34/42），组间对比差异有统 计学意义（P ＜ 0.05）。结论  HMB 应用于下肢骨折伴营养不良术后患者中可改善其营养状况，增加四肢肌肉组织水平， 同时有效降低术后并发症发生率，提高患者满意度。

 Objective  To study the effect of HMB on postoperative patients with lower extremity fracture and malnutrition. Methods  From February 2016 to August 2017, 84 patients with lower limb fracture and malnutrition in affiliated hospital of Hebei university of engineering were selected as the subjects. They were divided into a study group and a control group by random number table. The control group was given with 2013 version of Chinese annual dietary nutrient intake to provide dietary intervention. The study group was treated with HMB (1 packet/time, 2 times/d, 20 g/d) on the basis of the control group. The patients in both groups were treated for 3 months. TP, Hb and ALB levels and other nutritional indicators were compared between the two groups before and after intervention. Using Inbody 720 muscle diagnostic instrument detect and compare the muscle volume of two groups before and after intervention. The incidence of postoperative complications and satisfaction were compared. Results  There was no significant difference in nutritional index level between two groups before intervention (P>0.05). After the intervention, the study group of TP, Hb, ALB level was (65.12±4.90)g/L, (114.30±8.29)g/L and (31.59±3.17)g/L respectively, which were significantly higher than the control group of (50.39±6.24)g/L, (106.26±7.15)g/L and (26.15±3.47)g/L, differences between groups were statistically significant (P<0.05). There was no signifcant difference in  limbs muscle tissue level between two groups before intervention (P>0.05), After the intervention, the study group of limbs muscle tissue level was (24.39±2.76) kg, which was signifcantly higher than level before intervention of (20.87±2.50)kg, the limbs muscle tissue level of control group after  intervention was (24.39±2.76), which was not signifcantly higher than level before intervention of (20.76±2.51)kg (P>0.05), the limbs muscle tissue level of study group after  intervention was was signifcantly higher than level of control group (P<0.05). The study group of postoperative pulmonary infection and fracture healing, muscle weakness, muscle atrophy rate were 2.38% (1/42), 2.38% (1/42), 0.00% (0/42), 0.00% (0/42), which were significantly lower than the control group of 19.05% (8/42), 16.67% (7/42), 11.90% (5/42), 9.52% (4/42), differences between groups were statistically significant (P<0.05). The satisfaction of study group was 95.24% (40/42), which was significantly higher than 80.95% (34/42) of the control group, and the difference between groups was statistically significant (P<0.05). Conclusions  HMB used in lower limb fractures associated with poor nutrition in postoperative patients can improve the nutritional status, increase the limb muscle tissue level, at the same time effectively reduce the incidence of postoperative complications, improve patients’ satisfaction.