探讨锁定加压钢板（locking compression plate，LCP）与顺行磁力导航带锁髓内钉固定技术治疗肱骨干骨折的临床疗效。

选取2013年8月至2017年10月，北京大学人民医院接受内固定手术治疗的肱骨干骨折患者56例，其中男35例，女21例；年龄18~70岁，平均42岁。交通事故致伤11例，摔伤36例，高处坠落伤9例。骨折采用AO分型：A型19例，B型24例，C型13例。根据治疗方法将56例患者分为两组，应用顺行磁力导航带锁髓内钉治疗肱骨干骨折患者25例，为髓内钉组；应用LCP治疗肱骨干骨折患者31例，为LCP组。髓内钉组：取沙滩椅位，于肩峰外侧作纵行直切口4~5 cm，于肱骨大结节内侧1 cm、肱二头肌沟后方0.5 cm处用骨锥开口，插入导针，并与髓腔轴向一致，X线透视下复位，穿入髓内钉，磁力导航引导下锁入螺钉；LCP组：近、中段骨折取前外侧切口，远段取上臂后正中切口，找到并保护桡神经，清理骨折断端，复位骨折，克氏针临时固定。将LCP预弯后放置，视情况打入皮质骨螺钉及锁定螺钉固定骨折。对两组患者进行门诊随访，回顾性对比分析两组疗效。

术后56例患者均得到随访，随访时间10~26个月，平均（18.7±3.6）个月。手术时间45~110 min，平均手术时间（74±14）min。2例发生浅表伤口感染，经清创换药后恢复良好。1例发生术中医源性桡神经损伤，经神经电刺激及联合神经营养药物治疗，术后6周完全恢复腕关节及拇指背伸功能。骨折8~24周达到临床愈合，平均（13±4）周，无延迟愈合或不愈合，愈合率达100％。肩关节外展95°~170°,平均151°±11°；前屈100°~175°,平均153°±12°。肘关节伸直0°~10°,平均5°±2°；屈曲122°~145°,平均131°±5°。在本组患者的随访中，肩关节功能依据美国加州大学洛杉矶分校评分标准:优53例，良3例。肘关节功能依据Mayo评分标准:优55例，良1例。对比髓内钉组与LCP组，两组性别比例、年龄、手术时间、住院时间、骨折类型分布未见显著差异。对比两组预后，髓内钉组无一例感染、神经损伤发生，而LCP组发生了2例浅表伤口感染及1例桡神经损伤，但组间比较差异无统计学意义。除髓内钉组术后肩峰撞击比率显著高于LCP组，肩关节前屈外展活动范围显著低于LCP组外，其余预后指标差异均无统计学意义。

LCP固定有着较高的伤口感染及桡神经损伤发生率，但与髓内钉系统相比差异无统计学意义。髓内钉固定的患者术后肩峰撞击的发生率较高，显著高于LCP组，同时肩关节活动度也显著下降。

The humeral shaft fracture is a common type of fractures in adults, accounting for about 2%-3% of all fractures in the body. The humeral shaft fractures with severe displacement and combined injury need surgical treatments. In recent decades, with the development of internal fixation technology and fixation material design, more choices have been made for surgical methods, and controversy has also appeared. At present, the two most commonly used surgical methods are closed reduction intramedullary nail fixation and open reduction plate internal fixation. Both methods have their own advantages and disadvantages. The advantage of antegrade intramedullary internal fixation is minimal invasive, thus the blood supply around the periosteum and the fracture is well protected, and the fracture end is less stimulated; the disadvantage is that the rotator cuff would be cut when the nail is inserted, and patients with limited shoulder activity and the shoulder pain were reported. The advantages of the plate fixation are that the anatomical reduction can be obtained under direct vision, and the fracture can be firmly and stably fixed; the disadvantages are that the trauma is large with more blood supply damage , and there is a risk of radial nerve injury. At present, the advantages and disadvantages of the two surgical methods are always debated. The previous RCT studies have relatively low level of evidence, and several meta-analytical studies have different conclusions, thus there is no clear conclusion now.

1. General information.Inclusion criteria: Patients with humeral shaft fractures who underwent internal fixation surgery in the Department of Trauma and Orthopaedics of Peking University People's Hospital from August 2013 to October 2017. Exclusion criteria: Open fracture, pathological fracture, old fracture, radial nerve injury, severe multiple injury, abnormal function of shoulder and elbow joint of the affected limb before the injury.A total of 56 patients met the standard, including 35 males and 21 females, aged 18-70 years, with an average age of 42 years. There were 11 cases of traffic accidents, 36 cases of falls, and 9 cases of falls from height. The fractures were classified by the AO clasification: 19 cases were type A, 24 cases were type B, and 13 cases were type C. Locking compression plate fixations were performed in 31 cases (AO company or Biomed company) , and antegrade magnetic navigated interlocking intramedullary nails were in 25 cases (Smith and Nephew Company) . 2. Surgical methods:All patients underwent general anesthesia with tracheal intubation combined with brachial plexus block analgesia. (1) antegrade magnetic navigated interlocking intramedullary nail: The patient took the beach chair position, a vertical straight incision was made on the lateral side of the shoulder for about 4 to 5 cm, the guide needle was inserted at 1 cm medial to the greater tuberosity of the humerus and 0.5 cm behind the biceps groove, parallel to the axial direction of the medullary cavity. Reduction was achieved under X-ray, then the intramedullary nail was inserted, the locking screws were guided magnetically. (2) Locking compression plate: The anterior lateral incision was made in the proximal and middle fractures, and the posterior incision was taken in the distal fracture to find and protect the radial nerve; the fracture was cleared and aligned, and then the Kirschner wires were temporarily fixed. The prebent AO or Biomet locking compression plate (LCP) was placed, and then the cortical bone screws and the locking screws were inserted to fix the fracture depend on the situation.3. Postoperative treatment:The postoperative forearm sling suspension protection lasted 3 weeks. From the second day after surgery, the patients could perform passive shoulder and elbow joint function exercises within the allowable range of pain. Active shoulder and elbow joint exercises were performed 3 weeks after surgery. The affected limb should avoid carrying heavy objects within 2 months. The X-ray was reviewed monthly for 4 months after surgery to understand the fracture healing. X-ray examination was performed once every 3 months after the fourth month, and once every 6 months after 1 year. The operation time, postoperative complications, fracture healing time, and range of motion of the shoulder and elbow joints were recorded. The shoulder and elbow function scores were evaluated 1 year after surgery. The shoulder joints were scored by the University of California, Los Angeles (UCLA) based on pain (10 points) , activity (10 points) , the range of forward flexion (5 points) , forward flexion strength (5 points) and patient satisfaction (5 points) . The score was divided into excellent (34-35 points) , good (29-33 points) , and poor (<29 points) . The elbow joint function used the Mayo score, which was based on pain (45 points) , range of joint activity (20 points) , degree of stability (10 points) , and daily function (25 points) . It was divided into excellent (90 points or more) , Good (89-75 points) , fair (60-74 points) , poor (<60 points) .

All the 56 patients were followed up for 10 to 26 months, with an average of (18.7±3.6) months. The operation time was about 45-110 minutes and the average operation time was (74±14) minutes. Two cases of superficial wound infection occurred, and finally recovered well after debridement and dressing change. One case of intraoperative iatrogenic radial nerve injury was treated with nerve electrical stimulation combined with neurotrophic drugs. The wrist and thumb extension functions were completely restored 6 weeks after operation. The fractures reached clinical union at 8-24 weeks, with an average of (13±4) weeks. There was no delayed union or nonunion. The union rate reached 100%. The shoulder abduction was 95°-170°, with an average of (151±11) °; and forward flexion was 100°-175°, with an average of (153±12) °. The elbow joint extension was 0°-10°, with an average of (5±2) °; the flexion was 122°-145°, with an average of (131±5) °. In the follow-up of all patients, the shoulder function was evaluated using the UCLA score: 53 cases were excellent and 3 cases were good. According to the Mayo score, the elbow joint functions were excellent in 55 cases and was good in 1 case.Comparing the intramedullary nail group with the LCP group, there was no significant difference in gender ratio, age, operation time, length of hospital stays, and fracture types between the two groups, so the two groups were comparable. There was no infection or nerve injury in the intramedullary nail group. There were 2 cases of superficial wound infection and 1 case of nerve injury in the LCP group, but there was no significant difference between the groups. The acromion impingement ratio of intramedullary nail group was significantly higher than that of LCP group. The range of shoulder flexion and abduction activity was significantly lower than that of LCP group. There was no significant difference in the other prognosis indicators.

Locking compression plate fixation group had a higher incidence of wound infection and a higher incidence of radial nerve injury, but there was no significant difference compared with the intramedullary nail fixation group. The incidence of postoperative acromion impact ratio was higher in patients with intramedullary nail, and the mobility of the shoulder joint was also significantly decreased. Therefore, this study found that the use of intramedullary nails and LCP had their own advantages and disadvantages, the overall safety and effectiveness of both were high. All patients could obtain excellent shoulder and elbow joint function. Therefore, the surgeon should take the strength and avoid weakness when selecting the fixation method, for example the surgeon should minimize the damage to the rotator cuff when using the intramedullary nail and improve the surgical technique to properly handle the intramedullary needle cap to avoid acromion impact. Large-scale prospective randomized controlled trials are still needed to validate the result.