探究肱骨远端骨折切开复位内固定术中使用尺神经前置处理的临床功效。

本研究自2014年1月至2020年12月，连续纳入就诊于首都医科大学附属北京朝阳医院骨科需接受切开复位内固定手术的肱骨远端骨折（AO/OTA分型为13-C）患者76例，根据术中是否使用前臂筋膜覆盖下尺神经前置处理分为以下两组：前置组17例，对照组59例。收集患者一般资料及手术资料信息，包括性别、年龄、骨折分型、手术时间，本研究还记录了随访信息，包括患肢骨愈合时间和术后并发症。截取统一的随访节点（术后1年），门诊医生会对患者的肘关节活动度（肘屈伸角度和前臂旋转角度）进行测量，为客观、全面的量化患者的肘关节术后表现，本研究选用Mayo肘关节功能评分系统（Mayo elbow performance score，MEPS）。对于患肢的尺神经存在症状或异常者，及时记录，选用经改良的McGowan预后评级以量化展示术后患者的尺神经的临床情况。

共76例肱骨远端骨折患者接受至少1年的随访，其中尺神经前置组17例，平均年龄为54.3（31~71）岁；尺神经不前置组59例，平均年龄为56.7（28~73）岁，两组患者在骨折分型、骨折愈合时间的差异均无统计学意义。尺神经前置组中，肘关节平均屈伸活动度为（130.4±12.7）°和（25.6±3.0）°，平均前臂旋前、旋后活动度为（60.8±5.5）°和（61.8±5.4）°；尺神经非前置组，肘关节平均屈伸活动度为（128.6±9.3）°和（24.1±3.4）°，平均前臂旋前、旋后活动度为（59.7±4.3）°和（61.2±5.2）°。尺神经前置/非前置的两组病例在患侧肘-前臂活动范围差异无统计学意义（P>0.05）。经筋膜覆盖下尺神经前置的患者随访结果提示存在尺神经损伤状况的有9例，后续的复查发现仍旧存在4例残留尺神经恢复不佳的不良事件，这些患者的改良McGowan评级系统提示1级7例、2级2例，采用组内相关系数（intraclass correlation coefficient, ICC）评价该评分系统的信度和效度，发现均为良好（0.78和0.84）。术中未进行尺神经前置的患者随访发现尺神经症状的有10例，后续复查观察到有4例残留尺神经功能不佳，其中改良McGowan分级1级8例、2级2例，统计学结果提示尺神经前置/非前置的上述结果差异无统计学意义（P>0.05）。

在肱骨远端骨折进行切开复位内固定时进行尺神经前置没有提供任何益处，事实上可能会使患者有更大的神经损伤风险。基于此，本研究提示肱骨远端骨折手术处理过程中行原位松解尺神经前置术的临床效果不显著。

Statistics show that elbow fractures account for about 4% of fracture types in adults, and distal humerus fractures account for 30% of all elbow fractures. Due to the complex neurovascular structure of the distal humerus, it is often difficult to treat such fractures, and surgeons face many challenges. Accurate movement of the ulnar nerve and its protection throughout open reduction and internal fixation (ORIF) operation is crucial, as it can significantly reduce the risk of iatrogenic nerve injury. Nevertheless, ulnar neuropathy is a relatively common complication after ORIF surgery for distal humeral fractures, with an incidence of up to 38%. A variety of potential causes can cause ulnar nerve dysfunction. Among them, ulnar nerve preposition is a technical method often considered in the surgical intervention of elbow fractures. Fascia covering adequately protects the ulnar nerve during the preposition process from subsequent damage to the ulnar nerve by surrounding tissues (scar, ectopic ossification, healed bone tissue) and internal fixation devices.On the other hand, the method used by the surgeon to peel the ulnar nerve during the preposition process will extensively separate the soft tissue, and there is a risk of iatrogenic damage to the ulnar nerve. At present, in the field of orthopedic trauma, whether or not ulnar nerve preposition is used by surgeons in open reduction and internal fixation of elbow fractures, especially distal humerus fractures, and how this operation affects the function of ulnar nerve after surgery is still a controversial issue. According to the study of Ruan et al., ulnar nerve preposition is significantly effective in improving ulnar nerve dysfunction during open reduction and internal fixation. However, other studies have suggested that ulnar preposition has no additional benefit and may even increase the risk of ulnar nerve dysfunction.

To investigate the clinical efficacy of ulnar nerve preprocessing in open reduction and internal fixation of distal humerus fracture.

From January 2014 to December 2020, 76 patients with distal humerus fracture (AO/OTA classification 13-C) requiring open reduction and internal fixation in the Department of Orthopedics, Beijing Chaoyang Hospital Affiliated to Capital Medical University were continuously included in this study. They were divided into two groups according to whether the anterior treatment covered the inferior ulnar nerve with forearm fascia during the operation: pretreatment group =17 cases, control group =59 instances. Patients ' general data and surgical information were collected, including gender, age, fracture type, and operation time. Follow-up information was also recorded, including the healing time of the affected limb bone and postoperative complications. A unified follow-up node (1 year after surgery) was intercepted, and the outpatient doctor would measure the patient’s elbow joint motion (elbow flexion and extension Angle and forearm rotation Angle) . In order to objectively and comprehensively quantify the postoperative performance of the patient’s elbow, the Mayo elbow performance score was used in this study. MEPS) . Patients with symptoms or abnormalities of the ulnar nerve in the affected limb were recorded on time. The modified McGowan prognostic rating was used to quantify the clinical status of the ulnar nerve in the patients after surgery.

A total of 76 patients with distal humerus fractures were followed up for at least one year, including 17 patients in the ulnar nerve preposition group, with an average age of 54.3 (31-71) years, and 59 patients in the ulnar nerve non-preposition group, with an average age of 56.7 (28-73) years. The two groups had no statistically significant differences in fracture classification and fracture healing time. In the anterior ulnar nerve group, the mean flexion and extension range of the elbow joint was (130.4±12.7) ° and (25.6±3.0) °, and the mean pronation and supination range of the forearm were (60.8±5.5) ° and (61.8±5.4) °. In the non-anterior ulnar nerve group, the mean flexion and extension range of the elbow joint was (128.6±9.3) ° and (24.1±3.4) °, and the mean pronation and supination range of the forearm were (59.7±4.3) ° and (61.2±5.2) °. There was no significant difference in the elbow-forearm range of motion between the two groups with ulnar nerve anterior/non-anterior (P > 0.05) . Follow-up results of patients with inferior ulnar nerve preposition covered by fascia indicated 9 cases of ulnar nerve injury, and a follow-up review found that there were still 4 cases of adverse events with poor recovery of residual ulnar nerve. The modified McGowan rating system for these patients indicated that there were 7 cases of grade 1 and 2 cases of grade 2. intraclass correlation coefficient (ICC) was used to evaluate the reliability and validity of the scoring system, and it was found that both were good (0.78 and 0.84) . There were 10 cases of ulnar nerve symptoms in the patients who did not undergo ulnar nerve preposition during the operation, and four cases of poor residual ulnar nerve function were observed in the follow-up review, including 8 cases in grade 1 and 2 cases in grade 2 of the modified McGowan classification. The results indicated no statistical difference between ulnar nerve preposition and non-preposition (P > 0.05) .

Ulnar nerve preposition during ORIF for distal humerus fractures does not provide any benefit and may put patients at greater risk of nerve damage. Based on this, the present study suggests that the clinical effect of in situ ulnar nerve release in the surgical treatment of distal humerus fracture is insignificant.