When the proximal third of the radial shaft fracture occurs, the proximal end of the fracture is affected by the bicipital tendon and the supinator muscle, which is prone to lateral and rotational displacement. Therefore, most of them need surgical treatment to obtain anatomic reduction and rigid fixation. The proximal palmar incision of forearm is the most commonly used surgical approach. As the palmar approach is adjacent to the lateral antebrachial cutaneous nerve, there is certain risk of nerve injury during the operation, causing a loss of sensation in the innervating region.

1. Research object: From January 2012 to April 2016, a total of 21 patients (16 males and 5 females) in this group were treated with modified preoperative surface localization of incisions. Their ages ranged from 19 to 52 years old with an average of 34 years old. The causes of injury included 15 cases of damages, 3 cases of traffic injuries, 2 cases of high fall injuries and 1 case of fight. There were 12 cases on the left side and 9 cases on the right side, and all of them were closed proximal third of radial shaft fractures without symptoms of radial nerve injuries or forearm sensory disturbance. According to AO classification, there were 13 cases of type A fractures, 6 cases of type B fractures and 2 cases of type C fractures. The time from injury to surgery ranged from 1 to 9 days, and the mean time was 4 days. 2. Treatment methods: Under brachial plexus block anesthesia or general anesthesia, the affected upper extremity was abducted on the operating table and operated under the balloon tourniquet. The forearm was fully rotated. The incision was designed as a line connecting the flexor carpi radialis muscle tendon and the radial edge of bicipital tendon, which extended from cubital crease to distal end. The appropriate length of the incision was selected according to the specific part of the fracture. At the proximal end, the deep fascia was cut open along the radial edge of the bicipital tendon. Attention should be paid during the cutting to avoid the damage of the trunk of the lateral forearm cutaneous nerve. After that, the gap between pronator teres and brachioradialis was separated distally, and the superficial branch of radial nerve and the radial artery and vein should be protected as well. Both superficial branch of radial nerve and brachioradialis were retracted to the radial side, and the radial artery and vein were retracted to the ulnar side. The recurrent branch of radial artery crossed in front of the lower segment of the bicipital tendon. According to the situation, the excision and ligation of the above blood vessel could be performed if it affected the surgical field exposure, which was beneficial to retract the radial artery to the ulnar side. The forearm was maintained in the maximum supinator position. The bicipital tendon was slightly retracted to the ulnar side to expose its insertion point. The submucosal dissection was dissected at the starting point of supinator muscle (from the ulnar side to the radial side) , and thus the proximal radius was exposed. The supinator muscle was reversed to the lateral side to protect the deep branch of radial nerve. According to the specific part of the fracture, the gap between pronator teres and supinator muscle was separated and extended distally, or part of the insertion point of pronator teres was peeled off to fully reveal the operation field. After fracture reduction under direct vision, the plate was placed and fixed on the palmar side of radius and the lateral side of the insertion point of bicipital tendon. The fracture reduction, internal fixator position, forearm rotation mobility and whether the bicipital tendon would rub against the plate were checked. After the examination, the supinator muscle was repaired without tension, and the incision was closed layer by layer. 3. Postoperative management: Plaster external fixation was not commonly required, and the affected extremity was elevated until its swelling subsided. On the 2nd day after operation, the patient was instructed to perform active flexion and extension of the elbow, wrist and fingers, and the slight rotation of forearm. During the early activities, the patient was instructed to hold the affected wrist with the unaffected hand, and slowly flex and stretch the elbow joint, or rely on gravity to perform the elbow extension training. According to the review of the X-ray film, before the fracture was healed, the patient was prohibited from participating in vigorous activities, and the affected limb was prohibited from holding heavy objects and twisting hard. 4. Follow ups and therapeutic evaluation: The anteroposterior and lateral radiographs of the forearm were taken within 1 week after surgery to evaluate the fracture reduction and fixation. The patients were reviewed monthly for the first 3 months after operation. The healing of the fracture was judged by X-ray film. The standards of fracture union included the disappearance of fracture line revealed in the X-ray film, and negative tenderness or percussion on the local site. According to Grace and Eversmann criteria for forearm rotational function, the fracture healing and forearm rotational function that reached over 90% of those on the healthy side were considered excellent, those reached over 80% were considered good, those reached over 60% were considered moderate, and those reached less than 60% were considered poor.

All the patients in this group were followed up for 11 to 24 months (an average of 14 months) . All fractures obtained bone healing and the healing time was less than 6 months. All patients recovered well without complications of infection, internal fixation failure or neurovascular injury, etc. In the later stage, there were no symptoms of radial nerve stimulation or innervation area sensory disturbance of lateral antebrachial cutaneous nerve. In the last follow up, according to Grace and Eversmann criteria for forearm rotational function evaluation, 15 cases were excellent, 4 cases were good, and 2 cases were moderate, and the good and excellent rate was 90.5%. The range of forearm rotation is 159° (110°-180°) on average, the flexion and extension of the elbow and wrist are normal without any effect on daily activities.

AThe modified body surface positioning of the forearm palmar approach can avoid the laterally selected incision, and it is not prone to damage the lateral antebrachial cutaneous nerve intraoperatively. The bicipital tendon is an important anatomical landmark. Its position is superficial, easy to touch, and easy to identify during surgery. In the palmar approach of the forearm, the bicipital tendon regarded as a reference is critical for the design of the incision, the separation of the radial artery and the protection of the deep branch of radial nerve. During the operation, all the procedures are performed on the radial side of the bicipital tendon, which is safer and more reliable.