[Abstract] Objective To summarize the efficacy of closed reduction percutaneous needle fixation of humeral surgical neck fractures. Methods Retrospective analysis of 31 cases, 23 males and 8 females, with a mean age of 52 years (4-66 years), who underwent percutaneous needle fixation of humeral surgical neck fractures from March 2003 to June 2008 to obtain complete cases; according to neer fracture typing: 21 cases of two-part fractures and 10 cases of three-part fractures. All were fixed by percutaneous needle penetration for humeral surgical neck fractures. The results were followed up for a mean of 11 months (1 to 18 months). Using the modified constant-murley scale, the mean score was 92 (77~100), with an excellent rate of 90%. Conclusion Percutaneous needle fixation of two- and three-part humeral surgical neck fractures is an effective method. Keywords humeral surgical neck fracture; percutaneous needle penetration; fixation. Humeral surgical neck fracture is a common clinical fracture type with more treatment methods. We review the satisfactory results of percutaneous needle fixation treatment for 31 cases of two- and three-part fractures of the proximal surgical neck of the humerus that got follow-up in our hospital and report them as follows. 1. Clinical data 1.1 General data From March 2003 to June 2008, a total of 31 cases, 23 males and 8 females; mean age 52 years (4~66 years), with a history of trauma, were treated with percutaneous through-needle internal fixation of humeral surgical neck fractures. The fractures were typed according to the neer fracture typing criteria [1], including 21 cases of two-part fractures and 10 cases of three-part fractures. 1.2 The surgical method was selected from interosseous groove block anesthesia or general anesthesia, with the patient lying supine and the affected shoulder to the outside of the surgical bed. The upper arm was placed in an inversion, anterior flexion and mild internal rotation position to relax the pectoralis major muscle, traction and compression of the humeral stem to the posterior side to correct the forward angulation, outward pushing to correct the distal inward displacement, C-arm fluoroscopic monitoring, after satisfactory orthogonal and axillary repositioning, maintenance of repositioning, sterilization, towel laying, the operator used 2-3 2-2.5 mm Kirschner pins to penetrate percutaneously for fixation, and threaded pins could be used. First, a Kirschner needle is used to penetrate from the proximal end of the greater tuberosity of the humerus obliquely and medially down to the distal end of the fracture to stabilize the fracture alignment; then a sleeve is used to protect the needle tip from sliding and avoid soft tissue injury, and the needle is inserted from the distal fracture end above the deltoid stop, either anterolaterally, anterolaterally, or posterolaterally to the humeral stem, and the most commonly used needle is the anterolateral approach. Avoid penetrating the articular surface of the humeral head. The tail of the needle is clipped to the subcutaneous or left outside the skin. 1.3 Postoperative treatment Postoperative cast or forearm sling was used to brake the shoulder joint, and fist clenching was practiced after surgery. The cast was removed after 3-4 weeks of braking and functional exercise of the shoulder joint was started, and the fracture was photographed at 6 weeks with scab formation, and the needle was removed and functional training to strengthen the shoulder joint was performed. 2. Results 2.1 Appointment to come to the hospital for follow-up radiographs. The follow-up period was from 1 month to 18 months after surgery, with a mean follow-up of 11 months (1-18 months). The mean score of the follow-up results was 92, with 21 excellent, 7 good, 3 acceptable, and 0 poor cases. The excellent rate was 90%. 3 cases that were acceptable were neer three part fractures, all combined with different osteoporosis. One case of postoperative pin tract infection was healed after drug change and pin removal, and two cases of loosening of three internal fixation pins did not cause any significant complications. 3. Discussion Surgical neck fractures of the humerus account for about 90% of proximal humerus fractures. The purpose of humeral surgical neck fracture treatment is not only to require fracture healing, but also to restore a painless shoulder joint with a range of motion as close to normal as possible, so the choice of surgical method for humeral surgical neck fracture is important. The selection of surgical indications is critical, and we classify it as a contraindication for four-part fractures, as well as for patients with combined rotator cuff and vascular nerve injuries. Percutaneous needle fixation is mainly suitable for two- and three-part fractures that can be closed and repositioned. For patients with severe swelling, manual repositioning is often difficult. Our experience is that we perform manual repositioning for all patients who come to the hospital within 6 hours after the injury and whose swelling is not too severe. If the swelling is severe, the affected limb can be suspended with the elbow higher than the heart, and then after the swelling has subsided, we can perform a manual repositioning and fixation. However, for children with surgical neck fractures of the humerus, fracture healing is relatively fast, so it is important to hurry and strive for surgery within 4-5 days after emergency or early injury. During the percutaneous needle penetration procedure we have summarized the following operational experience: ① Retrograde kerfing needle through the greater tuberosity should penetrate the bone cortex at the distal fracture end, to make the insertion of the needle satisfactory, and the needle body should not be left too long when drilling. The needle body should not be left too long when drilling, lest the needle body swing when drilling and lose the strength to stabilize the fracture. The fracture line should be kept as far away from the fracture line as possible, and the threaded needle should be placed as close as possible to 0.5-1.0 cm below the humeral head, under the cartilage of the articular surface where the bone is relatively dense, so as to improve the holding power of the needle body in the humeral head. The use of a threaded Kirschner needle is emphasized here whenever possible. All three Kirschner pins loosened in this group of cases were unthreaded Kirschner pins. Another case was reported by James and colleagues in which a loose Kirschner pin was passed into the thoracic cavity. (iii) When drilling from the anterolateral aspect of the humeral stem, the Kirschner needle is drilled at an angle of 45 degrees to the humeral stem on the coronal plane and at an angle of 30 degrees to the humeral stem on the dislocated plane, which ensures access to the center of the humeral head. In postoperative rehabilitation we recommend that early functional exercise should be determined by the type of fracture, stability, degree of fixation and patient’s understanding of the functional exercise process as passive, active and range of motion and strength exercises. Early postoperative exercises are the most effective method and should be given adequate attention. After surgery, the fingers and wrist joints should be opened for extension and flexion activities, and fist clenching should be practiced gradually. In 3-4 weeks after surgery, the external fixation is removed and replaced by forearm sling suspension, while the shoulder joint activities are practiced. The percutaneous needle technique has the advantages of less pain, simpler operation, less trauma, less damage to the epiphysis, shorter hospital stay, fewer comorbidities, and reliable efficacy. Percutaneous needle fixation of two- and three-part fractures of the surgical neck of the humerus can achieve satisfactory clinical results, and is therefore worth promoting as a practical treatment method.