Proximal humeral fracture refers to the fracture of humerus above the humeral neck. It is a common type of fracture in clinic, accounting for 4%-6% of the total fractures. Such fractures are more common in the elderly population who were often combined with osteoporosis. With the aging population and raising life expectancy, the incidence increases year by year. For non-displaced fractures, conservative treatment can achieve a better prognosis. However, for 2-part, 3-part and 4-part proximal humeral fractures with obvious displacement, the non-surgical treatment often results in fracture malunion with the difficulty of achieving satisfactory results in functional recovery, and thus surgical treatment is recommended. The current treatment methods include internal fixation and arthroplasty, but there are no surgical procedure for all types of proximal humeral fractures. Each method has its own advantages and limitations. In the treatment of proximal humeral fractures with intramedullary nail, the main nail is inserted into the medullary cavity along the axial direction of the humeral shaft. For fractures of humeral head involving humeral shaft or proximal humeral fractures combined with segmental humeral shaft, the treatment with intramedullary nail has remarkable biological advantages. The fracture is reduced through a small incision with less soft tissue exfoliation. Thus the blood supply of fracture ends is less affected and the postoperative complications are significantly decreased. Multiloc intramedullary nail is a new generation of straight type for treatment of proximal humeral fractures. Compared with the traditional intramedullary nail, the insertion point is on the inner side, which can reduce the risk of rotator cuff injury and can complete multidimensional locking according to the condition to make the internal fixation more rigid. Objective To investigate the clinical efficacy of Multiloc intramedullary nail in the treatment of proximal fractures.

From January 2015 to July 2017, a retrospective analysis of 33 patients with proximal humeral fractures were treated with Multiloc intramedullary nailing in the department of orthopaedics, Beijing Chao-yang hospital, capital medical university. The operation time, intraoperative blood loss, fracture healing status and operative complications were recorded, and visual analogue scale (VAS) and Constant-Murley scoring system were used for evaluation of postoperative shoulder joint function.

A total of 33 patients were included. The ages ranged from 44 to 83 years with an average of (68.7±15.7) years. Among them, 22 patients were Neer 2-part fractures and 11 patients were Neer 3-part fractures. The operation was successfully completed. The mean operation time was 93.2 min (70-150 min) , and the mean intraoperative blood loss was 108.2 ml (30-200 ml) . The follow-up time was 13-40 months with an average time of (22.4±7.3) months. At the last follow-up, the mean VAS score was 0.47 points (0-2 points) . The mean fracture healing time was (15.7±2.9) weeks. The mean range of motion was 140.2°of flexion, 135.9°of abduction, 36.0°of internal rotation and 54.4°of external rotation. The mean postoperative Constant score was (85.9±10.8) points, of which 11 cases were excellent, 17 cases were good, and 3 cases were moderate. The excellent and good rate was 90.9%. At the last follow-up, there were no complications such as wound infection, fracture nonunion, rotator cuff injury, etc.

Multiloc intramedullary nail has less surgical trauma, fewer complications, rigid internal fixation, excellent recovery of joint function, and satisfactory therapeutic effect for proximal humeral Neer 2 and 3-part proximal humeral fractures.