In this study, we compared the clinical efficacy of minimally invasive locking plate technique and intramedullary nail technique in the treatment of two-part and three-part proximal humeral fractures. It was found that there was no significant difference in intraoperative blood loss, incision length, operation time, fracture healing time, ASES and Constant-Murley score of patients at 1 year after operation between the two groups. The postoperative complication rate of study group was significantly lower than that of control group (7.14% vs 28.12%, P < 0.05). The results revealed that intramedullary nailing is superior to locking plates in controlling the incidence of complications.
Proximal humerus fractures occur mostly in elderly patients, often accompanied by osteoporosis, and belong to intra-articular fractures, which require high reduction requirements and often require surgical treatment. Improper treatment can easily lead to limb disability5. At present, there is still a lot of controversy about how to treat displaced proximal humeral fractures, and there are many types of surgical methods, such as artificial joint replacement6, Pickerner wire fixation7, internal fixation system, etc. In recent years, with the change of treatment concept and the development of new orthopedic instruments8,9, the treatment of proximal humeral fractures is developing towards minimally invasive direction. At present, percutaneous minimally invasive locking plate technique and intramedullary nail technique are most commonly used clinically.
The traditional incision for the treatment of proximal humeral fractures is the deltoid approach, which has the advantages of full exposure and intuitive reduction. However, this approach requires extensive dissection of soft tissue, which is highly traumatic and bleeding, and is not suitable for elderly patients with osteoporosis. In this paper, the author used the lateral deltoid approach, intraoperative just blunt separation of deltoid muscle fibers, without cutting off muscle and affecting postoperative activity of shoulder joint. The intraoperative incision is small and the bleeding is less, which is conducive to the postoperative recovery of the patients. Moreover, we combined with MIPO technology10, percutaneous plate insertion, indirect reduction, protected the blood supply of the broken end of the fracture, and reduced the probability of nonunion and humeral head necrosis. MIPO combined with the new proximal humeral locking plate, the proximal humeral screw is a locking screw, and the multi-angle fixation, compared with the traditional plate, it effectively increases the holding force of the proximal humeral, reduces the incidence of postoperative reduction loss and varus malunion. However, compared with the intramedullary nail, the locking plate belongs to eccentric fixation. From the perspective of biomechanics, its bending resistance and torsion resistance are weaker than those of intramedullary nail, which has been confirmed by relevant biomechanical experiments. Moreover, the proximal incision of this approach is distal to the axillary nerve, and improper operation is likely to cause iatrogenic axillary nerve injury. The results of this study showed that the treatment of proximal humeral fractures with minimally invasive locking plate technique had the advantages of less bleeding, less incision, and better postoperative shoulder joint function, but there were 9 complications (axillary nerve injury in 4 patients, screw removal in 3 patients, and varus malunion in 2 patients).
The early intramedullary nail of the proximal humerus is not a straight nail design, with a 5° valgus Angle, and the opening of the intramedullary nail is outside, which is prone to damage the rotator cuff tissue. Postoperative patients often have symptoms of supraspinatus muscle tendon injury, such as restricted abduction and pain, and the incidence of which is reported in relevant literature to be up to 40%11. The new type of proximal humeral interlocking intramedullary nail has improved the early stage by adopting straight nail design, opening at the highest point of the humeral head and the muscle belly of the supraspinatus muscle, without injury to the rotator cuff, and reducing postoperative complications such as limited pain of the shoulder joint. Compared with plate, intramedullary nail has the biomechanical advantage of central fixation, and the moment arm is smaller than that of eccentric fixation plate, which reduces the possibility of varus displacement after operation. Many previous studies have shown that there is no significant difference in the clinical efficacy of proximal humeral intramedullary nail compared with locking plate, but the postoperative complications of intramedullary nail are lower. Konrad G et al.12 studied the difference in clinical efficacy between intramedullary nail and locking plate in the treatment of three-part proximal humeral fractures. After one year of follow-up, they found that the clinical efficacy of intramedullary nail was similar, but the postoperative complications of intramedullary nail were less than that of locking plate. Von Ruden C et al.13 found that the use of proximal humeral intramedullary nail in the treatment of proximal humeral fractures has the advantages of less trauma, less muscle, soft tissue and periosteal dissection compared with plate, which can enable patients to have early functional exercise, so as to obtain better long-term shoulder joint function. The results of this study showed that there were fewer postoperative complications in the study group compared with the control group, and there were 2 postoperative complications. (1 case had acromion impingement, which was caused by insufficient depth of intramedullary nail insertion; One patient had rotator cuff injury after surgery, which was found to be caused by the deviation of the opening after arthroscopic revision.)