The proximal ulna includes the ulnar olecranon and part of the proximal ulna, which is mainly composed of olecranon fractures, which are common elbow injuries in adults, accounting for 10% of all upper limb fractures, which can be caused by direct or indirect violence. Because the olecranon fracture is an intra-articular fracture, except for a small number of reports that use non-surgical treatment, most doctors believe that surgery is needed to restore the normal articular surface and the shape of the pulley in order to achieve predictable results. In recent years, there are some controversies in the treatment methods and intraoperative fixation of proximal ulnar fractures. Currently, the most commonly used methods in clinical practice are tension band technique and plate internal fixation technology, but each technique has its own indications, advantages and disadvantages. This study retrospectively analyzed 45 patients with proximal ulnar fractures who underwent surgery in our department from June 2014 to June 2017. The purpose of this study was to investigate the clinical features of different types of proximal ulnar fractures, internal fixation options, surgical strategies and clinical efficacy.

I. Inclusion and exclusion criteria.Inclusion criteria: (1) fractures involve proximal ulnar. (2) fresh fractures. (3) without vascular and/or nerve injury. (4) closed fractures. (5) without serious medical diseases. (6) follow-up time≥12 months.Exclusion criteria: (1) fractures do not involve proximal ulnar. (2) old fracture. (3) with vascular and/or nerve injury. (4) with open fractures. (5) can not tolerate the operation. (6) follow-up time<12 months or lost to follow-up.Ⅱ. General information.In this study, 45 patients with proximal ulnar fractures were included. Including 26 males and 19 females; aged 19-65 years, mean 40.8 years; 18 cases on the left and 27 on the right. 45 patients were all closed injuries, and 13 patients had proximal humeral and elbow ligament injuries. Causes of injury: 25 cases of falls, 12 cases of fall from height, and 8 cases of traffic injuries. The proximal ulnar fracture was classified according to AO/OTA: 32 cases of type B and 13 cases of type C. The time from injury to surgery was 1 to 5 days (mean 2.6 days) .Ⅲ. Treatment.1.Preoperative preparation:After the patient was admitted to the hospital, the distal limb blood supply and ulnar nerve, radial nerve and median nerve examination were routinely performed. All patients underwent anterior and lateral radiographs of the elbow and CT scan combined with three-dimensional imaging to determine the type of fracture. All patients were given a temporary external fixation with a brace or plaster cast after admission, and all patients were treated with swelling before surgery. Antibiotics were routinely used to prevent infection 0.5 to 1.0 hours before surgery. 2.Surgical methods:After satisfactory brachial plexus block anesthesia or general anesthesia, the patient was placed in the supine position, the affected limb was placed on the chest, and the pressure tourniquet was placed on the affected limb. The pressure was set at 35-40 kpa. The posterior median approach incision was used, the layers were separated and revealed, and the fracture was reduced. Tension band technique: After the fracture was reduced, it was temporarily fixed with a point-shaped reduction forceps. The tip of the olecranon is 30° from the posterior edge of the ulna, and two K-wires were inserted in parallel through the subchondral bone to the cortex. At 2-3 cm distal to the ulnar fracture line, in the middle of the anterior and posterior ulnar cortex, a transverse hole was drilled perpendicular to the longitudinal axis of the ulna, through which the wire passed through the wire, and the "8" shape was crossed by the triceps tendon passing through the depths and tighten the knots under the Kirschner wire. The Kirschner wiretail, was gutted and bended and flipped to the olecranon. Plate technique: The fracture was reduced and temporarily fixation with Kirschner wires. The appropriate length of ulnar olecranon anatomical plate was selected and placed on the dorsal side of the ulna. Triceps tendon could be released longitudinally to make the plate fit the contour of proximal ulna. The plate was fixed with the first cortical screw at shaft, and the second or third screw was used to fix the proximal fragment, and then the screws of the ulnar shaft were fixed in turn. For complex comminuted fractures of the proximal ulna, these two techniques can be used in combination. The ulnar coronoid process fractures were fixed with an endobutton. The radial head fractures were treated with mini-plate fixation or metal radial head replacement. When the ligament injury was combined, the 3.0 mm suture anchor was used for suture fixation. The wound was routinely irrigated and closed.Ⅳ. Postoperative treatment and efficacy evaluation.Postoperative prevention of infection, swellingand pain control was routinely performed. The elbows were allowed to active flexion and extension exercises 1-2 days after operation. If necessary, the CPM machine was used to perform limb function training. In the elbow joint flexion activity training, the range of motion of the elbow joint should be controlled between 30°-120°, avoiding implant failure.The anterior-posterior and lateral X-ray of the affected limb were reviewed at 3 days, 1 month, 2 months, 3 months, 6 months and 1 year after operation. CT scan and 3D imaging of the elbow joint were performed 3 days after operation. All patients were evaluated for the function of the elbow joint using the Mayo elbow performance score (MEPS) , including pain (45 points) , joint mobility (20 points) , joint stability (10 points) and daily functions (25 points) . The score ≥ 90 is divided into excellent, 75- 89 is good, 60 -74 is medium, < 60 is poor.

45 patients were followed up for 12 to 24 months (mean 15.6 months) , and all had bone healing. The healing time was 8 to 16 weeks, with an average of 11.2 weeks. At the last follow-up, the elbow flexion was 80°-135°, with an average of 121°; the elbow extension was 0-30°, with an average of 8°.The MEPS score was 50-100 points, with an average of 88.2 points: 26 cases were excellent, 15 cases were good, 2 cases were medium, and 2 cases were poor. The excellent and good rate was 91.1%. All patients had no complications such as neurovascular injury, implant failure, elbow instability, and severe infection during follow-up. Follow-up of 24 patients with plate fixation showed that the fractures healed well, the internal fixation was in place, and the function of the elbow joint was satisfactory. Three of the 13 patients with tension band fixation showed loosening of the Kirschner wire. After the fracture was well healed, the internal fixation was removed. In one patient with tension band combined with plate fixation, elbow joint stiffness occurred in 2 patients, and 2 patients developed heterotopic ossification. In 2 patients, shallow wound infection was healed after anti-infection and dressing treatment.

The fractures of proximal ulna have different morphology, should be evaluated for the fracture severity and classified by the injury mechanism, fracture characteristics and patients’ situation.Reasonable methods of internal fixation and active postoperative rehabilitation is important to obtain the satisfactory function of elbow joint.

Ulna; Proximal; Fracture fixation; Clinical efficacy