Traumatic instability caused by elbow dislocation is one of the most common upper limb injuries in clinic. Traumatic dislocation is often accompanied by injury of articular capsule and ligament, as well as bone structural injury, such as radial capitulum fracture, ulnar coronoid process fracture, humeral condylar fracture, etc. The injury of medial and lateral collateral ligaments is often the cause of elbow instability. For the treatment of elbow dislocation, plaster cast after manual reduction is often used in clinic, but how to evaluate the stability of elbow joint after reduction is still one of the clinical difficulties. At present, there is no convincing physical examination method to prove the function or stability of elbow joint. Because of the influence of pain, it is difficult to conduct stress tests to determine the stability of ligaments. Ultrasound is a commonly used method to evaluate the condition of ligaments in clinic. Ultrasound is used to check the integrity of the medial and lateral collateral ligaments of elbow, and stress test under anesthesia is used to judge the stability of elbow, so as to guide the choice of treatment. Objective To investigate the reliability and clinical significance of ultrasonography in the diagnosis of elbow stability.

From January 2014 to December 2017, 23 cases (11 males and 12 females) of lateral collateral ligament injury of elbow were treated in our hospital. The ages ranged from 15 to 68 years with an average of 41.5 years. According to the integrity of collateral ligament examined by high-frequency ultrasound, combined with the results of intraoperative stress test, the treatment of elbow ligament injury is decided. The ligament exploration anchor fixation and reconstruction suture were used in the operation, and the elbow function scores and fracture healing were followed up.

Ultrasound examination revealed that 14 patients had tear of medial and lateral collateral ligaments, and 8 patients had lateral collateral ligament injury with 5 cases of complete interruption and 1 cases of medial collateral ligament injury. The results of the stability test of the collateral ligament of the elbow joint under intraoperative anesthesia were used as a reference standard, and the sensitivity and specificity were 97% and 70%. Mayo elbow function scoring system were used, and there were 17 excellent cases, 3 good cases, 3 moderate cases. The excellent and good rate was 87%.

Ultrasound is an inexpensive, safe and effective way to judge the stability of the collateral ligament in elbow injury. It is also helpful for clinicians to make a clear judgment on the management of collateral ligament injury of elbow joint by combining the results of intraoperative stress test.