Résumé
Objective:To evaluate the reliability and clinical application of a self-established classification system for the lower 1/3 humeral fractures in adults.Methods:A retrospective study was performed to analyze the 88 patients with lower 1/3 humeral fracture who had been admitted to Department of Orthopedics, The Second Hospital of Fuzhou between January 2013 and December 2020. There were 61 males and 27 females with an age of (34.6±12.7) years. The lower 1/3 humeral fractures were classified according to the location of the fracture line, displacement, and bone mass into 3 types: type Ⅰ: transverse and short oblique ones; type Ⅱ: oblique and spiral ones; type Ⅲ: oblique and spiral ones with butterfly-shaped bone mass. After a junior orthopedic surgeon, an intermediate orthopedic surgeon, a senior orthopedic surgeon, and a radiologist had learned this novel classification system, they were asked to classify the lower 1/3 humeral fractures in this cohort independently to assess the reliability of the classification system. Our treatments were based on this novel classification. Open reduction and internal fixation with a unilateral plate through a lateral approach was performed for type Ⅰ fractures, internal fixation with a unilateral plate plus compression screws through a lateral approach for type Ⅱ fractures, and double plate internal fixation through the ulnar and anterolateral approaches for type Ⅲ fractures. The functions of the radial, ulnar, and musculocutaneous nerves and fracture healing time were observed postoperatively. The shoulder and elbow functions were evaluated using Neer shoulder function score and Mayo elbow function score.Results:Of the 88 patients in this cohort, 20 were type Ⅰ, 25 type Ⅱ, and 43 type Ⅲ. The mean Kappa value for inter-observer reliability was 0.878 at the first stage and 0.914 at the second stage, and the mean Kappa value for intra-observer reliability was 0.950. All patients were followed up for (14.1±3.7) months. Iatrogenic injury to the radial nerve was observed in 2 patients, but no injury to the ulnar nerve, the musculocutaneous nerve or important blood vessels or failure of internal fixation was reported. All patients achieved bony union after (12.7±2.0) weeks. The maximum elbow flexion was 137.8°±4.8°, and the maximum elbow extension 2.4°±1.6°. The Mayo elbow function score was (92.0±3.1) points and the Neer shoulder function score (92.2±3.2) points.Conclusions:Our classification system for the lower 1/3 humeral fractures in adults is reliable. As the treatments corresponding to the novel classification system can achieve satisfactory clinical outcomes, the classification system has a clinical value.