【Abstract】 Objective To review the progress in pathoanatomy, diagnosis, and treatment of posterolateral rotatory instability (PLRI) of the elbow. Methods Related literature concerning PLRI of the elbow was extensively reviewed, comprehensive analysis was done. Results The lateral collateral ligament complex (LCLC), radial head, capitellum, and coronoid process are important constraints to PLRI. Muscle groups that cross the lateral elbow are secondary constraints to PLRI. Clinical examination includes lateral pivot-shift test, lateral pivot-shift apprehension test, chair sign, active floor push-up sign, tabletop relocation test, and posterolateral rotatory drawer test. Radiology, arthroscopy, and ultrasound can help diagnosis of PLRI. Reconstruction of bony fixation or soft tissue fixation can be used for treatment of injured LCLC. Conclusion The primary constraints to PLRI is LCLC. Ultrasound imaging is accurate for identification and measurement of normal LCLC. Therefore, ultrasound may prove valuable in assessment of abnormal lateral ulnar collateral ligaments. Reconstruction of soft tissue fixation, which can avoid iatrogenic fracture, is a selective treatment method.