1.The depth of the clavicle hook is not the “degree” in the conventional sense, but the length. 2.The “degree” of the clavicle hook is based on the thickness of the acromion. ” is designed according to the thickness of the acromion, which is also the lateral thickness of the acromion. This design plays an important reference role for intraoperative placement selection of the clavicle hook. The thickness of the acromion should be measured intraoperatively, and then the clavicle hook plate of the corresponding depth should be selected accordingly (and most of us in the clinic do not notice this). 3. The clinical significance of the clavicle hook depth: If the clavicle hook plate is too short: it is easy to cause difficulty in repositioning and increase the stress on the hook after repositioning, which is easy to cause stress fracture, decoupling, broken hook, etc. If the clavicle hook plate is too long: it is easy to enter the subacromial space and produce symptoms of rotator cuff injury and wear of the hook end (I don’t know if the wear of the hook end is noticed when taking the hook plate in the clinic).