When this comes about, immediate surgery to relieve the pressure is needed. If still left untreated, compartment syndrome can cause everlasting tissue problems and lack of purpose. In some cases the deep muscles with the shoulder joint (rotator cuff muscles) might be injured concurrently since the fracture. Following the recommendation https://www.theorthopaedicandpainpractice.com/what-is-a-proximal-humeral-fracture/