A shoulder implant device includes one or more fixation features including an acromial intrusion element and an inflatable humeral balloon portion that receives a fluid through the acromial intrusion element. The intrusion element comprises a valve that can receive multiple needle sticks to add or remove fluid to or from the inflatable humeral balloon. The device is implanted in a subacromial space such that the one or more fixation features at least secure the device to the acromion and the inflatable balloon portion rests against the proximal end of the corresponding humerus. Fluid in the balloon portion maintains separation of the acromion and the humerus to reduce or prevent impingement.