Rotator cuff injuries are a common occurrence in older adults. One study found that about half of all people over the age of 60 have rotator cuff injuries of varying degrees, but these people do not experience shoulder discomfort or dysfunction. This suggests, on the one hand, that people can live with an incomplete rotator cuff without discomfort and, on the other hand, that rotator cuff injuries do not necessarily require surgical treatment afterwards. Each rotator cuff has a certain width and thickness, and if only a portion of a rotator cuff is broken, it does not necessarily affect its overall function. Follow-up of patients with rotator cuff repair has also shown that even though some patients have only healed 60 to 70 percent of their rotator cuffs after repair, the shoulder joint function has recovered well. People with rotator cuff injuries can be divided into those with functional rotator cuff injuries and those without functional rotator cuff injuries, depending on the functional status of the shoulder joint. Functional rotator cuff injury means that despite having rotator cuff injury, the shoulder joint lifting function is basically normal, which is further divided into two categories based on symptoms: painless and painful. People with a painless functional rotator cuff injury cannot be called patients because these people can live a normal life despite having an incomplete or imperfect rotator cuff; they are imperfectly normal people. People with a painful functional rotator cuff injury are the ones who can be considered patients. These people have pain that affects their quality of life to some degree because they have pain, even though the shoulder joint is functioning okay. People with non-functional rotator cuff injuries are true patients because these people are unable to lift their shoulder joints and this affects their normal life. Painful nonfunctional rotator cuff injuries are the most serious because the patient not only has limited function, but also has more severe pain in the shoulder joint during activity or at rest, which has the greatest impact on daily life. Painless non-functional rotator cuff injury means that there is no discomfort in the shoulder joint, but the patient is unable to lift it, which also affects eating, brushing teeth and combing hair. This particular type of rotator cuff injury is also known as pseudo-paralysis, which means that the patient’s shoulder looks like he or she has had a stroke and is paralyzed, and can be lifted with the good hand to help the bad hand, but the bad hand falls off when the good hand is released. If there is a rotator cuff injury, but the shoulder joint is functioning normally and there is no pain, which is a painless functional rotator cuff injury, then surgery is not needed. If it is a painful functional rotator cuff injury, the first step can be to take conservative treatment to stop the pain. If conservative treatment is not effective for some patients, surgery may be considered. For painful but functional rotator cuff injuries, the purpose of surgery is not to repair the rotator cuff, but to remove the pain-causing factor. In rotator cuff injuries, that is, when there is a rupture in the rotator cuff, the rupture itself does not produce pain. Most of the pain is caused by other factors, such as compression of the rotator cuff edge, impingement of the rotator cuff, calcification of the rostral shoulder ligament, subacromial bursitis, biceps tendonitis, acromioclavicular arthritis, etc. By removing these pain-causing factors during surgery, the overall function of the shoulder joint will be significantly improved even if the rotator cuff is not repaired. Of course, the surgeon will not leave the torn rotator cuff unattended during surgery and will repair it accordingly. However, for functional rotator cuff tears, it is not advisable to make a major effort to repair the rotator cuff, otherwise the rotator cuff that was functional may become non-functional due to excessive anatomical changes, which may outweigh the losses. Patients with non-functional rotator cuff injuries will require surgery if they want to improve function. Generally speaking, patients with painful non-functional rotator cuff injuries benefit the most from surgery, because the reason why the shoulder joint is not functional in these patients is not necessarily due to a complete rotator cuff rupture, but rather because the pain is more intense and inhibits the defective rotator cuff from performing its residual function. Of course, repair of the rotator cuff at the time of surgery is also a guarantee of restoration of shoulder function. For this type of patient, pain relief surgery is as important as rotator cuff repair surgery. Painless non-functional rotator cuff injuries are the biggest test for the surgeon. This is because the reason these patients have a nonfunctional rotator cuff is indeed caused by a rotator cuff rupture. To have reliable restoration of shoulder function, it is entirely dependent on effective surgical treatment to re-establish rotator cuff function.