The rotator cuff at risk
After shoulder dislocation, a patient usually feels immediate relief after having his or her shoulder reassembled. But pain and other symptoms often linger in older men and women because of changes that occur in the aging shoulder.
Over time, the muscles and tendons that form the rotator cuff become weak and brittle. These changes make the rotator cuff much more likely to tear if you dislocate a shoulder or have a related injury.
Among people 40 and older, shoulder dislocations cause a torn rotator cuff in anywhere from 35 percent to 86 percent of cases. A 2012 U.K. study published in the Journal of Bone and Joint Surgery found that women 60 and over who dislocate shoulders in falls have the highest risk for tearing a rotator cuff (as well as fracturing a bone, especially in the upper arm).
By contrast, younger people who dislocate shoulders are more likely to damage other supporting tissues, such as the labrum, a type of cartilage that helps stabilize the head of the humerus.
In addition to shoulder dislocations, simple stress and overuse is a major cause of rotator cuff tears, too. If you play sports that require a lot of throwing or other overhead arm movements, such as baseball, tennis or swimming, you may be at risk for rotator cuff problems. The same is true if you perform manual labor that involves similar repetitive movement of the shoulders, such as house painting and carpentry.
Bone spurs, or overgrowths, can tear tendons in the rotator cuff as well. What's more, blood supply to these tissues may diminish with age, which interferes with your body’s ability to repair these tears.
Rotator cuff tears cause pain, especially in the upper and outer shoulder, and particularly when you reach upward or sleep on your injured side. Your shoulder may feel weak and make a clicking or cracking sound when you move it.
In older patients, doctors usually recommend treating these symptoms with rest, over-the-counter pain relievers or, if the latter don't work, cortisone injections. Stretching and strength exercises can restore shoulder movement and strength and help prevent future problems, too.
If you're still experiencing pain and loss of strength despite these steps, a doctor may recommend surgery to repair a torn rotator cuff, which usually involves reattaching the tendon to the head of the humerus. The procedure can be performed in the traditional "open" manner or with arthroscopy, in which a surgeon uses a tiny scope and instruments to perform surgery.
Nerve injuries and other collateral damage
Doctors sometimes misdiagnose rotator cuff tears as damaged nerves. However, the latter are a concern in older men and women who suffer shoulder dislocations, likely because nerve tissue becomes less resilient with age. One study found that a little over 9 percent of patients 60 and older with shoulder dislocations displayed weakness and loss of sensation.
In particular a dislocation can stretch a network of nerves called the brachial plexus, which conducts signals from the spine to the shoulder, arm and hand. That can lead to temporary shoulder paralysis, which typically fades within a few months. Doctors sometimes call the combination of shoulder dislocation, torn rotator cuff, and damaged brachial plexus the "terrible triad of the shoulder."
Damage to blood vessels is a less common injury that can accompany shoulder dislocation, but one that's more likely to occur in older adults: More than 90 percent of artery injuries related to shoulder dislocations occur in people over 50. That's probably because arteries become stiff and lose elasticity with age, making them more likely to tear when stretched.
Signs that you might have sustained artery damage include pale skin, a burning or tingling sensation, a drop in body temperature, low pulse in the arteries in your wrist and bruising that appears to be growing worse. See a doctor immediately if you develop any of these symptoms.
Simon Cavendish Mears, MD, PhD, Associate Professor of Orthopaedic Surgery, Johns Hopkins Medicine
Shoulder dislocations occur in older adults most typically due to falls. While, generally, these are treated with a closed reduction, there may be additional injuries to the shoulder such as rotator cuff tears or nerve damage that aren't diagnosed at the time of dislocation.
If you've been treated for a dislocated shoulder, yet pain, discomfort or limited range of motion persists long after, don't put off telling your doctor. He or she should check for underlying rotator cuff or nerve injuries. As the researchers noted, older patients who develop shoulder problems can have excellent outcomes if they're diagnosed early and treated promptly.
Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50