Impingement is a common shoulder condition that causes pain as a result of pressure on the rotator cuff from the shoulder blade. The rotator cuff is a group of muscles and tendons that stabilizes the shoulder and permits lifting and rotating movements. When impingement occurs and the arm is lifted, a bone or ligament can rub against the rotator cuff, producing pain and limiting movement.
Impingement typically worsens over time. At first, patients may feel mild pain in the shoulder, which often radiates from the front of the shoulder to the side of the arm. The pain may worsen upon lifting the arm, reaching for something or throwing or serving a ball while playing a sport. There may be some swelling and tenderness at the front of the shoulder as well. As impingement progresses, pain and stiffness worsen until the patient may not be able to lift or lower the affected arm. Eventually, if left untreated, the condition may severely limit arm motion to the point that the arm becomes difficult to move at all.
This condition is common in young athletes and older adults, as it is often caused by overuse and certain repetitive motions. Symptoms of impingement can range from mild to severe and may include pain during activity and rest, and pain that radiates down the arm.
Once impingement has been established as a diagnosis after a physical examination and imaging tests of the shoulder, a treatment plan will be designed. This will often initially focus on conservative measures such as resting the arm, used of non-steroidal anti-inflammatory medications, corticosteroid injections and a regimen of physical therapy. However, if these techniques do not provide adequate pain relief, surgery will most likely be recommended.
Severe cases of impingement may require surgery to remove the pressure and create more space for the rotator cuff. The most common procedure for treating impingement is subacromial decompression. This surgery involves the removal of some of the affected tissue and part of the bursa, which is the small sac that has become inflamed due to the impingement. In some cases, the front edge of the shoulder blade must be removed as well. Either general or local anesthetic will be administered prior to the start of the procedure.
A subacromial decompression can be performed through arthroscopy or an open technique, depending on the severity of the condition. When arthroscopy is used, two to three tiny incisions are made in the shoulder area. The arthroscope and specialized surgical tools are inserted into the incisions and the surgeon uses a video monitor to view the damaged area and excise the tissue and bone as needed. Once sufficient space has been created to allow for free movement of the tendons of the rotator cuff, the surgeon will withdraw the instruments and suture the incisions closed. If the surgery is performed using an open technique, one incision is made in the shoulder, and muscles and tissues are separated to provide access to the joint and subacromial space.
The length of recovery from a subacromial decompression procedure will depend on a number of factors, including whether the surgery was performed arthroscopically or through an open method. A sling may be needed after surgery to immobilize the arm and encourage initial healing. Once the sling is no longer necessary, a rehabilitation program can begin that will focus on increasing strength and range of motion in the affected shoulder. Improvements to the shoulder in comfort and function are typically apparent within a few months after the subacromial decompression procedure, but full recovery may take longer to achieve.