Rotator cuff tears are among the most common conditions affecting the shoulder.
The tendons of the rotator cuff, not the muscles, are most commonly torn. Of the four tendons, the supraspinatus is most frequently torn; the tear usually occurs at its point of insertion onto the humeral head at the greater tuberosity.
Shoulder pain is variable and does not always correspond to the size of the tear.
For rotator cuff tears the history is variable and may include a discreet episode of trauma or no trauma at all. The pain may have started suddenly or may have come on gradually. The pain may be constant, intermittent, or only activity related. The pain may be mild to severe and weakness may or may not be noted.
Pain in the anterolateral aspect of the shoulder can be due to many causes, symptoms may reflect pathology outside of the shoulder which cause referred pain to the shoulder from sites such as the neck, heart or gut.
Patient history will often include pain or ache over the front and outer aspect of the shoulder, pain aggravated by leaning on the elbow and pushing upwards on the shoulder (such as leaning on the armrest of a reclining chair), intolerance to overhead activity, pain at night when laying directly on the affected shoulder, pain when reaching forward (e.g. unable to lift a gallon of milk from the refrigerator). Weakness may be reported, but is often masked by pain and is usually found only through examination. With longer standing pain, the shoulder is favored and gradually loss of motion and weakness may develop which, due to pain and guarding are often missed by the patient and are only brought out during the examination.
Primary shoulder problems may cause pain over the deltoid muscle that is made worse by abduction against resistance, called the impingement sign. Impingement reflects pain arising from the rotator cuff but cannot distinguish between inflammation, strain, or tear. Patients may report their experience with the impingement sign when they report that they are unable to reach upwards to brush their hair or to reach in front to lift a can of beans up from an overhead shelf.
Magnetic resonance imaging (MRI) is the study of choice to examine soft tissues such as the rotator cuff. The MRI can reliably detect most full thickness tears, although very small pin point tears can be missed. If a small pin point tear is suspected, an MRI combined with an injection of contrast material, called an MR-arthrogram (MRA) may help to confirm the diagnosis. With larger tears, a false positive, is less likely. However, a normal MRI cannot fully rule out a small tear (a false negative). Partial thickness tears are not as reliably detected on MRI . The MRI is sensitive in identifying tendon degeneration (tendinopathy), however, the MRI may not be able to reliably distinguish between a degenerative tendon and a partially torn tendon. Magnetic resonance arthrography can improve the differentiation of rotator cuff degeneration from partial or complete rotator cuff tears . Stetson et al, in 2005 showed a false-negative rate of 9% and sensitivity at 91%, the authors concluded that magnetic resonance arthrography was a very reliable test in the detection of partial-thickness rotator cuff tears. The routine use of magnetic resonance arthrography was not advised and the test was reserved in cases where the diagnosis was unclear.
Ultra sound studies have also been reported as a means of identifying rotator cuff tears. Unlike x-rays which require exposure to radiation and MRI studies which are costly, ultra sound studies have been advocated as an alternative, when read by experienced clinicians. When ultrasonography and magnetic resonance imaging studies have been read by investigators with comparable experience, they have been shown to have comparable accuracy for identifying and measuring the size of full-thickness and partial-thickness rotator cuff tears . Ultrasound can also reveal the presence of other conditions that may mimic rotator cuff tear at clinical examination, including tendinosis, calcific tendinitis, subacromial subdeltoid bursitis, greater tuberosity fracture, and adhesive capsulitis . The MRI provides more information about adjacent structures in the shoulder such as the capsule, glenoid labrum muscles and bone. These are factors to be considered in each case when selecting the appropriate study.
Clinicians and patients are advised to use clinical judgement and not rely on MRI images or x-rays to determine the cause of shoulder pain or treatment, since rotator cuff tears are found in people without any pain or symptoms. The role of x-rays, MRI and ultrasound, are part of the entire clinical picture and serve to confirm the diagnosis, which is provisionally made by a thorough history and physical examination. Over reliance on x-rays or MRI imaging may lead to over treatment or distraction from the true underlying problem.
As part of clinical decision making, a simple minimally invasive in-office procedure may be performed, called the rotator cuff impingement test. A few cc’s of a local anesthetic and an injectable cortisone preparation are injected into the subacromial space to block pain and to provide anti-inflammatory relief. If the pain dispears and function remains good no further treatment or testing are pursued. The test helps to confirm that the pain arises from the shoulder primarily and is not referred pain from the neck, heart or gut. It is thought that the cortisone helps diminish inflammation of the bursa that directly over lies the rotator cuff (sub-acromial bursitis). The test, if pain is relieved, is considered positive for rotator cuff impingement, of which tendinitis and bursitis are a part. However, partial rotator cuff tears may also have good pain relief and a good response cannot rule out a partial rotator cuff tear. In the face of good function and no pain, even with a partial rotator cuff tear, treatment would not change and the impingement test is useful in relief of pain and avoiding over testing or unnecessary surgery.
Since many patients with partial tears and some even with complete tears can respond to non-operative management, generally conservative care is offered first. If a significant trauma such as a shoulder dislocation, or fracture, or high energy force is known to have been followed by complete to near complete loss of rotator cuff- mediated motion and strength, then an operative work-up is initiated with plans to proceed to surgery for repair, if confirmatory.
Patients with pain and maintenance of reasonable function are generally treated for pain relief at first. Non-operative treatment of shoulder pain thought to be related to the rotator cuff, or a tear of the rotator cuff, includes oral medications that provide pain relief such as anti-inflammatory medications, topical pain relievers such as cold packs and if warranted a subacromial cortisone/local anesthetic injection to block the pain and start direct instillation of anti-inflammatory treatment. A sling may be offered for comfort for a day or two, with the awareness that the shoulder can become stiff with prolonged immobilization, which is to be avoided. Early physical therapy may afford pain relief with modalities (ex. e-stim) and help to maintain motion. As pain decreases, strength deficiencies and biomechanical errors can be corrected. Home exercises may be obtained from the clinician’s office or physical therapist.
Work restrictions may be advised along with modifications and restrictions for activities of daily life (ADLs) to prevent re-injury.
Surgical treatment options include an open repair of the rotator cuff, a mini-open repair with arthroscopic assistance or a fully arthroscopic repair. The most appropriate surgical approach is determined by both the degree of tendon disruption as well as the presence or absence of bone spurs that may be contributing to the tear. Recent advances in mesenchymal stem cell therapy have shown promise in the regeneration of soft tissues such as cartilage Autologous_Mesenchymal_Stem_Cell_Transplant_for_Cartilage_Growth and ligaments.