OVERVIEW / ANATOMY
The rotator cuff is composed of four muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) that originate from the shoulder blade (scapula) and insert by way of a common tendon on the upper arm (front, back and top of the humerus). The rotator cuff is not only responsible for movements such as rotation and lifting of the shoulder, but is also important in the stability of the shoulder joint itself (fig. 1).Rotator cuff tears are a very common cause of shoulder pain in the adult population. Of the four muscles that comprise the rotator cuff, the supraspinatus is the most commonly injured. Tears of the rotator cuff usually occur in patients over 50, and may be due to a sudden trauma (such as a fracture or dislocation) but can result from repetitive overhead work (such as painters or construction workers) or athletes who do overhead activities (such as pitchers and tennis players). Rotator cuffs tears can commonly occur without trauma because of the poor blood supply seen in these tendons as we age.
SIGNS AND SYMPTOMS
The signs and symptoms of a rotator cuff tear may develop either slowly or may happen following a specific traumatic event (such as a fall or lifting). Most commonly, the onset is gradual and is a result of wear and tear such as repetitive overhead activities. Signs and symptoms that may be present with a gradual onset include:
- Stiffness and loss of motion
- Pain or weakness when you lift or rotate your arm
- Pain when you lower your arm from a raised position
- Pain when laying on the affected shoulder at night
- General shoulder pain that interrupts sleep at night
- Difficulty and pain performing overhead activities such as combing hair
- Pain or difficulty placing your hand behind your back
If the onset is more sudden, you may experience acute pain, a “pop” or “snapping” sensation and sudden weakness in the affected shoulder.
I diagnose a rotator cuff tear (RCT) is based on the symptoms you are experiencing, the physical examination, and diagnostic imaging tests such as MRI (Magnetic Resonance Imaging) and x-rays (fig. 2).Part of the physical exam that I perform includes putting the shoulder through range of motion testing (moving it in all directions), touching it to identify tender areas, testing the strength of the shoulder muscles, and performing special tests that check for instability of the shoulder joint. I will examine your cervical spine (neck) to make sure the pain is not coming from a “pinched nerve” in the neck.
Even though most RCTs can be diagnosed by history and physical exam, I may order x-rays (which will show bone detail) and/or an MRI or ultrasound (which will show the rotator cuff and soft tissue more clearly).
Sometimes, a MRI can distinguish between a full-thickness/complete RCT and a partial-thickness RCT. It can also show if the tear is in the tendon itself or if the tendon is detached from the humerus. Occasionally your doctor may order an arthrogram, which involves injecting dye into the shoulder joint prior to imaging
Depending on the severity and extent of the RCT, I will recommend the most appropriate treatment. Surgical and non-surgical options can be discussed. Examples of non-surgical (or conservative) treatment include:
- Limited activity / Rest
- Use of a sling
- Steroid injections
- Anti-inflammatory medication
- Physical therapy for strengthening and work on shoulder range of motion
Many times surgery will follow a failed non-surgical attempt to relieve pain and loss of function. Depending on the location and severity of the RCT, I may recommend different types of procedures. If it is a partial-thickness RCT, I may only need to smooth and trim the tendon. This procedure is called “debridement”. If the tear is a full-thickness tendon tear, then the tendon can be sewn back together, or if the tendon has detached from the bone, it must be re-attached to the bone using suture anchors. In addition, I may shave the under surface of the shoulder blade (called the acromion) with a motorized rotating shaver blade (Fig. 3). This helps to prevent the tear from recurring with overhead shoulder motion, with abrasion (pinching/shearing) of the tendon (impingement) on the above bone (acromion).
My most common type of surgery for rotator cuff tears is an arthroscopic repair. This involves making small incisions and inserting a fiber optic camera (called an “arthroscope”) and small tools to sew and perform the cuff repair. The camera transmits the images to a video screen that allows me to see inside the joint and perform the repair (fig. 4).
There are also open and “mini-open” surgical repairs that involve a larger incisions and a slightly small incision, respectively. Occasionally, biologic implants may be used to promote healing of the rotator cuff. The use of these implants is new. Involves sewing a patch over/around the cuff to strengthen the repair and promote healing (fig. 5)After the surgery, you will be placed in a sling and pillow to rest the repair site for better healing. I will send you to physical therapy to increase the range of motion and strength as the repair gradually heals. Passive (non-muscle contracting motion done by you and the physical therapist) can begin immediately with active (rotator cuff muscle contraction) motion beginning at 6-8 weeks when early tendon healing has occurred. Adhering to this program is essential for a good surgical outcome.