The Rotator Cuff is the combination of four tendons covering the top, front and back of the humeral head. The humeral head is the bone creating the ball in the “ball & socket” of the shoulder. These four tendons fuse to create the Rotator Cuff and are responsible for the motion (in various directions) of the arm and shoulder.
- The Supraspinatus is directly over the top of the humeral head. It is predisposed to degeneration because of its location between the humeral head and acromion bone above. The acromion compresses the tendon during shoulder movement. If the acromion has a protruding bone spur, which is common, then the tendon can be inflamed or develop partial tears (Impingement). Full tears can occur gradually or even suddenly.
- The Infrapinatus & Teres Minor cover the back of the humeral head.
- The Subscapularis crosses the front of the shoulder joint and reinforces the front capsule.
The end portions of the supraspinatus and infraspinatus tendons lay upon the humeral head and form a common continuous insertion upon the humeral head greater tuberosity.
- The incidence of full tears of the rotator cuff ranges from 7% to 40% across multiple studies
- Complete supraspinatus tears may occur in up to 20% after age 32 years
- After the age of 40, about 30% of patients will have cuff tears, and after the age of 60 years, there will be cuff tears in up to 80% of patients
- Asymptomatic full-thickness tears are present in 13% of the population between the age of 50-59, and in over 50% of people older than 80 years old
Impingement Syndrome: This accounts for 75% of Rotator Cuff (RTC) Tears. Impingement syndrome describes pain in subacromial space (between the under portion of the acromion bone and the gliding rotator cuff below) when the humerus is elevated or rotated.
During this motion the RTC tendon and bursa become trapped between the sharp corner of the acromion and the humerus bone. This syndrome causes wear away and gradual weakening of the Rotator Cuff Tendons which eventually leads to a tear. Once the tendon(s) is disrupted there will often be further impingement and irritation which can lead to biceps tearing and subsequent rupture as well.
Shoulder Instability: This accounts for 15% of RTC tears. It should be considered in any young and active patient. It should be considered in long term instability and in chronic or large labral tears.
Trauma: This occurs in 10% of patients. It should be noted that a displaced fracture of the greater tuberosity (bone to which the tendon attaches) is considered equivalent to a RTC tear.
History and Physical Exam: Certain key aspects of the patient history and physical exam will lead an experienced Orthopedic Surgeon to proceed with radiological testing.
X- ray: Allows assessment of the bone shape and configuration. The acromion bone in particular is evaluated. There are 3 different types of shapes of the acromion reported:
- Type 1: A flat acromion (17% of shoulders): 3% of all RTC tears have this type.
- Type 2: A curved acromion (43%): 27% of all RTC tears have this type.
- Type 3: A hooked acromion (40%): 70% of RTC tears have this type.
MRI: There are multiple views utilized by an MRI. The Coronal Oblique is often a vital view to identify the Rotator Cuff Tear, as the supraspinatus and infraspinatus inserting on to the bone. It will also show the relationship between the tendon and the acromion bone as well, as the AC (acromion- clavicular) joint.
This primarily involves a short course of non-steroidal anti-inflammatory medications (NSAIDS) if medically warranted. Physical Therapy can be used for strengthening and range of motion, as well as pain control. Activity modification is an option for older patients or those that live a more dormant lifestyle. Steroid injections may be helpful in temporarily alleviating pain. It is not recommended to have too many injections within a set time span.
ARTHROSCOPIC SURGERY TREATMENT:
Arthroscopic repair is often recommended for the following reasons:
- Your tear is caused by a recent and acute trauma
- You are active
- You are young
- You are an athlete or athletic
- You do overhead work
- Significant weakness
- Large tear
- Symptoms have been present for an extended time
The goal of Rotator Cuff repair is to restore the normal anatomy. Careful attention must be taken to avoid placing the tendon back under excessive tension. Restoration of the footprint (the site of rotator cuff attachment on the bone) with appropriate tension while having significant security is one key to a successful repair.