Rotator Cuff Tears

Definition

Rotator cuff tendinitis, partial-thickness and full-thickness tears all fall under the category of rotator cuff disease and is the most common shoulder disorder treated by orthopedic surgeons and sports medicine specialists. In fact, with over 17 million people at risk, the prevalence of sustaining a full-thickness rotator cuff tear is between 7% and 40%. The treatment for each case must be carefully tailored to the individual patient, as each individual case differs due to a variety of factors and variables. These include, but are not limited to, patient factors such as age and occupation, history of the illness and previous trauma, medical comorbidities (ex. diabetes), relevant past surgical history, age related degenerative changes, work status and employment, handedness, and social factors including smoking history, among others. Tear characteristics are also vitally important to consider when deciding on the best treatment algorithm. These include size and pattern of the tear, tendon retraction, muscle atrophy and fatty infiltration, previous surgeries and scar tissue around the shoulder, and other degenerative changes and associated pathology within and around the shoulder joint.

Previously, symptomatic full-thickness rotator cuff tears were treated with open rotator cuff repair surgery. Open surgery was flawed by the fact that it required either a splitting or detachment of the deltoid muscle, along with a large surgical incision to visualize the tear and perform the repair. This ultimately caused higher complication rates and increased failure rates in patients undergoing open repair surgery. However, with advanced technology and improved surgical technique (along with the advent of the arthroscope), rotator cuff tears are now treated arthroscopically through three or four “keyhole” size incisions around the shoulder, utilizing one of two techniques. A single-row suture anchor repair is optimal for smaller tears. A double-row suture anchor repair can be very effective when treating larger rotator cuff tears but has not been clinically proven in prospective trials. Newer techniques, such as the superior capsular reconstruction (SCR), have enabled us to repair or reconstruct cuff tears that were previously deemed irreparable.

Anatomy

The rotator cuff is comprised of four muscles: supraspinatus, infraspinatus, teres minor and subscapularis, all of which begin from the scapula and insert onto the bony tuberosities of the proximal humerus. The four muscles combine into a common tendon that forms a “cuff” of tissue over the proximal humerus – hence, the “rotator cuff.” Both the supraspinatus and infraspinatus are responsible for two-thirds of the posterior rotator cuff and fuse into one tendon that inserts onto the tuberosity. Tears of these two tendons are the most common type of rotator cuff tear.

The insertion site of the rotator cuff is commonly referred to as the footprint. The footprint of the supraspinatus is shaped like a triangle and averages 6.9mm in length (medial to lateral) and 12.6mm in width (anteroposterior width). The footprint of the infraspinatus is shaped like a trapezoid and averages 10.2 mm in length (medial to lateral) and 32.7 mm in width (anteroposterior width). Understanding the natural cuff anatomy is important as this helps direct the surgeon to achieve an “anatomic repair” during surgery. Furthermore, the theoretic advantage of the double-row cuff repair is a more appropriate reconstruction of the anatomic footprint on the humerus.

Pathogenesis

The etiology of rotator cuff tears and disease is multifactorial. Tears are caused by various factors such as age-related degenerative changes, trauma, chronic subacromial impingement, and physiologic loading of the tendon and attrition over time. Genetics have also been shown to have a significant role in the predisposition of a patient to develop a tear; a family history of rotator cuff disease is very common. The most relevant factor in determining the presence of a tear in a patient presenting with shoulder pain is still patient age, which is supported by clinical studies. The older the patient, the higher the incidence of rotator cuff pathology.

Natural History

Because symptomatic rotator cuff tears are often treated, asymptomatic rotator cuff tears can tell us more about the natural history of the disease. Asymptomatic rotator cuff tears are surprisingly very common (in asymptomatic patients 60 years and older, 55% will have a RCT when evaluated by MRI). The progression of asymptomatic tears is an important consideration: in fact, one study showed that 51% of patients with an asymptomatic rotator cuff tear developed symptoms over an average time span of 2.8 years. As a general rule, 50% of asymptomatic rotator cuff tears will become symptomatic within 2 to 3 years. In addition, 50% of symptomatic full-thickness tears will progress at 2 years and bigger tears progress at a faster rate. Partial thickness tears are also likely to progress into full thickness tears with time. As a result, the management of a partial thickness rotator cuff tear poses a challenging clinical dilemma to the clinician. Generally speaking, partial thickness cuff tears where the tear is greater than 50% the diameter of the tendon are converted through surgery into full thickness tears and then repaired. If the tear is less than 50% of the tendon’s diameter, the approach and management strategy is more debatable. Biologics, including platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) or mesenchymal stem cells, may bridge this gap in the near future by helping reduce the incidence of these tears progressing in size and severity.

Physical Examination

Patients with rotator cuff tears complain of pain, weakness, and decreased range of motion within the shoulder joint. They may also complain of weakness and pain when completing usual activities of daily living that involve the hand at or above shoulder level (ex. brushing one’s hair or reaching for a glass in an elevated cupboard). Patients will also complain of difficulty with regular sporting activities or exercises that involved the shoulder (ex. tennis, golf, swimming, etc). In most cases, the symptoms develop gradually over time. Surprisingly, some patients with large tears will have very reasonable functionality. The patient may complain of localized pain, pain with use of the affected shoulder, and sleep disruption due to pain. In the event of a chronic rotator cuff tear, the physician may be able to identify atrophy of the supraspinatus and infraspinatus muscles which may be evident on physical examination through inspection and comparison of the patient’s shoulders. In this case, the examiner should examine for the presence of previous surgical incisions and test the range of motion of the shoulder. The shoulder should be tested with strength tests to isolate the various muscle of the rotator cuff. Tests such as the Belly press test, Lift-off test, and Bear-hug test can help test strength of the rotator cuff. The Neer impingement test, the empty-can test, and hornblower’s sign (inability to achieve external rotation in a 90-degree abducted position) can all help diagnose a rotator cuff tear.

Imaging and Diagnostics

The four standard shoulder radiographs can be taken to help determine whether further imaging is needed and to diagnose associated pathology around the shoulder. An X-ray will not show a full-thickness rotator cuff tear. However, an X-ray may show proximal humeral migration which may indicate a large, retracted rotator cuff tear. A T2 MRI can show rotator cuff tears as well as muscle atrophy. Alternatively, patients with a pacemaker may need a CT scan or an ultrasound to diagnose a rotator cuff tear. The gold standard (aside from shoulder arthroscopy) to diagnose a rotator cuff tear is an MRI of the shoulder. It is important to remember that in asymptomatic patients older than 60, approximately 55% will have a rotator cuff tear on MRI. Full-thickness tears can be clearly identified, muscle atrophy can be graded (via the Goutallier classification), and associated pathology can be identified and assessed (ex. biceps pathology, SLAP or other labral tears, glenohumeral osteoarthritis, AC joint osteoarthritis, etc.). Dr. Dold will typically order an MRI to assess for a rotator cuff tear and review the findings with you in his office.

Differential Diagnosis

  • Rotator Cuff Tendinitis

  • Partial-Thickness Rotator Cuff Tear

  • Rotator Cuff Contusion

  • Adhesive Capsulitis

  • Arthritis

  • Calcific Tendinitis

  • Biceps Tendon Pathology

  • Suprascapular Nerve Entrapment

  • Internal Impingement

  • SLAP or Labral Tear

Non-Operative Management

Some non-operative management options include anti-inflammatory medications (NSAIDs) and physical therapy. In some cases, a subacromial corticosteroid injection may be used to help relieve pain. One should remember, however, that multiple studies have been published which illustrate the negative effect of corticosteroid injections on the results of future surgery, if later indicated. As I have mentioned above, the treatment of a partial thickness rotator cuff tear is a difficult clinical dilemma. Orthobiologics (PRP and mesenchymal stem cells) may help limit or prevent the progression of these partial thickness tears over time.

Surgical Management

With the failure of conservative management options, surgical repair of the rotator cuff is often indicated. Dr. Dold will repair the rotator cuff arthroscopically through 3 to 4 keyhole size incisions around the shoulder. In addition, associated pathology around the shoulder can be treated at the same time as the rotator cuff repair. Following surgery, a PRP or mesenchymal stem cell injection is often used to help expedite healing and improve the integrity of the repair for improved function of the shoulder.

Post-Op

Patients are placed in a sling for approximately 6 weeks after surgery.  An abductor pillow is often used to relieve tension off the repaired tissue. It is important to note that the rate-limiting step for recovery is biologic healing of the repaired rotator cuff tendon to the greater tuberosity, which is believed to take between 8 and 12 weeks. Physical therapy usually begins within 2 weeks of surgery and focuses on regaining range of motion in the shoulder through passive and active-assisted range of motion exercises for the first 6 weeks. Active abduction of the shoulder is usually restricted for the first 6 weeks following surgery. You will be given a personalized, structured, detailed physical therapy protocol by Dr. Dold following your surgery which you will take with you to your first PT appointment. This will outline your various phases of rehabilitation following surgery up until 6 to 9 months post-op.

Complications

  • Infection

  • Anesthetic Complications

  • Postoperative Stiffness or Arthrofibrosis

  • Neurologic injury