Rotator Cuff Injury
What is a Rotator Cuff Injury?
Rotator cuff disease is a spectrum disease. Stage 1 is impingement syndrome which is a tendinosis and reversible with disease of the inflammation of the cuff. Stage 2 is partial thickness tearing with various forms including intrasubstance tearing, bursal surface tearing, PASTA lesions which are articular lesions, not part of the continuum. Stage 3 is a full thickness tear. This can become retracted and would equal a massive tear. There are also irreparable tears of the rotator cuff when they are allowed to exist in a chronic state where the tendon continues to retract to a point where it is reparable. Tears associated with chronic impingement syndrome typically begin on the bursal surface or within the tendon substance, in contrast to those that have the PASTA lesion which is an entirely different mechanism. This is undersurface tear due to instability or overload or tensile failure.
A variety of types of rotator cuff tears exist including full thickness tears that can be U-shaped or L-shaped, or can be a massive contracted pattern. The pattern is often used to determine the repair technique. The majority of tears involve the supraspinatus and infraspinatus. There can be involvement of the subscapularis tendon. Tears are classified as small (less than 1 cm), medium (1-3 cm), large (3-5 cm), and massive (greater than 5 cm). Classification does not predict prognosis as tears increase in size with chronicity and muscle fatty and fatty infiltration occur.
28% of patients older than 60 have full thickness rotator cuff tears. 65% of those older than 70 have a full thickness tear. Patients older than 60 with a tear have a 50% risk of having bilateral tears. Those with bilateral painful full thickness tears have a 56% chance of having an asymptomatic contralateral full or partial thickness tear. Of those with asymmetric tears, 50% will develop symptoms in three years and, in these patients, 40% may have progression of the tear.
On history and physical exam, patients typically present with the insidious onset of pain exacerbated by overhead activities, complaints of night discomfort, pain in the deltoid region, weakness and difference in active versus passive range of motion. More significant weakness and loss of motion indicate a higher degree of cuff involvement. Acute pain and weakness may be seen after traumatic rotator cuff rupture. In young athletes, it is critical to confirm or exclude glenohumeral instability as a cause of secondary impingement from primary impingement.
Typically x-rays are important to rule out other pathologic entities. Obtaining a Grashey view, an outlet view and an axillary view is standard for any shoulder evaluation. One of the measurements that is important is the subacromial height from the top of the humeral head. If this is 4 mm or greater, there is no proximal humeral migration. If it is less than, proximal humeral migration is considered and, if that is the case, this is a chronic irreparable rotator cuff tear. MRI is useful to define the extent of the tear, the degree of the tear and the retraction present, as well as submuscular atrophy and fatty infiltration. Tangent sign is defined as a failure of the supraspinatus belly to cross the line from the superior border of the coracoid to the superior border of the scapular spine. This has been found to correlate with muscle atrophy and fatty infiltration. Greater than 50% of supraspinatus atrophy would mean an irreparable tendon with poor prognosis, and a positive tangent sign would also point to an irreparable rotator cuff tear.
Nonoperative treatment for asymptomatic full thickness tears is possible for noncompliant elderly patients older than 65 years age, with medical complications to surgery and rotator cuff arthropathy, and athletes with a combined situation of instability and cuff tearing resulting from an articular sided partial thickness failure.
Activity modifications, avoiding repeated forward flexion beyond 90 degrees, and an aggressive program for strengthening the rotator cuff and stabilizing the scapula would be initiated. In addition, oral anti-inflammatory medications, therapeutic modalities and judicious use of steroid injections may be implemented.
Operative treatment is indicated for significant pain with full thickness tears that have failed to respond to nonoperative surgery. Full thickness acute tears should be repaired early because the disease process is accelerated in this setting.
Surgery reliably decreases pain and improves motion and function. The techniques are typically arthroscopic with an all arthroscopic approach. In some instances, it may be necessary to resort to a mini open or deltoid sparing technique. Regardless of the technique, the rate for biologic healing necessitated requires a minimum of 8-12 weeks. Acromioplasty is done only in situations where there is a small tear that is easily repaired. With a large full thickness tear, it is not recommended to perform an acromioplasty in the event that the repair fails.
It is necessary to have the ligament as a secondary restraint against the anterior/superior migration of the humeral head in the event of a failed rotator cuff. Repair of the rotator cuff is achieved from the peribursal tissue and bone anchor site. Vascularity has been shown to increase with exercise. Articular side partial thickness tears, tears that have more than 7 mm of bone lateral to the articular margin, should be considered significant when representing 50% of the tendon. Considerations include the depth of the tendon tear and the footprint.
Patients with a preponderance of impingement and a tear less than 50% may benefit from debridement and subacromial decompression. Large and massive tears have a higher failure rate. Irreparable tears are more likely to occur when the acromiohumeral distance is less than 7 mm. Larger more retracted tears 40 mm in length and width are characterized by fatty atrophy. Although excellent results have been reported with rotator cuff repair, a higher percentage of these tears either do not heal or recur. The majority of failures occur within the first 3-6 months. Failure typically occurs as a result of tissue pulling through the sutures. Despite the outcome, functional and subjective results remain excellent. Correlation appears to exist between younger age and repair success. Failure rates have been reported to be higher in the following patient groups: Age 65 years or older; Massive tear; Moderate to severe muscle atrophy; 50% fatty infiltration of the involved rotator cuff muscle belly; Tear retraction; Diabetes; Smokers; Inability to participate in rehabilitation.
Rehabilitation following rotator cuff repair is standard. Patients should have about six weeks of passive range of motion and then active range of motion should be started after six weeks.
Typically a time frame of greater than three months may be necessary, but usually three months is sufficient. Subscapularis tears can also occur and those would be repaired arthroscopically at the time of surgery.