Anatomy of the Components of the Rotator Cuff

The rotator cuff consists of four muscles. These are the subscapularis, the supraspinatus, the infraspinatus and the teres minor muscles. The supraspinatus muscle takes origin in the supraspinous fossa, and after its tendon fuses with the capsular fibers, it inserts into the greater tuberosity just posterior to the bicipital groove. The infraspinatus muscle takes origin from the infraspinous fossa on the posterior aspect of the scapula, and its tendon together with the fibrous capsule inserts into the greater tuberosity. The subscapularis muscle is a large, flat structure arising from the subscapular fossa. Some of the fibers of this muscle insert directly into the shaft of the humerus immediately below the tendinous insertion.

Pathogenesis of Rotator Cuff Tears

There are many etiologies implicated in the pathogenesis of rotator cuff tears: intrinsic factors, extrinsic factors, traumatic injuries or a combination of all these.

Intrinsic factors refer to injury mechanisms that occur within the rotator cuff itself. The reduced number of functional fibroblasts/fibrocytes may contribute to impaired collagen metabolism culminating in RC degeneration. There is an increase of apoptotic cells in degenerative supraspinatus tendon compared with normal subscapularis tendon that could affect the rate of collagen synthesis and repair. Impaired or dysfunctional protein synthesis may lead to weaker tendon and eventually increase the risk for rupture.

Extrinsic factors Clinical studies have found that the majority of pathologic changes occur on the articular side of the supraspinatus and infraspinatus tendon insertions, away from the acromion. Once RC damage and weakness occurs, the tendons are unable to effectively oppose the superior shear stresses imparted by the larger and stronger deltoid muscle. This leads to dynamic superior instability of the humeral head with arm elevation. This inappropriate superior migration of the humeral head causes secondary impingement of the RC against the Coracoacromial (CA) ligament arch. The CA ligament may experience increased tensile stress and undergo degenerative changes, forming a reactive traction spur at its insertion into the anteromedial corner of the acromion.

Type of Rotator cuff tear

Rotator cuff tears can be classified as: Full-thickness tears with complete detachment of the tendons from bone. This type of tear is also called a complete tear. Full-thickness tears are “through-and-through”. These tears can be small pinpoint, larger buttonhole, or involve the majority of the tendon where it still remains substantially attached to the humeral head and thus maintains function. Partial thickness cuff tears often appear as fraying of an intact tendon. This type of tear is also called an incomplete tear. It damages the tendon, but does not completely sever it.

Treatment of Rotator Cuff Tears

FULL-THICKNESS TEAR
Conservative treatment of full-thickness tear of the Rotator Cuff is indicated in patients whose symptoms do not involve significant pain. A functional improvement can be achieved by modifying the activities, intra-articular infiltration with cortico-steroids, and physical therapy to restore the strength to your shoulder, and in order to a re-education of muscle recruitment, coordination of muscle contraction, peri-scapular strengthening, maintenance of joint movement and improvement of proprioception. Patients should be instructed in long-term adaptation techniques through which they can avoid excessive stress on the shoulder girdle. Many different types of surgeries are available for rotator cuff injuries, but regardless of the procedure, it should be performed arthroscopically on the shoulder to minimize surgical aggression, and consequently cause less postoperative pain and accelerate recovery:

  1. Debridement and decompression – The sole purpose is to soften pain in patients whose function is relatively preserved, or in those patients unable to co-operate with an extensive rehabilitation program. The pain may be due to a “bursitis” or inflammation of the bursa overlying the rotator cuff or a “tendonitis” of the cuff itself. In some cases, a partial tear of the rotator cuff may cause impingement pain;
  1. Tenotomy or tenodesy – This procedure is indicated for the treatment for partial or full-thickness biceps tendon tears, severe biceps tendonopathy, or biceps instability associated with a rotator cuff tears. Biceps tenodesis involves detaching the LHB from its superior labrum in the shoulder and reattached to the humerus bone just below the shoulder;
  1. Rotator cuff complete repair – The difficulty in mobilizing the tendon to its insertion site in the trochyter is potentially overcomed by removing adhesions and releasing the interval between the joint capsule and the labrum glenoid, but complete repair may be conditioned by the quality of the existing tendon, and also because excessive tendon mobilization (greater than 3 cm) may lead to suprascapular nerve injury, with inferior results.
  1. Rotator cuff repair with graft augmentation – It still lacks legal basis, with some studies showing 100% failure rates, and prospective randomized comparative studies showing worse results in cases where the graft was used in the repair.
  1. Partial thickness tears – When a repair cannot be accomplished because of insufficient tendon quantity and quality the comfort and function of the shoulder are often improved by a “smooth and move” procedure in which the upper surface of the rotator cuff and the arm bone (humerus) are smoothed and immediate post-operative motion is used to prevent the reformation of scar tissue.
  1. Tendon transfer surgery – Depending on the type of injury, Latissimus dorsi muscle, Subscapularis muscle or Pectoralis major may be an option in young patients whose primary complaint is muscle weakness, and whether a complete or a partial repair of the Rotator Cuff, is not feasible.
  1. Reverse total shoulder replacement – A reverse total shoulder replacement works better for people with cuff tear arthroplasty because it relies on different muscles to move the arm. Reverse total shoulder replacement may be recommended for elderly patients who have tried other treatments, such as rest, medications, cortisone injections, and physical therapy, that have not relieved shoulder pain. It has to be an open repair surgery.

 

ROTATOR CUFF TEARS
Although the conservative treatment does not promote the healing of a tear, it is effective in patients whose symptoms do not involve significant pain. Nevertheless, the patient should be informed of the natural course of tendon rupture, as one of the aims of surgical treatment is to prevent the progression to a massive rupture of the rotator cuff. When conservative treatment is performed, age, activity, and the patient’s expectations should be taken into account. As conservative treatment is usually more effective in patients under 60 years and if they have a good chance of recurrence, surgery should be the option. Nevertheless, for elderly individuals with few functional expectations, the conservative approach could be justified.

PARTIAL TEAR OF THE ROTATOR CUFF
In the event of a partial rupture of the symptomatic rotator cuff, treatment should aim at correcting the primary diagnosis, such as a sub acromial impingement, or shoulder instability, which may be producing secondary partial tear. During this time, non-invasive treatments can be attempted to allow the tendon to heal whether by modifying activities or by using non-steroidal anti-inflammatory medication. The doctor might recommend, as well, a steroid injection into the shoulder joint. Physical therapy can help to restore and maintain normal shoulder mechanics, and can often address the symptoms caused by the injury. If the symptoms have lasted up to three months, then surgery has to be considered. There are a few different ways to address a partial tear of the rotator cuff at the time of surgery, depending on the type of injury. Determining the proper surgical procedure depends on which arthroscopic measures are performed. Surgical repair options depend on the patients’ age or activity. While debridement might be recommended for older people, on the other hand, for active, young people rotator cuff repair might be the best option.
No matter what type of surgery you have, a full recovery will take time. The surgeon; physiatrist and physiotherapists will work to reduce your pain, which can help you recover from surgery faster. Recovery from arthroscopic surgery is typically quicker than open tendon repair. Since open tendon repair is more involved, you may also have more pain right afterwards. The patient’s specific limitations can be specified only by the surgeon who performed the procedure. Physical therapy will be a key part of your recovery. The movements you learn will help you regain your shoulder strength and range of motion. If you have been through debridement and decompression the surgeon will focus mainly on pain control and early active mobilization.

Bibliography
  1. Mazzocca AD, Cole BJ, Romeo A. Arthroscopic repair of full-thickness rotator-cuff tears: surgical technique. Operative Techniques Jh Orthopaedics, 2002. 12(3): 167-175
  1. Stetson W, Ryu R. Bittar E. Arthroscopic Treatment of Partial Rotator Cuff Tears. Oper Tech Sports Med. 12:135-148. 2004.
  1. McConville O, Iannotti JP: Partial thickness tears of the rotator cuff: Evaluation and JAAOS 17:32-43, 1999
  1. Walch G, Boileau P, Noel E, et al: Impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim: An arthroscopic study. J Shoulder Elbow Surg 1:238-45, 1992
  1. Neri BR, Chan KW, Kwon YW. Management of massive and irreparable rotator cuff J Shoulder Elbow Surg 18: 808-818, 2009
  1. Sclamberg SG, Tibone JE, Itamura JM, Kasraeian S. Six-month magnetic resonance imaging follow-up of large and massive rotator cuff repairs reinforced with porcine small intestinal submucosa. J Shoulder Elbow Surg. 13:538-41, 2004
  1. Iannotti JP, Codsi MJ, Kwon YW, Derwin K, Ciccone J, Brems JJ. Porcine small intestine submucosa augmentation of surgical repair of chronic two-tendon rotator cuff tears. A randomized, controlled trial. J Bone Joint Surg Am. 88:1238-44, 2006
  1. Burkhart SS. Partial repair of massive rotator cuff tears: the evolution of a concept. Orthop Clin North Am. 28:125-32, 1997
  1. Mallon WJ, Wilson RJ, Basamania CJ. The association of suprascapular neuropathy with massive rotator cuff tears: a preliminary report. J Shoulder Elbow Surg. 15:395-8, 2006