Abstract
Arthroscopic management of rotator cuff tears is one of the greatest changes of the past 25 years. It has become a standard procedure, but the techniques are variable and are advancing with technology. The basics of management, though, have remained the same. Diagnostic tools include clinical exam and history, ultrasound, magnetic resonance imaging, magnetic resonance arthrography, and arthroscopy itself. We have a better understanding of the natural history of rotator cuff tears and can better recommend surgical and nonsurgical options. Surgical fundamentals include glenohumeral joint inspection, subacromial space inspection, partial bursectomy, assessment of rotator cuff tendon reparability, identification of tear geometry, coracoacromial ligament management, acromioplasty, greater tuberosity repair site preparation, anchor placement, suture placement, and knot tying. The standard types of repair include single row, double row, and transosseous equivalent repairs. Initially, only supraspinatus and infraspinatus tears were addressed arthroscopically, but with arthroscopy, we can now better identify subscapularis tears and repair them as well.
Keywords
supraspinatus, subscapularis, single row, double row, transosseous equivalent, rotator cuff repair
An arthroscopic rotator cuff repair consists of the following elements: glenohumeral joint inspection, subacromial space inspection, partial bursectomy, assessment of rotator cuff tendon reparability, identification of tear geometry, coracoacromial ligament (CA) management, acromioplasty, greater tuberosity repair site preparation, anchor placement, suture placement, and knot tying. Each of the individual elements can be accomplished arthroscopically; however, performing them in a single operation requires strict adherence to a systematic operative technique.
Historical Review
Since the mid-1990s, the repair of full-thickness rotator cuff tears has undergone a transition from open techniques to combined open and arthroscopic methods (mini-open repair) to exclusively arthroscopic repairs. During this time, orthopedic surgeons have documented the successful arthroscopic treatment of the entire spectrum of rotator cuff lesions, including impingement and partial- and full-thickness tears.
Initially, the issue was one of efficacy—whether an expert surgeon could technically reproduce all the elements of an open rotator cuff repair arthroscopically. Despite a modest amount of skepticism, the orthopedic community recognized that this was possible. The next step was to determine whether other surgeons could reproduce the operation—the effectiveness issue. This too was resolved (after some interesting sturm und drang ) in favor of arthroscopic rotator cuff repair. Analyses of the clinical results paralleled these technical issues, but necessarily followed them as we awaited patient follow-up. As reports demonstrated patient outcomes as good as or better than those obtained with open repair, the general consensus emerged that arthroscopic rotator cuff repair was a successful operation.
A great degree of attention was focused (and continues to be focused) on the technical aspects of the operation, such as anchor types, suture patterns, suture materials, and instruments. More recently, studies have focused on healing rates after arthroscopic rotator cuff repair, using methods such as magnetic resonance imaging (MRI), contrast-enhanced MRI or computed tomography, and diagnostic ultrasonography. These studies present a wide spectrum of healing rates ranging from 90% for isolated supraspinatus tears to 0% for large and massive tears. Appropriately, this is an area of intense focus. Most interesting is the interpretation of why healing rates are so low. At least one editorial has attributed low healing rates to arthroscopic repair techniques. Those who fault arthroscopic repair argue that arthroscopic healing rates are inferior to the good clinical results of open rotator cuff repair. However, this is a breakdown in intellectual reasoning because it is a classic “apples to oranges” comparison. Critics do not compare the clinical results of arthroscopic rotator cuff repair to the clinical results of open repair, nor do they compare the MRI or ultrasound (US) healing rates of arthroscopic repair to the healing rates of open repair (although this would be valuable information). Instead, there is an oblique linking of two related but not truly comparable concepts: clinical outcome and anatomic healing. The thinking appears to be that the good clinical results of open rotator cuff repair were the result of a high anatomic tendon-to-bone healing rate. However, there is no evidence that this is true. Early arthrogram studies demonstrated a high percentage of patients with dye leakage, and Harryman’s classic US work demonstrated that 80% of isolated supraspinatus tears and less than 50% of large tears were healed. Somehow these studies were dismissed as aberrant because everyone knew that their own results were inconsistent with such high failure rates. Again, intellectual confusion occurred. Surgeons knew that their clinical results were good and therefore assumed that their anatomic results must be good as well, despite scientific evidence to the contrary. It was as if we could not believe that Harryman’s healing rates applied to our own efforts. Further, our misplaced confidence in anatomic healing affected patients’ rehabilitation regimens. Because we knew the repair was secure and would heal, the most important obstacle became return of motion; thus, the prevailing dogma was early passive range of motion. These notions were called into question by the work of Deutsch, who demonstrated better rotator cuff repair healing with a rehabilitation program that moved more slowly than previous protocols called for. This concept has subsequently been reinforced in several studies.
The real lesson in this dialogue is that although patients do well clinically in the early to midterm period, we should try to increase the rate of anatomic healing for potential longer-term benefit. This can be attempted by changing the repair construct (double-row suture bridge), rehabilitation program (limited, gentle, passive range of motion), and outcome analysis (diagnostic ultrasonography to evaluate repair integrity). Furthermore, in the future, biologic and synthetic measures will likely help us increase tendon healing to bone.
Diagnosis
The clinical presentation of patients with full-thickness rotator cuff tears is similar to that of patients with impingement, although complaints of weakness, particularly with overhead activity, may be greater. Plain radiographs are essential to evaluate the shoulder for glenohumeral arthritis, superior migration of the humeral head, acromioclavicular joint arthritis, inferior acromioclavicular joint spurs, and acromial shape. MRI provides information about the size and retraction of the rotator cuff tear and, more important, the degree of atrophy and fatty infiltration of the rotator cuff muscles ( Figs. 12.1–12.5 ).
The findings of the clinical examination are most commonly correlated with those of radiologic studies (arthrography, MRI, diagnostic ultrasonography) to make the diagnosis. Arthroscopy can also be used to diagnose the presence and size of a complete rotator cuff tear, although no authors have suggested that this be done routinely. The arthroscope is most useful in diagnosing complete tears in patients who have false-negative imaging studies. False-negative results occur most frequently with arthrography, particularly if the synovial lining remains intact, or with MRI if the tear is smaller than 1 cm. The injection of contrast material (gadolinium) can be helpful in increasing the accuracy of MRI, particularly in patients with partial-thickness rotator cuff tears.
Management
The basic elements of nonoperative treatment are similar to those for patients with impingement. They consist of selective rest and activity modification (avoidance of painful activities and positions), nonsteroidal antiinflammatory medication to reduce pain, and a home rehabilitation program designed to correct deficits of motion (with passive stretching) and to strengthen the uninvolved shoulder muscles.
The presence of a full-thickness rotator cuff tear is not an absolute indication for operation. The decision for surgery is complex, and a long list of factors to consider include patient age, patient activity level, patient’s desired function, patient willingness to endure a long surgical recovery, patient compliance, size of tear, retraction of the tear, site of the tear, health of the muscle, acuity of the injury, pain, and functional deficit. Older patients with nontraumatic tears with minimal pain and minimal perceived functional deficit can be treated non-operatively. When patients first present with a nontraumatic tear with pain and a functional deficit, they are offered non-operative management, and their progress is followed for a 6- to 12-week period. At that point, if a patient has significant pain or functional impairment, the decision to operate is straightforward. If their pain is controlled and they have good function, options are discussed. They are informed that our current understanding of full-thickness rotator cuff tears is that the best results are achieved with prompt surgical repair. Delay in repair results in tendon retraction, muscle atrophy, and fatty infiltration, which can have no positive impact on the ultimate outcome. It is explained that they may find that their symptoms recur in the future and their tear may or may not be reparable.
We usually recommend surgery for acute tears of the supraspinatus, infraspinatus, and subscapularis if there is an acute loss of function, no atrophy, and no fatty infiltration, unless the patient is low demand or has a contraindication for surgical management. If the tear is partial or small, we may recommend non-surgical management. For all acute subscapularis tears, we recommend surgery as soon as possible. The surgeon must review the MRI carefully to ensure that the “acute” tear is not an acute on chronic tear that is perhaps not reparable. Sometimes the acute loss of function is due to an acute on chronic injury.
The decision is also easier in patients who already have significant tendon retraction and muscle atrophy; in these patients, nonoperative treatment is less risky because the rate of tendon healing after operation is low, and pain relief is the goal.
Surgery Discussion
Although the skin incisions are smaller and the deltoid is left attached when comparing arthroscopic and open surgery, arthroscopic repair still incorporates all the elements of open repair, so the pain of surgery is still moderate and the recovery time is still similar. It is important to convey this to the patient. The benefits of arthroscopy are improving the visualization of the tear and associated pathology, lessening the pain due to the lack of a large skin incision, lowering the potential for infection, eliminating the incidence of deltoid repair failure, and reducing the severity of deltoid adhesions from the lack of an incision.
It is helpful to present patients with printed information or referral to websites outlining the postoperative rehabilitation and activity limitations. Patient retention of this information is generally poor, so the visual information is helpful.
Operative Technique
Anesthesia
We use interscalene block anesthesia supplemented with general anesthesia. Regional anesthesia lessens the use of an anesthetic agent, minimizes postoperative side effects, and provides excellent pain relief in the postoperative period. General anesthesia eliminates movement due to patient discomfort on the operating table.
Positioning
We prefer to have the patient in the sitting position. The orientation of the shoulder is similar to that during open procedures, and this position allows easy access to the anterior, lateral, and posterior aspects of the shoulder. Particular attention is paid to the inclination of the acromion, which should be horizontal. The amount of posterior acromial slopes varies from patient to patient, and failure to position the patient so that the acromion is parallel to the floor results in the surgeon directing the arthroscope more vertically and having to work “uphill.” Patient positioning is greatly facilitated by the use of a specialized bed that exposes the shoulder blade and that has an armholder. We use the Schloein patient positioner (Orthopedic Systems Inc., Union City, California), and the arm is controlled with a McConnell arm holder (McConnell Orthopedics, Greenville, Texas) or a Spyder arm positioner (Smith-Nephew Endoscopy, Andover, Massachusetts). The Schloein speeds patient positioning and allows excellent access to the posterior shoulder without translating the patient off the side of the operating table. The Spyder or the McConnell allows the surgeon to position the arm without help from the assistant, and is invaluable in maintaining proper arm rotation so that the repair site is directly underneath the operating cannula ( Figs. 12.6 and 12.7 ).
Portals
Three or four standard portals are used depending on the technique. If the repair is done with the camera in the posterior portal, an additional lateral, and anterior portal are needed. If the repair is done with the camera in the lateral portal, an anterolateral portal is added. The posterior portal is within 1 cm medial and inferior to the posterolateral acromial border and is more superior to the traditional point of entry in the “soft spot” so that the arthroscope enters the subacromial space parallel to, and just underneath, the acromial undersurface ( Fig. 12.8 ). This maximizes the distance between the arthroscope and the rotator cuff tear and improves the surgeon’s ability to determine tear size and geometry. The lateral portal is at the midway point of the lateral acromion approximately 2 to 4 cm lateral to the acromion, and the anterior portal is anterior to and within 2 cm of the anterolateral acromial corner. The anterolateral portal is about 4 cm distal to the anterolateral acromial corner down between the anterior and lateral portals. Besides the posterior portal, all of the portals have some variability as they are established using the outside–in technique with a spinal needle ( Fig. 12.9 ).
The lateral portal should allow the cannula to enter midway between the humeral head and the acromion. This location facilitates acromioplasty and enables the surgeon to tilt the cannula inferiorly toward the humeral head for easy placement of suture anchors in the greater tuberosity for rotator cuff repair. It also allows for a good view when performing the repair with the camera laterally ( Figs. 12.10 and 12.11 ). This is especially helpful for subscapularis repairs.
The anterior cannula is used for retrieving sutures, but it can also be used for insertion of an anterior anchor and for lesser tuberosity anchors. This cannula is inserted after the acromioplasty. The precise location is identified with a spinal needle. If the cannula is too medial, it is difficult to retrieve sutures from the anchors owing to interference from the patient’s head. Conversely, suture retrieval from the bursal rotator cuff surface is difficult if the anterior cannula is located too laterally ( Figs. 12.12 and 12.13 ). Other accessory portals are used as needed.
Glenohumeral Joint
The range of motion and stability of the shoulder are examined under anesthesia prior to arthroscopic glenohumeral joint inspection. Intra-articular lesions are not visualized during open repair, precluding an adequate comparison with arthroscopic findings. Most arthroscopic studies report abnormalities, such as focal synovitis, partial biceps tendon tears, arthritic changes in the humeral head or glenoid, labrum tears, and loose bodies. It is uncertain whether these intra-articular lesions arise because of the cuff tear or are merely part of the normal aging process. Arthroscopic findings in older patients with irreparable tears include arthritic changes, synovitis, and biceps tendon tears. Not surprisingly, these findings occur with a higher frequency than in patients with partial or complete rotator cuff tears that are reparable. Overall, glenohumeral joint abnormalities occur in 12.5% of patients and include osteoarthrosis, biceps tendon tears (partial or complete), labrum tears, labrum separations (superior labrum from anterior to posterior [SLAP] lesions), synovitis, and capsular contracture. During arthroscopy of the glenohumeral joint, full-thickness tears can be visualized and marked with a spinal needle if required ( Fig. 12.14 ). The anterior portal is often established here to palpate structures and to view the posterior structures prior to entering the subacromial space. Subscapularis tears are addressed later in the chapter, but repair can be initiated or completed in the glenohumeral space.
Subacromial Space
The cannula and trocar are redirected through the same posterior skin incision into the subacromial space and used to palpate the acromial undersurface. The cannula is swept medially and laterally to make certain that no portion of the rotator cuff is adherent to the acromion ( Figs. 12.15–12.17 ).
The arthroscope is then inserted. The camera is oriented so that the acromion appears horizontal and parallel to the floor. The maximal distance between the arthroscope and the tendon lesion should be maintained to allow optimal viewing of the tendon tear ( Figs. 12.18 and 12.19 ).
The lateral portal is identified with a spinal needle inserted percutaneously and positioned midway between the acromion and the greater tuberosity. The goal is to have the lateral cannula positioned in the center of the rotator cuff tear in the anterior–posterior plane and midway between the acromion and the rotator cuff insertion site (see Fig. 12.10 ). A stab wound is made and either a cannula is placed or instruments are placed directly through the skin. The first goal is clear visualization of the subacromial space. Bursae that obscure visualization are removed with a power shaver ( Fig. 12.20 ). Care is taken removing any bursa medial to the rotator cuff musculotendinous junction, because this area is very vascular. A cautery may be used here. Once good visualization is obtained, the acromion and CA are examined for signs of impingement such as erythema, fraying, and fibrillation ( Fig. 12.21 ).
Often, an anterior portal has already been established to examine the glenohumeral joint. If so, the anterior cannula is inserted and redirected into the subacromial space. If not, one is established using a spinal needle ( Figs. 12.22–12.25 ).
Tear Classification
The arthroscope is rotated so that it points directly down at the rotator cuff tear. With small to medium-sized tears, their size and geometry are easily appreciated. Tear size is measured by comparing it to the known diameter of the lateral cannula or measuring it with an arthroscopic probe. The length of the tear from anterior to posterior, as well as the amount of medial retraction, is noted ( Figs. 12.26–12.31 ).
Straight medial retraction or retraction in an elliptical shape is the most common finding. As the tear size increases, the surgeon is less able to appreciate tear geometry. In the right shoulder, reverse L -shaped tears with a longitudinal component along the rotator interval allow the tear to rotate posteriorly. L -shaped tears have a longitudinal limb posteriorly, often at the junction of the supraspinatus and infraspinatus, in addition to the lateral, transverse detachment at the greater tuberosity ( Figs. 12.32–12.36 ). Longitudinal tears may occur in the area of the rotator interval and occasionally within the substance of the supraspinatus.
Only when tear geometry is appreciated can the surgeon perform an effective repair. For this reason, it is helpful to put the arthroscope in the lateral portal. A tissue grasper is used to pull on the tear edge, attempting to determine the repair site location. Varying both the direction of pull and the arm positions of elevation, abduction, and rotation is often required. Typically, the arm is positioned in 20 degrees of elevation, 15 degrees of abduction, and 10 degrees of internal rotation ( Figs. 12.37–12.46 ). The arm is maintained in this position with a mechanical arm holder (e.g., Spyder or McConnell).
Coracoacromial Ligament and Acromioplasty
A soft tissue subacromial decompression and acromioplasty is done as described in previous chapters. Care is taken to preserve as much of the CA as possible. The primary indication for an acromioplasty in a patient with a full-thickness or bursal rotator cuff tear is for a type 2 or 3 acromion with a frayed CA ligament attachment. The goal of acromioplasty is to increase the size of the subacromial space. Therefore, it is indicated if the subacromial space is tight, limiting visualization and instrument maneuvering. A type 2 or 3 acromion is converted to a flat, type 1 acromion. Unless the bone is extremely thick, there is no need to perform acromioplasty for a type 1 acromion.
Acromioclavicular Joint
After the soft tissue decompression and acromioplasty, if appropriate, are completed, the acromioclavicular joint comes into view. Routine clavicular coplaning (removing the inferior one-third of the distal clavicle with a bur) or distal clavicle excision is not indicated. If the patient has symptoms consistent with acromioclavicular joint arthritis based on the preoperative history (pain localized to the acromioclavicular joint with cross-body adduction or behind-the-back internal rotation) and examination (acromioclavicular joint tenderness on palpation), a distal clavicle excision is warranted. This can be done prior to or after the rotator cuff repair. We prefer to do it after the rotator cuff repair in order to minimize swelling of the shoulder during the rotator cuff repair.
Cuff Mobilization
Adhesions may form within the subacromial space between the rotator cuff and the acromion or between the rotator cuff and the deltoid, interfering with tendon mobilization. Adhesions to the coracoid or a coracohumeral ligament contracture may restrict rotator cuff tendon excursion and thereby give the false impression of irreparability.
Posterior adhesions usually are not dense and can often be released by inserting a metal trocar and cannula through the lateral portal, placing it superior to the anterior tear edge and sweeping it posteriorly directly beneath the acromion. Occasionally, electrocautery is used to divide adhesions if they are particularly thick. It is unwise to attempt to remove dense adhesions with a power shaver; bleeding often results, and it is difficult to control owing to the medial location of the bleeding vessels. Anterior adhesions to the coracoid are usually very thick and require release with electrocautery. This is particularly true in the area of the coracohumeral ligament ( Figs. 12.47–12.49 ).
Repair Site Preparation
The next step is preparation of the bone surface at the repair site. A power shaver or power bur is used to prepare a cancellous bed for the tendon. One millimeter or less of cortical bone is removed until a bleeding surface is visible ( Figs. 12.50–12.53 ).
