As described in Chapter 53 , rotator cuff tears can be successfully treated nonsurgically. However, atraumatic tears that fail nonoperative treatment and traumatic tears are commonly treated surgically. This chapter describes tear patterns and classification and discusses the options for operative management. Finally, the expected structural and functional outcomes of rotator cuff repair are reviewed.
Classification of rotator cuff pathology
Normal shoulder function requires balanced forces on the front and back of the shoulder, normal capsular laxity, and concentricity of the glenohumeral and cuff-coracoacromial spheres of rotation. , Rotator cuff pathology spans a spectrum of severity that includes rotator cuff tendinopathy, partial-thickness tears, full-thickness tears, and rotator cuff arthropathy. Physical examination can assist in making the diagnosis, but often advanced imaging is required to distinguish tendinosis, partial-thickness tears, and small full-thickness tears—all of which can cause anterolateral shoulder pain and present without substantial weakness.
The terms rotator cuff tendinitis and tendinopathy are often used interchangeably to describe a broad range of painful conditions of the shoulder. However, the term tendinitis implies inflammation and may be misleading because numerous studies have shown that little inflammation is actually present in these syndromes. , The terms tendinosis or tendinopathy may be more appropriate in this setting.
Numerous classification systems have been devised to try to better describe rotator cuff pathology. Neer initially described three different stages of cuff lesions :
Stage 1: Reversible edema and hemorrhage are present in a patient younger than 25 years.
Stage 2: Fibrosis and tendinitis affect the rotator cuff of a patient typically in the 25- to 40-year-old age group. Pain often recurs with activity.
Stage 3: Bone spurs and tendon ruptures are present in a patient older than 40 years.
Neer’s original classification of rotator cuff pathology has been subsequently modified by many other classification systems to include the structural integrity of the tendon and also to differentiate between articular-sided partial-thickness tears, bursal-sided partial-thickness tears, and intrasubstance delamination. As imaging techniques and technology advanced with time, classification systems began incorporating more tear characteristics, including tear size, tear shape, and muscular atrophy.
A commonly referenced classification system for partial-thickness tears was described by Ellman and is based on tear location, depth, and area ( Table 54.1 ). This is considered a subclassification of the stage 3 cuff lesion described by Neer. Grade 1 involves less than 3 mm of tendon or a quarter of the footprint thickness, grade 2 involves 3 to 6 mm or less than half of the footprint thickness, and grade 3 involves greater than 6 mm of the footprint. Tears are also divided into articular-sided, bursal-sided, or interstitial.
Snyder et al. devised a more detailed classification system based on arthroscopic findings. In this system, A, B, and C represent articular-sided, bursal-sided, and complete tears. Grade 0 represents a normal rotator cuff, grade 1 is superficial fraying less than 1 cm in size, grade 2 involves fraying 1 to 2 cm in size, grade 3 is tissue disruption in 2 to 3 cm of tendon, and grade 4 is a substantial cuff tear that involves a sizable flap and more than one tendon.
Habermeyer et al. also developed a classification for articular-sided tears based on arthroscopic findings that not only accounts for size in the coronal plane but also accounts for sagittal tear extension. In this classification, type A tears involve the coracohumeral ligament up to the medial border of the supraspinatus, type B tears are isolated within the crescent tissue, and type C tears extend from the lateral border of the pulley system over the medial border of the supraspinatus to the crescent tissue.
Despite the numerous types of classifications for partial-thickness tears, studies have demonstrated poor interobserver reliability in distinguishing tears that are greater than and less than 50% using both magnetic resonance imaging (MRI) and arthroscopic examinations. ,
There are numerous classification schemes of full-thickness tears, all of which are extremely diverse in their attempts to describe the tear size, number of tendons involved, tear shape, chronicity, tendon quality, and muscle atrophy.
Tear size/number of tendons torn
One of the most commonly used classifications for the size of full-thickness rotator cuff tears was described by DeOrio and Cofield. Groups are stratified by tear size from anterior to posterior: less than 1 cm is small, 1 to 3 cm is medium, 3 to 5 cm is large, and more than 5 cm is massive.
A classification system described by Harryman et al. is based on the size and number of tendons involved. Stage 0 is an intact rotator cuff, stage IA is a partial-thickness tear of the supraspinatus, and stage IB is a full-thickness tear involving only the supraspinatus. Stage II includes the supraspinatus and a portion of the infraspinatus. Stage III includes the supraspinatus, infraspinatus, and subscapularis tendons. Stage IV is used to describe rotator cuff arthropathy.
A classification developed by Ellman and Gartsman attempted to characterize tears by their three-dimensional shapes. This classification includes crescent, reverse L, L-shaped, trapezoidal, and massive tears ( Fig. 54.1 ).
Burkhart also described a classification system based on tear pattern. Type 1 tears are crescent tears that are short on the coronal image but wide on the sagittal image. Type 2 tears are U- or L-shaped tears that are wide on the coronal image and short on the sagittal image. Type 3 tears are massive tears that are wide on both coronal and sagittal imaging. Type 4 tears are massive tears with concomitant glenohumeral arthrosis. The advantage of this classification is the potential for guiding repair technique: type 1 tears may benefit most from tendon-to-bone repair, whereas type 2 tears may benefit from margin convergence.
Patte developed a complex and comprehensive classification system that incorporates both tear size coronal and sagittal imaging, tendon retraction, muscle atrophy, and integrity of the long head of the biceps tendon ( Box 54.1 ). Topography in the frontal plane is grouped into three stages ( Fig. 54.2 A): stage 1 is minimal retraction, stage 2 is tendon retraction to the level of the humeral head, and stage 3 is tendon retraction at the level of the glenoid. In the sagittal plane, tears were grouped into six segments (see Fig. 54.2 B–C).
Extent of tear
Group I: Partial tears and full-thickness tears <1 cm in sagittal diameter
A: Deep, partial tears
B. Superficial tears
C. Small, full substance tears
Group II: Full substance tears of the entire supraspinatus
Group III: Full substance tears involving more than one tendon
Group IV: Massive tears with secondary osteoarthritis
Topography of tear in sagittal plane
Segment 1: Subscapularis tear
Segment 2: Coracohumeral ligament tear
Segment 3: Isolated supraspinatus tear
Segment 4: Entire supraspinatus and half of infraspinatus tear
Segment 5: Entire supraspinatus and infraspinatus tear
Segment 6: Subscapularis, supraspinatus, and infraspinatus tear
Topography of tears in frontal plane
Stage 1: Proximal stump close to bony insertion
Stage 2: Proximal stump at level of humeral head
Stage 3: Proximal stump at level of glenoid
Trophic quality of muscle of torn tendon
State of long head of biceps
Muscle atrophy and fatty infiltration
The most common reference for classification of fatty infiltration of the rotator cuff musculature is that described by Goutallier et al. Advanced muscle atrophy typically indicates chronic retraction of a tear, which has been shown to be of prognostic importance and should be considered in all rotator cuff tears. Table 54.2 shows the successive stages of fatty infiltration that were originally described by Goutallier on a sagittal computed tomography cut that incorporates the tip of the coracoid and the inferior glenoid. This classification has since been adapted for use on T1 sagittal oblique imaging on MRI ( Fig. 54.3 ). Fuchs has simplified the original Goutallier classification to three categories by combining grades 0 and 1 as normal and grades 3 and 4 as advanced degeneration.
|Grade 0||Normal muscle without fatty streaks|
|Grade 1||Muscle has some fatty streaking|
|Grade 2||Fatty infiltration present but less than muscle|
|Grade 3||Equal amount of fat and muscle tissue|
|Grade 4||More fat than muscle|
Two other methods have been described to characterize the amount of muscle atrophy. Zanetti’s “tangent sign” is a simple binary method of defining atrophy. A line is drawn from the superior border of the coracoid to the superior border of the scapular spine ( Fig. 54.4 ). If the muscle belly of the supraspinatus fails to intersect this line, the tangent sign is positive and indicates significant muscular atrophy. Thomazeau et al. described an “occupation ratio” that takes into account the cross-sectional area of the muscle belly in relation to the size of the fossa. This measurement is performed on a sagittal oblique cut at the level of the medial border of the coracoid process. An occupation ratio between 0.6 and 1.0 is considered normal or indicates slight atrophy; 0.4 to 0.6 indicates moderate atrophy; and less than 0.4 indicates severe atrophy.
A grading system specific for subscapularis tears was described by LaFosse et al. Type I involves a partial-thickness tear of the superior third of the subscapularis, type II involves a complete tear of the superior one-third, type III involves a complete tear of the superior two-thirds, type IV is a complete tear of the entire tendon with a well-centered head and less than 50% fatty infiltration, and type V is a complete tear with significant fatty infiltration. Partial- or full-thickness tearing of the subscapularis should increase suspicion for long head of biceps subluxation and tearing.
Arthroscopic rotator cuff repair
Advances in arthroscopic equipment and increased surgeon familiarity with shoulder arthroscopy have made arthroscopic surgery the preferred method of rotator cuff repair for many shoulder surgeons. It offers numerous advantages over traditional open repair techniques. More thorough visualization, diagnosis, and treatment of lesions within the joint are facilitated. Arthroscopy allows a more comprehensive assessment of intra-articular pathology and rotator cuff tear configuration by viewing from multiple angles. Tendon mobilization is also facilitated by precise releases of adhesions that limit tendon excursion, leading to an improved ability to anatomically reduce the edge and create a tension-free repair. Injury to the deltoid muscle is minimized. The acromial deltoid origin is preserved, eliminating the risk of deltoid dehiscence, a potentially devastating complication. The risk of infection is also lessened by arthroscopy. Another key theoretical benefit of arthroscopic repair is decreased postoperative pain secondary to less soft tissue trauma. This aids in postoperative rehabilitation and may help to minimize narcotic use postoperatively.
A potential disadvantage of arthroscopic repair had historically been the inability to completely mirror the open procedure with regard to fixation options. Concerns due to the necessity of using suture anchors as fixation and the inability to use tissue-grasping stitches have eased with the advent of improved implants, suture materials, suture-passing devices, and anchor-less arthroscopic techniques. Anatomic footprint restoration is now possible, with fixation at both the suture-tendon interface and the anchor-bone interface that approximates traditional open transosseous repairs.
Historically, arthroscopic repair was performed using a single row of bone anchors placed within the tuberosity ( Fig. 54.5 A). The double-row technique involved the use of two rows of suture anchors, one medially and one laterally (see Fig. 54.5 B). This allows for additional points of fixation of the tendon to the bone and better coverage of the footprint area. Newer techniques have involved using a medial row of suture anchors, with suture strands passed to a lateral row of anchors to compress the tendon down to the bone (see Fig. 54.5 C). The double-row technique has been advocated as a better biomechanical construct and a more anatomic repair strategy. Although in biomechanical studies the double-row repair outperforms single-row repair in failure strength, superior clinical results with double-row fixation over single-row fixation is still controversial. ,
The goal of surgical repair is to restore the attachment of the torn cuff tendon(s) back to its (their) insertion on the tuberosity in a near anatomic fashion with minimal tension to best restore the proper muscular balance of the rotator cuff and allow for healing.
Arthroscopic rotator cuff repair can be performed with the patient in either the beach chair or lateral decubitus position. The beach chair position allows for easier movement of the surgical extremity and the ability to convert to an open procedure if needed. The lateral position avoids the cerebral desaturation events that can be experienced in the beach chair position. General or regional anesthesia can be used depending on the surgeon’s and anesthesiologist’s preferences. Bursal bleeding may limit visualization in the subacromial space, which may be minimized by hypotensive general anesthesia. The use of a regional nerve block (interscalene block) in conjunction with general anesthesia is useful in postoperative pain control and may also help intraoperatively with blood pressure management.
After a sterile prep and drape and administration of appropriate perioperative intravenous antibiotics, a standard posterior portal is created to initiate arthroscopy. Although most surgeons have advocated a posterior portal that is 2 cm distal and 2 cm medial to the posterolateral border of the acromion, we prefer to place our portal more lateral and in line with the posterolateral corner of the acromion. It is important to avoid placing portals too close to the acromion because, as soft tissue swelling increases during the procedure, the angle of approach to the subacromial space may be affected, leading to contact between the arthroscope and the posterior border of the acromion.
The glenohumeral joint is first entered with the arthroscope, and an anterior portal is created by localizing both the placement and trajectory using a spinal needle. The anterior portal is placed just lateral to the tip of the coracoid. This allows for evaluation and management of any concomitant intra-articular pathology such as articular cartilage lesions, labral tears, rotator cuff tears (particularly the subscapularis), and long head biceps tearing or subluxation. If a subscapularis repair is anticipated, the anterior portal is placed slightly more laterally to aid in suture passage and anchor placement.
Although most subscapularis repairs can be adequately performed with a 30-degree arthroscope, a 70-degree arthroscope should be available to aid for challenging cases, to visualize the subscapularis and its footprint. Any tearing of the upper subscapularis may be accompanied by instability of the long head of the biceps tendon, both of which should be addressed while in the intra-articular space ( Fig. 54.6 ). Due to the limited working space in the anterior shoulder, subscapularis tears should be addressed before any posterosuperior cuff tears. The biceps tendon can be treated with either tenotomy or tenodesis. Our preference is to tenodese the biceps tendon in the bicipital groove, above the pectoralis major, and using the most anterior lateral row anchor being used as part of the rotator cuff repair.
Repair of a subscapularis tear can be performed intra-articularly or extra-articularly via the subacromial space. In partial-thickness upper border tears (type I), additional portals are not necessary. The lesser tuberosity footprint is debridement of soft tissue and burred. A self-retrieving suture-passing device is used via the anterior portal, and a nonabsorbable tape suture is passed into the upper border tear. Both suture limbs from this tape are then passed into a knotless anchor placed into the lesser tuberosity footprint. In full-thickness tears of the upper border, an anterosuperolateral portal (through the superior and lateral rotator interval) is established at the anterolateral corner of the acromion. This portal is used to grasp the subscapularis and provide traction on the tendon while a single-row repair is used with tapes and anchors as described earlier. In retracted subscapularis tears (type III and IV) ( Fig. 54.7 A), identification of the “comma sign,” which represents the superior glenohumeral/coracohumeral ligament complex and medial sling of the biceps, will mark the superolateral border of the subscapularis tendon. The viewing portal is changed to view from posterolaterally through the subacromial space. A bursectomy is performed for visualization and attention is turned toward mobilizing the subscapularis. Release of adhesions around the anterior, superior, and posterior tendon should be performed after placement of a traction suture in order to obtain enough lateral excursion to perform a tension-free repair (see Fig. 54.7 B). I do not routinely open the rotator interval unless it is necessary to obtain adequate excursion. A grasper can be used to pull the retracted tendon laterally while this release is performed. Some surgeons advocate performing a coracoplasty to increase the amount of space between the coracoid tip and the anterior subscapularis.
In these cases, I typically place a medial row anchor(s) through the anterior portal (see Fig. 54.7 C–D). Sutures are then sequentially retrieved and passed through the subscapularis from inferior to superior via the anterosuperior portal (see Fig. 54.7 E). Knots are then tied sequentially from inferior to superior through the anterior portal to complete the medial row repair. One limb from each knot is then passed into one of two knotless anchors placed inferior-laterally and superior-laterally (see Fig. 54.7 F).
Partial-thickness (in situ) repair
Articular-sided partial-thickness tears involving only a small portion of the cuff footprint can be treated with debridement. , More extensive partial-thickness articular-sided tears can typically be repaired without removal of the intact bursal-sided tendon (in situ repair), although good results have been reported with detachment of the remaining tendon before repair ( Fig. 54.8 ). After debridement of the footprint and exposing a bed of bleeding bone, the quality of the intact bursal-sided tendon tissue should be evaluated. If the tissue tears easily with probing, it may be best to detach the degenerative tendon. If the tissue quality is good, the repair technique can be to keep the tendon intact.