Partial-thickness rotator cuff tears

Partial-thickness tears of the rotator cuff have been diagnosed with increased frequency because of a heightened awareness of the condition by clinicians and improved diagnostic methods. Research into the causes, natural history, and optimal treatment of this condition lags behind that of full-thickness tears. However, despite the limitations in the existing literature, there has emerged a consensus among shoulder experts that partial-thickness rotator cuff tears should be aggressively treated in the active athlete because of the unfavorable natural history of these lesions and success of accepted surgical algorithms. This review will provide an overview of the theories regarding the origins of partial-thickness rotator cuff tears, discuss the relative accuracy of accepted diagnostic techniques, and summarize the indications and methods of operative repair with an emphasis on the results of various treatment approaches.     

Histopathology of rotator cuff tears

The pathogenesis of rotator cuff tears is multifactorial. Tendon abnormalities of the rotator cuff include alteration of collagen fiber structure, tenocytes, cellularity, and vascularity. Ruptured tendons show marked collagen degeneration and disordered arrangement of collagen fibers. Fibroblast population decreases as the size of the tear in the rotator cuff increases. The larger fibroblast population seen in the smaller tears is also actively proliferating and is part of an active reparative process. Inflammatory cell infiltrate correlates inversely to rotator cuff tear size in the torn supraspinatus tendon samples, with larger tears showing a marked reduction in all cell types. As tear size increase, there is also a progressive decrease in the number of blood vessels. Whether rotator cuff tear heals spontaneously is an important pathologic and clinical question. Histologic changes indicative of repair and inflammation lead to consider biological options in addition to biomechanical treatment of the rotator cuff tears.     

MR evaluation of factors predicting the development of rotator cuff tears

PURPOSE: The purpose of this work was to assess the incidence of various factors predicting impingement in the shoulder. METHOD: MR examination was used to assess various anatomic parameters in 46 patients with clinical abnormalities of the shoulder and 40 asymptomatic volunteers. All patients had undergone surgery, showing no rotator cuff tear. RESULTS: A few of the parameters evaluated were significantly different in the two groups: The acromion was more frequently curved or hook-shaped in patients than in volunteers. The acromiohumeral distances differed (4.87 mm in patients and 6.05 mm in volunteers); so did the coracohumeral distances (7.9 mm in patients and 8.9 mm in volunteers). The shape of the acromioclavicular joint and the anterior covering of the humerus, defined on the coronal view, also differed (1.07 mm in patients and 1.49 mm in volunteers). Only the shapes of the acromioclavicular joint and of the acromion were linked with age. CONCLUSION: All these factors reflected a decrease in the acromiohumeral space, except for the anterior covering of the acromial arch, which could be due to anterior instability.     

Sonographic detection of rotator cuff tears

Thirty-nine consecutive patients referred for shoulder arthrography underwent shoulder sonography to determine the ability of sonography to detect rotator cuff tears. Fifteen patients had arthrographically proven rotator cuff tears. Of these, 14 were detected by sonography, for a sensitivity of 93%. The three sonographic criteria indicative of rotator cuff tear were (1) discontinuity in the normal homogeneous echogenicity of the rotator cuff; (2) replacement of the normal homogeneous echogenicity by a central echogenic band; and (3) nonvisualization of the cuff. Twenty patients had normal sonographic examinations, 19 of which were normal by arthrography. Therefore, the predictive value of a negative sonogram was 95%. On the basis of these findings, sonography can provide a noninvasive means of screening patients with suspected rotator cuff tears.     

Repair of partial tears of the rotator cuff

Partial-thickness rotator cuff tears present partial disruption of tendon fibers with no communication between the subacromial bursa and the glenohumeral joint. The clinical presentation is surprisingly variable, ranging from mild discomfort to decreased throwing speed, chronic pain, and shoulder inability. The first approach to partial-thickness rotator cuff tears is usually conservative, but the hypovascularity of the critical zone and mechanical factors often result in poor spontaneous tendon healing. Surgical options include arthroscopic cuff "debridement" or "repair," performed arthroscopically or by open surgery, and subacromial decompression or debridement if necessary. No agreement has been reached on the best surgical management. However, repair is usually indicated if bursal-sided and articular tears involve more than 50% of tendon thickness; debridement is generally undertaken if <50% of the rotator cuff is torn. There is a need for randomized clinical trails formulating and testing guidelines of management and for further studies on imaging or intraoperative measures and methods to assess the thickness of the rotator cuff to inform management.     

Value of ultrasonography in preoperative diagnosis of rotator cuff tears and postoperative follow-up

Four hundred and six patients presenting with shoulder pain underwent bilateral shoulder ultrasonography. Rotator cuff lesions were diagnosed in 197 patients. In 155 of the 308 patients who had additional arthrographic examinations, the arthrogram documented rotator cuff tears. Sixty-eight patients underwent surgery. There was good correlation between the ultrasonographic and arthrographic findings as well as the surgical results, with a sensitivity of 91% for each examination technique. Thirty-six postoperative patients were studied ultrasonographically; a minor to marked increase in rotator cuff echogenicity was demonstrated in them all. Its high predictive value makes ultrasonography the method of choice in diagnosing rotator cuff tears. Based on the evaluation of particular criteria, rotator cuff tears (greater than 1 cm) are commonly documented by ultrasonography. Only in patients with indeterminate or negative ultrasonograms in whom there is a high index of clinical suspicion, should arthrography be performed as a complementary imaging test. In postoperative follow-up the degree of scar formation at the reinsertion of the tendon is adequately documented by ultrasonography.     

Radiographic signs of rotator cuff tears in the shoulder

In 42 patients affected by disruption of the whole layer of the shoulder rotator collar the authors compared radiographic changes on a simple radiograph in anterior-posterior projection with operation findings. The proliferative changes on the large trochanter of humerus and the humeroacromial distance were decisive for prognosis of the operation therapy for the disrupted collar. The patients with a shorter humeroacromial distance were affected, after the operation, by a worse external rotation of the arm, worse extension and muscular strength of the arm in the extension position. Radiographic changes observed on the shoulder together with other factors are decisive for the strategy of conservative and operation therapy.     

Biological factors in the pathogenesis of rotator cuff tears

Rotator cuff tears are common, and lead to shoulder pain and functional impairment. Despite their frequency and related disability, etiology and pathogenesis are still debated. Multiple factors contribute to tears of the rotator cuff. Extrinsic factors are anatomic variables, such as acromial morphologic characteristics, os acromiale, and acromial spurs that compress the rotator cuff by bony impingement or direct pressure from the surrounding soft tissue. Intrinsic factors arise from the tendon itself, because of tensile overload, aging, microvascular supply, traumatisms, or degeneration. Little information is available from a cellular and molecular point of view. We reviewed the biological factors involved in the pathogenesis of rotator cuff tears. Understanding the mechanism of rotator cuff pathology would facilitate the rationale for therapeutic interventions, by guiding the design, selection, and implementation of treatment strategies such as biologic modulation and preventive measures.     

Evaluation and treatment of rotator cuff tears

Rotator cuff injuries are common problems and a frequent reason for patients to present to primary care physicians. These injuries are seen more frequently now with the aging population. These muscles allow for movement of the arm in overhead activities and controlled movements through space. A thorough physical examination can lead to the diagnosis of rotator cuff pathology. Radiographic imaging may offer some insight into the underlying pathology, and magnetic resonance imaging provides for excellent visualization of the rotator cuff. Many rotator cuff tears, especially partial tears, will symptomatically improve with conservative management. Surgical treatment may offer improved pain relief and function in those patients for whom nonoperative care is insufficient. In cases in which rotator cuff repair is not possible, the reverse total shoulder arthroplasty is a possibility. New technologies are also under investigation that allow for biological augmentation of rotator cuff tears.     

MR imaging of rotator cuff tears]

A total of 115 patients with clinical symptoms and signs suggesting rotator cuff tears underwent MR imaging with a 1.5-Tesla system. The body coil was used as the receiver coil in 24 patients and a single 10 cm surface coil in 91. Arthrography or MR imaging with intra-articular Gd-DTPA (MR arthrography) was performed in 95 of the 115. T2-weighted images with the body coil showed high signal intensity lesions in rotator cuffs in only seven of the 10 patients who had tears demonstrated by arthrography or MR arthrography. On the other hand, T2-weighted images with the surface coil demonstrated high signal intensity lesions in cuffs in all 27 patients who were diagnosed to have tears by arthrography or MR arthrography. In 12 patients, T2-weighted images with the surface coil showed high signal intensity lesions in cuffs, while arthrography and MR arthrography did not show tears. Surgery was performed in four of the 12 patients and partial tears were confirmed. A single 10 cm surface coil, 3 mm slice thickness and 2.5 second repetition time seem to account for the fine visualization of cuff tears by the T2-weighted images. These results suggest that T2-weighted images obtained with the surface coil are superior to arthrography and MR arthrography.     

Interobserver agreement in the classification of rotator cuff tears

BACKGROUND: Six classification systems have been proposed for describing rotator cuff tears designed to help understand their natural history and make treatment decisions. PURPOSE: To assess the interobserver variation for these classification systems and identify the method with the best interobserver agreement. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Six rotator cuff tear classification systems were identified in a literature search. The components of these systems included partial-thickness rotator cuff tears and classification by size, shape, configuration, number of tendons involved, and by extent, topography, and nature of the biceps. Twelve fellowship-trained orthopaedic surgeons who each perform at least 30 rotator cuff repairs per year reviewed arthroscopy videos from 30 patients with a random assortment of rotator cuff tears and classified them by the 6 classification systems. Interobserver variation was determined by a kappa analysis. RESULTS: Interobserver agreement was high when distinguishing between full-thickness and partial-thickness tears (0.95, kappa = 0.85). The investigators agreed on the side (articular vs bursal) of involvement for partial-thickness tears (observed agreement 0.92, kappa = 0.85) but could not agree when classifying the depth of the partial-thickness tear (observed agreement 0.49, kappa = 0.19). The best agreement for full-thickness tears was seen when the tear was classified by topography (degree of retraction) in the frontal plane (observed agreement 0.70, kappa = 0.54). CONCLUSION: With the exception of distinguishing partial-thickness from full-thickness rotator cuff tears and identifying the side (articular vs bursal) of involvement with partial-thickness tears, currently described rotator cuff classification systems have little interobserver agreement among experienced shoulder surgeons. Researchers should consider describing full-thickness rotator cuff tears by topography (degree of retraction) in the frontal plane.     

MR imaging diagnosis of rotator cuff tears

Thirty-one symptomatic patients were studied with MR imaging to evaluate the sensitivity and specificity of shoulder MR in the diagnosis of rotator cuff tears. Correlative studies included arthroscopy in 19 patients and arthrography in 12 patients. Images were obtained on either a 0.5- or 1.5-T Philips superconducting magnet using spin-echo pulse sequences (650-850/30 [TR, TE], 2000/30, 100) with 5-mm slices oriented in an oblique coronal plane perpendicular to the glenohumeral joint. The MR studies were initially interpreted without knowledge of the results of other diagnostic procedures. The MR diagnosis of cuff tear was made when irregularity, discontinuity, and increased signal were identified in the rotator cuff. MR images showed tears in 10 patients (32%) and were negative for tear in 21 patients (68%). MR correlated with arthroscopy and arthrography in 17 of 18 normal patients, in eight of 10 patients with complete tears, and in one of three patients with partial tears. For complete rotator cuff tears, the sensitivity, specificity, and accuracy were 80%, 94%, and 89%, respectively. For all tears (partial and complete), the sensitivity, specificity, and accuracy were 69%, 94%, and 84%, respectively. These data suggest that MR imaging is an accurate procedure for the diagnosis of complete rotator cuff tears. The number of partial tears (three) in this series is too small to evaluate the value of MR imaging in the diagnosis of partial tears.     

Synthetic augmentation for massive rotator cuff tears

The management of massive, irreparable rotator cuff tears is challenging. They are associated with persistent defects, weakness, and poor outcomes, and can cause an uncoupling of forces across the glenohumeral joint, with unstable shoulder kinematics. There has been much interest in the development of scaffolds to bridge massive rotator cuff tears. As allograft materials may produce inflammatory responses in the host, there is notable interest in developing synthetic grafts for surgical use. Benefits and limitations of the available synthetic scaffolds for augmentation of rotator cuff tears are reported in the present review.     

Indications for repair of full-thickness rotator cuff tears

Rotator cuff repair surgery for full-thickness tears is common and accepted in orthopaedics today. Given that a significant number of people have asymptomatic rotator cuff tears, the indications for surgery are, however, somewhat unclear. Multiple factors such as duration of symptoms, acuity and size of the tear, patient age, and others require consideration and can influence the decision to perform surgery. This article reviews these variables and the indications for surgery to repair full-thickness rotator cuff tears.     

Repair of rotator cuff tears in tennis players.

Twenty-three tennis players with a symptomatic full-thickness rotator cuff tear underwent anterior acromioplasty and rotator cuff repair. There were 8 small tears (less than 1 cm), 5 moderate tears (1 to 3 cm), 2 large tears (3 to 5 cm), and 8 massive tears (greater than 5 cm). The dominant shoulder was involved in all patients and all were unable to play tennis before surgery. Eleven patients experienced a traumatic event that caused an injury, 6 while playing tennis, and 12 patients had a gradual onset of symptoms. At average follow-up of 42 months, 19 patients (83%) achieved a good result, were pain-free, and were able to play tennis at their presymptomatic competitive level. Three patients (13%), all with massive tears, had a satisfactory result and were able to play tennis, although at a lower competitive level secondary to weakness. One patient (4%), who also had a massive tear, had an unsatisfactory result and was unable to play tennis.     

The teres minor muscle in rotator cuff tendon tears

Objectives  

Although the teres minor has received little attention in the literature compared to the other musculotendinous units of the rotator cuff, it is an important component of shoulder function. Our purpose was to study the appearance of the teres minor muscle on CT and MRI images in various patterns of rotator cuff tears.