Sonography of the rotator cuff: analysis of interobserver variability

OBJECTIVE: The purpose of our study was to determine the interobserver variability in the sonographic evaluation of the rotator cuff. SUBJECTS AND METHODS: Two radiologists independently scanned 61 patients with shoulder pain. Each radiologist categorized the rotator cuff as normal, partially torn, or fully torn. When a tear was present, the tendons involved were specified. All diagnoses were made prospectively without knowledge of the findings of the other radiologist. RESULTS: The radiologists were in full agreement in the categorization of 92% (56/61) of the patients. In four of the five discrepant cases, the disagreement was whether there was a full-thickness or a partial-thickness tear. The radiologists were in agreement concerning which tendons were involved in 80% (41/51) of the patients in whom a tear was detected by both observers. In all 10 discrepant cases, the disagreement was whether a tear involved both the supraspinatus and infraspinatus tendons or was isolated to one or the other of these tendons. CONCLUSION: The level of interobserver variability in the sonographic detection and characterization of rotator cuff tears is low.     

Ultrasonography of the rotator cuff

The authors suggest that sonography may be the best screening study for the diagnosis of rotator cuff tears.     

Imaging of the rotator cuff

The imaging evaluation of the rotator cuff augments the clinical evaluation. Radiography, computed tomography, and magnetic resonance imaging all have various roles in the assessment of the rotator cuff, which can be combined with arthrography for added detail. Furthermore, ultrasound is a very useful technique that provides functional information that is not offered by simple anatomic imaging.     

MR imaging of the rotator cuff

MR imaging is the optimal method for evaluating suspected rotator cuff pathology.Current techniques of fast spin-echo imaging without and with fat suppression allow accurate identification and characterization of tendinous and myotendinous abnormalities of the rotator cuff. Impingement disorders, tendon degeneration, instability,and trauma comprise the multifactorial nature of rotator cuff disease. This article addresses the role of MR imaging in evaluating the rotator cuff and the importance of MR imaging in identifying other lesions that may mimic rotator cuff pathology. A rationale for protocol design, including MR arthrography and the use of specialized positioning, such as abduction and external rotation (ABER), are discussed.     

The vascularity of the rotator cuff

The major arterial supply to the rotator cuff is derived from the ascending branch of the anterior humeral circumflex artery, the acromial branch of the thoracoacromial artery, as well as the suprascapular and posterior humeral circumflex arteries. The pathogenesis of rotator cuff tears has been considered to be influenced by the microvascular supply of the rotator cuff tendons. Most cadaver studies have demonstrated a hypovascular area within the critical zone of the supraspinatus tendon. It has been suggested that this area of hypovascularity has a significant role in the attritional degeneration of the aging tendon. More recent studies of the microvascular supply to the supraspinatus tendon in symptomatic patients with impingement syndrome suggest that in the area of greatest impingement, i.e., the critical zone, there is actually hypervascularity. In contrast to the cadaver investigations, these studies seem to imply that hypervascularity or neovascularization is associated with symptomatic rotator cuff disease secondary to mechanical impingement.     

Multimodal approach to postoperative pain control in patients undergoing rotator cuff repair

Purpose  

This prospective study was undertaken to compare the effectiveness and safety of a multimodal pain control protocol with those of intravenous patient-controlled analgesia in rotator cuff repair.     

US evaluation of the rotator cuff

Ultrasonographic (US) evaluation of the moving shoulder is a new method for evaluating the integrity of the rotator cuff. In the past, contrast arthrography has provided the only nonoperative technique for demonstrating defects in the rotator cuff. We present the details of this new technique and describe 79 patients whose US results were correlated with the findings at arthrography and/or surgery. US allows evaluation of both shoulders at once, an advantage over arthrography, where usually only one side is evaluated at a single sitting. Improvements in US instrumentation, especially the introduction of high-resolution linear-array devices and the use of experienced ultrasonographers, have improved the accuracy of US. Because US is rapid, safe, noninvasive, and inexpensive, we advocate its use instead of arthrography as the routine test of rotator cuff integrity.     

Arthroscopic rotator cuff repair

The use of the arthroscope to address shoulder pathology is continuously evolving. Many aspects of shoulder arthroscopy are readily accepted and used by orthopedic surgeons, but some procedures can be technically difficult. Arthroscopic rotator cuff repair has traditionally involved the use of cumbersome knot tying techniques, deterring many surgeons from using this technique. Although open and mini-open rotator cuff repair is commonly used with predictable results, there still remains inherent morbidity to any open technique. This article will outline a technique that avoids knot tying and suture management in arthroscopic rotator cuff repair. Although the indications are evolving, arthroscopic rotator cuff repair allows predictable results with excellent pain relief and return to function.     

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.     

Current imaging of the rotator cuff

Rotator cuff pathology is a common cause of shoulder pain, and imaging plays a major role in the management of shoulder problems. General radiography may be useful as an initial screening test particularly in trauma and arthritis. Musculoskeletal ultrasound and magnetic resonance imaging are the most suitable modalities for the investigation of the rotator cuff, having high sensitivities and specificities for full-thickness tears. Musculoskeletal ultrasound and magnetic resonance imaging are less accurate in the detection of partial-thickness tears with greater observer variability. This article reviews the normal and pathologic imaging features of the rotator cuff and highlights the potential usefulness and limitations of various imaging modalities in the assessment of the tendon and the potential impact of imaging findings on clinical patient care.     

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.     

Rehabilitation of rotator cuff tendinopathy

Rehabilitation of the dysfunction that is associated with rotator cuff tendinopathy should be based on the evidence known about the pathoetiology of the tendinopathy, what is known about the extent of the local anatomic injury, the local and distant physiological and biomechanical alterations, and on the knowledge developed regarding progressive loading of the injured or altered structures. Prehabilitation, or prospective exercises to minimize future rotator cuff loading stresses, should be included at the end of rehabilitation as part of the return to function.     

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.     

Prospective evaluation of the effect of rotator cuff integrity on the outcome of open rotator cuff repairs

BACKGROUND: Open rotator cuff repairs have led to excellent clinical results; however, several studies have linked postoperative structural integrity to patient outcomes. The purpose of this study is to prospectively assess postoperative cuff integrity after open rotator cuff repair and assess its relationship to clinical outcome. HYPOTHESIS: Preoperative rotator cuff tear size and postoperative rotator cuff integrity are important factors in overall clinical outcomes. STUDY DESIGN: Prospective nonrandomized clinical outcomes study. METHODS: Forty-seven consecutive patients undergoing repair of full-thickness rotator cuff tears by a single surgeon were enrolled in this prospective study. A standardized evaluation was performed preoperatively and postoperatively at annual intervals. All patients underwent postoperative magnetic resonance imaging at least 1 year after surgery. Statistical evaluation was performed using paired and unpaired 2-tailed t tests for comparison. RESULTS: Thirty-two patients were available for evaluation. Overall, the patients experienced a significant (P < .05) improvement in their American Shoulder and Elbow Surgeons survey (40-85) and Constant (53-80) scores. The overall retear rate was 31%. Although patients with large tears preoperatively and retears postoperatively had lower overall outcomes scores, this was not significant. CONCLUSION: These data support open rotator cuff repair as an effective technique that restores excellent shoulder function. The authors did not find postoperative cuff integrity to have a significant effect on outcomes when compared with those with an intact cuff. In fact, those with a retear still had a significant improvement in all clinical areas assessed, including strength.     

Pitfalls of rotator cuff sonography

Experience with rotator cuff sonography in 106 patients was analyzed to identify the causes of scan misinterpretation. Possible interpretive errors may be classified into four categories: those from failure to recognize normal anatomy, those caused by soft-tissue abnormalities, those caused by bony abnormalities, and those caused by technical limitations of the study. Errors in recognition of normal anatomy are easily overcome by experience and comparison to the normal, contralateral rotator cuff. Errors resulting from soft-tissue abnormalities were seen in two patients with calcific tendinitis simulating rotator cuff tears. Problems in interpretation resulting from fractures in two patients and inferior glenohumeral subluxation in two other patients could have been avoided by review of the plain films before performing sonography. The major technical limitation of the study arises from the inability to image the rotator cuff beneath the acromion. Fortunately, rotator cuff tears are rarely isolated in this location, and passive maneuvers often allow otherwise hidden parts of the cuff to be imaged.