Published online before print June 6, 2002, 10.1148/radiol.2241011261
(Radiology 2002;224:470-476.)
© RSNA, 2002
Horizontal Component of Partial-Thickness Tears of Rotator Cuff: Imaging Characteristics and Comparison of ABER View with Oblique Coronal View at MR Arthrography— Initial Results1
Sang Yong Lee, MD2 and
Joong K. Lee, MD
1 From the Department of Radiology, Albany Medical Center Hospital, 43 New Scotland Ave, Albany, NY 12208. Received July 23, 2001; revision requested September 11; revision received October 23; accepted December 10. Address correspondence to J.K.L. (e-mail: jlee@communitycare.com).
 |
ABSTRACT
|
|---|
PURPOSE: To determine the characteristics of horizontal components of partial-thickness tears of the rotator cuff at magnetic resonance (MR) arthrography and to determine whether use of the abduction and external rotation (ABER) position improved detection of a horizontal component in partial-thickness tears.
MATERIALS AND METHODS: MR studies in 16 patients (mean age, 32 years) who had partial-thickness tear with a horizontal component were retrospectively evaluated. All 16 patients had undergone arthroscopic surgery. The depth and extent of the horizontal component were measured on MR images, and the presence or absence of articular surface tear was recorded. The characteristics of the horizontal component on ABER views were compared with those on oblique coronal views.
RESULTS: A horizontal component (24 lesions; one tendon involved in eight patients and two tendons involved in eight patients) was observed in 100% of the lesions on ABER views and in 21% of the lesions (n = 5) on oblique coronal images. The mean length of the horizontal components, measured on ABER views, was 1.9 cm (range, 0.6–4.5 cm). Thirteen (54%) of the 24 lesions were classified as grade I (<3 mm) in depth, four (17%) were classified as grade II (3–6 mm), and seven (29%) were classified as grade III (>6 mm). Articular separation sites with a flap lesion were visualized in 15 (62%) of 24 lesions on ABER views.
CONCLUSION: MR arthrography of the shoulder with patients in the ABER position may provide additional information in cases of partial-thickness tears of the rotator cuff with a horizontal component.
© RSNA, 2002
Index terms: Shoulder, arthrography, 414.122 • Shoulder, injuries, 414.4813, 414.4819 • Shoulder, MR, 414.121411, 414.121415, 414.12143
|
INTRODUCTION
|
|---|
The treatment of patients with partial-thickness tear of the rotator cuff remains problematic and controversial. Initial treatment for partial-thickness tear of the rotator cuff is usually conservative (1,2). Although conservative treatment reduces symptoms, a successful result is achieved in fewer than 50% of patients with degenerative partial-thickness tear (1).
Persistent pain that does not respond to conservative treatment is the usual indication for surgery. Surgical procedures such as arthroscopic or open subacromial decompression, débridement of the rotator cuff, open division of the coracoacromial ligament, open excision of the damaged portion of the tendon with tendon repair, or some combination of these are used for treatment of partial-thickness tear (1,2). Surgical management of partial-thickness tear of the rotator cuff is guided by clinical judgments such as a failure of conservative treatment, impairment of the patient’s quality of life, and presence of symptoms and signs of partial-thickness tear of the rotator cuff (3). To the best of our knowledge, the relationship between the diagnosis of partial-thickness tear of the rotator cuff on the basis of findings at magnetic resonance (MR) imaging and the patient’s prognosis has not been clarified.
The classification of a partial-thickness tear of the rotator cuff depends on whether it occurs on an articular surface or a bursal surface. On the basis of the vertical thickness of the tears, one can classify them according to the following scale: grade I, less than 3 mm; grade II, 3–6 mm; and grade III, greater than 6 mm (4). A horizontal component of partial-thickness tears has been noted by orthopedic surgeons (1,4,5–7), but it has not received much attention from either orthopedic surgeons or radiologists. The horizontal component has not been used in the classification system of partial-thickness tears of the rotator cuff (4,8).
MR imaging of the shoulder joint has been considered the procedure of choice for evaluation of rotator cuff tears (9–14). Quinn et al (13) reported that the biggest diagnostic problem was the detection of partial tears and the differentiation of high-grade partial tears from small, focal, complete tears in fat-suppressed MR imaging series. MR arthrography improves the ability to diagnose partial-thickness tears of the rotator cuff (9,15). Tirman et al (9) observed tears that extended into the depth of the tendon in two patients and stated that MR imaging with the patients in the abduction and external rotation (ABER) position was beneficial.
The purposes of this study were to determine the characteristics of the horizontal component of partial-thickness tears of the rotator cuff and to determine whether use of the ABER view at MR arthrography improved the detection of a horizontal component of partial-thickness tears.
|
MATERIALS AND METHODS
|
|---|
Patients
Of 407 patients who underwent MR arthrography of the shoulder at one of three facilities from January 1999 through November 2000, 16 (3.9%; mean age, 32 years; age range, 20–52 years) were included in our retrospective study on the basis of MR arthrographic findings that indicated the presence of a horizontal component in a partial-thickness tear of the rotator cuff. Arthroscopic reports were available for analysis for all patients. Fifteen patients were men and one was a woman. Patients with partial-thickness tears of the rotator cuff that did not have a horizontal component were excluded from this study. Eight of the 16 study patients had a history of recurrent anterior dislocation of the shoulder joint, six had impingement syndrome, and two had experienced shoulder trauma. The mean interval between MR arthrography and shoulder arthroscopy for these 16 patients was 3
months (range, 1 to 10 months). One patient had previously undergone arthroscopy of the shoulder because of a posterior labral injury. The study was approved by our institutional review board, and written informed consent was obtained from each patient.
MR Imaging
The glenohumeral joint was entered with a 22-gauge spinal needle with an anterior approach and fluoroscopic guidance. The spinal needle was coupled with connective tubing to a syringe filled with contrast material. First, a 4 mL solution composed of 2 mL of nonionic iodinated contrast material (iohexol, Omnipaque; 260 mg/mL; Nycomed Amersham, Princeton, NJ) and 2 mL of 1% lidocaine (Abbott Laboratories, North Chicago, Ill) was injected to confirm the intraarticular location of the 22-gauge spinal needle. We used 1% lidocaine to facilitate positioning of the patient in the ABER position. This was followed by an injection of 8–10 mL of a solution composed of 2 mL of gadopentetate dimeglumine (Magnevist; Schering, Berlin, Germany) diluted with 250 mL of normal saline. Radiographs were obtained in all patients after gentle movement of the shoulder in the positions of internal and external rotation; the patients were then sent to the MR suite, where MR arthrograms were immediately obtained without further movement of the shoulder. No complications related to injection of the nonionic iodinated contrast material, injection of 2 mL of 1% lidocaine, or injection of the mixture of gadopentetate dimeglumine and saline occurred during MR arthrography.
MR arthrography of the shoulder was performed at one of three facilities at 1.5 T (Signa; GE Medical Systems, Milwaukee, Wis) with a dedicated phased-array shoulder coil. First, all patients underwent MR imaging with the humerus in a neutral position or in a position of mild external rotation. MR imaging was performed with a T1-weighted spin-echo sequence (repetition time msec/echo time msec, 450–750/9–20; 12–16-cm field of view; 2–5-mm section thickness; 0–2-mm intersection gap; 256 x 192 matrix; one to two excitations) in the transverse, oblique coronal, and oblique sagittal planes. Additional oblique coronal spin-echo T1-weighted MR images with fat suppression (450–800/9–20, 12–16-cm field of view, 3-mm section thickness, 0.5–1.0-mm intersection gap, 256 x 160 matrix, one to two excitations) and transverse fast spoiled gradient-recalled-echo MR images with fat suppression (450–550/10–15, 17°–25° flip angle, 16-cm field of view, 3-mm section thickness, 0.3–1.0-mm intersection gap, 256 x 224 matrix, one to two excitations) were obtained.
The patients were then repositioned with the hand of the imaged extremity placed posterior to the head or neck with the elbow flexed, so the shoulder would be in the ABER position. A coronal localizer sequence (two-dimensional spoiled gradient-recalled-echo sequence, 34/4.2, 60° flip angle, 34-cm field of view) was performed. Oblique transverse T1-weighted images (500–800/9–20, 12–16-cm field of view, 3-mm section thickness, 0–0.5-mm intersection gap, 256 x 192 matrix, one to three excitations) were obtained from the localizer image along the humeral axis with the shoulder in the ABER position. In two patients, fat-suppressed oblique transverse T1-weighted images were obtained.
Image Evaluation
All MR arthrograms were evaluated in consensus by two musculoskeletal radiologists (S.Y.L., J.K.L.) for the presence of a horizontal component in a partial-thickness tear of the rotator cuff. The presence of a horizontal component in a partial-thickness tear was defined as the presence of linear intrasubstance pooling of contrast medium that extended along the long axis of the rotator cuff. The fat-suppressed oblique coronal T1-weighted MR images obtained with the humerus in a neutral position or in a position of mild external rotation and the oblique transverse T1-weighted MR images obtained with the shoulder in the ABER position were evaluated for the presence of an articular surface abnormality, such as a flap component in a partial-thickness tear, and for the vertical thickness (depth) and length of the horizontal component of the partial-thickness tear. Any other associated abnormalities were also noted.
The horizontal component of partial-thickness tears was categorized according to the shape and signal intensity of the articular surface of the rotator cuff as it appeared on MR arthrograms. A horizontal component of a tear without a definite articular surface abnormality was categorized as type A, a horizontal component with increased signal intensity or irregularity of the articular surface was categorized as type B, and a horizontal component with a definite flap tear (torn edge) of the articular surface was categorized as type C (Fig 1). Side-by-side comparison between the fat-suppressed oblique coronal MR images and the MR images obtained with the patient in the ABER position was performed to evaluate the horizontal component of partial-thickness tears.
View larger version (120K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1a. Drawings show the classification of the horizontal component of partial-thickness tears according to the appearance of the articular surface. (a) Drawing of a normal shoulder in the ABER position shows the relationship between the humerus (H), glenoid surface (G), acromion (A), rotator cuff tendon (arrows), and articular cavity (C). (b-d) Drawings of shoulders in the ABER position. White areas in the rotator cuff tendon indicate the horizontal component of a partial-thickness tear. A = acromion, C = articular cavity, G = glenoid surface, H = humerus. (b) A type A lesion appears as a horizontal or intrasubstance component in a partial-thickness tear and is associated with no abnormality of the articular surface (arrowheads). (c) A type B lesion exhibits irregularity of the articular surface (arrow). (d) A type C lesion is associated with a flap lesion (arrow) along the articular surface.
|
|
View larger version (121K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1b. Drawings show the classification of the horizontal component of partial-thickness tears according to the appearance of the articular surface. (a) Drawing of a normal shoulder in the ABER position shows the relationship between the humerus (H), glenoid surface (G), acromion (A), rotator cuff tendon (arrows), and articular cavity (C). (b-d) Drawings of shoulders in the ABER position. White areas in the rotator cuff tendon indicate the horizontal component of a partial-thickness tear. A = acromion, C = articular cavity, G = glenoid surface, H = humerus. (b) A type A lesion appears as a horizontal or intrasubstance component in a partial-thickness tear and is associated with no abnormality of the articular surface (arrowheads). (c) A type B lesion exhibits irregularity of the articular surface (arrow). (d) A type C lesion is associated with a flap lesion (arrow) along the articular surface.
|
|
View larger version (121K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1c. Drawings show the classification of the horizontal component of partial-thickness tears according to the appearance of the articular surface. (a) Drawing of a normal shoulder in the ABER position shows the relationship between the humerus (H), glenoid surface (G), acromion (A), rotator cuff tendon (arrows), and articular cavity (C). (b-d) Drawings of shoulders in the ABER position. White areas in the rotator cuff tendon indicate the horizontal component of a partial-thickness tear. A = acromion, C = articular cavity, G = glenoid surface, H = humerus. (b) A type A lesion appears as a horizontal or intrasubstance component in a partial-thickness tear and is associated with no abnormality of the articular surface (arrowheads). (c) A type B lesion exhibits irregularity of the articular surface (arrow). (d) A type C lesion is associated with a flap lesion (arrow) along the articular surface.
|
|
View larger version (118K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1d. Drawings show the classification of the horizontal component of partial-thickness tears according to the appearance of the articular surface. (a) Drawing of a normal shoulder in the ABER position shows the relationship between the humerus (H), glenoid surface (G), acromion (A), rotator cuff tendon (arrows), and articular cavity (C). (b-d) Drawings of shoulders in the ABER position. White areas in the rotator cuff tendon indicate the horizontal component of a partial-thickness tear. A = acromion, C = articular cavity, G = glenoid surface, H = humerus. (b) A type A lesion appears as a horizontal or intrasubstance component in a partial-thickness tear and is associated with no abnormality of the articular surface (arrowheads). (c) A type B lesion exhibits irregularity of the articular surface (arrow). (d) A type C lesion is associated with a flap lesion (arrow) along the articular surface.
|
|
|
RESULTS
|
|---|
In the arthroscopic reports, a horizontal component of partial-thickness tears was described in only two patients. In both patients, side-to-side suture of the horizontal component of a partial-thickness tear was performed during the arthroscopic procedure. Four patients had superior labral anterior posterior (SLAP) lesion as an associated abnormality, four had Bankart lesion and Hill-Sachs deformity, two had posterior labrum tear, two had Bankart lesion and SLAP lesion, one had Bankart lesion, and one had Bankart lesion, Hill-Sachs deformity, and SLAP lesion. Two patients had only rotator cuff tears. The presence of associated MR findings was confirmed at surgery.
The MR findings of the horizontal component of partial-thickness tears of the rotator cuff are summarized in the Table. The horizontal component of partial-thickness tears was detected more frequently on MR images that were obtained with patients in the ABER position than it was on oblique coronal MR images. The horizontal component of partial-thickness tears was detected in 16 patients (supraspinatus tendon, n = 11; infraspinatus tendon, n = 13) on MR images obtained with patients in the ABER position and in four patients (supraspinatus tendon, n = 3; infraspinatus tendon, n = 2) on oblique coronal MR images (Fig 2). Both the supraspinatus and the infraspinatus tendon were involved in eight patients.
View this table:
[in this window]
[in a new window]
|
Summary of Clinical and Imaging Characteristics of Horizontal Component of Partial-Thickness Tears in 16 Patients
|
|
View larger version (147K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2a. Images demonstrate a horizontal component in a partial-thickness tear that was visualized only with ABER views in a 20-year-old man. (a-c) Consecutive oblique coronal fat-suppressed T1-weighted spin-echo MR images (800/14) obtained after intraarticular injection of contrast material show the irregularity of the articular surface (solid arrows) at the insertion of the infraspinatus tendon and scalloped cortical erosions (open arrows) adjacent to the cuff lesion. (d-f) Consecutive T1-weighted spin-echo MR images (500/14) obtained with the patient in the ABER position show the grade III horizontal component (white arrowheads) of a partial tear of the infraspinatus tendon extending along the long axis of the infraspinatus tendon. The horizontal component of the tear was confirmed at surgery. Line (black arrows) between the articular cavity (C) and the area of intratendinous contrast material pooling (P) represents the articular surface of the infraspinatus tendon. On ABER views, the irregularity of the articular surface (black arrowheads) is demonstrated, indicating a type B horizontal component. An anterior labral tear (curved arrow) is also well demonstrated in d and e, and cortical bone erosions of the humeral head (open arrows) are seen in e and f.
|
|
View larger version (156K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2b. Images demonstrate a horizontal component in a partial-thickness tear that was visualized only with ABER views in a 20-year-old man. (a-c) Consecutive oblique coronal fat-suppressed T1-weighted spin-echo MR images (800/14) obtained after intraarticular injection of contrast material show the irregularity of the articular surface (solid arrows) at the insertion of the infraspinatus tendon and scalloped cortical erosions (open arrows) adjacent to the cuff lesion. (d-f) Consecutive T1-weighted spin-echo MR images (500/14) obtained with the patient in the ABER position show the grade III horizontal component (white arrowheads) of a partial tear of the infraspinatus tendon extending along the long axis of the infraspinatus tendon. The horizontal component of the tear was confirmed at surgery. Line (black arrows) between the articular cavity (C) and the area of intratendinous contrast material pooling (P) represents the articular surface of the infraspinatus tendon. On ABER views, the irregularity of the articular surface (black arrowheads) is demonstrated, indicating a type B horizontal component. An anterior labral tear (curved arrow) is also well demonstrated in d and e, and cortical bone erosions of the humeral head (open arrows) are seen in e and f.
|
|
View larger version (159K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2c. Images demonstrate a horizontal component in a partial-thickness tear that was visualized only with ABER views in a 20-year-old man. (a-c) Consecutive oblique coronal fat-suppressed T1-weighted spin-echo MR images (800/14) obtained after intraarticular injection of contrast material show the irregularity of the articular surface (solid arrows) at the insertion of the infraspinatus tendon and scalloped cortical erosions (open arrows) adjacent to the cuff lesion. (d-f) Consecutive T1-weighted spin-echo MR images (500/14) obtained with the patient in the ABER position show the grade III horizontal component (white arrowheads) of a partial tear of the infraspinatus tendon extending along the long axis of the infraspinatus tendon. The horizontal component of the tear was confirmed at surgery. Line (black arrows) between the articular cavity (C) and the area of intratendinous contrast material pooling (P) represents the articular surface of the infraspinatus tendon. On ABER views, the irregularity of the articular surface (black arrowheads) is demonstrated, indicating a type B horizontal component. An anterior labral tear (curved arrow) is also well demonstrated in d and e, and cortical bone erosions of the humeral head (open arrows) are seen in e and f.
|
|
View larger version (145K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2d. Images demonstrate a horizontal component in a partial-thickness tear that was visualized only with ABER views in a 20-year-old man. (a-c) Consecutive oblique coronal fat-suppressed T1-weighted spin-echo MR images (800/14) obtained after intraarticular injection of contrast material show the irregularity of the articular surface (solid arrows) at the insertion of the infraspinatus tendon and scalloped cortical erosions (open arrows) adjacent to the cuff lesion. (d-f) Consecutive T1-weighted spin-echo MR images (500/14) obtained with the patient in the ABER position show the grade III horizontal component (white arrowheads) of a partial tear of the infraspinatus tendon extending along the long axis of the infraspinatus tendon. The horizontal component of the tear was confirmed at surgery. Line (black arrows) between the articular cavity (C) and the area of intratendinous contrast material pooling (P) represents the articular surface of the infraspinatus tendon. On ABER views, the irregularity of the articular surface (black arrowheads) is demonstrated, indicating a type B horizontal component. An anterior labral tear (curved arrow) is also well demonstrated in d and e, and cortical bone erosions of the humeral head (open arrows) are seen in e and f.
|
|
View larger version (140K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2e. Images demonstrate a horizontal component in a partial-thickness tear that was visualized only with ABER views in a 20-year-old man. (a-c) Consecutive oblique coronal fat-suppressed T1-weighted spin-echo MR images (800/14) obtained after intraarticular injection of contrast material show the irregularity of the articular surface (solid arrows) at the insertion of the infraspinatus tendon and scalloped cortical erosions (open arrows) adjacent to the cuff lesion. (d-f) Consecutive T1-weighted spin-echo MR images (500/14) obtained with the patient in the ABER position show the grade III horizontal component (white arrowheads) of a partial tear of the infraspinatus tendon extending along the long axis of the infraspinatus tendon. The horizontal component of the tear was confirmed at surgery. Line (black arrows) between the articular cavity (C) and the area of intratendinous contrast material pooling (P) represents the articular surface of the infraspinatus tendon. On ABER views, the irregularity of the articular surface (black arrowheads) is demonstrated, indicating a type B horizontal component. An anterior labral tear (curved arrow) is also well demonstrated in d and e, and cortical bone erosions of the humeral head (open arrows) are seen in e and f.
|
|
View larger version (142K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2f. Images demonstrate a horizontal component in a partial-thickness tear that was visualized only with ABER views in a 20-year-old man. (a-c) Consecutive oblique coronal fat-suppressed T1-weighted spin-echo MR images (800/14) obtained after intraarticular injection of contrast material show the irregularity of the articular surface (solid arrows) at the insertion of the infraspinatus tendon and scalloped cortical erosions (open arrows) adjacent to the cuff lesion. (d-f) Consecutive T1-weighted spin-echo MR images (500/14) obtained with the patient in the ABER position show the grade III horizontal component (white arrowheads) of a partial tear of the infraspinatus tendon extending along the long axis of the infraspinatus tendon. The horizontal component of the tear was confirmed at surgery. Line (black arrows) between the articular cavity (C) and the area of intratendinous contrast material pooling (P) represents the articular surface of the infraspinatus tendon. On ABER views, the irregularity of the articular surface (black arrowheads) is demonstrated, indicating a type B horizontal component. An anterior labral tear (curved arrow) is also well demonstrated in d and e, and cortical bone erosions of the humeral head (open arrows) are seen in e and f.
|
|
The length of the horizontal component of partial-thickness tears was not well delineated on oblique coronal MR arthrograms. The length of the horizontal component of partial-thickness tears of the rotator cuff ranged from 0.6 cm to 4.5 cm (mean length, 1.9 cm) on 24 MR images obtained with 16 patients in the ABER position. On oblique coronal MR images (n = 5) the length of the horizontal component of partial-thickness tears ranged from 0.6 cm to 4.0 cm (mean length, 1.8 cm). The vertical thickness (depth) of the horizontal component of partial-thickness tears on MR images obtained with patients in the ABER position was classified as grade I in 13 (54%) of 24 involved tendons, grade II in four (17%) tendons, and grade III in seven (29%) tendons. In eight patients with shoulder dislocation, the vertical thickness of the horizontal components ranged from grade I in four (33%) of 12 involved tendons to grade II in four (33%) tendons and grade III in four (33%) tendons. However, most of the horizontal components of partial-thickness tears of the rotator cuff that occurred in six patients with impingement syndrome were classified as grade I (78%, seven of nine tendons).
On MR images obtained with the patients in the ABER position, the most common appearance of the horizontal component was type C (62%, 15 of 24 tendons), with a flap tear on the articular surface (Fig 3). Type B lesions that included an irregularity on the articular surface were observed in five (21%) of 24 tendons (Fig 4). Type A lesions that showed no signal intensity abnormality on the articular surface were observed in four (17%) of 24 rotator cuff tendons on MR images obtained with patients in the ABER position (Fig 5).
View larger version (143K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3. T1-weighted spin-echo MR image (500/14) obtained in a 44-year-old man in the ABER position shows a horizontal component in a tear of the supraspinatus tendon associated with a flap lesion (solid arrows) along the articular surface. This appearance is characteristic of a type C horizontal component. The horizontal component of the partial-thickness tear communicates with the articular cavity through the flap tear. A detached anterior labrum (open arrow) is also depicted. Most flap lesions were clearly demonstrated only on ABER views rather than on oblique coronal MR images.
|
|
View larger version (103K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4. Fat-suppressed oblique transverse T1-weighted MR image (550/10) obtained in a 31-year-old man after intraarticular injection of contrast material and with the patient in the ABER position shows a type B horizontal component in a tear of the supraspinatus tendon, with irregularity of the articular surface (arrowheads) adjacent to the head of the humerus.
|
|
View larger version (172K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5. T1-weighted spin-echo MR image (500/14) obtained in a 34-year-old man with the patient in the ABER position shows the horizontal component in a tear of the infraspinatus tendon but reveals no abnormality of the articular surface, indicating a type A horizontal component. The horizontal component of the tear of the infraspinatus tendon (H) extends from the cortex of the humeral head along the long axis of the infraspinatus tendon; the articular surface (arrowheads) of the tendon is intact. The vertical thickness of the horizontal component was grade II.
|
|
|
DISCUSSION
|
|---|
A partial-thickness tear of the rotator cuff can occur on either an articular surface or a bursal surface of the rotator cuff. However, most partial-thickness tears have been observed to occur on the articular side of the rotator cuff (16,17). Ellman (4) graded the severity of partial-thickness tears according to their depth (ie, the vertical thickness of the tear) as grade I (<3 mm deep), grade II (3–6 mm deep), and grade III (>6 mm deep). In Ellman’s classification, superficial fraying of the articular capsule was excluded from the classification of partial-thickness rotator cuff tears. A horizontal component of partial-thickness tear was not included in Ellman’s classification (4). Several researchers (1,4,5–7) have postulated the existence of a horizontal component in partial-thickness tears of the rotator cuff and have called it intratendinous tear or laminated tear. In the case of partial-thickness tears that are associated with a horizontal component but which demonstrate no surface abnormality on either the articular or the bursal side, the horizontal component cannot be identified at arthroscopic examination (4). In a series of five throwing athletes, Tirman et al (9) reported that an intratendinous tear was observed in two patients and that use of the ABER position at MR arthrography was beneficial. Although four of 24 rotator cuff tendons in our study were associated with a horizontal component of a partial-thickness tear on ABER views, there was no signal intensity abnormality on the articular surface.
The exact pathogenesis of partial-thickness tears in young athletes and in a subpopulation of patients older than 40 years has not been clearly established (1,2,6). Budoff and Nirschl (2) reported that the causes of disorders of the rotator cuff could be classified into one of two groups: those involving an intrinsic factor, such as an intrasubstance tear with degeneration resulting from avascularity, aging, overuse, and/or overload; and those involving an extrinsic factor, such as outlet stenosis (subacromial impingement) or glenohumeral instability. In their report of a study of en bloc histologic specimens obtained in a series of patients whose mean age was 49.8 years, Fukuda et al (7) asserted that intratendinous tears were caused by shear within the degenerated tendon. The precise pathogenesis of intratendinous tear in young athletes, especially throwing athletes, has not been determined. In a series of patients with impingement of the supraspinatus tendon on the posterosuperior glenoid rim, Walch et al (6) observed that some tears extended into the depth of the tendon, resulting in dissection of the tendon into two layers. However, there was no discussion of the pathogenesis of the intratendinous tears.
In our series, a horizontal component in partial-thickness tears was demonstrated in patients with anterior instability of the shoulder, in patients with internal impingement of the supraspinatus tendon on the posterosuperior glenoid rim, and in patients with acute trauma. The pathogenesis of the horizontal component of partial-thickness tears may be related to both degenerative changes and traumatic shear of the rotator cuff.
Factors that influence surgical decision making in treatment of partial-thickness tears of the rotator cuff include the extent of tearing; underlying pathologic features; and the patient’s preference, age, and response to conservative treatment (1). Ellman (4) reported that when torn and degenerated marginal tissues are encountered they should be excised. Patte (8) reported that the extent of necrosis of the proximal stump, which determines the amount of tissue to be resected, is impossible to judge. Although the pathologic consequences of a horizontal component (intratendinous tear) in partial-thickness tears have not been established, preoperative determination of the exact location and size of a partial-thickness tear is mandatory.
The horizontal component of partial-thickness tears was best demonstrated on MR images obtained with patients in the ABER position. On standard oblique coronal MR images, only 21% (five of 24 tendons) of the horizontal components of partial-thickness tears were demonstrated. We agree with Tirman et al (9) that abduction of the arm allows separation of the tendon from the superior surface of the humerus and promotes spreading of the frayed and torn edges of the articular surface of the rotator cuff. We also believe that the same mechanism is responsible for better delineation of the horizontal component of partial-thickness tears. There were four cases with a horizontal component of partial-thickness tear in which we could not detect an abnormality along the articular surface of the tendon on coronal and ABER views. Palmar et al (10) reported that imbibition of contrast material by the rotator cuff may indicate a fraying and friability of the tendon. We hypothesize that minimal friability of the articular surface of the involved tendon might not have been detected on MR images in the four rotator cuff tendons in which a horizontal component of a partial-thickness tear was identified but no articular surface abnormality was detected. Another mechanism leading to intratendinous pooling of contrast material in the horizontal component without evidence of an articular surface abnormality may be the transportation of contrast material through the connections between the injured rotator cuff tendons.
Surgical procedures for treatment of partial-thickness tears include arthroscopic or open subacromial decompression, open division of the coracoacromial ligament, and arthroscopic débridement of the rotator cuff (2–4,18). Ellman (4) and Patte (8) recommend that partial-thickness tears and necrotic tissue encountered during shoulder surgery be excised. Budoff and Nirschl (2) recommend that the decision to pursue surgical treatment be made on the basis of demonstrated pathologic anatomy of the rotator cuff. Several methods have been proposed for identifying degenerative pathologic changes, such as direct palpation over the critical zone, probing the superficial surface of the rotator cuff, performing a blush test with a dilute solution of methylene blue, and performing the Nirschl scratch test (3). The exact location of a tear of the rotator cuff tendon influences the surgical treatment plan. We believe that it is important to recognize the horizontal component of a partial-thickness tear in determining the extent of the partial-thickness tear.
MR arthrography of the shoulder is more effective in the demonstration of glenolabral (15,19–24) and rotator cuff injuries (9–12,25) than is conventional MR imaging of the shoulder. Several investigators have studied the utility of fat-suppressed MR arthrography and MR arthrography performed with patients in the ABER position in increasing sensitivity for the diagnosis of rotator cuff lesions (9,10). To our knowledge, no study has addressed the detection of the horizontal component of partial-thickness tears with MR arthrography. We believe that MR arthrography performed with patients in the ABER position is especially valuable for demonstrating the horizontal component of partial-thickness tears of the rotator cuff.
One of the drawbacks of MR arthrography of the shoulder with patients in the ABER position is patient discomfort. Injection of 2 mL of 1% lidocaine into the joint during shoulder arthrography facilitated patient assumption of the ABER position.
Our study had several limitations. Although all patients had undergone arthroscopy of the involved shoulder, the surgeons had described the horizontal component of partial-thickness tears in arthroscopic records in only two patients. These two patients underwent extensive débridement and side-to-side suture of the involved rotator cuff tendon. In surgical notes, there was no description of the horizontal component of partial-thickness tears in 14 patients. This could reflect the surgeon’s focus on the correction of shoulder instability and a lack of familiarity with the intratendinous horizontal component of rotator cuff tendon tears. Because of the retrospective nature of our study and the collection of cases from three MR imaging facilities, the same pulse sequences were not used to obtain the T1-weighted oblique coronal images and the T1-weighted oblique transverse images with patients in the ABER position that were used in our comparison. In addition, the fact that we did not use coronal oblique T2-weighted MR images may have resulted in an underestimation of the utility of standard coronal oblique MR images in the detection of the horizontal component of partial-thickness tears of the rotator cuff (14).
In conclusion, we believe that MR arthrography of the shoulder with patients in the ABER position provides additional information about the grade of partial-thickness tears and the presence of a horizontal component in a partial-thickness tear. Preoperative knowledge of a horizontal component in a partial-thickness tear may aid surgical planning.
|
ACKNOWLEDGMENTS
|
|---|
We acknowledge the help of Michael Ciarmiello in the preparation of the illustrations presented in this article.
|
FOOTNOTES
|
|---|
2 Current address: Department of Radiology, Chonbuk Medical School, Jeonbuk, Korea. 
Abbreviations: ABER = abduction and external rotation,
SLAP = superior labral anterior posterior
Author contributions: Guarantor of integrity of entire study, J.K.L.; study concepts and design, S.Y.L., J.K.L.; literature research, S.Y.L., J.K.L.; clinical studies, S.Y.L., J.K.L.; data acquisition and analysis/interpretation, S.Y.L., J.K.L.; statistical analysis, S.Y.L., J.K.L.; manuscript preparation and definition of intellectual content, S.Y.L., J.K.L.; manuscript editing, revision/review, and final version approval, J.K.L.
|
REFERENCES
|
|---|
- Breazeale NM, Craig EV. Partial-thickness rotator cuff tears: pathogenesis and treatment. Orthop Clin North Am 1997; 28:145-155.[CrossRef][Medline]
- Budoff JE, Nirschl EJ. Debridement of partial-thickness tears of the rotator cuff without acromioplasty: long-term follow-up and review of the literature. J Bone Joint Surg Am 1988; 80:733-748.[Free Full Text]
- Nirschl RP. Rotator cuff disease: etiology, pathology, treatment. In: Pettrone FA, eds. Athletic injuries of the shoulder. New York, NY: McGraw-Hill, 1994; 155-165.
- Ellman H. Diagnosis and treatment of incomplete rotator cuff tears. Clin Orthop 1990; 254:64-74.
- Codman EA, Akerson ID. The pathology associated with rupture of the supraspinatus tendon. Ann Surg 1931; 93:348-359.[Medline]
- Walch G, Boileau P, Noel E, Donell ST. Impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim: an arthroscopic study. J Shoulder Elbow Surg 1992; 1:238-245.
- Fukuda H, Hamada K, Nakajima T, Tomonaga A. Pathology and pathogenesis of the intratendinous tearing of the rotator cuff viewed from en bloc histologic sections. Clin Orthop 1994; 304:60-67.
- Patte D. Classification of rotator cuff lesions. Clin Orthop 1990; 254:81-86.
- Tirman PF, Bost FW, Steinbach LS, et al. MR arthrographic depiction of tears of the rotator cuff: benefit of abduction and external rotation of the arm. Radiology 1994; 192:851-856.[Abstract/Free Full Text]
- Palmer WE, Brown JH, Rosenthal SI. Rotator cuff: evaluation with fat-suppressed MR arthrography. Radiology 1993; 188:683-687.[Abstract/Free Full Text]
- Tirman PF, Bost FW, Garvin GJ, et al. Posterosuperior glenoid impingement of the shoulder: findings at MR imaging and MR arthrography with arthroscopic correlation. Radiology 1994; 193:431-436.[Abstract/Free Full Text]
- Hodler J, Kursunoglu-Brahme S, Snyder SJ, et al. Rotator cuff disease: assessment with MR arthrography versus standard MR imaging in 36 patients with arthroscopic confirmation. Radiology 1992; 182:431-436.[Abstract/Free Full Text]
- Quinn SF, Sheley RC, Demlow TA, Szumowski J. Rotator cuff tendon tears: evaluation with fat-suppressed MR imaging with arthroscopic correlation in 100 patients. Radiology 1995; 195:497-501.[Abstract/Free Full Text]
- Sanders TG, Tirman PF, Feller JF, Genant HK. Association of intramuscular cysts of the rotator cuff with tears of the rotator cuff: magnetic resonance imaging findings and clinical significance. Arthroscopy 2000; 16:230-235.[Medline]
- Flannigan B, Kursunoglu-Brahme S, Snyder S, Karzel R, Del Pizzo W, Resnick D. MR arthrography of the shoulder: comparison with conventional MR imaging. AJR Am J Roentgenol 1990; 155:829-832.[Abstract/Free Full Text]
- Ozaki J, Fujimoto S, Nakagawa Y, Masuhara K, Tamai S. Tears of the rotator cuff of the shoulder associated with pathological changes in the acromion: a study in cadavera. J Bone Joint Surg Am 1988; 70:1224-1230.[Abstract/Free Full Text]
- Payne LZ, Altchek DW, Craig EV, Warren RF. Arthroscopic treatment of partial rotator cuff tears in young athletes: a preliminary report. Am J Sports Med 1997; 25:299-305.[Abstract/Free Full Text]
- Arroyo JS, Flatow EL. Management of rotator cuff disease: intact and repairable cuff. In: Iannotti JP, Williams GR, eds. Disorders of the shoulder: diagnosis and management. Philadelphia, Pa: Lippincott Williams & Wilkins, 1999; 31-56.
- Palmer WE, Brown JH, Rosenthal DI. Labral-ligamentous complex of the shoulder: evaluation with MR arthrography. Radiology 1994; 190:645-651.[Abstract/Free Full Text]
- Jee WH, McCauley TR, Katz LD, Matheny JM, Ruwe PA, Daigneault JP. Superior labral anterior posterior (SLAP) lesions of the glenoid labrum: reliability and accuracy of MR arthrography for diagnosis. Radiology 2001; 218:127-132.[Abstract/Free Full Text]
- De Maeseneer M, Van Roy F, Lenchik L, et al. CT and MR arthrography of the normal and pathologic anterosuperior labrum and labral-bicipital complex. RadioGraphics 2000; 20:S67-S81.[Abstract/Free Full Text]
- Bencardino JT, Beltran J, Rosenberg ZS, et al. Superior labrum anterior-posterior lesions: diagnosis with MR arthrography of the shoulder. Radiology 2000; 214:267-271.[Abstract/Free Full Text]
- Chan KK, Muldoon KA, Yeh L, et al. Superior labral anteroposterior lesions: MR arthrography with arm traction. AJR Am J Roentgenol 1999; 173:1117-1122.[Abstract/Free Full Text]
- Chandnani VP, Yeager TD, DeBerardino T, et al. Glenoid labral tears: prospective evaluation with MRI imaging, MR arthrography, and CT arthrography. AJR Am J Roentgenol 1993; 161:1229-1235.[Abstract/Free Full Text]
- Roger B, Skaf A, Hooper AW, Lektrakul N, Yeh L, Resnick D. Imaging findings in the dominant shoulder of throwing athletes: comparison of radiography, arthrography, CT arthrography, and MR arthrography with arthroscopic correlation. AJR Am J Roentgenol 1999; 172:1371-1380.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
T. Herold, M. Bachthaler, O. W. Hamer, R. Hente, S. Feuerbach, C. Fellner, M. Strotzer, M. Lenhart, and C. Paetzel
Indirect MR Arthrography of the Shoulder: Use of Abduction and External Rotation to Detect Full- and Partial-Thickness Tears of the Supraspinatus Tendon
Radiology,
July 1, 2006;
240(1):
152 - 160.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
O. P. Krief and D. Huguet
Shoulder Pain and Disability: Comparison with MR Findings.
Am. J. Roentgenol.,
May 1, 2006;
186(5):
1234 - 1239.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. B. Stetson, T. Phillips, and A. Deutsch
The Use of Magnetic Resonance Arthrography to Detect Partial-Thickness Rotator Cuff Tears
J. Bone Joint Surg. Am.,
December 1, 2005;
87(suppl_2):
81 - 88.
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. J. Matava, D. B. Purcell, and J. R. Rudzki
Partial-Thickness Rotator Cuff Tears
Am. J. Sports Med.,
September 1, 2005;
33(9):
1405 - 1417.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Kassarjian, M. Torriani, H. Ouellette, and W. E. Palmer
Intramuscular Rotator Cuff Cysts: Association with Tendon Tears on MRI and Arthroscopy
Am. J. Roentgenol.,
July 1, 2005;
185(1):
160 - 165.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Waldt, A. Burkart, P. Lange, A. B. Imhoff, E. J. Rummeny, and K. Woertler
Diagnostic Performance of MR Arthrography in the Assessment of Superior Labral Anteroposterior Lesions of the Shoulder
Am. J. Roentgenol.,
May 1, 2004;
182(5):
1271 - 1278.
[Abstract]
[Full Text]
[PDF]
|
|
|
TOP
ABSTRACT
INTRODUCTION
