ELSEVIER

MASSIVE ROTATOR CUFF TEARS SCREENING BY ROUTINE RADIOGRAPHS

KUNIYUKI KANEKO, MD, EDWARD H. DE MOUY, MD, AND MICHAEL E. BRUNET, MD

To clarify their usefulness in screening massive rota- tor cuff tear, routine radiogmphs of the shoulder were compared in three groups: (1) shoulders with a mas- sive rot&or cuff tear (MIXT), (2) shoulders with a small full-thickness rotator cufftear (SRCT), and (3) normal control shoulders. Two different statistical methods were employed to assess the gmdation (order) of corre- lation in 83 shoulders (22 were MRCTs, 31 with SRCTs, and 36 controls). Superior migration of the humerus and deformity of the greater tuberosity showed by far the more significant contribution to MRCT than did other abnormalities. When the shoulders were screened for these two abnormalities, the sensitivity was 78% (21127) and specificity was 98% (55156).

KEY WORDS:

Rotator cuff tear; Supraspinatus tendon; Radiographs

INTRODUCI’ION

Although plain radiographs play only a supplemen- tal role in the diagnosis of rotator cuff tear (RCT), they are usually the first imaging modality employed in screening patients for further evaluation. Traditionally, superior migration of humeral head has been used as an important sign for RCTs (1,2). Several degenerative changes of the shoulder joint have also been associated with rotator cuff diseases (1,3-8). However, the grada- tion (order) of these radiographic findings has not been analyzed. We reviewed routine radiographs of shoul- ders with or without rotator cuff disease to determine

From the Departments of Radiology (K.K., E.H.D.) and Ortho- pedic Surgery (M.E.B.), Tulane University Medical Center, New Orleans, Louisiana.

Address reprints requests to: Edward H. De Mouy, MD, Depart- ment of Radiology, Tulane University Medical Center, 1430 Tulane Avenue, New Orleans, LA 70112-2699.

Received November 10, 1993; accepted February 20, 1994.

CLINICAL IMAGING 1995;19:8-11 o Elsevier Science Inc., 1995 655 Avenue of the Americas, New York, NY 10010

the radiographic indicators useful for the screening of massive rotator cuff tear (MRCT).

MATERIALS AND METHODS

Three groups were selected for the analysis: 22 shoul- ders with MRCTs, 31 shoulders with small to moder- ate full-thickness rotator cuff tears (SRCTs), and 30 shoulders without RCTs as controls. MRCT was defined as a full-substance tear of the entire supraspinatus ten- don with retraction of the supraspinatus muscle. The diagnosis of MRCT was made at surgery (seven pa- tients) or with magnetic resonance imaging (MRI) (15 patients). Sixteen ware men and six were women. Sub- jects ranged in age from 47 to 79 years (mean, 64 years). SRCT was defined as a small to moderate full-substance tear of supraspinatus tendon (<4 cm). SRCT was diag- nosed at arthroscopy (24 patients), by MRI arthrogra- phy (five patients), or with both (two patients). Twenty- four were men and 7 were women. Subjects ranged in age from 23 to 75 years (mean, 42 years). Absence of a RCT was confirmed at arthroscopy (30 patients). Twenty were male and 10 were female. Subjects ranged in age from 16 to 63 years (mean, 37 years). Four shoul- ders with superficial partial RCT (grade l(9)) were in- cluded in the control group because these tears did not alter therapeutic modalities.

Standard anteroposterior views of the shoulder with the humerus in internal and external rotation were ob- tained for all subjects and used for this review.

MRI examinations were performed at 1.5 T (Signa, General Electric Medical Systems, Milwaukee, WI) using a dedicated shoulder coil. Oblique coronal views were obtained with T2weighted (TR 2000/TE 70) and proton density-weighted (TR 2OOO/TE 20) spin-echo pulse sequences, 4-mm slice thickness, l-mm intersec- tion gap, 256 x 198 matrix, 16-cm field of view (FOV), and one excitation. Oblique coronal, oblique sagittal,

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JANUARY -MARCH 1995 MASSIVE ROTATOR CUFF TEARS 9

FIGURE 1. Antemposterior radiograph shows superior sub- luxation of the humerus in a patient with a massive rotator cuff tear.

and axial views were obtained by multiplanar gradient- recalled (MPGR) fast scans with TR 500/TE 13/flip an- gle 150, a-mm slice thickness, l-mm intersection gap, 256 x 198 matrix, 16-cm FOV, and four excitations. For MRI arthrography, 20 mL of isotonic saline solution was injected into the glenohumeral joint prior to MRI scanning (10).

MRCT was diagnosed by MRI when discontinuity of the supraspinatus tendon with retraction was dem- onstrated on both oblique coronal and sagittal images. SRCT was diagnosed by MRI arthrogram when a dis- section of saline solution into the subacromial space was demonstrated without supraspinatus muscle retraction.

The following radiographic findings were selected to be correlated with rotator cuff lesions: (a) superior migration of the humeral head (acromiohumeral in- terval <6 mm); (b) acromial shape (according to Bigliani et al. (7)); (c) acromial spur; (d) inferior spurs of the acromioclavicular joint (>2 mm); and (e) de- generative changes of the greater tuberosity, such as sclerosis, cystic change, and deformity (flattening or irregularity).

First, a cross table was made to compare the inci- dence of radiographic abnormalities in the three groups. Since the purpose of this analysis was to screen for MRCTs, control and SRCT data were combined to cal- culate odds ratios that would reflect the degree of risk. Acromial shape types 1 and 2 were also combined for this calculation because type 3 acromion has been

FIGURE 2. Antemposterior radiograph shows a flattening deformity of the greater tuberosity of the humerus in a pa- tient with a massive rotator cuff tear.

reported to correlate with RCT (7). Next, a method of discriminant analysis was used to calculate the cate- gory score that would quantitatively express the de- gree of correlation. For the calculation of this score, Hayashi’s theory of quantification II (11) was employed. The order of the range of results was interpreted to rep- resent the degree of correlation.

RESULTS

Incidence of Radiographic Abnormalities and Odds Ratios

Shoulders with an MRCT had a higher incidence of superior migration of the humerus (Figure l), type 3 acromion, acromial spur, inferior acromioclavicular spur, and deformity of the greater tuberosity (Figure 2 and Table 1). However, superior migration of the hu- merus and deformity of the greater tuberosity revealed considerably large odds ratio when compared with the other deformities.

Quantitative Analysis

According to the category score, superior migration of the humerus and deformity of the greater tuberosity contributed the most to MRCT (Table 2). Showing nega- tive scores, all other radiographic abnormalities also contributed to MRCT; however, the degrees of contri- bution (range) were small.

10 KANEKO ET AL. CLINICAL IMAGING VOL. 19, NO. 1

TABLE I. Incidence of Radiographic Abnormalities and Odds Ratios

Radiographic findings Control (n = 30) SRCT (n = 31) MRCT (n = 22) Odds ratio

Superior migration of the humerus

t Acromial shape

Type 1 Type 2 Type 3

Acromial spur

+ Inferior spur at acromioclavicular joint

t Sclerosis of the greater tuberosity

+ Cystic change of the greater tubemsity

+ Deformity of the greater tuberosity

t

30 (100%) 0

17 (57%) 9 (30%) 4(13%)

26 (93%)

2 (7%)

25 (16%) 6 (19%)

26(67%) 20 (65%) 4 (13%) 11 (35%)

26 (93%)

2 (7%)

26 (93%) 2 (7%)

29 (97%)

1(3%)

26 (90%) 3 (10%)

6 (26%) 16 (56%) 5 (16%)

19 (61%) 12 (39%)

16(57%) 13 (43%)

26 (90%) 3 (10%)

6 (36%) 33.6 14 (64%)

1 (5%) 6.19 11 (50%) 10 (46%)

16 (73%) 2.46 6 (27%)

6 (36%) 5.37 14 (64%)

16 (73%) 1.26 6 (27%)

13 (59%) 2.12 9 (41%)

6 (36%) 24.9 14 (64%)

SRCT, small full-thickness rotator cuff tear; MRCT, massive rotator cuff tear.

TABLE 2. Category, Category Score, and Range for Each Parameter Determined by Hayashi’s Theory of Qualification II, Accounting for Massive Rotator Cuff Tear

Parameters Category Category

score Range corder1

Superior migration of the humerus t

Acromial shape Type 1 Type 2 Type 3

Acromial spur +

Inferior spur at acromioclavicular joint t

Sclerosis of the greater tuberosity +

Cystic change of the greater tuberosity +

Deformity of the greater tubemsity t

Criterion variable Control SRCT MRCT

Correlation coefficient

SRCT, small full-thickness rotator cuff tear; MRCT, massive rotator cuff tear.

+ 0.26 1.26 (1) - 1.02

t 0.20 0.32 (4) - 0.12 - 0.03

t 0.05 0.26 (5) - 0.23

t 0.06 0.22 (7) - 0.14

t 0.09 0.36 (3) - 0.27

+ 0.06 0.26 (6) - 0.16

t 0.23 1.05 (2) - 0.62

0.77 0.16

- 1.31

0.69

DISCUSSION

We reviewed shoulder radiographs to clarify the prac- tical role of routine radiography in the diagnosis of RCTs. Although several new imaging modalities have been introduced, the confirmation of rotator cuff dis-

ease is complex and expensive work; accordingly, less complicated diagnostic tests are preferable. In addition, it is often necessary to propose screening tools that can be rapidly and economically applied to many people.

A narrow acromiohumeral interval was the single

JANUARY-MARCH 1995 MASSIVE ROTATOR CUFF TEARS 11

most reliable indicator of MRCT since all 13 shoulders with an acromiohumeral interval less than 6 mm had either MRCT or SRCT. However, eight (36%) of 22 shoulders with MRCT had an acromiohumeral inter- val greater than 7 mm (7 to 11 mm). Retraction of the supraspinatus, atrophy of the supraspinatus, cuff de- generation (3)) and impairment of a balance between the deltoid and supraspinatus (2) were believed to cause upward migration of the humeral head. In addi- tion, hematoma in the subacromial space can modify the acromiohumeral interval in shoulders with acute MRCT (4). Therefore, MRCT cannot be effectively screened by only using narrow acromiohumeral in- terval.

radiographs can only demonstrate degenerative changes associated with clinical impingement or fractures as- sociated with trauma.

When we diagnose the shoulders with either supe- rior migration of the humerus or deformity of the greater tuberosity as having an MRCT, the sensitivity is 78% (2l/27) and specificity is 98% (55/56). Among six shoulders with a false-positive finding, five were found to have an SRCT. Although the number of sub- jects in our series is not large enough to evaluate spec- ificity or sensitivity, most shoulders with an MRCT (21/22) could be screened by routine radiographs.

Although the age distribution was different for the three groups, shoulders with MRCT or SRCT showed a higher incidence of degenerative changes. Acromial spurs develop as a result of traction by the coraco- acromial ligament (12) and can narrow subacromial channels. Inferior acromioclavicular spur can injure the rotator cuff during abduction (6). Degenerative changes of the greater tuberosity result from chronic mechanical stress by the rotator cuff (3), and can be explained by progressive stages in shoulder impinge- ment theory (12). Therefore, these changes usually in- dicate rotator cuff impingement or chronic stress of the rotator cuff. As a rule, most MRCTs are chronic in ori- gin; shoulders with an MRCT show a higher incidence of these changes. In addition, secondary osteoarthri- tis of the acromiohumeral joint develops with the ab- sence of a rotator cuff. However, these degenerative changes are not specific to MRCT.

We conclude that we can reliably screen MRCT by focusing our attention to the decreased acromiohu- meral interval and deformity of the greater tuberosity as seen on plain films.

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Our analysis revealed that superior migration of the humeral head and deformity of the greater tuberosity although not specific, are by far the most important indicators of MRCT. Although all other abnormalities showed some association with MRCT, the degrees of correlation were small. On quantitative analysis, shoul- ders with an MRCT tended to show negative values and then revealed differences from the other two groups. This result means that shoulders with an MRCT can be screened by radiographs to some extent. However, shoulders with an SRCT cannot be screened by radio- graphs, probably because SRCTs occur in tendons that are weakened by some combination of numerous fac- tors, such as age, impingement (12), repeated minor trauma due to exercise (13), hypovascularity of the ten- don (14)) and major injuries. However, of these factors,

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