Classification and Clinical Significance of Acromial Spur in Rotator Cuff Tear: Heel-type Spur and Rotator Cuff Tear

Abstract

Acromial spurs reportedly relate to the impingement syndrome and rotator cuff tears. We classified the morphologic characteristics of the acromion (shape and thickness) and acromial spurs and determined whether they correlated with rotator cuff tears. We measured acromial shape and thickness using simple radiography and MR arthrography or CT arthrography in 106 patients with full-thickness rotator cuff tears and in 102 patients without tears. Acromial spurs could be classified morphologically into six types: heel, lateral/anterior traction, lateral/anterior bird beak, and medial. We found acromial spurs in 142 of the 208 patients (68%), and their incidence increased with age. The acromial spur was more common in the cuff tear group. The heel type was most common and detected in 59 patients (56%) in the cuff tear group and in 36 patients (35%) in the control group. The flat acromion was more common (60%) than curved and hooked acromion; however, there was no major difference between acromial shape and cuff tear. The mean acromial thickness was 8.0 mm, and the cuff tear group had thicker acromion. These data suggest acromial spurs can be classified according to the distinct morphology, and the most common heel-type spur might be a risk factor for full-thickness rotator cuff tears.

Clinical features of partial anterior bursal-sided supraspinatus tendon (PABST) lesions

“…1,2,23 One study showed that acromial spurs can be classified according to the distinct morphology and that the most common heel-type spur might be a risk factor for FTRCT. 25 In this study, heel-type spurs were most common and were detected in 19 shoulders (76%) in the PABST group, 169 shoulders (72.2%) in the FTRCT group, and 15 shoulders (71.4%) in the small FTRCT group.…”

“…Acromial spur formation and acromion shape are known to be related to subacromial impingement and rotator cuff tears. 2,23,25 We checked for acromial spurs on the coronal and sagittal planes with MRI 25 and found a higher frequency of coronal acromial spurs in the PABST group compared with the FTRCT group (P ¼ .021); however, this difference was not evident between the PABST group and the small FTRCT group. This could be one of the characteristics of PABST lesions, even though debate still exists regarding whether acromial spurs are a cause or consequence of rotator cuff tears.…”

“…The mean difference in symptom duration was determined by use of the Welch t test for possibly unequal variances. We also determined differences in the trauma history, sex, operation site, and presence of coronal-plane (inferiorly directed spur) or sagittalplane (anteriorly directed spur) acromial spurs using MRI 25 and sports activity between the two groups using the c 2 test. We used the Fisher exact test to analyze the acromion morphology between the two groups.…”

Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the assessment of sub-coracoacromial spurs causing subacromial impingement syndrome

“…The maximal width (mm) of inferiorly directed spurs was measured. Ossification of the coracoacromial ligament or presence of a sub-coracoacromial spur can be identified in the sagittal oblique plane [28,29] as well as on oblique coronal sequences [28]. To achieve a high level of comparability to the reference standard (conventional radiography), we used oblique coronal sequences for size measurements and illustration of subcoracoacromial spurs on MR images.…”

“…Therefore, ultrasound of the shoulder is not performed in all MSK centres and can be associated with limitations including: 1) Dependence on operator experience and acoustic window; and 2) Limited reproducibility and standardization. MR and radiographs are more common today for diagnosis of shoulder disorders and sub-coracoacromial spur formation as they provide more consistent and accurate information, and they can provide three-dimensional images of the acromion, spur shapes as well as rotator cuff and labral disorders at the same time [27,28]. Patients with SAIS may benefit from the addition of SWMR to a standard shoulder imaging protocol as it offers additional anatomical information in three dimensions without radiation exposure, offers a comparable short acquisition time of 4.5 minutes, and enables visualization of not only spur formation but also other important features of SAIS simultaneously.…”