Can a high acromion index predict rotator cuff tears?
OBJECTIVE
The purpose of this study was to identify the relationship between an acromion index (AI) and the size of a rotator cuff tear. The hypothesis of our study was that an AI will be higher in patients with a full-thickness tear than in patients with a partial-thickness articular-side tear, and that it can be used as a predictor for the size of a rotator cuff tear.


METHODS
We included 284 patients who had been diagnosed with rotator cuff tears and had undergone arthroscopic rotator cuff repair at our institute. All patients were divided into five distinct groups (partial-thickness articular side tear, and four subgroups of full-thickness tears) depending on the size of the rotator cuff tear on arthroscopy. In each patient, an AI was measured on the pre-operative oblique coronal MR images and then analysed to determine the difference between groups.


RESULTS
There were statistically significant differences between the partial-thickness articular side rotator cuff tear and large-to-massive rotator cuff tear groups (p < 0.01), and the mean value of an AI was highest in the large-sized full-thickness tear group. The AI of the partial-thickness articular-side rotator cuff tear group was statistically different from the large-to-massive rotator cuff tear groups.


CONCLUSIONS
The AI can be a predictor which can differentiate a partial-thickness articular-side tear and a large-to-massive rotator cuff tear pre-operatively. However the AI could not provide useful guidance on predicting the differences in tear size in full-thickness tear patients. We suggest that a high AI can be one of the associated factors for progression to large-to-massive rotator cuff tears in a rotator cuff disease.
Department of Orthopaedic Surgery, CHA Bundang Medical Center, CHA University School of Medicine, 351 Yatap-dong, Bundang-gu, Sung-nam, South Korea.
Jung Ryul
JR
Kim
Keun Jung
KJ
Ryu
In Tae
IT
Hong
Byung Kook
BK
Kim
Jae Hwa
JH
Kim
D000174:Acromion / Q000293:injuries* / Q000601:surgery; D000368:Aged; D001182:Arthroscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000601:surgery; D000070636:Rotator Cuff Injuries; D012720:Severity of Illness Index; D013708:Tendon Injuries / Q000175:diagnosis* / Q000601:surgery; D013710:Tendons / Q000601:surgery*