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

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. Level of Evidence: Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.Ouellette H, 2008, SKELETAL RADIOL, V37, P491, DOI 10.1007/s00256-007-0389-0Nyffeler RW, 2006, J BONE JOINT SURG AM, V88A, P800, DOI 10.2106/JBJS.D.03042Ogawa K, 2005, J SHOULDER ELB SURG, V14, P591, DOI 10.1016/j.jse.2005.03.007Fealy S, 2005, J SHOULDER ELB SURG, V14, P542, DOI 10.1016/j.jse.2005.02.006Tucker TJ, 2004, ARTHROSCOPY, V20, P744, DOI 10.1016/j.arthro.2004.06.018Chambler AFW, 2003, J SHOULDER ELB SURG, V12, P314, DOI 10.1016/S1058-2746(03)00030-2Hirano M, 2002, J SHOULDER ELB SURG, V11, P576, DOI 10.1067/mse.2002.127097HAYES PR, 2002, ARTHROSCOPY, V18, pE44Bonsell S, 2000, J BONE JOINT SURG BR, V82B, P1135Anderson K, 1999, ARTHROSCOPY, V15, P788Liotard JP, 1998, J SHOULDER ELB SURG, V7, P134Panni AS, 1996, ARTHROSCOPY, V12, P531NICHOLSON GP, 1996, J SHOULDER ELB SURG, V5, P1TOIVONEN DA, 1995, J SHOULDER ELB SURG, V4, P376EPSTEIN RE, 1993, RADIOLOGY, V187, P479JIM YF, 1992, SKELETAL RADIOL, V21, P449EDELSON JG, 1992, J BONE JOINT SURG BR, V74, P589BIGLIANI LU, 1991, ORTHOPADE, V20, P302CHANSKY HA, 1991, CLIN SPORT MED, V10, P807HARRYMAN DT, 1990, J BONE JOINT SURG AM, V72A, P1334OGATA S, 1990, CLIN ORTHOP RELAT R, P39OZAKI J, 1988, J BONE JOINT SURG AM, V70A, P1224BIGLIANI LU, 1986, ORTHOP T, V10, P228NEER CS, 1983, CLIN ORTHOP RELAT R, P70NIXON JE, 1975, ORTHOP CLIN N AM, V6, P423NEER CS, 1972, J BONE JOINT SURG AM, VA 54, P41