Evaluation of Coraco-Acromial Arch in Patients with Impingement Syndrome

Journal of the Korean Shoulder and Elbow Society 1999;2(1):35-40.
Published online June 30, 1999.

Kwang Jin Rhee, Ki Young Byun, Soon Tae Kwun, Kyn Hwan Byun

Department of Diagnostic Radiology, College of Medicine, Chungnam National University Department of Orthopaedic Surgery, College of Medicine, Chungnam National University

견관절 충돌 증후군 환자에서 오훼 견봉궁의 자기공명영상 평가

이광진, 변기용, 권순태, 변규환

충남대학교 의과대학 정형외과학교실, 충남대학교 의과대학 진단방사선학교실

Abstract

Impingement syndrome is caused by a conflictual status between rotator cuff, subacromial bursa and anatomic and functional coracoacromial arch. The purpose of this study was to assessment the coracoacromial arch by MRI and to determine major factors among five components of coracoacromial arch. We analyzed forty-two cases of clinical impingement sign and test positive and postoperative confirmed diagnosed from March, 1991 to January, 1999. We evaluated acromial end abnormality according to the Bigliani acromial type and formation of osteophyte. Clavicular end abnormality classified flat, outward protrusion, inward protrusion to coracoacromial arch. Acromioclavicular joint abnormalities were advanced osteoarthritis and positive signal change. Coracoacromial ligament thickening was above 2 mm in oblique sagittal image. Coracoid process abnormality was inward protrusion to coracoacromial arch. All consecutive patients abnormalities were as follows : clavicular end osteophyte formation and inward protrusion to coracoacromial arch were 30%, acromial end osteophyte formation was 28%, advanced acromioclavicular joint arthritis and osteophyte formation were 56%, coracoacromial ligament thickening was 249o and no coracoid process inward protrusion to coracoacromial arch. Impingement syndrome combined with rotator curt tear group abnormalities were clavicular end(40%), acromial end(40%), acromioclavicular joint(20%), coracoacromial ligament(20%) and coracoid process abnormality(0%) respectively. Only impingement syndrome group abnormalities were clavicular end(25%), acromial end(31%), acromioclavicular joint(62%), coracoacromial ligament(25%) and coracoid process(0%) respectively. Acromial type Ⅰ(flat) were 6 cases, type Ⅱ(curved) were 26 cases and type Ⅲ(hooked) were 10 cases. We concluded that the most important contributing factors for impingement syndrome was acromial type and second was acromioclavicular joint arthritis and bony spur formation.

Key Words: Coracoacromial arch, Impingement syndrome, MRI,