2015 ISAKOS Biennial Congress ePoster #2101
Stress Pattern in Glenohumeral Capsule According to Shoulder Movement
Byung-Su Kim, MD, Hwaseong-Si, Gyeonggi-Do KOREA, REPUBLIC OF
Kyu-Cheol Noh, MD, PhD, Prof., Seoul KOREA, REPUBLIC OF
Yon-Sik Yoo, MD, PhD, Hwaseong-Si, Gyeonggi-do KOREA, REPUBLIC OF
Yoonsuk Hyun, MD, Seoul KOREA, REPUBLIC OF
Seong-jin Lee, Kyeongkido KOREA, REPUBLIC OF
Hallym University, Seoul, seoul, SPAIN
FDA Status Not Applicable
Summary: Pathomechanics of frozen shoulder characterized by glenohumeral motion limitation had complicated pathogenic mechanism asserted by high stress in anteroinferior glenohumeral capsule, abnormal location in scapula, and resulting in imbalance of muscles strength.
The pathomechanics in stiff shoulder have not been fully investigated.
The purpose of this study was to explore the glenohumeral kinematics in frozen shoulder using a 3-dimensional finite element model and to suggest a hidden scapulothoracic pathogenic mechanism which influences restriction of glenohumeral motion.
MATERIALS & METHODS
Both shoulders of 10 patients diagnosed with unilateral idiopathic frozen shoulder were scanned using a high resolution computed tomography at matched maximum humeral abduction positions. The modeling programs were used to simulate glenohumeral and scapulothoracic motion based on reconstructed CT images. The finite element models of glenohumeral capsule were also constructed based on CT arthrogram at 0° abduction. We evaluated the changes in scapular position between matched humeral abduction angles and measured the degree of scapular abduction, external rotation and posterior tilt of scapulas. The tension changes and stress pattern of the capsule during various shoulder motion were also assessed
With matched maximal humeral abduction, the abduction angle of scapula on affected shoulder and contralateral shoulder were 58±7° and 38±8°, respectively (p<0.05). The posterior tipping of affected and contralateral scapula were 25±5° and 26±2° (p=0.12). The abduction, external rotation at full abduction and internal rotation caused the increase in the stress of anteroinferior capsule than other portions of capsule with statistical significance (6.1±0.9Mpa, 7.9±1.1Mpa and 5.4±0.7Mpa). The anterosuperior capsule did not show any prominent stress in various motions except early step of internal rotation and external rotation at 0 degree abduction.
The scapula in idiopathic frozen shoulder showed an increment in scapular abduction and decrease in external rotation or adduction of scapula but no change in posterior tipping at maximum abduction position. Pathomechanics of frozen shoulder characterized by glenohumeral motion limitation had complicated pathogenic mechanism asserted by high stress in anteroinferior glenohumeral capsule, abnormal location in scapula, and resulting in imbalance of muscles strength.