Analysis of collagen and elastic fibers in shoulder capsule in patients with shoulder instability.
This study examined collagen cross-links, collagen fibril diameter and density, amino acid composition, and elastic fibers in shoulder capsule and skin in four patient groups: 1) unidirectional anterior instability (N = 8); 2) multidirectional instability/primary surgery (N = 6); 3) multidirectional instability/revision surgery (N = 6); and 4) no history of instability (N = 5). Compared with normal capsule, capsule from groups 1 and 2 had more stable and reducible collagen cross-links, significantly greater mean collagen fibril diameter, more cysteine, and a higher density of elastin staining. Compared with shoulder capsule in groups 1 and 2, shoulder capsule from group 3 contained significantly more reducible cross-links, smaller-diameter collagen fibrils, decreased collagen fibril density, and an increased density of elastin staining. There were no significant differences in any parameters between groups 1 and 2. We hypothesized that repeated capsular deformation in patients with shoulder instability results in changes in the capsule that increase its strength and resistance to stretching. Skin analyses demonstrated a significantly smaller mean collagen fibril diameter in skin from group 2 compared with group 1, suggesting the possibility of an underlying connective tissue abnormality.
Laboratory for Soft Tissue Research, Hospital for Special Surgery, New York, New York 10021, USA.
S A
SA
Rodeo
K
K
Suzuki
M
M
Yamauchi
M
M
Bhargava
R F
RF
Warren
D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000032:analysis; D016022:Case-Control Studies; D003094:Collagen / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure; D004396:Coloring Agents; D003240:Connective Tissue Diseases / Q000378:metabolism / Q000473:pathology; D003545:Cysteine / Q000032:analysis; D004547:Elastic Tissue / Q000737:chemistry* / Q000473:pathology; D004549:Elastin / Q000032:analysis / Q000737:chemistry; D005109:Extracellular Matrix / Q000737:chemistry / Q000648:ultrastructure; D005260:Female; D006801:Humans; D017746:Joint Capsule / Q000737:chemistry* / Q000473:pathology / Q000601:surgery; D007593:Joint Instability / Q000145:classification / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008297:Male; D012086:Reoperation; D012785:Shoulder Joint / Q000737:chemistry* / Q000473:pathology / Q000601:surgery; D012867:Skin / Q000737:chemistry / Q000473:pathology; D013314:Stress, Mechanical
D000596:Amino Acids; D004396:Coloring Agents; D003094:Collagen; D004549:Elastin; D003545:Cysteine