History Of Impingement Research Articles

Measurement of the coracohumeral distance on magnetic resonance imaging in a large patient cohort

Coracoid impingement syndrome is an increasingly recognized etiology of anterior shoulder pain. Numerus studies have documented the coracohumeral distance (CHD) as a primary or secondary measurement in symptomatic individuals, but there lacks an evaluation of CHD in a large cohort of asymptomatic individuals. The purpose of this study was to quantify a normative distribution of the CHD in a large cohort of healthy, asymptomatic subjects with no history of impingement or shoulder instability. Incoming first-year students in the United States Military Academy were offered enrollment in this study as part of a prospective cohort to assess the normal anatomic relationships of the shoulder girdle. Magnetic resonance images were obtained, and a board-certified, fellowship-trained musculoskeletal radiologist performed measurements of the smallest distance from the coracoid to the humeral head on axial images. Magnetic resonance images of 714 subjects were available for analysis, including 630 males and 84 females, with a total of 1120 individual shoulders with images of adequate quality. The mean CHD for all shoulders imaged was 13.7 mm. The mean CHD in male shoulders was 13.8 mm, and in female subjects the average was 12.4 mm. This study is the largest of its kind to evaluate the CHD in asymptomatic, healthy shoulders to dateand demonstrates a mean CHD of 13.7 mm for all subjects. This information can help to standardize "normal" ranges and act as a comparison for future work, when taken in the context of age and imaging in neutral rotation.

Localised deposition of amyloid in tears of the rotator cuff

Age-related localised deposition of amyloid in connective tissue has been found in degenerative articular and periarticular tissue. Biopsies of the supraspinatus tendon of 28 patients undergoing repair of the rotator cuff were analysed histologically for the presence of localised deposition of amyloid. There was a long history of impingement in 20 patients, and eight patients had suffered an acute traumatic tear with no preceding symptoms. Localised deposition of amyloid identified by Congo Red staining was detected in 16 samples (57%). Amyloid was present in 14 (70%) of the degenerative tears, but in only two (25%) of the acute tears. Immunohistochemical staining showed that the amyloid deposits were positive for P component, but negative for κ and λ light chains, prealbumin, and β2 microglobulin. Critical electrolyte staining revealed highly-sulphated glycosaminoglycans at sites of deposition of amyloid. The presence of localised deposition of amyloid in tears of the rotator cuff is likely to represent irreversible structural changes. These findings support the theory that impingement and tears are due to intrinsic degenerative changes within the tendons of the rotator cuff.

Localised deposition of amyloid in tears of the rotator cuff.

Age-related localised deposition of amyloid in connective tissue has been found in degenerative articular and periarticular tissue. Biopsies of the supraspinatus tendon of 28 patients undergoing repair of the rotator cuff were analysed histologically for the presence of localised deposition of amyloid. There was a long history of impingement in 20 patients, and eight patients had suffered an acute traumatic tear with no preceding symptoms. Localised deposition of amyloid identified by Congo Red staining was detected in 16 samples (57%). Amyloid was present in 14 (70%) of the degenerative tears, but in only two (25%) of the acute tears. Immunohistochemical staining showed that the amyloid deposits were positive for P component, but negative for kappa and lambda light chains, prealbumin, and beta2 microglobulin. Critical electrolyte staining revealed highly-sulphated glycosaminoglycans at sites of deposition of amyloid. The presence of localised deposition of amyloid in tears of the rotator cuff is likely to represent irreversible structural changes. These findings support the theory that impingement and tears are due to intrinsic degenerative changes within the tendons of the rotator cuff.