Biomedical subjects

H Graichen

Publications and source records attributed to H Graichen.

39 records · Page 3Linked to original sources

PubMedDate not supplied

[An MR-based technique for determination of the subacromial space width in subjects with and without shoulder muscle activity].

INTRODUCTION: The occurrence of the impingement syndrome of the shoulder is dependent on muscle activity and arm position. However, the current radiological workup is based on conventional radiographs, CT or MRI obtained at 0 degree of abduction and at muscular relaxation. The objective of this study was the development of a technique for simultaneous visualization of the humerus, scapula, clavicle and their relationship to the M. supraspinatus--in different arm abduction positions with and without muscle activity--as well as the determination of the minimal acromio-humeral distance. METHOD: The shoulder joints of 8 volunteers were examined in an open MRI system at 60 degrees, 90 degrees and 120 degrees of abduction, using a T1 weighted 3D gradient echosequence. Forces of 10 N were applied at the distal humerus. After 3D reconstruction, the acromio-humeral distance was computed with Euclidian distance transformation. RESULTS: With increasing abduction, the acromio-humeral distance decreased significantly (p < 0.05), but the distance vector was localised laterally to the M. supraspinatus at 120 degrees. With muscle activity a reduction of the subacromial space of 29% (p < 0.05) occurred at 60 degrees whereas at 120 degrees a 51% (p < 0.05) increase was noted. At 90 degrees, no significant difference was observed. CONCLUSION: With the technique presented it is possible to determine the subacromial space width in different arm positions independent of the specific section orientation, with and without muscle activity. The method can be used as a basis for biomechanical investigations and for the clinical diagnosis of impingement syndrome.

Adult↗

PubMedDate not supplied

[Value of glenoid osteotomy in treatment of posterior shoulder instability].

UNLABELLED: Purpose of this retrospective study was to evaluate the midterm results of glenoid osteotomy in the treatment of posterior instability and furthermore to evaluate the relevance of etiopathogenesis on the outcome. METHOD: Between Jan. 83 and May 94 32 patients underwent surgery due to posterior instability. Retrospectively these patients were classified based on their etiopathogenesis. 28 patients could be reexamined clinically and radiologically after and average of 4.85 years, of which 21 were treated with a glenoid osteotomy. For evaluation the Constant-Murley and the Rowe-Score were used. RESULTS: The Constant-Score showed 82,2% and the Rowe-Score 71,5% good or excellent results. Evaluation of glenoid osteotomy demonstrated for the patients with atraumatic genesis an excellent result in 76.9% with a recurrence rate of only 15.4%. On the other hand patients with traumatic instability showed a recurrence rate of 50%. The radiologic assessment demonstrated degenerative changes in nearly 30% of cases treated with glenoid osteotomy. CONCLUSION: This study shows that glenoid osteotomy can provide good result in the surgical treatment of posterior atraumatic instability. For treatment of traumatic instability, however, glenoid osteotomy is not the procedure due to high recurrence and arthrosis rates. RELEVANCE: Posterior glenoid osteotomy should be reserved for patients with atraumatic posterior instability combined with an increased retroversion angle of the glenoid especially because of the high rate of arthrosis.

Adolescent↗

PubMedDate not supplied

Sex-specific differences of subacromial space width during abduction, with and without muscular activity, and correlation with anthropometric variables.

The objectives of this study were to determine sex-specific differences of the subacromial space width during active and passive arm abduction and to analyze the correlation of this space with general and regional anthropometric variables. Fourteen healthy subjects (7 men, 7 women) were examined with an open magnetic resonance system at 30 degrees and 90 degrees of abduction (with and without muscle activity). After 3-dimensional reconstruction, the minimal acromiohumeral distance, the glenoid size, and the humeral head radius were determined. At 30 degrees of abduction, a significant difference of the acromiohumeral distance was observed between men (8.18 +/- 1.0 mm) and women (6.98 +/- 0.75 mm) (P < .05), but not at 90 degrees (6.7 +/- 2.0 mm versus 5.9 +/- 1.0 mm) or under muscle activity (4.9 +/- 2.4 mm versus 3.5 +/- 2.1 mm). Significant correlations between the acromiohumeral distance and anthropometric variables were found at 30 degrees of abduction (r = 0.48 to 0.72), but not at 90 degrees, with or without muscle activity (r = 0.21 to 0.55). The results demonstrate that at physical rest, the subacromial space width is dependent on sex, but the interindividual variability increases substantially during abduction and under muscle activity.

Adult↗