Arch Inclination Research Articles

Correlative study of vertebra arch angle, facet joint degeneration and lumbar spondylolisthesis

Objective The aim of this study was to analyze the mechanism of degenerative spondylolisthesis (DS) through measuring vertebra arch angle and facet joint degeneration with 64-slice spiral computed tomography (CT). Methods One hundred and six patients complained of lumbodynia were examined with 64-slice CT. In 28 of 106 patients have lumbar spondylolisthesis, while the other 78 cases have not. The vertebra arch angles of all cases were measured and the facet joint degenerations were analyzed. Results L4--5 vertebra arch angle in DS group were 119. 0°±2. 2°(left) and 118. 8°±1.9° (right) ,respectively. L4--5 vertebra arch angle in control group were 102.9°±1.2°(left) and 104. 7°± 1.2° (right) ,respectively. The joint angle in DS group were 41.1°±1.2°(left) ,and 29.0°±1.2°(right), respectively. The joint angle in control group were 45.5°±2. 1°(left), and 45. 1°±1.2°(right), respectively. There were significant differences of L4--5 vertebra arch angle and more serious of facet joint degeneration( P < 0. 05 ). Conclusion L4 vertebra arch inclination and facet joint degeneration were important to diagnosis of spondylolisthesis. Key words: Spondylolysis; Lumbar vertebrea; Zygapephyseal joint; Tomography, X-ray computed

Coracoid tip position on frontal radiographs of the shoulder: a predictor of common shoulder pathologies?

The coracoacromial arch is a static anterior-superior stabilizer of the humeral head. Thus coracoacromial arch inclination, which varies depending on coracoid tip position, may be related to shoulder pathologies. Therefore, we retrospectively analysed coracoid tip positions in the true anterior posterior view of different shoulder pathologies: reference shoulders (n=27), shoulders with rotator cuff tear (supraspinatus tear n=29; subscapularis tear n=21) and shoulders with anterior glenohumeral instability (traumatic n=17; atraumatic n=14). In supraspinatus tear shoulders, the coracoid tip projected onto inferior glenoid half in 86% of cases (type I coracoid), extending more inferiorly compared with reference group (p=0.0002) or subscapularis tear shoulders (p<0.0001). In contrast, 78% of cases with subscapularis tear show the coracoid tip projected onto the superior glenoid half (type II coracoid). Atraumatic glenohumeral instabilities had a more superior coracoid tip position than traumatic instabilities (p=0.04), but no differences were observed on basis of coracoid type or in comparison with normal controls. We conclude that coracoid tip position is highly variable. Since type I coracoids are predominant in shoulders with supraspinatus tears and type II coracoids in shoulders with subscapularis tears, coracoid tip position may thus provide a simple diagnostic complement for a probable site of rotator cuff tears.