Cortical Erosions

Fig. 10.71. Caput ulnae syndrome in rheumatoid arthritis. Schematic drawing of a transverse view through the distal radioulnar joint outlines the rupture of the triangular fibrocartilage (arrowheads) and marginal erosions at the distal radio-ulnar joint level due to intra-articular pannus (asterisks). As a result, the ulna subluxes dorsally (gray arrow). Pannus (star) inside the extensor carpi ulnaris tendon (open arrow) sheath leads to cortical erosions, tear of the retinaculum and tendon thinning and splitting. St, styloid of the ulna Rad, radius...

It has been known for many years that sodium intake is one of the major determinants of urinary calcium excretion. It has been estimated that urinary calcium losses increase by approximately 1 mmol per 100 mmol sodium intake. Experimentally sodium intake increases calcium excretion but also induces markers of bone resorption. It is hypothesized that trabecular demineralization may occur, leading to postmenopausal changes and an increased risk of vertebral fractures and cortical erosions. Further research is required in this area. 

More recently, enormous thickenings of cortices or epinecral layers of placodial and crustose lichens were reported from northeast Afghanistan (Poelt and Wirth, 1968), from the Atacama (Follmann, 1965b), and from the Negev in Israel (Galun, 1963), where almost 60% of the heteromerous lichens have a more or less voluminous, amorphous upper layer. Until we can obtain experimental data from these desert lichens, the question of whether illumination is the primary cause of cortex thickening will remain unanswered. The thickening may also be a response to wind erosion. 

Carroll KW, Helms CA, Otte MT et al (2003) Enlarged spi-noglenoid notch veins causing suprascapular nerve compression. Skeletal Radiol 32 72-77 Chan R, Kim DH, Millett PJ, et al (2004) Calcifying tendinitis of the rotator cuff with cortical bone erosion. Skeletal Radiol 33 596-599... 

Drakeford MK, Quinn MJ, Simpson SL et al (1990) A comparative study of ultrasonography and arthrography in evaluation of the rotator cuff. Clin Orthop 253 118-122 Durr HR, Lienemann A, Silbernagi H,et al (1997) Acute calcific tendinitis of the pectoralis major insertion associated with cortical bone erosion. Eur Radiol 7 1215-1217 Edelson JG, Taitz C (1992) Anatomy of the coracoacromial arch relation to degeneration of the acromion. J Bone Joint Surg Br 74 589-594... 

Fig.l0.70a,b. Bone erosions. a,b Transverse 12-5 MHz US images over the ulnar head in two patients with longstanding rheumatoid arthritis reveal bone erosions (arrows) as small regular defects of the cortical outline. Note the synovial pannus (arrowheads) located inside and around them... 

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