Figure 1. (a) Anteroposterior view of the right wrist demonstrating transradial styloid lunate dis-location. The lunate is seen overlapping the capitate, creating the classic " piece-of-pie " sign (white arrow). (b) Lateral view of the right wrist demonstrating lunate dislocation. The lunate is displaced and angulated out of the lunate fossa, producing the " spilt teacup " appearance (black arr...

Perilunate dislocations are a devastating injury to the carpus that carry a guarded long-term prognosis. Mayfield type 4 perilunate dislocations are rare, high-energy injuries that carry a risk for avascular necrosis (AVN) of the lunate. When AVN ensues and the carpus collapses, primary treatment with a proximal row carpectomy or arthrodesis has been advocated. This case reports a successful cl...

BACKGROUND Evolving wrist arthroscopy requires creating new portals, and creating portals reciprocally leads to increased indications for arthroscopic wrist procedures. To facilitate access to the lunate bone and fossa for new arthroscopic procedures, a new portal was used. This is a cadaveric study of this portal. OBJECTIVES In this cadaveric study, we evaluated a portal in wrist arthroscopy...

A series of pyroclastic density currents were generated at Tungurahua volcano (Ecuador) during a period of heightened activity in August 2006. Dense pyroclastic flows were confined to valleys of the drainage network, while dilute pyroclastic density currents overflowed on interfluves where they deposited isolated bodies comprising dune bedforms of cross-stratified ash exposed on the surface. He...

The downwind margin of White Sands dune field is an abrupt transition from mobile aeolian dunes to a dunefree vegetated surface. This margin is also relatively stable; over the past 60 years it has migrated several times more slowly than the slowest dunes within the dune field, resulting in a zone of dune coalescence, aggradation, and, along most of the margin, development of a dune complex (i....