The database is administered by APEX, a high altitude medical research charity. A few cases support the possibility of reascent following recovery and acclimatization after an episode of HAPE precipitated by rapid ascent. See also
Hazards of outdoor recreation
High-altitude cerebral edema (HACE)
High-altitude flatus expulsion (HAFE)

References


== External links ==
Boutonniere deformity is a deformed position of the fingers or toes, in which the joint nearest the knuckle (the proximal interphalangeal joint, or PIP) is permanently bent toward the palm while the farthest joint (the distal interphalangeal joint, or DIP) is bent back away (PIP flexion with DIP hyperextension). Causes include injury, inflammatory conditions like rheumatoid arthritis, and genetic conditions like Ehlers-Danlos syndrome. Pathophysiology
This flexion deformity of the proximal interphalangeal joint is due to interruption of the central slip of the extensor tendon such that the lateral slips separate and the head of the proximal phalanx pops through the gap like a finger through a button hole (thus the name, from French boutonnière "button hole"). The distal joint is subsequently drawn into hyperextension because the two peripheral slips of the extensor tendon are stretched by the head of the proximal phalanx (note that the two peripheral slips are inserted into the distal phalanx, while the proximal slip is inserted into the middle phalanx). This deformity makes it difficult or impossible to extend the proximal interphalangeal joint. Diagnosis
Stages
Mild extension lag, passively correctable
Moderate extension lag, passively correctable
Mild flexion contracture
Advanced flexion contractureHigher numbers indicate a more severe problem and greater likelihood of a poor outcome. Treatment
Usually treated with a splint placing the proximal interphalangeal joint in extension for 4–6 weeks. Occasionally surgery is needed when splinting is unsuccessful. See also
Swan neck deformity
Z-deformity

References
Further reading
Coons, Matthew S.; Green, Steven M. (August 1995). "Boutonniere deformity". Hand Clinics. 11 (3): 387–402. doi:10.1016/S0749-0712(21)00060-3. PMID 7559817. Souter, William A. (October 1974).