Bilateral avascular necrosis of the trapezoid

Pathophysiology of Avascular Necrosis

Avascular necrosis is a complicated, multifactorial disease with potentially devastating consequences. Although the underlying root cause is a lack of appropriate vascular perfusion to affected bone, there are often varying patient-specific, anatomic-specific, and injury-specific predispositions. These factors generally fall into 3 categories: direct vascular disruption, intravascular obliteration, or extravascular compression. The initial stages of disease can be insidiously symptomatic because edematous bone marrow progresses to subchondral collapse and subsequent degenerative arthritis. Although much of the current literature focuses on the femoral head, other common areas of occurrence include the proximal humerus, knee, and the carpus. The low-incidence rate of carpal avascular necrosis poses a challenge in establishing adequately powered, control-based validated treatment options, and therefore, optimal surgical management remains a continued debate among hand surgeons. Appreciation for expectant fracture healing physiology may help guide future investigation into carpal-specific causes of avascular necrosis.

Idiopathic Avascular Necrosis of Trapezoid in Adolescence: 3-Year Follow-Up

Avascular necrosis (AVN) is relatively uncommon in the carpal bones, although it most frequently involves the lunate and scaphoid. The trapezoid has abundant vascular channels from a rich network of dorsal and palmar vessels, and only a few cases of AVN have been reported in adults who sustained a traumatic insult. We present a rare case of idiopathic AVN of the trapezoid in an adolescent presenting with refractory pain at the second metacarpal base. Over a period of 36 months, follow-up symptom evaluations and serial magnetic resonance images showed prominent gradual improvement, consistent with spontaneous resolution.

Avascular Necrosis of the Carpal Bones Other Than Kienböck Disease

Avascular necrosis (AVN) of the carpal bones other than Kienböck disease is a rare cause of chronic pain of the wrist. The scaphoid, capitate, and a smaller percent of lunates are at greater risk to develop AVN because of their peculiar intraosseous circulation; however, AVN has been reported in all the carpal bones. On the plain radiograph, AVN of the carpal bones may evolve through a normal radiograph, sclerosis, fragmentation, cyst formation, fracture, bone collapse, change of the carpal height, and alignment and progressive degenerative changes of the wrist joint. In the early stage of AVN, magnetic resonance imaging enhanced with gadolinium is a more sensitive and specific diagnostic tool than plain radiograph to demonstrate the bone marrow viability. Because of the rarity of case reports, the natural history of AVN of the carpal bones other than Kienböck disease is not well understood. The aims of different treatments are to prevent bone collapse, restore normal carpal height and alignment, and reduce the risk of progressive degenerative changes of the wrist joint.