The sagittal bands encircle the metacarpophalangeal (MP) joint stabilizing the extensor tendon, especially during MP joint flexion.
Sagittal band rupture is commonly seen in patients with rheumatoid arthritis and those who experience significant trauma (common in boxers), but occasionally spontaneous rupture associated with minor resistance to extension occurs. Additionally, elderly patients may experience spontaneous rupture with relatively little resistance. Examples are reaching with one hand to pull up a growing cabbage and flicking someone or a marble with a finger.
The radial sagittal band is the most side to rupture and the middle finger is the most frequent location (See image). Traditionally treated with surgical repair, closed non-traumatic ruptures are increasingly managed with non-surgical orthotic care: Catalano LW III, et al. Closed treatment of nonrheumatoid extensor tendon dislocations at the metacarpophalangeal joint. J Hand Surg Am. 2006 Feb;31(2):242-5.
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