These three pulleys shorten 50% with finger flexion and play little role in the prevention of bowstringing. The cruciate pulleys serve to modulate force transmission as the finger flexes and the palmer plate moves.
Clinically apparent bowstringing requires the rupture of both the A2 and A4 pulleys.
From this study, they concluded that isolated pulley rupture did not produce clinically evident bowstringing. A3 never ruptured first, most likely, because it serves to transfer forces to the stiffer A2 and A4 pulleys.
Generally, for patients without clinically apparent bowstringing, a nonoperative treatment protocol is indicated.
Conservative treatment with rest, ice, taping, and gradual return to activity is indicated in those patients who lack clinically evident bowstringing. Primary surgical repair is indicated for acute injuries with bowstringing, and reconstruction is indicated with those patients who have chronic bowstringing.