Which tendon is most commonly ruptured?

Which tendon is most commonly ruptured?

• A. Patellar tendon
• B. Flexor digitorum longus tendon
• C. Achilles tendon
• D. Rotator cuff

Answer: (C)

The main idea here is that tendons handle different levels of stress, and the one bearing the greatest repetitive or acute load with relatively limited blood supply is the Achilles tendon. It transmits the bulk of the calf’s force during push-off, and its midportion near the calcaneus has relatively poor vascularity, making it susceptible to degeneration and rupture with sudden impact or overuse. Because of this combination of high mechanical demand and vulnerable blood supply, the Achilles tendon is the most commonly ruptured among the options. Clinically, a rupture often presents as a sudden, sharp pain in the back of the leg and an inability to push off with the foot. On ultrasound, you’d look for a gap, discontinuity, or irregular, hypoechoic areas within the tendon, sometimes with retraction of the distal segment. MRI would show discontinuity with high signal on T2 in the affected region. In contrast, patellar tendon ruptures tend to occur in younger athletes during jumping and involve the knee extensor mechanism; rotator cuff tears are common but involve the shoulder rather than the Achilles; ruptures of the flexor digitorum longus are much rarer.

The main idea here is that tendons handle different levels of stress, and the one bearing the greatest repetitive or acute load with relatively limited blood supply is the Achilles tendon. It transmits the bulk of the calf’s force during push-off, and its midportion near the calcaneus has relatively poor vascularity, making it susceptible to degeneration and rupture with sudden impact or overuse. Because of this combination of high mechanical demand and vulnerable blood supply, the Achilles tendon is the most commonly ruptured among the options.

Clinically, a rupture often presents as a sudden, sharp pain in the back of the leg and an inability to push off with the foot. On ultrasound, you’d look for a gap, discontinuity, or irregular, hypoechoic areas within the tendon, sometimes with retraction of the distal segment. MRI would show discontinuity with high signal on T2 in the affected region.

In contrast, patellar tendon ruptures tend to occur in younger athletes during jumping and involve the knee extensor mechanism; rotator cuff tears are common but involve the shoulder rather than the Achilles; ruptures of the flexor digitorum longus are much rarer.