Quadriceps tendon rupture: what to know

The quadriceps tendon connects the front-thigh muscles to the upper kneecap. It transfers force through the kneecap so the leg can straighten. A rupture may happen during a forceful landing, jump, fall, or sudden contraction, and may be more likely when the tendon has been weakened by previous problems or certain medicines. Sudden pain, a tearing sensation, swelling, bruising, and an inability to perform a straight-leg raise are concerning features. Examination and sometimes imaging help distinguish a partial tear from a complete disruption.

Stop sport and protect the leg until it has been assessed. Avoid repeatedly testing extension, deep knee bending, or walking without support if the knee feels unstable. A complete tear may be treated with tendon repair surgery, while a smaller partial tear may have a non-operative plan based on strength and function. After treatment, post-operative rehabilitation usually moves from protection and controlled motion toward muscle activation, balance, and strengthening. The treating team sets the pace according to healing and examination findings.

Seek same-day assessment after an injury that causes loss of straight-leg control, a visible hollow above the kneecap, or inability to bear weight. Get emergency help for a cold or numb foot, rapidly worsening swelling, chest pain, or breathing difficulty. During recovery, report a new pop, sudden weakness, increasing wound redness, drainage, or fever without delay.

Ask whether the tear is partial or complete, what examination or imaging shows, which brace and walking limits apply, whether surgery is advised, and what rehabilitation milestones must be met before activity increases.