What should you know about left patellar tendon rupture?

The patellar tendon connects the kneecap to the shinbone and helps the quadriceps straighten the knee. A complete tear can cause sudden pain, swelling, bruising, a gap below the kneecap or a kneecap that sits higher than usual. Some people cannot lift the straight leg from a bed or chair. A partial tear may preserve some movement, so the absence of total weakness does not rule it out.

An examination may be followed by imaging to show the tendon and nearby structures. The clinician will also check circulation, sensation and the condition of the skin. The left-sided location matters for mobility and safe transfers, but treatment is chosen from the tear pattern, activity needs and general health.

Keep weight off the injured leg until a clinician advises otherwise. Support the knee in the position recommended for you, use a prescribed brace if provided, and avoid forceful bending or attempts to test strength. Elevating the leg can help swelling; use cold through a cloth for short periods if it is comfortable.

A complete rupture commonly needs surgical reattachment, followed by a carefully staged programme of protection, movement and strengthening. [Tendon Repair Surgery](/treatments/reconstructive-orthopedic-surgery/tendon-repair-surgery/) explains the repair discussion, while [Post-Operative Rehabilitation](/treatments/physiotherapy-and-rehabilitation/post-operative-rehabilitation/) covers the gradual return of knee control. Do not drive until you can control the vehicle safely and your treating team agrees.

Seek urgent medical assessment after a sudden knee injury with inability to straighten the knee, a visible change in kneecap position, marked swelling, or a snap followed by weakness. Go urgently if the foot becomes cold, pale, numb or unusually weak, or if pain and swelling rapidly worsen. A fall, cut or direct blow may also damage other structures and should not be assessed by home observation alone.

Ask whether the tear is partial or complete, whether the extensor mechanism is working, what imaging is needed, how the knee will be protected, and which movements or weight-bearing are allowed. Ask how wound care, physiotherapy, work, driving and sport will fit into the rehabilitation plan.