A patellar tendon rupture is a tear of the tendon that connects the kneecap to the shin bone, usually from a strong quadriceps contraction while landing or jumping. Without the tendon the patient cannot straighten the knee, and early surgical repair gives the best results.
Key symptoms
- Sudden pop and sharp pain below the kneecap
- Swelling of the front of the knee
- Unable to straighten the knee or walk normally
- Knee buckling when trying to stand
What you find on exam
- Palpable gap below the kneecap
- High-riding kneecap (patella alta)
- Unable to do a straight leg raise or hold the knee extended
- Neurovascular check of the leg
Tests
- Knee X-ray: high patella, rule out a fracture
- Ultrasound or MRI to confirm a full or partial tear
- Check risk factors: steroid use, fluoroquinolones, kidney disease, diabetes
Treatment basics
- Knee immobilizer in extension, ice, elevation and pain control
- Early surgical repair, ideally within 2 to 3 weeks, for complete tears
- Partial tears with intact extension: brace and physical therapy
- Structured rehab to regain motion and quadriceps strength
Red flags
- Inability to extend the knee after a fall or jump
- Increasing calf pain or swelling after injury or surgery, suggesting a clot
- Tense swelling with severe pain, numbness or a cool foot
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.