What are quadriceps and patellar tendon ruptures?
The quadriceps tendon connects the quadriceps muscle to the upper pole of the patella. The patellar tendon connects the lower pole of the patella to the tibia. Together they form the extensor mechanism, the system that allows you to straighten the knee, climb stairs and rise from a chair. A complete rupture of either tendon results in a sudden inability to extend the knee against gravity and is a true orthopaedic emergency.
What causes a tendon rupture?
- sudden, forceful contraction of the quadriceps with the knee bent, typically a fall, a missed step or landing from a jump
- underlying tendon degeneration (much more common in older patients)
- previous tendinopathy
- systemic conditions weakening the tendon (diabetes, chronic kidney disease, rheumatoid arthritis)
- long-term steroid use, including local cortisone injections
- fluoroquinolone antibiotics in some cases
Patellar tendon rupture tends to occur in younger, active patients; quadriceps tendon rupture is more common in patients over 40.
What are the symptoms?
- a sudden "pop" or tearing sensation at the front of the knee at the moment of injury
- immediate severe pain
- rapid swelling around the knee
- inability to straighten the knee against gravity or to walk normally
- a palpable gap above (quadriceps rupture) or below (patellar rupture) the patella
- the patella sits abnormally high (in patellar tendon rupture) or low (in quadriceps tendon rupture)
How is the diagnosis made?
- clinical history and examination, a complete rupture is usually clinically obvious
- X-rays, to assess patellar position and exclude fracture
- ultrasound, quick and accurate confirmation in most cases
- MRI, used in selected or partial cases for full assessment
What is the treatment?
Complete tendon ruptures require urgent surgical repair, ideally within 1–2 weeks of injury. Delayed surgery is technically more difficult and gives inferior results. Partial ruptures with preserved active extension can sometimes be treated non-operatively in a brace, with structured rehabilitation, but this is the exception rather than the rule.
I perform direct tendon repair using strong sutures passed through bone tunnels in the patella, restoring the continuity and tension of the extensor mechanism. Where the tendon quality is poor or the rupture is chronic, I augment the repair with additional measures (suture tape augmentation, allograft) to protect healing. I apply modern surgical techniques aiming for stable repair and optimal functional recovery.
What should the patient expect after surgery?
- knee brace for approximately 6 weeks, locked in extension initially and progressively unlocked
- protected weight-bearing in the brace
- early structured physiotherapy with progressive range of motion under protection
- intensive quadriceps rehabilitation from 6 weeks
- return to running typically at 4–6 months
- return to sport at 6–9 months
I make a point of explaining that the speed of presentation matters. Patients who suspect a tendon rupture should be assessed urgently, the sooner the repair is performed, the better the outcome.