Quadriceps & Patellar Tendon Tears
What is the Function of the Quadriceps and Patellar Tendons in the Knee?
The quadriceps and patellar tendons are vital components of the extensor mechanism of the knee, allowing you to straighten (extend) your leg.
The quadriceps tendon connects the quadriceps muscles (at the front of the thigh) to the top of the patella (kneecap).
The patellar tendon connects the bottom of the patella to the tibia (shin bone).
Together, they transmit the force generated by the quadriceps muscles to extend the knee — an essential function for walking, climbing stairs, standing up, and athletic movements such as jumping or kicking.
How Do Quadriceps & Patellar Tendon Tears Occur?
Tendon tears usually occur when a sudden straightening force is applied to the knee while it is bent.
Common causes include:
A sudden eccentric contraction of the quadriceps (e.g., trying to stop a fall or land from a jump).
Direct trauma to the front of the knee.
Degenerative changes or previous chronic tendinopathy that weaken the tendon. This often occurs in patients who take anabolic steroid or certain kinds of antibiotics.
Previous surgery, corticosteroid injections, or systemic diseases (e.g., diabetes, kidney disease, rheumatoid arthritis) that compromise tendon quality.
Quadriceps tendon tears occur more often in older patients, while patellar tendon ruptures are more common in younger/middle-aged individuals.
How Do You Diagnose Quadriceps and Patellar Tendon Tears?
Diagnosis involves a combination of history, physical examination, and imaging.
Clinical Assessment:
A sudden tearing or “popping” sensation in the front of the knee.
Immediate pain and swelling.
Inability to actively straighten the leg or lift the heel off the bed.
A palpable gap may be felt above (quadriceps tendon) or below (patellar tendon) the kneecap.
The patella may sit higher or lower than normal (patella alta or baja), depending on which tendon is torn.
Imaging:
X-rays: Can show abnormal patellar height, avulsion fragments, or calcification in chronic cases.
MRI: The gold standard for confirming partial vs. complete ruptures and evaluating tendon quality and associated injuries.
Ultrasound: Can be used in patients who cannot obtain an MRI to access partial or complete tears of the quadriceps/patella tendon.
What are the Long-Term Consequences of Quadriceps and Patellar Tendon Tears?
Without appropriate treatment or rehabilitation, tendon tears can lead to significant long-term problems, including:
Persistent weakness and loss of knee extension strength.
Difficulty/inability to walk, climbing stairs, or performing daily activities.
Early recognition and appropriate treatment are essential for restoring normal knee function.
What Are the Indications for Conservative Management of Quadriceps and Patellar Tendon Tears?
Non-surgical (conservative) management has a very limited role for the vast majority of cases.
Indications include:
Partial tear confirmed on imaging.
Intact extensor mechanism (able to perform a straight-leg raise).
Low-demand patients or those with medical conditions that preclude surgery.
Minimal retraction of the tendon ends.
Patients who do not ambulate at baseline
Conservative treatment typically involves:
Immobilization of the knee in extension (straight) with a brace for 4–6 weeks.
Gradual physiotherapy to restore flexibility, strength, and function.
Activity modification and progressive strengthening exercises.
Very close monitoring as failure of conservative management is best treated with surgery and delayed treatment may affect achieving an optimal outcome.
What are the indications for Surgical Management of Quadriceps & Patellar Tendon tears?
Surgery is required for complete tendon ruptures or when the extensor mechanism is disrupted. Indications include:
Complete rupture confirmed clinically or on imaging.
Inability to extend the knee or perform a straight-leg raise.
Significant tendon retraction or separation of the tendon ends.
High-demand or athletic patients requiring full restoration of strength.
Failed conservative treatment or persistent weakness after partial tear management.
Surgical repair involves:
Reattaching the torn tendon to bone using sutures or anchors.
In chronic or retracted cases, tendon grafts for soft tissue flap advancement may be required to bridge the gap.
The knee is typically protected in a brace postoperatively, with early, controlled rehabilitation to restore motion and strength.
Timely surgery generally leads to good recovery with patients able to regain the vast majority of their strength and function.
MELBOURNE ORTHOPAEDIC SURGERY