Quadriceps Tendon Rupture - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x Quadriceps tendon rupture is the loss of congruency, either partial or complete, of the quadriceps tendon. It is an infrequent but significant injury with an incidence of around 1.5 cases per 100000 per year. Quadriceps tendon ruptures are more common in males and occur almost always unilaterally. The quadriceps tendon is a member of the knee extensor mechanism (Fig. 1), forming the connection between the main muscles responsible for leg extension at the knee joint and the base of the patella. Rupture of the tendon typically occurs at the site of insertion with the superior pole of the patella. By TeachMeSeries Ltd (2020) Figure 1The extensor mechanism of the knee Risk Factors The main risk factor for quadriceps tendon rupture is increasing age, with ruptures rarely occurring in those <40yrs. Other risk factors include chronic kidney disease, diabetes mellitus, rheumatoid arthritis, and medication (specifically corticosteroids and fluoroquinolones). Clinical Features Patients presenting with quadriceps tendon rupture will typically report hearing a pop or feeling a tearing sensation. This is immediately followed by pain in the anterior knee or thigh, and difficulty in weight bearing. The mechanisms by which the injury most commonly occurs is typically following sudden and excessive loading of the quadriceps muscles, such as landing from a jump. On physical examination there will likely be localised swelling to the region. There will be a tender palpable defect above the superior pole of the patella. Complete tears will also be associated with an inability to straight leg raise and loss of the ability to extend the knee. In patients with partial tears, these are inhibited and sometimes absent. Differential Diagnosis Differentials for acute knee pain with similar injury mechanisms include patella tendon rupture, patella fracture, or a femoral shaft fracture. Investigations Quadriceps tendon rupture can be diagnosed on clinical suspicion alone, especially in complete tears where the clinical signs are more apparent. Plain film radiographs of the affected knee can show a caudally displaced patella in complete tears (Fig. 2), and will exclude any underlying fractures and cases of patella baja. For definitive diagnosis, ultrasound imaging can be used, especially important in measuring the degree of rupture. In cases of diagnostic uncertainty, MRI imaging can also be useful. https://commons.wikimedia.org/wiki/File:Quadriceps_Ruptur_Roe3.jpg Figure 2A plain film radiograph of a complete quadriceps tendon rupture, with a caudally-displaced patella and cranially-migrated quadriceps tendon Management Treatment of quadriceps tendon ruptures depends on the degree of rupture. Partial tears can be managed non-operatively providing the extensor mechanism is intact. This involves immobilisation of the knee joint in a brace in tandem with intensive rehabilitation. Complete tendon tears (or when the extensor mechanism is compromised) usually require surgical intervention, with the technique used depending on the position of the tear*. Tears at the point of insertion with the patella may be repaired using longitudinal drill holes or suture anchors (Fig. 3), whilst intra-tendinous tears can be repaired with end-to-end sutures. Post-operatively, the knee is immobilised in a brace before progressive strength and flexibility exercises are introduced at approximately 6 weeks post-repair. *Chronic ruptures (>2 weeks since the injury) may require a tendon lengthening procedure due to tendon retraction Thomas Zimmermann (THWZ), CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons Figure 3A quadriceps tendon repair, showing (1) patella (2) distal portion of the tendon (3) proximal portion of the tendon Key Points Quadriceps tendon rupture can be either partial or complete The main risk factor for quadriceps tendon rupture is increasing age Whilst diagnosis can be made on clinical grounds alone, for definitive diagnosis ultrasound imaging is most often used Complete tendon tears or those with a compromised extensor mechanism usually require surgical intervention Frequent questions What is a quadriceps tendon rupture? A quadriceps tendon rupture is a significant injury characterised by the partial or complete loss of integrity of the quadriceps tendon, often occurring at its insertion point on the superior pole of the patella. What are the main risk factors for quadriceps tendon rupture? The primary risk factor for quadriceps tendon rupture is increasing age, with most cases occurring in individuals over 40 years old. Other contributing factors include chronic kidney disease, diabetes mellitus, rheumatoid arthritis, and certain medications like corticosteroids. What are the clinical features of a quadriceps tendon rupture? Patients with a quadriceps tendon rupture typically report a popping sound or tearing sensation, followed by anterior knee or thigh pain and difficulty bearing weight. Physical examination often reveals localised swelling and a tender defect above the patella, with complete ruptures leading to an inability to extend the knee. How is a quadriceps tendon rupture diagnosed? Diagnosis of a quadriceps tendon rupture can often be made based on clinical signs alone, particularly in complete tears. Imaging techniques such as plain film radiographs can identify patellar displacement, while ultrasound is used for definitive diagnosis and to assess the extent of the rupture. What is the management approach for quadriceps tendon ruptures? Management of quadriceps tendon ruptures depends on the extent of the injury; partial tears may be treated non-operatively with immobilisation and rehabilitation, while complete tears typically require surgical repair. Post-operative care includes immobilisation followed by gradual introduction of strength and flexibility exercises after approximately six weeks. Rate This Article