Patellar tendon rupture
Background
- Occurs via forceful contraction of quadriceps muscle or falling on flexed knee
- Quadriceps rupture proximal to the patella while patellar tendon ruptures are distal
- Typically occur 2cm from insertion on patella
- Patellar tendon rupture
- Patients <40yr with history of tendinitis or steroid injections
- Quadriceps tendon rupture
- Patients >40yr
Clinical Features
- Sudden "pop" or tearing
- Diffuse swelling
- Defect may be palpable above or below the patella
- Partial tears lead to difficulty extending the knee
- Complete tears lead to absent straight leg raise while supine or extension of the knee again
Differential Diagnosis
Knee diagnoses
Acute knee injury
- Knee dislocation
- Knee fractures
- Meniscus and ligament knee injuries
- Patella dislocation
- Patellar tendonitis
- Patellar tendon rupture
- Quadriceps tendon rupture
Nontraumatic/Subacute
- Arthritis
- Gout and Pseudogout
- Osgood-Schlatter disease
- Patellofemoral syndrome (Runner's Knee)
- Patellar tendonitis (Jumper's knee)
- Pes anserine bursitis
- Popliteal cyst (Bakers cyst)
- Prepatellar bursitis (nonseptic)
- Septic bursitis
- Septic joint
- DVT
Work Up
- Ultrasound
- Separation of the tendon can be visualized
- X-ray
- Patella alta (or high-riding patella) is consistent with patella tendon rupture
- Patella baja/infera (or low-riding patella) is consistent with quadriceps tendon rupture
Management
- Ortho consult in the ED
- Knee immobilizer, can be weight bearing
- Operative repair advised within 7 days
References
- Uptodate
- Wheeless' Textbook of Orthopaedics