II. Risk Factors
- Patellar Tendinopathy may predispose to Patellar Tendon Rupture
III. Mechanism
- Forceful knee flexion against resistance
IV. Signs:
- Large Knee Effusion
- Defect between tibial tubercle and inferior Patella
- Difficult active knee extension
V. Differential Diagnosis
- Patellar Dislocation
- Quadriceps tendon rupture (elderly)
- Tibial tuberosity avulsion (adolescents)
VI. Imaging: Knee XRay
VII. Imaging: Advanced
- Knee Bedside Ultrasound
- Ruptured tendon will appear hypoechogenic with a separation between tendon ends
- Dynamic views may better define the tendon ends
-
Knee MRI
- Definitive study to identify extent of rupture and plan surgical repair
VIII. Management
- Surgical Correction within 10 days of injury
- Cast immobilization for 6 weeks following surgery
- Physical therapy
IX. Complications: Associated with delayed surgery
- Quadriceps contracture shortens extensor mechanism
X. References
- Hoppman and Shannon (2021) Crit Dec Emerg Med 35(11): 16-7