Patellar sleeve fracture
This type of osteochondral fracture of the patella is the result of high-impact jumping activities where the quadriceps contracts on a flexed knee (eccentric contraction). This leads the inferior pole of the patella to be avulsed from the rest of the patella's body. The sleeve fragment will be pulled inferiorly by the patellar tendon, and the patellar body will be pulled superiorly by the quadriceps tendon.
Classic history and presentation:
- A common feature in the patient's history of patellar sleeve fracture is the absence of direct knee trauma.
- The patient will describe their activity leading to injury as associated with sports or jumping activities.
- After the injury, the patient's knee joint will be swollen and painful, and the patient will be unable to perform a straight leg raise.
- Age – 8-12 years
- Sex / gender – More common in males (5:1)
Pathophysiology: Patellar sleeve fracture is the separation of the articular cartridge, retinaculum, periosteum, and small bony fragments of the patella. This is due to vigorous contraction of the quadriceps to a flexed knee, which leads to avulsion forces. This leads to the separation of the cartilage "sleeve" from the patella and thereby disrupts the extensor mechanism.
Grade / classification system:
- Inferior patellar pole – High-riding patella (patella alta) is the most common patellar sleeve fracture
- Superior patellar pole – Low-riding patella (patella baja) with an anterior tilt
S82.009A – Unspecified fracture of unspecified patella, initial encounter for closed fracture
51037009 – Fracture of patella
- Sinding-Larsen-Johansson disease
- Jumper's knee (see patellar tendonitis)
- Osgood-Schlatter disease
- Patellar fracture
- Quadriceps tendon rupture
- Patellar tendon rupture
- Meniscus tear
- Osteochondral defect
- Anterior cruciate ligament (ACL) tear
- Knee ligament injury
- Proximal tibia fracture
- Tibial plateau fracture
- Distal femoral fracture
- Tibial spine avulsion fracture