Knee Cartilage Injuries, Defects, or Chondral Lesions
When Your Kneecap Loose’s Its Balance
Your patella, or kneecap, is essential to the function of your knee, acting as a lever to maximise the strength and efficiency of your quadriceps muscles. It moves within the trochlear groove of the femur, allowing for smooth and controlled motion when bending and straightening your leg. Certain conditions however, can interfere with this movement, resulting in pain, instability, or even dislocation.
CAUSES OF PATELLA DISLOCATION OR INSTABILITY
Patella dislocation occurs when the kneecap is pushed out of its normal position in the trochlear groove. This often happens due to sudden twisting motions or direct trauma, such as during sports that involve quick changes in direction or impact. Some people, however, may have anatomical differences that make them more prone to patella dislocation or instability, even with minimal force or trauma.
SYMPTOMS OF PATELLA DISLOCATION OR INSTABILITY
A patella dislocation can be intensely painful and may lead to visible changes in the shape of the knee.
Common symptoms include:
- A loud popping sound at the time of dislocation
- A feeling of the knee “giving way” or buckling
- Swelling, stiffness, and tenderness around the knee
- Knee instability, especially during weight-bearing activities
- A sensation of locking or catching in the knee, which may indicate loose bodies or cartilage damage inside the joint
DIAGNOSING PATELLA DISLOCATION
If you suspect your patella has dislocated, it’s important to seek urgent medical attention. Even if the kneecap returns to its normal position, the injury may have caused damage to nearby ligaments or tendons. Diagnosis typically begins with a physical examination, followed by imaging tests such as an X-ray or MRI to determine the extent of the damage and to rule out other injuries.
TREATMENT OPTIONS FOR PATELLA DISLOCATION AND INSTABILITY
Treatment depends on how severe the dislocation is and whether there is any associated damage. Immediate care often includes repositioning the kneecap under anaesthesia, followed by the RICE method (rest, ice, compression, elevation) to manage swelling.
Crutches or a knee brace may be needed while the knee heals. Physiotherapy is crucial to strengthening the muscles around the knee, reducing the risk of future dislocations, and restoring normal movement.
For patients with recurring patella dislocations or significant instability, surgical options may be recommended. Dr Keeley may discuss the following procedures depending on the severity of your condition:
This procedure involves releasing the tight lateral structures around the knee, such as the lateral retinaculum, which can pull the kneecap out of alignment. By loosening these tissues, the patella can move more naturally and stay centred within the trochlear groove.
The MPFL is a key ligament that keeps the kneecap in place and prevents lateral dislocation. If this ligament has been damaged by repeated dislocations, it can be reconstructed using a graft, typically from the hamstring. This surgery restores stability to the knee by ensuring the patella stays correctly aligned.
When patella dislocation is linked to poor knee alignment, this procedure involves repositioning the tibial tubercle (the bony point at the top of the shin bone) to improve how the kneecap tracks within the groove. This realignment helps to reduce the likelihood of future dislocations.
During your consultation, Dr Keeley will provide personalised advice and discuss whether lateral release, MPFL reconstruction, tibial tubercle osteotomy, or another approach is most suitable for your specific case. These treatment options can be tailored to ensure the best possible outcome for your knee health.
LEARN MORE ABOUT PATELLOFEMORAL INSTABILITY SURGERY