Kneecap Dislocation

What is Kneecap dislocation?

The kneecap, also known as the patella, is a tiny bone which sits in a groove in front of the knee located at the end of the thigh bone. When you bend or straighten your leg, the kneecap glides over the groove.

The kneecap is held in place by a group of ligaments and muscles. A dislocation occurs when these ligaments and muscles are overstretched or torn, and the kneecap slides out of the groove. Typically, this movement happens suddenly. You are likely to experience sharp pain, and you might be unable to straighten your knee after that.

Kneecap Dislocation

What is Kneecap dislocation?

The kneecap, also known as the patella, is a tiny bone which sits in a groove in front of the knee located at the end of the thigh bone. When you bend or straighten your leg, the kneecap glides over the groove.

The kneecap is held in place by a group of ligaments and muscles. A dislocation occurs when these ligaments and muscles are overstretched or torn, and the kneecap slides out of the groove. Typically, this movement happens suddenly. You are likely to experience sharp pain, and you might be unable to straighten your knee after that.

Causes and Symptoms of Kneecap Dislocation

Causes of kneecap dislocation

Here are some scenarios where a kneecap dislocation could occur:

  • A sudden and abrupt direction change while the leg is anchored firmly on the ground will put pressure on the kneecap. Too much pressure will overstretch the support tissues causing dislocation. Likely scenarios for this situation is when playing sports like soccer or basketball.
  • A fall or a direct blow to the knee will tear or overstretch the support tissues hence leading to dislocation.
  • In some people, dislocation could result from bony abnormalities in the hip, knee or shin bone.
  • Loose ligaments make joints too flexible hence predisposing the individual to patella dislocation.

Symptoms of kneecap dislocation 

  • A visibly deformed knee
  • Difficulty in straightening a bent knee 
  • Tenderness and pain in the knee
  • Swelling knee

Subsequent symptoms after the kneecap has been put back in place include:

  • Kneecap is sloppy and can move sideways excessively
  • Sensation of the knee instability of the kneecap wanting to dislocate again
  • Pain and locking in the knee if there are other concomitant injuries following the dislocation

How is it diagnosed?

The doctor will usually ask questions regarding the injury and subsequent symptoms.

  • Physical examination

Your doctor will look for deformity around the knee, and instability of the kneecap. He will also look for other underlying causes that might predispose you to dislocate your kneecap.

  • Imaging Tests

X-rays and MRI scans may be performed to confirm the diagnosis and severity of the dislocation, as well as to look for concomitant injuries in the knee.

Kneecap Dislocation

How is it diagnosed?

The doctor will usually ask questions regarding the injury and subsequent symptoms.

  • Physical examination

Your doctor will look for deformity around the knee, and instability of the kneecap. He will also look for other underlying causes that might predispose you to dislocate your kneecap.

  • Imaging Tests

X-rays and MRI scans may be performed to confirm the diagnosis and severity of the dislocation, as well as to look for concomitant injuries in the knee.

Kneecap Dislocation

Treatment Options

There is a range of options for treating kneecap dislocation based on the extent and severity of the injury. The typical treatment is non-surgical where the kneecap is manipulated back into place, then followed by a period of splinting physiotherapy.

Keep in mind that if your condition requires surgery, your Orthopaedic Surgeon should always educate you on:

  • Risks of the surgery
  • How to prepare for a surgery
  • What will be required for post-op care

Patella manipulation
This involves relocating the kneecap back into its normal position.

Physiotherapy
Physiotherapy aims to strengthen the muscles that hold the kneecap in position, so as to compensate for the torn ligaments that usually stabilise the kneecap. Physiotherapy can also help to correct underlying functional abnormalities with knee and hip muscles which may predispose one to dislocating their kneecap.

Knee Reconstruction Surgery
In recurrent cases of knee dislocations, surgery may be required to stabilize the kneecap. This usually involves reconstructing the torn ligament known as the Medial Patello Femoral Ligament (MPFL). In cases where there is severe underlying bony deformity, your surgeon may have to cut and realign the bone or deepen the groove in which the kneecap normally sits.

Disclaimer

Shoulder | Elbow Orthopaedic Group does not endorse any treatments, procedures, products, or physicians that are referenced in this article. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her Orthopaedic Surgeon.

If you have any queries, please do not hesitate to contact us at [email protected]

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