Patella Dislocation Generally An Injury In Adolescence
A patella dislocation is a relatively common injury which typically is the result of either a twisting injury or from a direct impact to the knee with the knee in a slightly bent position. Patella dislocation injury are more common in the younger athletic population, with teenagers the most common age group to suffer this painful injury, specifically active female adolescents are the most likely demographic to dislocate their knee cap.
Risk Factors For Suffering A Patella Dislocation
A patella dislocation can occur in an otherwise normal knee when an abnormal force is exerted on the joint, such as, but not limited to a blow to the inside of the knee that pushes the kneecap laterally (outwards). Or, the kneecap can dislocate under less traumatic circumstances where the kneecap dislocates in relatively normal situations due to abnormal joint anatomy predisposing the individual to dislocations.
Potential Predisposing Factors To Suffering A Patella Dislocation:
There are a few underlying anatomical variations that can leave an individual with so call “abnormal anatomy” around the knee that may predispose them to suffering patella dislocations.
- Having generalised ligamentous laxity.
- Having “knocked kneed” lower limb posture.
- Quadriceps weakness, specifically VMO weakness.
- Having a relatively small knee cap, or small or abnormal groove that the kneecap slides up and down in.
The Presentation Of A Dislocated Patella
The diagnosis of a dislocated knee cap is usually pretty obvious when looking at the knee, in the acute situation where the individual as just dislocated the patella there will be a bulge on the outside (lateral) part of the knee where the kneecap has been pushed out of the groove. A dislocated kneecap will often relocate (reduce) when the individual tries to straighten their knee. Once “reduced” and the kneecap is resting back in the groove, the knee will often become very swollen and be quite tender when palpating the inside border of the kneecap which is where the tissues have been torn. Following a dislocation of the kneecap the individual will generally look to avoid bending of their knee and taking load on it such as going up and downstairs will be painful, there may also be an underlying “fear” that the kneecap feels like it is going to dislocate again further limiting activity.
Kneecap Dislocation Can Increase The Risk Of Arthritis
With the kneecap being forcefully pushed out of the groove when someone suffers a patella dislocation this trauma can result in cartilage damage to the patella or the groove itself , this disruption to the cartilage can potentially lead to in an increased risk of patellofemoral (knee cap) arthritis down the track. As well as the risk of osteoarthritis following a trauma like this to the joint, individuals who dislocate their kneecap may also experience ongoing symptoms of like pain, restricted movement, feelings of weakness around the knee, or repeat dislocations.
What Is The Management Of A Patella Dislocation?
Due to the potential risk for repeat dislocations and ongoing issues as discussed briefly above, it is essential that following a dislocation patients have an X-ray to assess the injury and any possible risk factors for suffering repeat dislocations as well as factors that may ultimately lead to a poor long term outcome. An MRI is also useful following dislocation to look at and grade the severity of an soft tissue and cartilage damage.
Surgery can be indicated for kneecap dislocations if the individual is young and active, in these situations surgery may be considered in an attempt to aid a return to sport as well as reduce the likelihood of any future dislocations. However if the person lives a more sedentary lifestyle they may be managed more conservatively with knee splints/ knee bracing and physiotherapy. The most desirable approach taken will be influenced by a number of factors including the number of previous dislocations, activity levels and the presence or absence of any risk factors. These risk factors will need to be addressed, it may be viable to address them with move conservative methods like physiotherapy, however sometimes more invasive surgical methods may be the most appropriate approach.
Disclaimer: Sydney Physio Clinic does not endorse any treatments, procedures, products mentioned. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific medical advice or assistance on Patella Dislocation Painfully Common should consult his or her general practitioner, physiotherapist or otherwise appropriately skilled practitioner.