OK, let’s start with an assumption.
As you read this post, you may have a specific kneecap in mind! Perhaps you’ve suffered your own dislocation, or you know someone who has. Secondly, that kneecap is now back in place. Unless you happen to be on your way to A&E at this very moment. Which is unlikely.
So now you want to know: how serious is this thing? And what happens next? Good questions. First, though, let’s look at some biology.
What is a kneecap dislocation?
The kneecap (properly known as the patella) is a small bone that protects your knee joint. Ordinarily it sits in a groove at the bottom of the thigh bone (the femur). The bone is held in place by muscles and ligaments, which act like guy ropes on a tent. If the guy ropes ‘lose their hold’ on the bone, it can pop right out of the groove. Result: dislocation. You may experience pain (from low to severe), sudden swelling or a ‘popping’ sensation. You may also be unable to walk or straighten your knee.
How does the kneecap get ‘un-dislocated’?
Clearly, Priority No 1 after a dislocation is to get the bone back in its groove. Sometimes this happens on its own, without intervention. Sometimes it needs to be physically manipulated by a doctor. This is known as a reduction. It’s usually straightforward, though you may need to take painkillers beforehand. Then you’ll go home and do the RICE treatment (rest, ice, compression, elevation) to help the healing: this 60-second NHS video for sprains and strains gives some good tips on that. You may also need crutches or a brace for support.
OK, but is it serious?
Well, that depends on why the dislocation happened in the first place. There are two key possibilities here. Either you had a nasty accident, or there’s an underlying congenital issue at play…
An accident
Traumatic dislocations usually happen after high-energy impacts. A car accident, say, where the knee suffers a major blow. Or maybe a twist in sport, where the leg plants on the turf while the knee jolts in another direction. If pain and swelling is low, you may just need rest and physio. A physiotherapist can recommend exercises to rebuild the muscles around your knee joint so they’re less likely to lose hold of the bone in future. If the trauma is severe, however, you’ll probably need an MRI scan. This will flag up any additional damage from the impact: a ligament rupture (eg an ACL injury), a fracture as the ligament pulled away from the bone, or damage to the cartilage surfaces as the kneecap went out of alignment.
A congenital issue
Congenital simply means ‘present from birth’ – in other words, you were born with a tendency to dislocate joints. This is more common in younger people, and more common in women than men. The most common reason is hyperlaxity: those ‘guy ropes’ are just a bit more stretchy than average – good for things like gymnastics and trampolining, less good in dislocations. As with a traumatic dislocation, we’ll want to get you moving again as soon as feasible (so you don’t weaken those muscles further) and then doing physio exercises to rebuild strength.
What to do when it’s serious – or not
By now you’ve probably picked up some clues about the seriousness of kneecap dislocations. Point One: they’re quite common – and, happily, not usually serious. Rest and physio should resolve the injury in a few weeks. And if the cause was a one-off accident and there’s no joint damage, we’d be reasonably confident you won’t suffer a re-dislocation. Particularly if you work on those supportive muscles.
On the other hand, some dislocations do require surgery. If there’s cartilage damage, for example, we may recommend keyhole surgery to repair it. If the kneecap keeps re-dislocating (for congenital reasons or otherwise) then we might look at reconstructing the ligaments that hold the bone in place – usually with a synthetic graft.
The bottom line: kneecap injuries happen a lot, so try not to worry. If you or someone you know has suffered a dislocation, there’s a lot we can do to help. You can read more about common kneecap problems on the website here, or drop us a line right now to book an appointment. Our reception team are always happy to take down your symptoms and help with the next course of action.
