'In the stretches we did before football, I could never do a quad stretch.'

London - Does your hip click when you bend to put your socks on? Do you find it impossible to sit cross-legged on the floor? Does your hip hurt with exercise?

If so, you could suffer from a “new” condition, possibly a precursor to osteoarthritis.

Femoral acetabular impingement (or FAI as it is more commonly called) occurs when the ball at the end of the thigh bone catches in the hip socket.

The condition affects an estimated 10 to 15 percent of the adult population, striking between the ages of 20 and 40.

“Either the hip socket is too big and it over-covers the ball, so as the femur tries to move, it catches on the socket - or there is a bump on the ball so when you bend your hip it catches in the socket, stopping the joint from moving freely,” explains Jig Patel, an orthopaedic surgeon specialising in knee and hip disorders at the London Orthopaedic Clinic.

This can lead to a “clicking” sound - caused by a loose bit of cartilage in the hip socket, or the impingement suddenly releasing - and pain.

Long term, this may damage the joint and may increase the risk of osteoarthritis, adds Aresh Hashemi-Nejad, consultant orthopaedic surgeon at the Royal National Orthopaedic Hospital and honorary senior lecturer at University College London.

Symptoms typically include pain in the groin in the front and side of the hip. Prolonged sitting, particularly in a forward flexed position (such as cycling), may exacerbate the pain, as can activities such as running.

“The other things people complain of are stiffness or a catching or tightening sensation in the hip, and a clicking or clunking sensation when bending to cut toenails or put on socks,” adds Mr Patel.

FAI was only recognised as a condition about 20 years ago. “Even 15 years ago it was poorly acknowledged and was rarely diagnosed,” says Mr Patel. But over the past five to ten years “there has now been an explosion in the number of cases being detected”.

“It’s probable that patients are born with or develop subtle anomalies in the shape of the ball or socket as they grow up,” he adds.

And Mr Nejad adds: “Sport aggravates the condition by using the hip more than normal, placing extra load on it and putting it into extreme positions.

“Interestingly, when patients are investigated, at least two-thirds have an abnormal shape in both hips, but quite often only one side causes problems.”

This was the experience of Iyad Elias, who had surgery last year to correct the condition. “From a young age I’ve always played a lot of sport, mainly football,” says Iyad, 27, who lives in North London and runs his own printing company and clothing label.

“Then about three years ago I’d had a really busy football season and towards the end started to get pain in my groin. A physio told me to rest it, which I did for six months, but there was no improvement when I started playing again. A scan showed I had two very small hernias, but these weren’t big enough to cause the symptoms I had.”

After another six months of rest and no improvement, frustrated, he sought another opinion. After being diagnosed with FAI, Iyad read everything he could about the condition.

“It all fell into place,” he recalls. “Looking back, despite being very fit and active, there were always certain movements I struggled with. In the stretches we did before football, I could never do a quad stretch - where you lift your ankle up to your bottom behind you - in my right [problem] leg. The left was always fine, though. I also developed a grating, or clicking sensation in the hip.

“The pain was a dull ache that would come on half an hour after I finished being active and I’d really feel it getting in and out of bed. If I moved sideways I’d feel like I had to pick my leg up and move it myself.”

Mr Nejad says: “Anything that puts the hip into a deeply flexed position past 90 degrees - such as cycling - should be avoided. Low impact exercise such as swimming may help.”

For patients in pain, surgery involves trimming away the excess bone around the ball of the femur, or the socket, and trying to tidy loose and frayed damaged cartilage. Iyad was told both his hips were in quite bad condition and without surgery on at least the right one he was probably going to suffer from arthritis later in life.

“With me, I think the problem is perhaps a mixture of genetics –- my mum has hip pain, too, and has been advised to have an operation - and the fact I was sporty early in life,” he says.

“Quite often the operation is done as a day procedure and the patient can put weight on it quite early on - there is an intensive physio programme after surgery.”

Those most suitable for surgery are people without arthritis or excessive damage to the joint as a result of the impingement.

But could it also help prevent the onset of arthritis? “There is no evidence that surgery staves off osteoarthritis - but it is attractive to think that would happen,” says Mr Patel.

“If the operation manages to stave off the pain permanently, then you won’t need a hip replacement, as pain is the primary reason people have a hip replacement. But for most people surgery is about (relatively) short-term relief. By the time FAI makes itself known, the damage to the hip has been done and is likely to progress to osteoarthritis.”

But surgery should help relieve the pain and improve movement, adds Mr Patel: “People say the joint feels a lot freer afterwards.”

For Iyad, surgery has been a real improvement. “Because of the level of pain I was in and how active I am, I was desperate to get back to playing sport, so agreed to surgery immediately.”

He underwent keyhole surgery to his right hip under general anaesthetic 18 months ago.

“I have three small scars on the side of my leg, but there was no pain after the op,” he says.

“Since then I’ve been fine - 100 percent better than I was before. I had a few months of rest and recovery and now I’m back playing Sunday league football and golf four times a week.

“I could still need hip replacements by the time I’m 40, but at the moment I’m pain free and can be active again.” - Daily Mail