What’s the most common cause of hip pain in young adults, how does it come about and how is it diagnosed and treated? Mr Parag Jaiswal, Consultant Trauma & Orthopaedic Surgeon at Highgate, takes a closer look.
Introduction to hip pain
Patients are often surprised to hear that hip pain is felt in the groin and can radiate down the thigh to the knee. Patients with arthritis or hip impingement have stiffness associated with this with further pain on rotational movements. Frequently, patients attribute their groin pain to muscle strain (even older patients with arthritis). Furthermore, athletes put their groin pain down to a muscle strain or sports injury. Considerable research has gone into the importance of the labrum in joint health.
With the realisation that labral tears cause groin pain, patients need to know ‘your hips do not lie’!
To understand how things go wrong, let’s look at your hip when everything is ok.
How the hip works
Your hip is a ball and socket joint with some unique features compared to other joints. The ball is the femoral head (the top of the thigh bone) and is normally spherical. The socket is the acetabulum, which is part of the pelvis. Both are lined with cartilage, a most incredible structure that nature has engineered. It provides friction-free load-bearing on joint surfaces, allowing smooth movement without joint pain. In most joints in the body articular cartilage lasts for 7 decades or more, wear and tear of this leads to arthritis.
The ball and socket joint is sealed by soft tissue called the labrum creating a vacuum seal and suction effect, keeping the synovial joint fluid in place and protecting your joint cartilage during physical activity. It also maintains the stability of your hip joint. This is particularly important in patients with poorly developed hip joints, known as hip dysplasia.
Tears in the labrum often occur in patients in which there are pre-existing structural abnormalities (such as femoroacetabular (hip) impingement or hip dysplasia). Less often they occur after trauma, or over-usage during high intensity repetitive activities such as in pivoting sports (eg football, tennis or golf) or ballet dancing. Left unchecked, labral tears can progress and often the hip joint cartilage starts to peel off, leading to further damage within the joint and eventually arthritis.
If you had a labral tear you may experience sharp, knife like, groin pain. This tends to occur in activities such as squats/lunges or getting in and out of a low car. The pain is usually activity-related initially but can be severe and disabling, affecting work, parenting, and leisure pursuits. As tears and symptoms progress, walking distance, standing or sitting for prolonged periods becomes more problematic.
Pain while sitting is another characteristic feature of labral tears. This could manifest itself with inability to drive long distances or air travel. I distinctly remember one case in which the patient became depressed as he could not go to the cinema! Other symptoms include a catching sensation or clicking, as well as your hip ‘giving way’. In some cases pain may be located in other areas such as buttock, in front of the thigh or the side the hip.
Femoroacetabular (FAI) impingement
Impingement is another problem I see frequently. It can be caused by excess bone around the ball, a hip socket that is too deep, or a combination of the two. Both can cause labral tears and damage to the cartilage lining the joints. 80% of patients with FAI complain of groin pain and usually affects active individuals between 30 to 45 years of age. Athletes and dancers can present in their teenage years or twenties.
Developmental dysplasia of the hip (DDH)
In DDH, the socket is shallow and does not completely cover the ball. The ball can partially or completely slip out of the socket. DDH can be present at birth or develop during childhood. In milder forms, the condition is diagnosed in adulthood when the hip becomes painful (often with labral tears!).
Diagnosis and treatment for labral tears
The diagnosis of labral tears is based on a thorough clinical history and examination as well X-rays, MRI and CT scans. By far, most labral tears are associated with the above conditions and therefore, treatment involves addressing the underlying cause as well as the labral tear. In a General Practice study, 50% of young adults (aged 18-55) presenting with groin pain were suspected to have FAI.
Initial management involves rest, activity modification, and anti-inflammatory medication. After symptoms have settled, physiotherapy is especially important to stretch and strengthen muscles around the hip. Injections into the hip joint are frequently performed. This allows the surgeon to assess how much of the pain is coming form the hip joint and give the patient a pain free interval to enable more effective physiotherapy.
If symptoms persist despite the above measures, then surgery may be indicated. This is usually in the form of keyhole surgery (arthroscopy). The torn labrum can be removed (debrided) or repaired). Recent scientific work has shown to have better results following repair of labrum rather than resection. Addressing the underlying cause involves removing the extra bone causing impingement or stabilising the labrum in hip dysplasia.
The most important advice one can give to patients considering treatment for their hip condition is to seek out a well trained young adult hip specialist who can explore in detail patients’ expectations and together devise a personalised plan to achieve the best possible outcome.