Impingement of the hip, also known as femoroacetabular impingement, is a condition associated with an abnormal shape of the ball and socket joint. It is common in active sportspeople and even more common in elite athletes. But what does it mean and how should you manage it?
What is impingement of the hip joint?
Femoroacetabular impingement of the hip occurs when an abnormal shape of the ball and socket joint causes restricted movement and pain. Commonly, bone spurs form around the hip joint. These bony spurs mean that the ball of the hip (top part of the femur) gets pinched in the socket portion (acetabulum) when you move the hip in certain directions. This pinching causes pain and restricted movements.
Symptoms of hip impingement
Often, people complain of pain with activity especially during change of direction sport. The location of the pain can vary but is usually at the front of the hip or in the groin. Sometimes, you can feel pain in the buttocks and even the low back. Also, a weak feeling and restricted movement of the hip are common.
If we suspect hip impingement, then we recommend a plain X-ray to show the shape of the hip. MRI is also useful to show potential cartilage damage. However, we need to be careful as some people with no pain have changes of hip impingement on imaging. In fact, 50% of elite athletes have hip impingement changes on X-ray but most do not have pain. Therefore, it is important to perform a thorough clinical assessment before ordering tests.
Does impingement of the hip lead to early arthritis?
Hip impingement is a possible risk factor for early arthritis. Progression to early arthritis is more common if you have a type of bony spur called a CAM – located between the head and neck of the femur. We also think that the larger the CAM, the more likely you’ll develop early arthritis. However, not everyone who has a CAM develops arthritis. Other factors for developing arthritis such as genetics and having other disease like diabetes and obesity are also important.
Bottom line is that a bony spur or CAM does not necessarily lead to arthritis. The decision to remove the bump surgically should only be done for pain and not to prevent arthritis. Also, we don’t know whether surgery to remove the bony spur prevents the progression of arthritis.
So how do we manage hip impingement?
In general, you should always give conservative management and physical therapy a go first. Pain relief and return to sport can occur without the need to remove the bony spur or fix a labral tear.
The goals of therapy are to improve range of motion and strength of the low back and hip while reducing pain. Exercise should be the main form of treatment of femoroacetabular impingement. Exercises could include:
- hip stretching and mobility exercises
- hip strengthening including glutes, hip flexors, and adductors
- balance exercises
- abdominal strengthening exercises
Often, pilates and yoga can help you achieve these therapy goals.
Another effective therapy is neuromuscular training. Put simply – you perform exercises correctly so that your low back, hips, and lower legs are in correct alignment while performing an activity. We think this type of training reduces stress on your hip joint.
How long should you give conservative management?
In general, you should notice an improvement in pain, strength and range of motion after about 8 weeks. You should aim to return to sport in 3-6 months and be prepared to continue with independent rehab for at least 6 months. If you don’t experience relief with therapy, you should speak to your doctor about other treatments.
In some cases, a cortisone injection into the hip joint reduces pain and allows you to continue with therapy. We should always perform injections with ultrasound for accuracy.
In other cases, hip arthroscopy to remove the bony spurs and repair the labrum may be needed. We know that key-hole surgery improves symptoms such as pain. However, not all patients who have a hip arthroscopy get better and some (approx 5%) do worse. In addition, do not expect to return to completely normal function after surgery. While surgery provides pain relief, the chances are that you won’t be able to go back to all activities.
Finally, some doctors think that hip arthroscopy should be seen as joint preserving surgery. They think that removing the CAM lesion halts further damage to the hip joint preventing arthritis. However, the evidence for hip preservation is controversial. In fact, a recent study comparing hip arthroscopy to physiotherapy in hip impingement found worsening joint metabolism at 12 months in the surgical group. Overall, keyhole surgery should not be done to prevent arthritis.
Hip impingement can cause pain and restriction limiting your activity and sport. We also know that hip impingement is a risk factor for arthritis but only a small percentage of patients with bony spurs get arthritis. Optimal management is subject to much debate, but treatment should almost always be conservative at least initially.
Other hip and groin conditions: