Femoroacetabular impingement syndrome (FAI)

The hip joint is the largest joint in the human body.

It’s made up of the head of the thigh bone and the joint socket (acetabulum) and is the main link between the lower limb and the torso. The two joint surfaces are covered by cartilage, which together with the synovial liquid reduce friction caused by movement.

Over time, the cartilage gets worn out and the muscles and tendons become more and more susceptible to damage.

Pain in the hip joint may appear due to a variety of problems affecting both the joint (arthritis, injury, congenital disorders) and the ligaments, tendons, muscles and other soft tissue surrounding the joint.

Sometimes, pain in the hip joint may come from other parts of the body, e.g. the lower back.

Pain in the hip joint is usually located in one of the following three areas:

  • frontal – the groin area;
  • rear – the backside;
  • the upper lateral area of the thigh.

These are the most common causes of pain in the hip joint.

  • Arthritic changes – as mentioned, over time the joint cartilage gets dehydrated; the synovial liquid decreases and friction between the joint surfaces increases. An imbalance develops between pressure on the joint and the cartilage’s ability to withstand it. This means it gets worn out more easily, which can lead to discomfort and pain in the hip joint. Coxarthrosis is more common in women and may affect one or both joints.
  • Bursitis – inflammation of the sacs around the joints (bursae) leads to an increase in pressure (because there’s more liquid) and to pain during movement. The bursa is a liquid-filled sac. Usually, bursae are located between the tissues such as bones, muscles and tendons. Their role is to reduce friction between the tissues. Near the hip joint there are two bursae: the trochanteric bursa and the iliopsoas bursa. If the trochanteric bursa gets inflamed it’s called trochanteric bursitis and pain occurs in the upper lateral side of the thigh. If the iliopsoas bursa gets inflamed it’s called iliopsoas bursitis and pain occurs in the groin area.
  • Tendonitis– inflammation of the muscle tendons. This is brought on most often by exercise consisting of heavy load-bearing and repetitive movements. Symptoms include pain during movement, reddening of the affected area and swelling.
  • Avascular necrosis – caused by interruption of blood flow to the bone. Causes may vary – injury, dislocation of thighbone, various conditions such as diabetes, pancreatitis, etc. Pain often comes on while sitting down, getting up and performing other actions which put a strain on the body, and is relieved when the patient is at rest.
  • Hip joint fracture – with age, the bones get more and more fragile and breakable. This is why hip joint fractures occur more often in people over 50. The most common injury is the femoral neck.

Comprehensive physiotherapy including electrotherapy, manual therapy and exercises reduces pain in the hip joint, strengthens the muscles around it and prevents further complications.