In a normal joint the end of the bone is covered by a layer of cartilage which is very strong and very smooth. The joint is lubricated by synovial fluid and the combination of cartilage and the lubricating fluid allows the joint to move with minimal friction which allows smooth pain free motion over a long period of time.
Hip impingement or Femoro-Acetabular Impingement (FAI) occurs when the bones of the hip joint impact each other where they shouldn’t. Normally the femur (which forms the ball in the hip joint, and goes down as the thigh bone) and acetabulum (which forms the socket of the hip and is part of the pelvic bone) move smoothly in the hip joint. In some hips the shape of the ball or socket or both means that they impact against each other abnormally during movement.
The labrum may develop tears within it or may tear away from the adjacent acetabulum. This creates a flap of loose labrum which may cause pain or catching with movement.
Labral tears may occur in a specific injury playing sports or working, or may result from repeated minor damage over time (for example hip impingement). They may be a sign that hip arthritis is developing.
Greater Trochanter Pain Syndrome
Most patients with hip joint problems feel their pain in the groin. Many patients feel pain on the side of the hip around the bony prominence called the trochanter and this most commonly is not from the hip joint itself.
This pain is called Greater Trochanter Pain Syndrome and is particularly common in post-menopausal women.