The hip can be seen as a similar joint to the shoulder but much bigger and more stable.
It basically has a central part- the ball and socket joint and an outside part. The ball is the top of the large leg bone called the femur and is covered in smooth cartilage. The socket is part of the pelvis which is also lined with smooth cartilage and holds the head of the femur with a suction lining or lip called the labrum. The outer part can be separated into basically four regions. The lateral (small toe side) compartment has the large muscle groups that lift your leg to the side and stop your pelvis from tilting and you from waddling.
It also has a large balloon that stops these muscles from rubbing against the tight tendon just under the skin, called the greater trochanter bursa. The posterior compartment comprises the joint that connects your pelvis to your back (sacroiliac joint), the bone you sit on (the ischial tuberosity) and the large muscles of the buttock mainly the gluteus maximus and the proximal (upper) hamstrings. The inner compartment is in the groin and has the hip joint as well as the groin muscles (adductors) and the psoas muscle tendon, which helps bend the hip. Finally, the anterior compartment which houses the muscles that bend the hip and straighten the knee and these are called the rectus femoris and sartorius muscles.
Problems can arise from any of these Regions
- Arthritis affects the smooth cartilage and leads to pain and stiffness.
- Crumbling of the bone of the head of the femur (avascular necrosis) causes severe pain and later stiffness of the hip.
- The lip of the hip if it tears or is loosens cause groin and buttock pain, especially with activity in younger people.
- Inflammation of the bubble on the side of the hip (bursitis) causes side hip pain with sleeping or sitting too long.
- Tearing or inflammation of the different muscles can cause pain in the different compartments – abductor tears cause outside pain, psoas tendon problems cause groin pain, proximal hamstring problems cause buttock pain around the sitting bone.
- The nerve pain from the back or abdomen or hernia areas can be felt in the groin or buttock or side of the hip and is known as referred pain.
Outside Room (small toe side) Problems
- Abductor muscle tears
- Calcific tendinitis of abductor tendons
- Proximal ITB friction syndrome
Central (groin) Problems
- Hip arthritis
- Avascualr necrosis of femoral head
- Neck of femur fractures
- Labral tears
- Femoral acetabular impingement syndromes ( CAM and Pincer and mixed lesions)
- Ligamentum teres ligament problems
- Psoas tendon inflammation or tears
Posterior (buttock) Problems
- Ischial tuberosity bursitis
- Proximal hamstring tendinitis
- Proximal hamstring tears
Inside Thigh Problems
- Adductor tendon inflammation or tears