The hip joint is a ball and socket joint formed between the head of the femur (thigh bone) and the hip socket (acetabulum).
The important parts of the hip are:-
- Ball and Socket Joint - The joint between the head of the femur and the acetabulum (socket) of the pelvis.
- Joint Capsule - flexible sac around the joint allowing a wide range of movements. The capsule keeps in place the lubricating synovial fluid.
- Greater Trochanter - the attachment point for many of the buttock muscles (hip abduction and external rotation)
- Lesser Trochanter - the attachment of iliopsoas muscle (hip flexion)
Hip Movements - in the standing position
- Flexion - move your leg forwards.
- Extension - move your leg backwards.
- Abduction - move your leg away from your side.
- Adduction - move your leg towards to other leg.
- Internal Rotation - rotate your foot towards the other (toes pointing towards each other).
- External Rotation - rotate your foot away from the other (toes pointing outwards).
is divided into 2 phases, the stance phase where one leg is static on the ground, and the swing phase, where one leg is off the ground swinging forwards to make the next step.
- During walking body weight is transferred from hip joint to hip joint. In order to prevent your toes from scraping on the ground during the swing phase, gluteus medius on the stance side contracts, tilting the pelvis upwards, lifting the leg clear of the ground.
- Weakness of gluteus medius causes the pelvis to dip downwards during the swing phase. This is known as a positive Trendelenburg Test. Gluteus medius can be weak due to either an L5 nerve root lesion in the spine, proximal myopathy (muscular dystrophy, hip osteoarthritis), or congenital hip deformities (coxa vara, congenital hip dislocation - CDH).
- Using vector diagrams it has been calculated that during the stance phase of walking, 4 times the body weight is applied to the load bearing surface of the hip joint. Being overweight therefore places an increased loading bearing burden on the hip joints leading to premature osteoarthritis.
- Gluteus Medius is the main hip abductor, and its tendon attaches to the lateral aspect of the greater trochanter.
- Gluteus Minimus is a lesser hip abductor and also produces some internal rotation. Its tendon attaches to the upper most part of the greater trochanter.
- Tensor Fascia Lata contributes to hip flexion, abduction, and internal rotation in that order. Its tendon blends with the iliotibial band.
- There are two main bursae (fluid filled lubricating sacs) in the area - a superficial one lies between the tensor fascia lata muscle and the gluteus medius tendon - the deep one lies between the tendons of gluteus medius and gluteus minimus.
Trochanteric Bursitis - the commonest soft tissue lesion around the hip area.
- Causes - overuse - seen in sporting activities involving excessive running, and also in overweight females with degenerative spinal problems.
- Clinical Findings - Inflammation of the superficial and deep bursae (fluid filled lubricating sacs) produces well localised pain over the trochanteric region as well as radiating pain down the outside thigh. The pain is aggravated by walking, climbing stairs, lying on the affected side in bed, and may disturb sleep. The pain can be reproduced by stretching the gluteus medius tendon, and by resisted abduction.
- Investigations - X-rays show calcification of the bursa in 20% of chronic cases.
- Treatment - rest, analgesics, ice, deep tendon massage, LA / Steroid Injections .
- Pectineus, Adductor Brevis, Adductor Longus, and Adductor Magnus are the main adductor muscles of the hip. They all originate from the lower pelvic ramus and insert on to the back of the femur (thigh bone).
Adductor Tendinitis (Tendonitis)
- Causes - overuse - common in athletes and has also been called "Rider's strain".
- Clinical Findings - Well localised tenderness over the muscle origin on the lower pubic ramus, or in the first few centimeters over the musculo-tendinous junction. Pain can be reproduced by stretching the adductors or by resisted adduction.
- Investigations - hip xrays can sometimes show tendon calcification in chronic cases.
- Treatment - rest, analgesics, stretching, deep friction, LA / Steroid Injections .
- Iliopsoas is a muscle made up of two parts - Iliacus and Psoas Major. Iliacus originates from the inside of the pelvic bone, whereas psoas major originates from the front of vertebrae L1 to L5. The two muscles then insert via their tendons onto the lesser trochanter of the femur. Iliopsoas is the primary flexor of the hip and is very powerful. A bursa separates the tendon from the front part of the hip joint, another bursa sits behind the insertion point on the lesser trochanter.
Iliopsoas Tendinitis / Bursitis
- Causes - overuse - common in athletes
- Clinical Findings - Localised tenderness over the insertion on the lesser trochanter. Pain can be reproduced by resisted flexion of the hip. The bursae are so deep that it is rarely possible to feel them as enlarged.
- Investigations - hip X-rays are necessary to help differentiate between tendinitis / bursitis and primary hip osteoarthritis. In young people X-rays also help to exclude a slipped femoral epiphysis.
- Treatment - Rest, analgesics, hip extension mobilisation techniques (see Hurdler Stretch), and LA / Steroid Injections . The bursa is injected using X-ray guidance so as to avoid the femoral vessels and nerves. It may also be worth injecting the lesser trochanter insertion point at the same time.
- The hamstrings consist of three muscles - biceps femoris, semitendinosus, and semimembranosus. All three have a common origin at the ischial tuberosity. Biceps femoris inserts onto the lateral part of the knee (fibular head and lateral tibial condyle). Semitendinosus and semimembranosus insert onto the medial knee joint and upper medial part of the tibia. The muscles contribute to hip extension and knee flexion.
Hamstring Tendinitis (Tendonitis)
- Causes - over use in long distance runners, especially hill runners.
- Clinical Findings - Tenderness over the ischial tuberosity intensified by resisted hip extension and full passive hip flexion.
- Investigations - in sprinters X-rays may show a bony fragment where the muscle tendon has avulsed a small piece of bone off the ischial tuberosity. Orthopaedic surgery is indicated if the fragment is more than 1 - 2 cm in size. Conservative measures are used in the majority of cases.
- Treatment - Rest, analgesics, LA / Steroid Injections , and Prolotherapy for chronic sprains.
- Rectus Femoris is the only one of the four quadriceps muscles that crosses two joints (Hip and knee). It's origin is from the anterior inferior iliac spine (AIIS), and it's insertion is into the common quadriceps tendon attaching to the patella. It contributes to hip flexion and knee extension.
Rectus Femoris Tendinitis
- Causes - over use in athletes especially during explosive sprint starts. Similar problems may occur with the sartorius origin at the anterior superior iliac spine (ASIS).
- Clinical Findings - Tenderness over the AIIS origin during passive hip extension and active hip flexion.
- Investigations - X-rays in athletes may reveal an avulsion of a small bony fragment from the AIIS.
- Treatment - Rest, analgesics, LA / Steroid Injection.
- Several bursae exist between the gluteal muscles and the blade of the ilium, and also between the three gluteal muscles. The function of these is to reduce friction between muscle layers during vigorous activity.
- See Gluteal and Piriformis muscle trigger points for other causes of hip and buttock pain.
Gluteal Bursitis (also known as Weaver's Bottom)
- Causes - prolonged sitting, repeated buttock trauma.
- Clinical Findings - localised tenderness over the inflamed bursa. Pain aggravated by passive hip flexion, abduction and adduction, as well as resisted hip abduction and extension.
- Investigations - plain X-rays to exclude osteoarthritis.
- Treatment - Rest, analgesics, exercises, LA / Steroid Injection .
- Capsulitis of the hip is much less common than in the shoulder. It is usually found in the middle aged and younger age groups, where it presents as pain and stiffness coming on for no apparent reason. Examination reveals a capsular pattern with pain on most passive movements. The pain usually subsides over several months, with restoration of hip joint movements taking much longer.
- Plain hip X-rays are normal. A hip joint arthrogram may show reduced joint volume and restricted joint recesses (recess = lax parts of the capsule normally allowing large hip movements).
- Rest, analgesics, exercises, LA / Steroid Injection combined with physical therapy stretching techniques immediately afterwards.
- Osteoarthritis (OA) is the commonest cause of hip pain. Primary OA is due to articular cartilage problems (wear and tear), whereas secondary OA is caused when the joint has been damaged by some other disease process:-
- Acetabular dysplasia (malformation of the acetabulum)
- Perthes disease (Slipped femoral epiphysis)
- Septic Arthritis (infection)
- Congenital Dislocation of the Hip (CDH) etc.
- Trigger points within the muscles of the hip and buttock can also cause local and referred pain - see Back, Hip and Buttock for more information.
- The onset is often insidious. There is no correlation between pain and the degree of X-ray damage.
- Pain on weight bearing or after unaccustomed vigorous exercise is the commonest presentation. Established hip arthritis presents as severe pain with restricted movements.
- X-rays may show joint wear of the upper joint surface where the femoral head lies in contact with the acetabulum. The wear may be commonly superior, supero-lateral or supero-medial.
- Regular hip exercises.
- Think about trying the Pain Gone Pen - a simple low-cost non-drug self-help arthritis pain relief device for home use.
- LA / Steroid Injection combined with physical therapy stretching techniques immediately afterwards.
- Oral Glucosamine supplements for early osteoarthritis
- Viscosupplementation with Ostenil on 5 occasions performed using X-ray screening. Please speak to your pain clinic specialist about this option.
- Intra-articular prolotherapy performed using X-ray screening.
- Surgical Total Hip Replacement for severe OA. The time to have hip surgery is when the pain is not helped by the above conventional treatments.
- All of the above conditions are examples of local pain problems around the hip joint.
- Below are some conditions which can mimic hip pain by causing referred pain there because of a shared nerve supply:-