Hip

Introduction

Dr. Paul Peters specializes in Hip Replacement Surgery, using minimally invasive techniques. Since 1992, Dr. Peters has performed hundreds of hip surgeries each year in Dallas. Dr. Peters’ goal is to restore the normal activity level of both the young and old patient receiving a hip replacement. Dr. Peters is an advocate of using new less-invasive techniques, and better materials for the active patient with a hip replacement.

Anatomy

The hip joint is the largest weight-bearing joint in the human body. It is also referred to as a ball and socket joint and is surrounded by muscles, ligaments, and tendons. The thigh bone or femur and the pelvis join to form the hip joint.

Any injury or disease of the hip will adversely affect the joint's range of motion and ability to bear weight.

The hip joint is made up of the following:

  • Bones and joints
  • Ligaments of the joint capsule
  • Muscles and tendons
  • Nerves and blood vessels that supply the bones and muscles of the hip

Bones and joints

The hip joint is the junction where the hip joins the leg to the trunk of the body. It is comprised of two bones: the thigh bone or femur and the pelvis which is made up of three bones called ilium, ischium, and pubis. The ball of the hip joint is made by the femoral head while the socket is formed by the acetabulum. The Acetabulum is a deep, circular socket formed on the outer edge of the pelvis by the union of three bones: ilium, ischium and pubis. The lower part of the ilium is attached by the pubis while the ischium is considerably behind the pubis. The stability of the hip is provided by the joint capsule or acetabulum and the muscles and ligaments which surround and support the hip joint.

The head of the femur rotates and glides within the acetabulum. A fibrocartilaginous lining called the labrum is attached to the acetabulum and further increases the depth of the socket.

The femur or thigh bone is one of the longest bones in the human body. The upper part of the thigh bone consists of the femoral head, femoral neck, and greater and lesser trochanters. The head of the femur joins the pelvis (acetabulum) to form the hip joint. Next to the femoral neck, there are two protrusions known as greater and lesser trochanters which serve as sites of muscle attachment.

Articular cartilage is the thin, tough, flexible, and slippery surface lubricated by synovial fluid that covers the weight-bearing bones of the body. It enables smooth movements of the bones and reduces friction.

Ligaments

Ligaments are fibrous structures that connect bones to other bones. The hip joint is encircled with ligaments to provide stability to the hip by forming a dense and fibrous structure around the joint capsule. The ligaments adjoining the hip joint include:

  • Iliofemoral ligament – This is a Y-shaped ligament that connects the pelvis to the femoral head at the front of the joint. It helps in limiting over-extension of the hip.
  • Pubofemoral ligament – This is a triangular shaped ligament that extends between the upper portion of the pubis and the iliofemoral ligament. It attaches the pubis to the femoral head.
  • Ischiofemoral ligament – This is a group of strong fibers that arise from the ischium behind the acetabulum and merge with the fibers of the joint capsule.
  • Ligamentum teres – This is a small ligament that extends from the tip of the femoral head to the acetabulum. Although it has no role in hip movement, it does have a small artery within that supplies blood to a part of the femoral head.
  • Acetabular labrum – The labrum is a fibrous cartilage ring which lines the acetabular socket. It deepens the cavity increasing the stability and strength of the hip joint.

Muscles and Tendons

A long tendon called the iliotibial band runs along the femur from the hip to the knee and serves as an attachment site for several hip muscles including the following:

  • Gluteals – These are the muscles that form the buttocks. There are three muscles (gluteus minimus, gluteus maximus, and gluteus medius) that attach to the back of the pelvis and insert into the greater trochanter of the femur.
  • Adductors – These muscles are located in the thigh which help in adduction, the action of pulling the leg back towards the midline.
  • Iliopsoas: This muscle is located in front of the hip joint and provides flexion. It is a deep muscle that originates from the lower back and pelvis, and extends up to the inside surface of the upper part of the femur.
  • Rectus femoris – This is the largest band of muscles located in front of the thigh. They also are hip flexors.
  • Hamstring muscles- These begin at the bottom of the pelvis and run down the back of the thigh. Because they cross the back of the hip joint, they help in extension of the hip by pulling it backwards.

Nerves and arteries:

Nerves of the hip transfer signals from the brain to the muscles to aid in hip movement. They also carry the sensory signals such as touch, pain, and temperature back to the brain.

The main nerves in the hip region include the femoral nerve in the front of the femur and the sciatic nerve at the back. The hip is also supplied by a smaller nerve known as the obturator nerve.

In addition to these nerves, there are blood vessels that supply blood to the lower limbs. The femoral artery, one of the largest arteries in the body, arises deep in the pelvis and can be felt in front of the upper thigh.

Hip movements:

All of the anatomical parts of the hip work together to enable various movements.
Hip movements include flexion, extension, abduction, adduction, circumduction, and hip rotation.

Conditions

Femoro Acetabular Impingement (FAI)

Femoroacetabular impingement (FAI) is a condition where there is too much friction in the hip joint from bony irregularities causing pain and decreased range of hip motion. The femoral head and acetabulum rub against each other creating damage and pain to the hip joint. The damage can occur to the articular cartilage (the smooth white surface of the ball or socket) or the labral tissue (the lining of the edge of the socket) during normal movement of the hip. The articular cartilage or labral tissue can fray or tear after repeated friction. Over time, more cartilage and labrum is lost until eventually the femur bone and acetabulum bone impact on one other. Bone on bone friction is commonly referred to as Osteoarthritis.

FAI impingement generally occurs as two forms: Cam and Pincer.

CAM Impingement: The Cam form of impingement is when the femoral head and neck are not perfectly round, most commonly due to excess bone that has formed. This lack of roundness and excess bone causes abnormal contact between the surfaces.

PINCER Impingement: The Pincer form of impingement is when the socket or acetabulum rim has overgrown and is too deep. It covers too much of the femoral head resulting in the labral cartilage being pinched. The Pincer form of impingement may also be caused when the hip socket is abnormally angled backwards causing abnormal impact between the femoral head and the rim of the acetabulum.

Most diagnoses of FAI include a combination of the Cam and Pincer forms.

Symptoms of FAI

Symptoms of femoroacetabular impingement can include the following:

  • Groin pain associated with hip activity
  • Complaints of pain in the front, side or back of the hip
  • Pain may be described as a dull ache or sharp pain
  • Patients may complain of a locking, clicking, or catching sensation in the hip
  • Pain often occurs to the inner hip or groin area after prolonged sitting or walking
  • Difficulty walking uphill
  • Restricted hip movement
  • Low back pain
  • Pain in the buttocks or outer thigh area

Risk Factors

A risk factor is something that is likely to increase a person's chance of developing a disease or condition. Risk factors for developing femoroacetabular impingement may include the following:

  • Athletes such as football players, weight lifters, and hockey players
  • Heavy laborers
  • Repetitive hip flexion
  • Congenital hip dislocation
  • Anatomical abnormalities of the femoral head or angle of the hip
  • Legg-Calves-Perthes disease: a form of arthritis in children where blood supply to bone is impaired causing bone breakdown.
  • Trauma to the hip
  • Inflammatory arthritis

Diagnosis

Hip conditions should be evaluated by an orthopaedic hip surgeon for proper diagnosis and treatment.

  • Medical History
  • Physical Examination
  • Diagnostic studies including X-rays, MRI scans and CT Scan

Treatment Options

Conservative treatment options refer to management of the problem without surgery. Nonsurgical management of FAI will probably not change the underlying abnormal biomechanics of the hip causing the FAI but may offer pain relief and improved mobility.

Conservative treatment measures

  • Rest
  • Activity Modification and Limitations
  • Anti-inflammatory Medications
  • Physical Therapy
  • Injection of steroid and analgesic into the hip joint

Surgical treatment

  • Hip arthroscopy to repair femoroacetabular impingement is indicated when conservative treatment measures fail to provide relief to the patient.

Inflammatory Arthritis of the Hip

Inflammation of the joints is referred to as arthritis. The inflammation arises when the smooth covering (cartilage) at the end surfaces of the bones wears away. In some cases, the inflammation is caused when the lining of the joint becomes inflamed as part of an underlying systemic disease. These conditions are referred to as inflammatory arthritis.

The most common types of inflammatory arthritic conditions of the hip include:

  • Rheumatoid Arthritis: Systemic disease of the immune system commonly affects multiple joints on both sides of the body at the same time.
  • Ankylosing Spondylitis: Chronic inflammatory disease of the spine and the sacroiliac joints (junction where the spine meets the pelvic bone)
  • Systemic Lupus Erythematosus (SLE): An autoimmune disease in which the body's immune system attacks its own healthy cells and tissues.

Symptoms

The typical symptom of arthritis is joint pain. Inflammatory hip arthritis is mainly characterized by an aching pain in the groin region, outer thighs or buttocks. The pain is commonly most severe in the morning which sometimes lessens with activity during the course of the day. Vigorous activities may result in increased pain and stiffness and limit your movement, making walking difficult.

Diagnosis

Inflammatory hip arthritis can be diagnosed by physical examination. Your doctor will ask you to move your hip in different directions to find out which motions are restricted or painful. X-rays and laboratory tests may be ordered to diagnose or rule out other conditions. X-rays may show thinning or erosion in the bones or loss in joint space. Laboratory studies will show the presence of a rheumatoid factor or other antibodies.

Treatment

The treatment options vary depending on the diagnosis.

Non-surgical treatment: Any infection in the hip joint is treated by non-surgical treatments which may provide relief with relatively few side effects.

  • Anti-inflammatory medications or corticosteroids may help reduce the inflammation.
  • Physical therapy may be recommended to help you increase the range of motion and strengthening exercises to maintain muscle tone.
  • Assistive devices such as canes or walkers can make your daily living activities easier.

Surgical treatment: Surgery is considered the last treatment resort when the above non-surgical treatment options fail to reduce the symptoms. The type of surgery to be performed depends on your age, condition of the hip joint, and the type and progression of the inflammatory disease. The goal of the surgery is to relieve pain and improve the joint motion. The most common surgical procedures include:

  • Total hip replacement: Indicated for patients with rheumatoid arthritis and ankylosing spondylitis.
  • Bone grafts: Recommended for patients with SLE. These grafts aim to build new blood cells to replace the old dead cells.
  • Core decompression: Helps to reduce bone marrow pressure and encourages blood flow. Core decompression is another treatment option for patients with SLE.
  • Synovectomy is the procedure of removal of a part or whole of the joint lining. This is indicated if the inflammation has not affected the cartilage, but is limited to the joint lining or synovium.

Treatments

Total Hip Replacement (THR)

Total hip replacement is a surgical procedure in which the damaged cartilage and bone is removed from the hip joint and replaced with artificial components. The hip joint is one of the body's largest weight-bearing joints, located between the thigh bone (femur) and the pelvis (acetabulum). It is a ball and socket joint in which the head of the femur is the ball and the pelvic acetabulum forms the socket. The joint surface is covered by a smooth articular cartilage which acts as a cushion and enables smooth movements of the joint.

A number of diseases and conditions can cause damage to the articular cartilage. Total hip replacement surgery is an option to relieve severe arthritis pain that limits your daily activities.

Disease Overview

Arthritis is inflammation of the joints resulting in pain, swelling, stiffness and limited movement. Hip arthritis is a common cause of chronic hip pain and disability. The three most common types of arthritis that affect the hip are:

  • Osteoarthritis: It is characterized by progressive wearing away of the cartilage of the joint. As the protective cartilage wears down, the bone ends rub against each other and cause pain in the hip. Rheumatoid arthritis: This is an autoimmune disease in which the tissue lining the joint (synovium) becomes inflamed, resulting in the production of excessive joint fluid (synovial fluid). This leads to loss of cartilage causing pain and stiffness.
  • Traumatic arthritis: This is a type of arthritis resulting from a hip injury or fracture. Such injuries can damage the cartilage and cause hip pain and stiffness over a period of time.

Symptoms

The most common symptom of hip arthritis is joint pain and stiffness resulting in limited range of motion. Vigorous activity can increase the pain and stiffness which may cause limping while walking.

Diagnosis

Diagnosis is made by evaluating medical history, physical examination and X-rays.

Surgical Procedure

Surgery may be recommended, if conservative treatment options such as anti-inflammatory medications and physical therapy do not relieve the symptoms.

The surgery is performed under general anesthesia. During the procedure a surgical cut is made over the hip to expose the hip joint and the femur is dislocated from the acetabulum. The surface of the socket is cleaned and the damaged or arthritic bone is removed using a reamer. The acetabular component is inserted into the socket using screws or occasionally bone cement. A liner made of plastic, ceramic or metal is placed inside the acetabular component. The femur or thigh bone is then prepared by removing the arthritic bone using special instruments, to exactly fit the new metal femoral component. The femoral component is then inserted to the femur either by a press fit or using bone cement. Then the femoral head component made of metal or ceramic is placed on the femoral stem. All the new parts are secured in place using special cement. The muscles and tendons around the new joint are repaired and the incision is closed.

Post-operative care

After undergoing total hip replacement, you must take special care to prevent the new joint from dislocating and to ensure proper healing. Some of the common precautions to be taken include:

  • Avoid combined movement of bending your hip and turning your foot inwards
  • Keep a pillow between your legs while sleeping for 6 weeks
  • Never cross your legs and bend your hips past a right angle (90)
  • Avoid sitting on low chairs
  • Avoid bending down to pick up things, instead a grabber can be used to do so
  • Use an elevated toilet seat

Risks

As with any major surgical procedure, there are certain potential risks and complications involved with total hip replacement surgery. The possible complications after total hip replacement include:

  • Infection
  • Dislocation
  • Fracture of the femur or pelvis
  • Injury to nerves or blood vessels
  • Formation of blood clots in the leg veins
  • Leg length inequality
  • Hip prosthesis may wear out
  • Failure to relieve pain
  • Scar formation
  • Pressure sores

Total hip replacement is one of the most successful orthopaedic procedures performed for patients with hip arthritis. This procedure can relieve pain, restore function, improve your movements at work and play, and provide you with a better quality of life.

Revision Hip Replacement

Revision hip replacement is a complex surgical procedure in which all or part of a previously implanted hip-joint is replaced with a new artificial hip-joint. Total hip replacement surgery is an option to relieve severe arthritis pain that limits your daily activities. During total hip replacement the damaged cartilage and bone is removed from the hip joint and replaced with artificial components. At times, hip replacement implants can wear out for various reasons and may need to be replaced with the help of a surgical procedure known as revision hip replacement surgery.

Indications:

Revision hip replacement is advised in patients with the following conditions:

  • Increasing pain in the affected hip
  • Worn out plastic or polyethylene prosthesis
  • Dislocation of previous implants
  • Loosening of the femoral or acetabular component of the artificial hip joint
  • Infection around the hip prosthesis causing pain and fever
  • Weakening of bone around the hip replacement (Osteolysis)

Revision hip replacement surgery is performed under general anesthesia. During the procedure, your surgeon will make an incision over the hip to expose the hip joint. Then the femur is dislocated from the acetabulum so that the old plastic liner and the metal socket can be removed from the acetabulum.

Revision hip replacement surgery is performed under general anesthesia. During the procedure, your surgeon will make an incision over the hip to expose the hip joint. Then the femur is dislocated from the acetabulum so that the old plastic liner and the metal socket can be removed from the acetabulum.

After removal, the acetabulum is prepared using extra bone and wire mesh to make up for the socket space and shape. Then the new metal shell is inserted into the socket using screws or special cement. A liner made of plastic, ceramic or metal is placed inside the metal socket.

Revision hip replacement surgery is performed under general anesthesia. During the procedure, your surgeon will make an incision over the hip to expose the hip joint. Then the femur is dislocated from the acetabulum so that the old plastic liner and the metal socket can be removed from the acetabulum.

After removal, the acetabulum is prepared using extra bone and wire mesh to make up for the socket space and shape. Then the new metal shell is inserted into the socket using screws or special cement. A liner made of plastic, ceramic or metal is placed inside the metal socket.

To prepare the femoral component, the top of the femur bone is cut into several pieces to remove the implant. The segments of bone are cleaned and the new femoral implant is inserted into the femur either by a press fit or using bone cement. The segments of the femur and the femoral component are held together with surgical wires. Then the femoral head component made of metal or ceramic is placed on the femoral stem. All the new components are secured in place to form the new hip joint. The muscles and tendons around the new joint are repaired and the incision is closed.

After undergoing revision hip replacement, you must take special care to prevent the new joint from dislocating and to ensure proper healing. Some of the common precautions to be taken include:

  • Avoid combined movement of bending your hip and turning your foot inwards because it can cause dislocation
  • Keep a pillow between your legs while sleeping for 6 weeks
  • Never cross your legs or bend your hips past a right angle (90 degrees)
  • Avoid sitting on low chairs
  • Avoid bending down to pick up things, instead a grabber can be used to do so
  • Use an elevated toilet seat

Risks:

As with any major surgical procedure, there are certain potential risks and complications involved with revision hip replacement surgery. The possible complications after revision hip replacement include:

  • Infection
  • Dislocation
  • Fracture of the femur or pelvis
  • Injury to nerves or blood vessels
  • Formation of blood clots in the leg veins
  • Leg length inequality
  • Hip prosthesis may wear out
  • Failure to relieve pain

Revision hip replacement removes your failed hip implants from a previous total hip replacement surgery, and replaces them with new ones, which will help make your hip strong, stable and flexible again. It improves mobility, strength and enables patients to return once again to normal activity with a pain-free hip.

Minimally Invasive Total Hip Replacement

The hip joint is one of the body's largest weight-bearing joints and is the point where the thigh bone (femur) and the pelvis (acetabulum) join. It is a ball and socket joint in which the head of the femur is the ball and the pelvic acetabulum forms the socket. The joint surface is covered by a smooth articular cartilage that cushions and enables smooth movements of the joint.

Hip arthritis is one of the painful and common diseases of the hip joint caused by damage to the cartilage. Total hip replacement surgery is an option to relieve severe arthritis pain that limits your daily activities.

Traditionally, total hip replacement will be performed through a 10–12-inch-long incision made on the side of the hip. A minimally invasive approach has been developed in recent years where surgery is performed through one or two smaller incisions rather than the single long incision as in the traditional approach. Advantages of the newer approach are lesser muscle dissection, minimal pain, quicker recovery, and faster rehabilitation.

Disease Overview

Arthritis is inflammation of the joints resulting in pain, swelling, stiffness and limited movement. Hip arthritis is a common cause of chronic hip pain and disability. The most common type of arthritis affecting the hip is osteoarthritis which is characterized by progressive wearing away of the joint cartilage. As the protective cartilage wears down, the bone ends rub against each other and cause pain in the hip. It is more common in individuals aged above 50 years and tends to run in families.

Symptoms

The most common symptom of hip arthritis is dull, aching joint pain and stiffness resulting in limited mobility. There may be pain in the groin, thigh and buttock area and sometimes pain may be referred to the knee. Vigorous activity and walking for long distances can increase the pain and stiffness which may cause limping while walking.

Diagnosis

Diagnosis is made by evaluating your symptoms, medical history, physical examination and X-rays. Sometimes, additional imaging tests such as MRI and CT scans may be needed to confirm the diagnosis.

Surgical procedure

Surgery may be recommended in patients with severe cartilage damage and if conservative treatment options such as anti-inflammatory medications and physical therapy do not relieve the symptoms.

For minimally invasive hip replacement, the surgical technique and artificial implants remain the same as traditional hip replacement however the difference is smaller incisions and minimal soft tissue dissection. The surgery is performed through either one or two smaller incisions. The procedure is performed under general anesthesia.

In single incision minimally invasive approach, your surgeon makes a 3–6-inch incision over the side of the hip to expose the hip joint. The muscles are minimally dissected to reach the joint. The femur is dislocated from the acetabulum. The surface of the socket is cleaned and the arthritic bone is removed using a reamer. The acetabular implant is inserted into the socket using screws or special cement. A liner material of plastic, ceramic or metal is placed inside the acetabular component. The femur or thigh bone is then prepared by removing the arthritic bone using special instruments and shaped to exactly fit the new metal femoral component. The femoral stem is then inserted into the femur either by a press fit or using bone cement. Then the femoral head component made of metal or ceramic is placed on the femoral stem. All the new parts are secured in place using special cement. The muscles and tendons around the new joint are repaired and the incision is closed.

If the surgeon uses the two-incision technique, a 2- to 3-inch incision is made over the groin for placement of the socket and a 1- to 2-inch incision is made over the buttock for placement of the femoral stem. This technique requires longer operative time and is performed under X-ray guidance.

Advantages

The advantages of minimally invasive total hip replacement as compared with traditional total hip replacement may include:

  • Smaller incisions
  • Shorter hospital stay
  • Less trauma to the surrounding tissues
  • Quicker recovery
  • Less blood loss
  • Less scarring
  • Faster rehabilitation
  • Minimal post-operative pain

Post-operative precautions

After undergoing minimally invasive total hip replacement, you must take special care to prevent dislocation of the new joint and to ensure proper healing.

  • Avoid combined movement of bending your hip and turning your foot inwards
  • Keep a pillow between your legs while sleeping for 6 weeks
  • Never cross your legs and bend your hips past a right angle (90°)
  • Avoid sitting on low chairs
  • Avoid bending down to pick up things, instead use a grabber device.
  • Use an elevated toilet seat

Risks and Complications

As with any major surgical procedure, there are certain potential risks and complications involved with total hip replacement surgery. They include:

  • Infection
  • Injury to nerves and blood vessels
  • Formation of blood clots in the leg veins
  • Implant malposition
  • Fracture of the femur or pelvis

Hip Replacement Videos

Total Hip Replacement

Revision Hip Replacement

Minimally Invasive Hip Replacement

  • American Association of Hip and Knee Surgeons
  •  American Academy of Orthopaedic Surgeons
  • North Central Surgical Center Hospital
  • Texas Health Presbyterian Hospital Dallas
  • Texas Scottish Rite Hospital for Children
  • Healthgrades