Hip pain results from damage to the hip joint – a ball and socket joint that connects the ball-shaped top of the leg bone (femur) to the hip socket. Damage to the hip joint can result from a number of causes, including:
- osteoarthritis which causes a degeneration of the cushioning of the surfaces of the hip socket
- rheumatoid arthritis which causes swelling of the hip joint
- avascular necrosis — an interrupted blood supply to the hip joint causing the eventual loss of bone tissue in that area
- injury caused either by a bone tumour or by a break or fracture of the hip joint
The hip joint is one of the most stable joints in the body and bears more of the body's weight than any other joint. It is made up of three sections:
- ilium: the broad portion of the hipbone (the crest of the pelvis)
- femoral head and neck: make up the "ball" portion of the joint.
- femur: the upper leg bone
The hip joint is a ball and socket joint that forms where the top of the thighbone (femur) meets the socket of the pelvic bone. The top of the femur is ball-shaped and fits snugly in the socket. The ball is normally held in the socket by very powerful ligaments that form a complete sleeve around the joint adding strength and elasticity for movement. Muscles and tendons also play an important role in keeping the hip joint stable and providing stability.
Types of Hip Injuries
Osteoarthritis of the hip is the gradual wearing down of the smooth gliding surfaces of the hip joint. When this occurs, raw bone becomes exposed within the hip joint. The causes vary but frequently the result is the same – increasingly persistent pain and decreasing activity level.
Bursae are strategically located in areas where muscles, ligaments, and tendons might otherwise rub against bones. The smooth surface of a bursa allows tissues to move across each other without friction. Bursae, however, can become inflamed, leading to a condition called bursitis.
- hip dislocation
A hip dislocation occurs when the ball of the thighbone (femur) is moved out of its place within the socket of the pelvic bone (acetabulum). Hip dislocations are rare and they can be severe.
- hip fracture
Older individuals are more likely to have hip fractures and are usually the result of a fall, an automobile accident or other trauma, or bone diseases.
- hip pointer
This type of hip injury, also known as a contusion, is usually the result of a fall. A hip pointer is a very common injury among athletes involved in contact sports such as football and hockey.
- hip strain
A muscle strain is an injury that damages the internal structure of the muscle. It is a partial tear of some of the small fibers that make up the muscle. The tearing may be so small that the damage can only be seen with a microscope. A muscle strain is caused by tension or stress applied to the muscle that it cannot withstand.
- labrum tear
The socket portion of the hip joint contains a rim of rubbery fibrocartilage called the labrum that acts like a seal allowing the joint to glide easily. It also helps to stabilize the joint. A tear to the labrum can occur after years of repetitive minor injuries or due to a sudden hip motion especially those associated with the sudden stops and turns in sports.
- sports-related hip injuries
In addition to labrum tears, muscle strains, and contusions, other sports-related hip injuries can include:
- loose hip joint
- ligament tears
- snapping hip
- loose pieces of bone or cartilage
Risk factors that may increase your chance of getting a hip injury include:
- improper or lack of proper stretching of the muscles and ligaments surrounding the hip joint
- improper technique or athletic movement
- not using proper protective sports equipment
- not wearing an automobile seatbelt
Symptoms of injuries to the hip joint may include:
- pain in the hip
- difficulty or inability to stand, walk, or move the hip
- abnormal appearance of the broken leg:
- looks shorter
- turns outward
- pain in the anterior groin, anterior thigh, buttock, greater trochanter, or medial knee
- persistent clicking, catching, or locking of the joint
- the hip joint gives way
- restricted range of motion
The doctor will ask about your symptoms, how the injury occurred, and then will perform a physical exam. Tests may include:
- x-ray or bone scan – to determine if the pelvis or leg bone is broken and how far out of place the pieces might have moved
- magnetic resonance imaging (MRI) scan – used if the fracture doesn't show up on x-rays but symptoms indicate a fracture has occurred
Non-surgical therapies are the first choice of treatment in most cases of hip pain and can include:
- physical therapy and pain relievers
Physical therapy is prescribed to strengthen the hip. Pain medication may include either non-aspirin relievers (ie, Tylenol) or non-steroidal pain and anti-inflammatory medications (NSAIDs) such as ibuprofen.
- steroid medications
In cases where NSAIDs are no longer effective and the diagnosis includes a form of inflammatory arthritis, steroid-based anti-inflammatory/pain medication such as prednisone may be prescribed. Because these don't control the pain for long and they have potential long-term side effects – weakening of joints, weight loss and/or a decrease in the functioning of the immune system – steroids are not considered a long-term option.
Occasionally, in young patients (under 30) or in patients with more demanding physical jobs (ie, construction workers), a corrective procedure known as an osteotomy may be done. In this procedure, the damaged portion of the hip joint is removed and the joint is reconfigured to its proper position. Recovery from an osteotomy may take anywhere from six to twelve months. In many cases, osteotomy requires additional treatments, and in most cases, it serves to delay rather than avoid the need for hip replacement surgery.
- total hip replacement
The most common type of hip surgical procedure is total hip replacement (THR), also known as hip arthroplasty. In the procedure, the surfaces of the cup (acetabulum) and ball (femoral head) are replaced with artificial materials. Hip replacement has proven to be a highly successful procedure as more than 200,000 people in the United States annually undergo THR to relieve pain and restore mobility.
- open hip surgery
Open hip surgery is commonly used when access to the hip capsule is required for a labral or ligament injury. Many orthopaedic surgeons prefer this procedure to arthroscopy (minimally invasive technique) but it requires a longer recovery period and rehabilitation time for the patient.
- arthroscopic hip surgery
The newest approach to the surgical repair of hip injuries is hip arthroscopy and it involves the familiar use of specialized instruments inserted into small incisions. The first of these instruments is a small camera/light that allows the surgeon to identify and confirm the hip injury. A second incision permits the insertion of other instruments that allow the surgeon to cut, shave, and suture accordingly.
Traditionally, arthroscopic repair of hip injuries has been difficult due to the anatomic complexity of the hip joint. But because of improved surgical techniques, advanced imaging, and more versatile instrumentation, hip arthroscopy can now be safely and effectively performed as an outpatient procedure.