The hip can be referred to as the acetabulofemoral joint. A hip is a joint situated between the femur and the acetabulum of pelvis. The hip is weight bearing part of the body that also maintains balance and is exposed to wear and tear.
A hip dislocation is a condition which occurs when the head of the thigh bone or the femur moves out of its socket in the bone of the hip that is in the pelvis. In about 90% of cases, the thighbone is pushed out of its socket in a reverse direction which is called as posterior dislocation leaving the hip in a fixed position by twisting and bending it in toward the mid line of the body. The thighbone when slipped out of its socket in a forward direction is called as anterior dislocation. In this case, there is a slight bend in the hip with leg twisting out and away from the mid line of the body.
A hip dislocation is associated with severe pain creating difficulty for the patient while moving the leg. Numbness in the ankle or foot area is experienced in case of nerve damage.
The hip joint works on the principle of ball and socket movement. The ball is formed on the upper side of the femur. The thigh bone and the pelvis form the socket. The structure of a ball and socket joint not only gives stability but also allows it to move smoothly. Hip dislocation often occurs due to high impact forces which are responsible for popping out the thighbone from its socket.
Hip may also get dislocated due to motor vehicle accidents. Wearing a seat belt helps greatly in decreasing the chances of these accidents. Apart from this, falling down from a height like falling down from a ladder and industrial accidents may also result in dislocating a hip.
In some cases hip dislocation may also be associated with other injuries, which include fractures in the legs, pelvis and head and back injuries.
Types of Hip Dislocation
Hip dislocations are broadly classified into three types:
- Anterior Hip Dislocation.
- Posterior Hip Dislocation.
- Inferior Hip Dislocation.
However, 90% of dislocations are posterior hip dislocations, which occur due to a backward force on a flexed knee. The major cause of this is dashboard injuries.
Causes and Risk Factors of Hip Dislocation
The hip joint consists of the ball shaped thigh bone and the acetabulum of the pelvis that is the socket into which the ball is situated. Strong ligament supports the joint.The labrum that is a ring of cartilage surrounding the acetabulum also contributes in keeping the femoral head in the socket. All of this together makes the hip joint to become a stable joint. Therefore, only high impact forces can cause dislocation of the hip joint.
Hip dislocations may also be caused due to road traffic accidents and falls. Children are more prone to hip dislocations when compared to adults.
Additional injuries such as fractures to the pelvis and the femur are also associated with the dislocation of the hip. Soft tissue is also damaged to some extent subsequently in all the cases of hip dislocation which also involves tearing of the ligaments and labrum of the hip joint.
Signs and Symptoms of Hip Dislocation
- Sudden pain in the hip on impact.
- Inability to move the hip joint.
- Awkward positioning of the leg, especially when crossing the affected leg over the other.
Treatment for Hip Dislocation
Hip dislocation must be treated immediately. Attempting movement of the hip and leg in order to place it back into its actual place must be strictly avoided. Treatment for hip dislocation focuses on placing the dislocated hip back into its actual place which is done in the operating room, which is done under anesthesia. Surgery is required only in case of fractured hip. Further treatment may include:
- Resting the affected hip by using crutches, walker and cane, which help in keeping the weight off of the legs.
- Non-steroidal anti-inflammatory drugs like ibuprofen, naproxen, ketoprofen and celecoxibhelp in reducing pain.
- Narcotic pain medication is also used for moderate to severe pain but this is taken only for very short period.
- Sedative or anesthetic helps in manipulating the bones back into their actual place, but only when there are no significant injuries associated with hip dislocation.
- Physical therapy for hip dislocation is important in speeding up the healing process. Physical therapy also decreases the likelihood of recurrences in the future.
Exercises for Hip Dislocation
Resistive Hip Abduction Exercise for Hip Dislocation:
This exercise is performed by using tubing or an exercise band to strengthen the muscles of the hip. The exercise band helps in strengthening by supplying increased resistance. Using sturdy chair or a table helps in performing this exercise. Tie an exercise band around the table or chair's leg and place the injured leg into it by placing the band around the ankle. Stand in such a way that the healthy side should come near the chair or table. Now hold the chair or table by placing hand on the healthy side. Gradually lift the injured leg away from the body in side ward direction.Hold the position for about three seconds and gradually bring the leg to the initial position. Repeat 10 times.
Upright Knee Raise Exercise for Hip Dislocation:
This exercise is performed by doing standing knee raises in order to strengthen the muscles. Stand in front of the chair and grab the back of the sturdy chair with the help of the hands. Now gradually raise injured leg from the floor and smoothly bend the knee.Then raise the leg toward the upper body. Avoid lifting the knee more than waist level. Hold the position for about three seconds. Gradually bring the leg to the initial position. Repeat 10 times. Perform four times daily.
Hip Flexion and Extension Exercise for Hip Dislocation:
This exercise is performed by stretching the muscles of the hip and leg by performing leg swings or hip flexions. This exercise can be performed either in the water or on the floor. If the exercise is being performed in water the water level must reach chest or waist. The unaffected side should be placed against the side of the pool. Now grab the side of the pool by placing hand on the healthy side. Gradually raise the affected leg from the surface and swing the leg in the forward direction away from the body.Hold the position for about five seconds. Now gradually swing the affected leg in the backward direction. Hold the position for about five seconds. Gradually bring the leg back to the initial position. Repeat 10 times. Note that only the hip is in motion and avoid moving the upper body and neck while performing this exercise.
If the exercise is being performed on floor, bring a sturdy chair and place the healthy side against the chair. Now grab the back of the chair by placing hand on the healthy side. Gradually raise the affected leg from the surface and swing the leg in the forward direction away from the body. Hold the position for about five seconds. Now gradually swing the affected leg in the backward direction. Hold the position for about five seconds. Gradually bring the leg back to the initial position. Repeat 10 times.Note that only the hip is in motion and avoid moving the upper body and neck while performing this exercise.
Tests to Diagnose Hip Dislocation
Generally a complete subjective and physical examination is performed to diagnose hip dislocation. Typically an x-ray is required for confirming the severity and to check for any other fractures in the thighbone and hip.
MRI or CT scans may be helpful only when blood vessel, nerve or other soft tissue damage is suspected for further evaluations.