An artificial replacement of a ball and socket hip joint can restore function to a hip compromised by injury or arthritis. The procedure is generally successful. However, during total hip replacement surgery, your doctor cuts through the ligamentous capsule and other soft tissues that surround and help center the ball of the joint in its socket. This reduces the stability of the hip joint and increases the risk of dislocation.
Certain surgical approaches during hip replacement increase the risk of dislocation. Prosthetic components may lack proper orientation or be grossly malpositioned. Certain designs may be inappropriate and cause components to lever out against bony prominences. Previous hip surgeries lead to laxity of the soft tissues. Post-surgical fractures can also cause a hip dislocation. Following hip replacement surgery, as the tissues are healing, your doctor gives you specific instructions on avoiding certain movements to prevent a dislocation. These include:
- Not bending the hip more than 90 degrees: You must avoid sitting on low sofas, instead use high chairs or beds that have been raised. While picking an object off the floor you must extend the operated leg backwards while supporting yourself on a piece of furniture.
- Not turning your knee inwards: You must not cross your knees while sitting and when lying on your side, instead raise your knee with a pillow to prevent it from falling inwards.
These precautions are compulsory for at least 6-12 weeks after the surgery so that there is minimal stress on the healing soft tissues and a thick capsule may form around the joint. Non-compliance to these instructions increases your risk for dislocations.
Artificial hip dislocation is rare but is likely to occur within the first 3 months after surgery. You may experience pain, a popping sound, inability to bear weight or move your leg/hip completely, a feeling that the hip has slipped out of its joint, or that the affected leg is shorter or turns inwards. X-rays are obtained to evaluate component orientation, malposition and wear of the components as well as soft tissue wear and nonunion. Bone and marrow samples may be obtained and sent to the laboratory to check for infection.
Early dislocations (before 6 weeks) usually occur due to relaxed soft tissues and immature scar tissue formation and are treated with bedrest followed by application of a brace or cast until the tissues strengthen. The dislocated artificial hip is usually treated without surgery by externally manipulating the ball back into the socket (closed reduction). This is usually accomplished under anesthesia, by stretching, traction and mobilization maneuvers. Medication may be administered to relax the hip muscles. As the procedure is painless, your doctor is able to use enough force to break up scar or soft tissue adhesions that have formed around the joint and separate the components before reducing them into correct position.
If joint dislocations become frequent, a revision surgery may be necessary. Revision surgery may involve the following:
- Removal of the misaligned prosthetic components and replacing them in proper anatomical position.
- Hardened cement that was used to fix the prosthesis has to be carefully removed to avoid a bone fracture. The freed components are then aligned in proper position.
- Soft-tissue balance may be restored by repositioning the soft tissues to provide adequate tension.
- Any impinging soft tissue, bone or cement is removed.
- As there is usually bone loss around the prosthetic component, your doctor may use a bone graft taken from your own body or a bone bank to reinforce the bone.
- If a fracture occurs, the fracture is repaired as part of the procedure.
- If infection is present, you will require a replacement of your prosthesis.
- In certain cases where dislocations are recurrent and no clear cause exists, a prosthesis that constrains your movement may be beneficial.
It is necessary to follow the precautions given and adhere to the rehabilitation program to maximize hip function and avoid future hip dislocations.
A dislocation is one of the most common injuries and will occur in any location where two or more of bones come together to form a joint. Dislocation of a joint is when the ends of the joint bones are forced out of the normal positions. Dislocations are painful injuries that temporarily immobilize and deform the injured joint.
Although the shoulders and fingers are the most common joints to be dislocated, other sites where dislocations can happen include the elbows, knees and hips. If you believe you have experienced a dislocated joint, seek medical attention as soon as possible to make sure there are no breaks in the bones and to return the bones to the proper positions.
When to see a doctor
It is, at times, difficult to tell the difference between a broken bone from a dislocated joint. If you or your child appears to have either type of injury, get medical help right away. If possible, ice the joint and keep it immobile while you’re waiting for medical treatment. Most dislocations, when treated properly by a medical professional, will return to normal function after several weeks of rehabilitation and proper rest. However, it is possible for some joints, for example the shoulder, may have an increased risk of repeat dislocation
A dislocated joint may be:
- Swollen and immovable
- Have some discoloration
- Be visibly out of place or deformed
- Intensely painful
Other signs or symptoms one might experience is numbness or tingling near or below the injury. An example of this includes numbness that is felt in the foot if the dislocated joint is the knee or in the hand if it’s a dislocated elbow.
Risk factors for all types of joint dislocation include:
- Susceptibility to falls. Experiencing falls is a risk everyone faces and exposes the person to possibly dislocating joints when the arms are used to brace one’s self for impact or if one lands forcefully on certain body parts, such as the shoulder or hip joints.
- Heredity. Some people, due to genetics, are born with ligaments that will be loose making them more likely than the average population to be prone to injuries
- Sports participation. Many athletes will dislocations due to participation in sports that are contact sports or high-impact, for example, wrestling, gymnastics, football, and basketball.
- Motor vehicle accidents. A leading cause of hip dislocations is motor vehicle accidents. One way to reduce the risk is the simple task of wearing a seat belt.
Dislocation after surgeries
Acquired hip dislocation tends to have the highest incidence rate immediately following a recent hip replacement surgery and possibly has the highest level of occurring within the first three months following the surgery.
Following the primary total hip replacement surgery, those who experience hip dislocation is approximately 3.9% of patients experience hip during the first 26 postoperative weeks.
Following a revision total hip replacement surgery, approximately 14.4% of patients experience hip dislocation during the 26 postoperative weeks. The incidence of hip dislocation following any type of hip replacement surgery will vary from person to person and greatly depends on the individual patient, hip implant and surgical team or other surgical factors.
The most influential contribution to hip dislocation and whether or not the hip is able to or not able to remain stable after surgery is the preoperative hip range of motion of the individual patient. Hip stability postoperatively depends greatly on the range of motion of the hip before the surgery making it crucial for the patient’s hips to fall within a certain range in order to ensure the best recovery and maximum possible stability after surgery.
At times, it can be difficult to tell the difference between a broken bone and a dislocated joint. Both situations are considered emergencies that requires urgent attention and first aid treatment.
Most dislocations can be easily treated in an emergency room or doctor’s office. During treatment, the patient may be given medicine that will numb the area and make the patient sleepy. sleepy. Depending on the severity of the injury, general anesthesia that will put the patient into a deep sleep is needed.
If treated early, almost all dislocations will not be the cause of a permanent injury.
You should expect that:
- Injuries to all of the surrounding tissues typically take an average of 6 to 12 weeks to heal. In some cases, surgery is needed to repair tears of the ligament that tears when the joint is dislocated.
- Injuries that cause damage to blood vessels or nerves can possibly result in permanent or long-term problems.
Once a dislocation of joint happens, it increases the chances of future dislocations very likely. After dislocations are treated in a doctor’s office or emergency room, patients are generally sent to an orthopaedic surgeon, or a joint and bone doctor for follow up.
Dislocations are usually caused by a sudden impact to the joint. This usually occurs following a blow, fall, or other trauma.
A dislocated joint may be:
- Accompanied by numbness or tingling at the joint or beyond it
- Very painful, especially if you try to use the joint or put weight on it
- Limited in movement
- Swollen or bruised
- Visibly out of place, discolored, or misshapen
Nursemaid’s elbow, or pulled elbow, is a partial dislocation that is common in toddlers. The main symptom is pain so that the child doesn’t want to use the arm. This dislocation can be easily treated in a doctor’s office.
First aid steps to take:
- Call 911 before you begin treating someone who may have a dislocation, especially if the accident that caused the injury may be life threatening.
- If the person has a serious injury, check their airway, breathing, and circulation. If necessary, begin CPR, or bleeding control.
- Do not move the person if you think that their head, back, or leg has been injured. Keep the person calm and still.
- If the skin is broken, take steps to prevent infection.
- Do not blow on the wound.
- Rinse the area gently with clean water to remove any dirt you can see, but do not scrub or probe.
- Cover the area with sterile dressings before immobilizing the injured joint.
- Splint or sling the injured joint in the position in which you found it.
- Do not move the joint. Immobilize the area above and below the injured area.
- Check blood circulation around the injury by pressing firmly on the skin in the affected area. It should turn white, then regain color within a couple of seconds after you stop pressing on it. To reduce the risk of developing infection, do not do this step if the skin is broken.
- Apply ice packs to ease pain and swelling, but do not put ice directly on the skin. Wrap the ice in a clean cloth.
- Take steps to prevent shock. Unless there is a head, leg, or back injury, lay the victim flat, elevate their feet about 12 inches, and cover the person with a coat or blanket.
- Do NOT move the person unless the injury has been completely immobilized.
- Do NOT move a person with an injured hip, pelvis, or upper leg unless it is absolutely necessary. If you are the only rescuer and the person must be moved, drag them by their clothing.
- Do NOT attempt to straighten a misshapen bone or joint or try to change its position.
- Do NOT test a misshapen bone or joint for loss of function.
- Do NOT give the person anything by mouth.
When to Contact a Medical Professional
Call 911 right away if the person has any of the following:
- A bone projecting through the skin
- A known or suspected dislocation or broken bone
- An area below the injured joint that is pale, cold, clammy, or blue
- Severe bleeding
- Signs of infection, such as warmth or redness at the injured site, pus, or a fever
To help prevent injuries in children:
- Create a safe environment around your home.
- Help prevent falls by placing gates at stairways and keeping windows closed and locked.
- Keep a watchful eye on children at all times. There is no substitute for close supervision, no matter how safe the environment or situation appears to be.
- Teach children how to be safe and look out for themselves.
To help prevent dislocations in adults:
- To avoid falls, do not stand on chairs, countertops, or other unstable objects.
- Eliminate throw rugs, especially around older adults.
- Wear protective gear when participating in contact sports.
For all age groups:
- Keep a first aid kit handy.
- Remove electrical cords from floors.
- Use handrails on staircases.
- Use nonskid mats on the bottom of bathtubs and do not use bath oils.