Every year, nearly 200,000 Americans undergo hip replacement surgery, mostly due to arthritis. The vast majority of those surgeries are done with the traditional method, using a posterior or lateral (side) approach to gain access to the hip joint. With the traditional lateral method, the chance of dislocating your new hip is greater than with the minimally invasive anterior approach.
Hip dislocation after hip replacement surgery rarely occurs, but to reduce the risk even further it’s essential to strictly follow your hip precautions (restrictions of certain hip positions/movements) taught to you by your physical therapist. Your new hip needs time to heal in place, particularly during the first 6 weeks following surgery. During this period, your hip muscles and bones are healing up around your new hip joint to keep it securely in place.
There are usually three main total hip precautions. 1) Don’t turn your toes inward, 2) don’t cross your legs, 3) and don’t bend your new hip more than 60-90 degrees. Your surgeon will also instruct you on how much weight he wants you to place on your surgery leg while walking.
1) Don’t turn your toes inward. Where your toes go, your hip follows. If you turn your toes in on your surgery leg (pigeon-toed), your hip will internally rotate. This motion can pop your hip out of its new joint. Internal rotation can also occur while standing in place and twisting toward the direction of your new hip. Let’s say your right hip was just replaced. If you reach across your body with your left arm, maybe to answer the telephone or lay an object down on the table, you’re at risk of dislocating your new hip due to internal rotation.
2) Don’t cross your legs. Moving your surgery leg across your body’s midline can cause your new hip to dislocate. This includes sitting in a chair with your ankles crossed or reclining in bed with your legs crossed.
3) Don’t bend your hip beyond a 60-90 degree angle. The best way to know if you’re complying with this precaution is to take a look at your surgery leg when you’re sitting down. Your knee should be lower than your hip. If your knee and hip are level with each other, your hip is at a 90 degree angle. The closer you move your knee to your chest, the greater your risk of dislocating your new hip. And reaching down toward your shoes or the floor also creates this same risk of dislocation. One way to reduce the chance of hip dislocation is to straighten your leg out in front of you when you’re sitting. This reduces the bend of your hip.
While you’re in a standing position, don’t bend down to retrieve something from the floor or a low cupboard. There are devices, called “reachers”, that aid you in picking things up from the floor or getting objects from high cupboard shelves. Your occupational therapist will train you in the proper use of this equipment along with equipment to aid you in putting on your socks, shoes, and pants.
If you have low chairs at home, use pillows to add height. Chairs with arm rests make it easier to sit down and stand up. Don’t sit on a low couch. The top of your bed mattress should be 27″ from the floor. Getting on and off your toilet seat can be difficult and hazardous if it’s too low. While in the hospital, you’ll be using a raised toilet seat. You’ll need one at home as well until your hip has healed. Your physical therapist will order one for home use before you get discharged from the hospital.
If you dislocate your hip, call 911. You want to get to the hospital as quickly as possible so your surgeon can pop your hip back into place. This will require another surgery and rehab. If your surgeon is concerned about another dislocation, he can fit you with a hip brace. Once the hip completely heals, the brace will no longer be needed.
After your hip replacement, your doctor will let you know how much weight you can safely place on your leg while walking. This is known as your “weight bearing status”. It should be strictly followed, as putting too much weight on the leg can damage your new hip. Your doctor will allow you to increase your weight bearing as the hip heals. The following are some common “Weight bearing” terms:
non-weight bearing- no weight at all on the leg
toe touch or toe down weight bearing- only your toes touch the floor, usually about 10% of your weight through your surgery leg
partial weight bearing- toes and front part of your foot down, about 25-50% of your weight through your surgery leg
weight bearing as tolerated- you’re allowed to put as much weight on your surgery leg as your pain level allows, heel down when walking/standing (heel/toe gait pattern)
full weight bearing- no weight bearing restrictions, heel down when walking/standing (heel/toe gait pattern)
Your surgeon will discuss your hip precautions with you before and after your surgery. Your physical therapist will teach you how to safely get in/out of bed, transfer, walk, sit, climb stairs, and get in/out of your car while maintaining your hip precautions. Following your hip precautions in the hospital and at home is an important part of your rehab and will greatly reduce your risk of hip dislocation.
Some of the above information may vary from patient to patient. Your doctor and physical therapist will instruct you in all total hip replacement precautions.
View illustrations of total hip replacement precautions.