Friday Q&A: Helping a Student with a Hip Replacement

Hip Joint from Behind

Q: I am a relatively new yoga instructor that teaches Gentle Hatha to (mostly) seniors.  Recently, a gentleman came in with bilat hip replacements from 10 and 12 years previous. He rides his bike and is in pretty good shape for a gent in his 60's. His hips were replaced by a posterior approach. How cautious do I need to be with this man? Do we modify mostly in the early days after the operation? Of course, I've modified the asanas to his ability and told him to not push it to the extreme. So is it fresh post op that we worry mostly about or for decades following? Thanks!

A: This is a great question and I am glad you asked it. In most cases, the hip replacement should outlast an individual’s lifespan. The literature states that total hip replacements typically last from 15-to-20 years after the initial surgery, but in some instances they can last over 30 years. But this is neither a guarantee nor assurance, for the simple reason that life is unpredictable.  Many factors affect the future of a hip replacement, such as accidents, fractures, late infections, and deterioration in overall health. Also, how well you take care of yourself down the road is something the surgeon cannot control. The longevity of a hip replacement thus depends on many factors, including the following:

• Surgeon skill in implanting the components
• Known history or track record of the implants
• How well you take care of yourself and your health
• Understanding and respecting the limitations of a prosthetic lifestyle
• Your activity level and body weight
• Avoiding high impact or extreme sports

Medical literature states that the most common reasons for individuals needing subsequent hip replacement surgery include:

• Loosening of the implant. 
• Dislocation of the implant
• Infection, such as staph infections either around the time of surgery or later through the introduction of the bacteria into the blood stream.

It is believed that the most common reason why hip replacements fail is because the weight-bearing surface wears out and the prosthesis begins to loosen. So, what is hip replacement loosening? When a hip replacement is placed into the body, it is either press-fit into the bone or cemented into position. Either way, it is fit tightly into the bone of the thigh (femur) and pelvis so that the implant cannot move. Hip replacement loosening occurs over time, and can cause problems with the normal function of the hip replacement prosthesis. When implants loosen, the hip replacement can begin to move small amounts. This can be caused by the shaft of the prosthesis becoming loose in the hollow of the thighbone or due to thinning of the bone around the implant.

Loosening of the joint can occur at any time, but it normally occurs 10-15 years after the original surgery was performed. Signs that the joint has become loose include pain and feeling that the joint is unstable and that there is increased loss of hip mobility. Another operation (revision surgery) may be necessary, although this cannot be performed on all patients.

Both physicians and patients are very concerned about the problem of hip replacement loosening because a hip replacement revision surgery (replacement of a joint replacement) is a much more difficult operation and hip replacement revisions are often not as successful as the first operation. After revision operations, patients tend to recover less overall motion of the joint. Also, the longevity of the implant decreases with each revision. Therefore, physicians tend to avoid joint replacement surgery until absolutely necessary, and try to get as much mileage out of each replacement as possible.

In about 1 in 20 cases, the hip joint can come out of its socket. This is most likely to occur in the first few months after surgery when the hip is still healing. But, unfortunately some people’s hips will dislocate very distant to the original hip replacement. My advice here is that a hip doesn’t typically dislocate without warning signs. Pain that increases as an activity is continued is the most prevalent symptom.

So how cautious should you be with your student? The surgical hips will have a certain degree of motion that is limited by their soft tissue, hip capsule, how the prosthesis sits in the acetabulum, and so on. Start by checking your student’s range of motion while he is lying in a supine position. Test all the movements of the hip (hip up toward chest with knee bent, same knee position but bring it out to side for abduction, and turn the hip out in abduction for external rotation by bringing the bent knee up toward the armpit. Then look at his hip mobility while standing: hip flexion, abduction, external rotation and extension. You should also see if he tolerates adduction by having him sit on a chair and cross one leg over the other. If he can't do this, then any pose that has internal rotation must be modified significantly. You should have your student do this for both hips to get a sense of how it feels to his hip and see if there is any pinching or grabbing. Then you can modify the asanas accordingly.

If you ask a surgeon if his patient has any precautions after three months post op, he will generally say no, but he will modify his statement telling the patient to “use your own judgment.” So do we continue with precautions forever? Well, that is an area of disagreement. I err on the side of moderation saying, “If it makes you anxious or causes pain, discomfort, pulling, or pinching, please stop.” A student can have the potential of dislocation forever if they are not mindful on how they move and move repeatedly into discomfort. And remember the combined positions of flexion, abduction and internal rotation are the holy triad. If your student can tolerate the movements separately then you can find his limits and slowly challenge his hips, but both you and he must be aware of how the hip feels. NO PAIN should be elicited from asana and that means soreness after class or the next day. Learning how to ask how a movement feels is tricky because not everyone will say something hurts, so this includes learning which words your student uses to describe sensation changes.

So for your student, keep making sure that he observes his body’s limits and doesn’t push beyond his current activity. And congratulate him for coming to your class and investing in his continued health!

—Shari