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Is it Time for a Knee or Hip Replacement?


There’s something comforting in a medical test that yields a clear recommendation. A positive strep test? Prescribe antibiotics. See a fracture on an X-ray? Time for a cast or surgery. But there’s no simple test to determine when a joint replacement is the best next step to alleviate a patient’s hip or knee pain. That’s because a patient’s subjective tolerance for pain is often the crucial factor in the decision.

Making that determination  “is probably more art than science,” says Michael Baratz, MD, an orthopaedic surgeon in the Total Joint Replacement Program at Tufts Medical Center.

There appears to be some genetic influence on how joints wear, but for the most part, knees and hips find themselves in need of replacement due to simple wear and tear. Eric Smith, MD, Director of Tufts Medical Center’s Total Joint Replacement Program, says that physical activity over many years causes a joint’s cartilage to wear down, like tires on a car. Once you’ve worn through the cartilage, you get to the bone. “And that’s when things can get extraordinarily painful,” Smith says. It can also set off a chain reaction, with the body producing a fluid that causes inflammation and swelling, which reduces motion and sets off even more pain.

That doesn’t all happen overnight, of course. The cartilage slowly wears and the pain begins to build. Many patients eventually reach a point where the pain becomes intolerable. “Typically, the decision to have surgery happens when people say the pain is interfering with their ability to enjoy their life the way they did before,” Dr. Smith says, “such as spending time with children or grandchildren, walking the dog, going shopping, or navigating staircases.”

Dr. Baratz says that primary care physicians can start to address joint pain by prescribing physical therapy and oral pain medication. If those remedies  don’t help, or if they stop working, it  may be time to refer the patient to an orthopaedist.

Community-based orthopaedists provide excellent care for otherwise healthy patients considering a joint replacement. Tufts Medical Center’s Total Joint Replacement Program specializes in caring for patients with complex conditions, such as diabetes, obesity, and cardiovascular issues. Drs. Smith and Baratz have advanced training in caring for patients with significant medical conditions, and Tufts MC’s capabilities as an academic medical center—for example, the availability of a surgical ICU—can be important for patients with a high risk of complications.

Additionally, Dr. Baratz says, “We often take on patients who have had complications elsewhere. This would include fractures, dislocations and infections.” Revision joint replacement surgery often involves complex reconstructions and very involved post-operative care, both of which Tufts Medical Center is adept at handling. Performing revisions requires additional training and can be time-consuming and physically challenging. Drs. Smith and Baratz both have vast experience with these procedures and pride themselves in taking on the toughest cases.

For patients thinking about a joint replacement, there are two other impor- tant considerations to factor into the decision. Dr. Smith says that even though the median age for a joint replacement is 65, patient ages can range from their 20s to 85. Those on the younger side have to weigh the possibility that they might one day need a replacement for their replacement. That’s because, depending on  their age and their level of activity,  there’s a chance they could wear  through their artificial joint as well.

And Dr. Baratz says patients should also keep in mind that recovering from joint-replacement surgery includes a period of pretty intense pain, as well as weeks of physical therapy. “For the most part, what we do as orthopaedic surgeons is make people’s lives better. And you have to decide whether this  makes your life better at this moment.  You pick a time in your life when it’s right for you, and we’ll make it work.”

If my knee is fine, why does it  hurt so much?

Michael Baratz, MD explains why joint problems aren’t always what they seem.

Believe it or not, there are times when someone will come in and say that their hip or knee hurts, and it’s actually their back that’s the problem. They could have a pinched nerve in their back and it’s radiating pain elsewhere. Similarly, a patient’s knee pain can sometimes really be a problem with their hip. There are times when it can be hard to convince a person where their actual problem is. I have had people come in with knee pain, and  I’ve explained that the knee is fine, that I have X-rays showing a worn-out hip. But when I move their hip, it hurts in their knee. It can be challenging  to convince them that a hip injection or a hip replacement is going to solve their knee pain.

The reason for all of this is that pain flows downhill so to speak. People with back problems can experience pain anywhere from their back all the way down to their toes. People with hip problems can have pain in their hip or their knees. This radiating pain is usually related to a nerve. Diagnostically, it can be a challenge. If necessary, we can do a ‘diagnostic injection’ of pain medicine to see if it cures the problem. We can do that right here in the office. It’s simple, it’s cheap, it’s minimally invasive, and the results can be powerful.

Not ready for a total hip or knee replacement?

Eric Smith, MD offers some tips for managing your joint pain.

Modify your activities. Identify what’s causing you pain and either look for alternatives to those activities or do them less often. For instance, if jogging every day causes your knee to swell, try walking or jogging less frequently.

  • Use a nonsteroidal anti- inflammatory pain reliever such as Aleve, Motrin, or  Advil (talk to your primary care physician because these can cause upset  stomach). Another option is 500 mg of Tylenol Arthritis.
  • Get a cortisone  injection in the joint.  “I don’t want to overstate it that it’s some kind of magic pill, but an injection of pain medication can help.”
  • Try an assistive device such as a cane. “Whether it’s  cultural or age-related, patients often say they don’t want to use a cane, but it does reduce the strain on the hip or knee.” The cane should be held in the opposite hand for a hip and the same hand for a knee.
  • Consider a “joint salvage procedure,” otherwise known as a “scope”. Only certain patients are good  candidates, however—those who are younger and who have milder conditions.

Out of Joint

For people suffering from debilitating hip pain, a replacement can mean relief and  a return to an active lifestyle. Even better, some hip-replacement patients  are candidates for a version of the surgery that results in an easier  recovery process: direct anterior hip replacement surgery.

Direct anterior hip replacement surgery differs from the traditional, or posterior,  method in two important ways. The first is that the incision is made in the front  (anterior) of the hip rather than the back (posterior). The second is that the  anterior procedure goes between muscles rather than through them.

“The traditional posterior hip replacement continues to deliver excellent  results for many patients,” says Eric Smith, MD, Director of the Total Joint  Replacement Program at Tufts MC. “But for those who are good candidates,  anterior hip replacement can have them back up on their feet in no time.”

Anterior hip replacement patients are often walking and even working with  Tufts MC physical therapists on the same day the surgery is performed, and many  of them are able to leave the hospital the next day. Posterior hip replacement  patients often spend three days recovering in the hospital.

Patients who are active and in good shape tend to see the most benefits from  the anterior surgery, says Michael Baratz, MD, a Tufts MC orthopaedic surgeon, but  anyone could be a candidate.

Dr. Smith and  Dr. Baratz can  be reached at 617-636-7846.