Ask the Doctors November 2013 Issue

Ask The Doctors: November 2013

Q: I recently had a total knee replacement. Is it true that I may need antibiotics before having any dental work because of my new knee joint?

A: It has long been the standard of care to give patients with joint replacements antibiotics before undergoing dental procedures to prevent possible infection. However, this changed recently when the American Academy of Orthopaedic Surgeons (AAOS) and the American Dental Association (ADA) issued a joint clinical practice guideline (CPG) that finds insufficient evidence to recommend such routine antibiotic use. The evidence-based CPG, “The Prevention of Orthopaedic Implant Infections in Patients Undergoing Dental Procedures” (January 2013), finds invasive dental procedures, with or without antibiotics, did not increase the risk of infection in a prosthetic joint. The guideline also notes “no direct evidence” exists that oral or topical antibiotics are linked to any protection against infection in a replaced joint. As a result, the CPG recommends oral care professionals reconsider routine use of antibiotics before dental procedures for joint replacement patients.

There are several good reasons to avoid what may be unnecessary antibiotic use, including an increase in bacterial resistance and avoiding side effects associated with taking the drugs. Yet, some joint replacement patients—those with inflammatory joint diseases such as rheumatoid arthritis and lupus, those on immunosuppressive drugs such as corticosteroids and disease-modifying anti-rheumatic drugs (DMARDs), and those who’ve had more than one joint replacement—should be evaluated for their need of antibiotics prior to undergoing a dental procedure, according to the AAOS. If you’ve had a joint replacement, it is always best to discuss the risk of infection with your surgeon prior to any dental work.

Q: I am 81 years old and still quite active, but I have considerable pain in my left knee due to osteoarthritis (OA). I’ve read that viscosupplementation or platelet rich plasma (PRP) injections in my knee joint may help. What are these injections, and do they relieve joint pain?

A: Viscosupplementation is a process in which a thick fluid called hyaluronate is injected into the knee joint. Hyaluronate, or hyaluronic acid, is a naturally occurring substance present in the synovial fluid of your joints. Viscosupplementation is thought to offer relief to the affected knee by improving the lubricating properties of the synovial fluid, reducing the pain from OA of the knee, improving mobility, and providing a higher and more comfortable level of activity. The Food and Drug Administration (FDA) approved viscosupplementation in 1997 to treat mild to moderate OA of the knee. The injections are usually used after other treatment options have been tried to relieve pain, with three to five injections, each one week apart, required. The greatest pain relief is typically experienced eight to 12 weeks after beginning treatment. The viscosupplement injection hylan G-F 20 (Synvisc-One®) is the only viscosupplement approved as a one-dose injection. Studies show this viscosupplement can provide up to six months of OA relief after just one injection.

Platelet-rich plasma (PRP) injections are developed from a patient’s own blood. Some studies have shown that the increased concentrations of growth factors in PRP can potentially speed up the healing process with chronic tendon, acute ligament and muscle injuries. At the current time, FDA approval of PRP is pending and these injections are considered “off label use.” As a result, Medicare (and private carriers) do not reimburse or pay for PRP injections.