When the evidence is lacking we often rely on the consensus of experts when it comes to patient care. Such is the case in the realm of metal hypersensitivity resulting in orthopedic implant complications. This month a letter was published in Current Orthopaedic Practice that highlights a recent consensus paper published in the journal, Dermatitis.
ACDS guidelines for implant-associated metal hypersensitivity reactions Vassantachart, Janna M. MD; Brod, Bruce A. MD; Schalock, Peter C. MD; Crawford, Glen H. MD; Jacob, Sharon E. MD Current Orthopaedic Practice: May/June 2017 - Volume 28 - Issue 3 - p 334–335
The paper outlines the key points of the consensus article published In Dermatitis.
Patch Testing for Evaluation of Hypersensitivity to Implanted Metal Devices: A Perspective From the American Contact Dermatitis Society Schalock, Peter C. MD; Crawford, Glen MD; Nedorost, Susan MD; Scheinman, Pamela L. MD; Atwater, Amber Reck MD; Mowad, Christen MD; Brod, Bruce MD; Ehrlich, Alison MD; Watsky, Kalman L. MD; Sasseville, Denis MD; Silvestri, Dianne MD; Worobec, Sophie M. MD; Elliott, John F. MD; Honari, Golara MD; Powell, Douglas L. MD; Taylor, James MD; DeKoven, Joel M De Koven. Dermatitis . 27(5):241-247, September/October 2016.
Key take home points from the consensus paper are listed below.
* We do not recommend routine preoperative patch testing in individuals who deny a history of adverse cutaneous reactions to metals and who deny a history of previous implant-related adverse events.
* Patients with a clear self-reported history of metal reactions should be evaluated by patch testing before device implant.
* Testing with manufacturer-provided metal discs has limited utility. We recommend use of standardized, commercially available test materials when possible.
* Positive patch test or LTT does not consistently predict in vivo metal-induced complications from metallic device implantation.
* Negative testing is only indicative of the current state of allergy.
* If preoperative patch testing is not performed in a patient with self-reported metal sensitivity, use of titanium or oxidized zirconium containing devices may be preferable.
* Documented informed consent is essential in situations when an allergen cannot be avoided.
* If testing before implant is not possible or refused, titanium- or oxinium-containing devices are preferable.
* Patients who are symptom free after implantation do not require patch testing.
* Patch testing is only 1 element in the assessment of causation. The decision as to whether or not to remove an implanted device must include an assessment of all clinical factors and a thorough risk-benefit analysis by the treating physician(s) and patient.
* Metal exposure from the implanted device can cause sensitization, but a positive metal test does not prove causality of symptoms. The prevalence of nickel sensitization in the population without implant is high (15%–20%). Other causes of implant failure treatable without device removal, such as infection, should be carefully considered.
* Fixed devices with poor healing or eruptions above or adjacent to the incision site are more indicative of potential MHR likely caused by allergy.
* Dynamic joint systems are complex. Replacement of hardware with a nonallergenic alternative may be helpful, but each case must be individually considered. There is not enough evidence at this time to make overreaching recommendation.
* Mucosal and cardiovascular devices present further challenges. The local environment may produce reactions locally, regionally, or systemically.
* Patch testing does not definitively predict reactions to the metal-containing device. Caution and careful assessment of risks of placement and potential hypersensitivity reaction should be weighed with the potential benefits of placement.
At the end of the day we want to make the best decision for our patients based on our clinical acumen and our findings on physical exam and laboratory testing including patch testing. It is important not to try to fit a square peg into a round hole when it comes to the management of positive patch test reactions to nickel. On the other hand, relevant reactions can make a real impact on patient care. Not long ago I saw a patient who reacted to Vanadium screws and manifested with a severe local reaction and a systemic reaction. After years of suffering the patient improved based on her positive patch test triggering a removal of the device and Vanadium screws. This was published along with another case in Dermatitis.
Hypersensitivity Reactions to Metallic Implants Containing Vanadium Asemota, Eseosa MD, MPH; Scheman, Andrew J. MD; Brod, Bruce A. MD Dermatitis: November/December 2016 - Volume 27 - Issue 6 - p 387–388
I welcome your thoughts and look forward to the start of a robust discussion on this topic.