The effect of patch testing on surgical practices and outcomes in orthopedic patients with metal implants.

OBJECTIVE: To determine the effect of patch testing on surgical decision making and outcomes in patients evaluated for suspected metal hypersensitivity related to implants in bones or joints.

DESIGN: Medical chart review.

SETTING: Tertiary care academic medical center.

PARTICIPANTS: All patients who had patch testing for allergic contact dermatitis related to orthopedic implants.

INTERVENTION: Patch testing.

MAIN OUTCOME MEASURES: The surgeon's preoperative choice of metal implant alloy compared with patch testing results and the presence of hypersensitivity complications related to the metal implant on postsurgical follow-up.

RESULTS: Patients with potential metal hypersensitivity from implanted devices (N = 72) were divided into 2 groups depending on timing of their patch testing: preimplantation (n = 31) and postimplantation (n = 41). History of hypersensitivity to metals was a predictor of positive patch test results to metals in both groups. Positive patch test results indicating metal hypersensitivity influenced the decision-making process of the referring surgeon in all preimplantation cases (n = 21). Patients with metal hypersensitivity who received an allergen-free implant had surgical outcomes free of hypersensitivity complications (n = 21). In patients who had positive patch test results to a metal in their implant after implantation, removal of the device led to resolution of associated symptoms (6 of 10 patients).

CONCLUSIONS: The findings of this study support a role for patch testing in patients with a clinical history of metal hypersensitivity before prosthetic device implantation. The decision on whether to remove an implanted device after positive patch test results should be made on a case-by-case basis, as decided by the surgeon and patient.