Clinical Results of Revision TKA in Patients With Presumed Metal and Cement Allergy

Metal and cement allergy affects a small subset of patients, causing severe pain and often systemic reaction after total knee arthroplasty (TKA). Revision with ceramic-surfaced femoral components has been reported to resolve these symptoms of metal allergy, but no solution currently is available for patients with allergies to metal and bone cement. Five patients (5 knees) with documented metal allergy were revised with custom porous-coated ceramic femoral components (Magnesia-stabilized Zirconia) from January 2007 to January 2013. An additional 23 patients (23 knees) met inclusion criteria from 2007 to 2015, but because the ceramic implant was unavailable, they underwent different treatment based on their underlying allergy to metal, cement, or both. Inclusion criteria included the history of clinically documented severe metal allergy, severe pain, swelling, and effusion >1 year after TKA, negative workup for infection, loosening, and ligament imbalance. Knee Society scores were compared for each cohort. Mean Knee Society scores for all 5 patients revised with custom cementless ceramic femoral components improved significantly for objective score (preoperative, 39 ± 5; most recent visit, 90 ± 2) and function score (preoperative, 33 ± 8; most recent visit 93 ± 4) (P < .0001). The 12 knees revised with off-the-shelf cemented ceramic-coated femoral components had similar results. The 7 unrevised knees (including 4 knees with allergy to metal and bone cement) and the 4 knees revised with standard CoCr femoral components did not improve and worsened over time. Symptoms resolved in the 5 patients revised with custom ceramic implants and in the 12 patients revised with ceramic-coated components, but did not improve in the patients unrevised or revised with CoCr femoral components. Symptoms presumed to be associated with metal or cement allergy improve with the use of ceramic femoral surfaces, but patients who are allergic both to metals and bone cement would be candidates only for porous-coated ceramic implants fixed without bone cement.