Adverse tissue reactions in modular exchangeable neck implants: a report of two cases.

Dual-modular femoral stems with exchangeable necks theoretically allow optimization of hip joint biomechanics via selective restoration of femoral anteversion, offset, and limb length. A potential disadvantage is the possible generation of metal ions and debris by fretting and crevice corrosion at the additional stem-neck interface. We present 2 cases of early-onset adverse inflammatory tissue reactions as a result of accelerated corrosion at the stem-neck interface of a dual-modular implant, requiring subsequent revision of well-fixed components.