In one embodiment, an impact absorber attaches a reference array of a computer-assisted surgery system to a medical implant. The impact absorber has a coupler that couples the reference array to the implant such that the reference array is rotatable relative to the implant from an undeflected orientation to a deflected orientation when an external impacting force is applied to the reference array, and from the deflected orientation to the undeflected orientation when the external force is removed. The impact absorber has an alignment feature that 1) engages with a corresponding alignment feature so as to align the reference array with the undeflected orientation and 2) disengages from the corresponding alignment feature when the reference array is rotated from the undeflected orientation to the deflected orientation. Allowing the reference array to be returned to the undeflected orientation after it is impacted can avoid a need to recalibrate the system.