- Patient's physical conditions that would impair adequate implant support and/or prevent the use of an appropriately sized implant, e.g., previous surgery, insufficient quality or quantity of bone, neuromuscular compromise or vascular deficiency in the affected limb in sufficient degree to endanger the success of the intervention e.g., absence of musculoligamentous supporting structures, joint neuropathy or other conditions that may lead to inadequate skeletal fixation