Implant Failure


Bone mass deficiency may also contribute to implant failure, because stabilization of a fracture with plates and screws depends on the secure fixation of screws in the bone fragments. In bone weakened by osteoporosis or other metabolic bone diseases, the screws may pull out, resulting in loss of fracture fixation and loss of reduction. In these patients, when loads are applied to the fractured limb, screw fixation may not be secure if inappropriate implants are used. Advancements in fracture fixation methods, such as the use of locking plates, have improved our ability to fix osteoporotic or weakened bone; however, these newer methods still rely on the body’s ability to eventually heal the fracture.


The risk of implant failure can be minimized by protecting the bone from excessive and repetitive stresses until full fracture healing has occurred. If the fixation is not secure, all loads must be avoided until radiographs clearly show evidence of fracture healing. Some devices, such as a dynamic compression screw, used in the treatment of certain intertrochanteric femur fractures, take advantage of the compression achieved across a fracture site when a patient bears weight on their injured limb. No matter what type of fracture or surgical treatment is performed, mobilization of patients as early as possible is of the utmost importance. If a patient remains immobilized in bed, the rate of multiple medical comorbidities such as respiratory insufficiency, pneumonia, deep venous thrombosis, pulmonary embolism, ileus, and overall deconditioning quickly elevates. Patients can usually begin protected weight bearing with crutches or a walker when fracture healing has been demonstrated. When delayed healing increases the risk of fatigue failure in a metal fixation device, the stresses of weight bearing should be minimized by external support of the fracture through the use of crutches, casts, or braces until adequate healing is documented on radiographs.


If the implant fails, it is usually removed and replaced with another fixation device. Bone autografts are usually incorporated in the revision surgery to expedite the healing process and minimize the risk of repeat implant failure.


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Jul 3, 2016 | Posted by in MUSCULOSKELETAL MEDICINE | Comments Off on Implant Failure
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