It’s necessary to remove the plate as soon as healing is done; this specifically applies to patients with normal bones. Once the bone is completely healed, the plate has no further function.
Another reason for removal of the plate is the possibility of corrosion, either directly or due to fretting between the plate and the underside of screw heads; such an effect is more likely when the orthopaedic implants are made of stainless steel.
It’s hard to tell if a fracture has healed when held under rigid compression. A bone plate should be removed after an arbitrary period that is based on clinical judgment as well as experience. In the upper limb, a metallic implant may be left in place. Removal should be considered in the existence of inflammatory reactions or if the ortho implants bother the patient mechanically. Plate removal from the proximal radius or humerus can jeopardize the radial nerve and should only be undertaken if significant complications or clinical symptoms are present.
In the lower limb a bone plate must be removed; however, isolated screws can be left permanently.
Bone re-fracture following a plate removal is a recognized possibility unless steps are taken to restrict weight bearing for a reasonable time. Plate-intended osteopenia may predispose the bone to re-fracture after removal of the plate as remodeling of the cortices during healing results in a bone of lower strength. Other discontinuities are also present due to screw removal. Discontinuities structures under load increase concentrations of stress. The existence of drill holes weakens the bone; the weakening effect of the holes is much more than would be expected. The resistance to torsional loading is lessened by 50%. The bone capacity to absorb energy to prevent fracture is decreased to 25% of normal. The resistance to bending loads is likewise reduced. Once the holes of the screw are filled by radiolucent bone, they stop to be a weak spot.
In experimental animals, the screw holes fill up in around 8 weeks.
Following removal of a plate, the bone should be protected from extreme stress until the post-healing cortical osteopenia slowly disappears as the bone takes the full load of the limb and remodeling of the bone happens to normal dimensions. The screw holes fill up as well as the concentration effect is eliminated.
There is more need for patient’s protection at the time of plate removal than after plating as the re-fracture strength of the bone is less than the strength of primary plated bone, and the injury is no longer acute and thus the functional level must be tempered by planned treatment, rather than the symptoms of patients. It takes much time before the bone recovers from the weakening effects of plate removal. The factors which affect recovery are:
- The age of the patient
- The nature of the associated injuries
- The location of the bone
Since muscle actions related to physiotherapy or functional activities load the bones improving blood supply, the recovery phase can extend from 3-4 months. This recovery may be enough for an unprotected return to everyday activities.
Plate removal of a double-plated fracture should be acted over time to lessen the risk of re-fracture. The removal should be done at 2 operations, four to six months apart, with cancellous bone grafting suggested at each operation.