Bunions, which are painful and often progressive deformities of the big toe joint, frequently require surgical correction known as a bunionectomy. This procedure involves cutting and repositioning the misaligned bones of the foot, an action called an osteotomy. To ensure the newly aligned bone segments remain stable and heal correctly, surgeons use internal fixation—typically small screws or plates—to hold the bones firmly in place during the recovery period. This hardware serves as a temporary internal scaffolding until the body’s natural healing process creates a solid, permanent bony union.
Understanding Internal Fixation and Potential Loosening
The primary purpose of the surgical hardware is to provide rigid stabilization across the osteotomy site to promote bone fusion. Modern internal fixation, often made of titanium, is designed to be highly stable, with the bone growing around the screw threads to secure it further. While the vast majority of screws remain securely fixed, the possibility of migration or loosening exists, although it is not a common event.
Screw loosening is usually a complication resulting from mechanical stress or biological factors, not a spontaneous failure of the hardware itself. The most frequent mechanical reason for hardware movement is premature or excessive weight bearing on the foot against the surgeon’s post-operative instructions. Applying too much force to the unhealed bone segments can cause the hardware to fail or the bone around the screw to break down, leading to instability.
A second major cause is a biological failure, specifically the non-union of the bone segments. If the osteotomy site does not heal with solid bone, the mechanical stress of walking continues to be placed solely on the hardware. This stress can eventually cause the screws to loosen or even break. Less commonly, an infection at the surgical site can compromise the bone quality and stability required to maintain the hardware’s grip.
Recognizing Signs of Hardware Complications
It is important for patients to monitor their recovery closely as the first signs of a complication often appear as changes in pain or sensation. While some post-operative pain and swelling are expected, persistent or increasing pain long after the initial surgical discomfort should be considered a warning sign. This pain is often localized near the hardware and does not improve with rest or elevation.
New or worsening localized swelling, especially if accompanied by increased warmth or redness, may suggest either an infection or significant inflammation around the hardware. Patients might also report a new, palpable bump or protrusion near the incision site, which can indicate that a screw head is working its way closer to the skin surface.
A less common but specific symptom is a mechanical sensation, such as a “clicking,” “catching,” or grinding feeling within the foot during movement. This sensation could signal that the hardware has become loose and is shifting. Any drainage from the surgical incision, particularly pus, combined with heat or fever, requires immediate consultation due to the risk of infection.
Timeline for Bone Fusion and Recovery
The hardware is most important during the initial period when the body is working to bridge the gap created by the osteotomy. Bone fusion typically begins shortly after surgery, but it requires time to become structurally sound. For most bunionectomy procedures, a solid bony union is achieved between six and twelve weeks after surgery.
During this time frame, the screws and plates bear the mechanical load, making strict adherence to weight-bearing restrictions mandatory. Once the surgeon confirms via X-ray that the bone has fully healed, the foot becomes stable, and the hardware is no longer structurally necessary.
In most cases, the hardware is biocompatible and is left in place permanently without causing any issues. However, removal may be necessary if the hardware causes localized irritation. Reasons for removal include the hardware being prominent beneath the skin, causing pain when wearing shoes, or leading to persistent cold sensitivity. If hardware removal is required, the procedure is usually performed six months to a year after the original surgery, well after a solid bone fusion has been confirmed.