A sudden or persistent feeling that an internal medical device has shifted is a common concern among people with implants. This sensation, whether subtle or an outright feeling of movement, can cause anxiety. While alarming, it does not always indicate a serious complication, but it always warrants medical evaluation. This article provides general information about why this sensation occurs and what steps you should take, but it is not a substitute for consulting directly with your healthcare provider or surgeon.
Implants Prone to Movement Sensation
Certain categories of implants are frequently associated with patient reports of feeling movement. Soft tissue devices, such as breast implants, are a common example, where patients might notice a change in contour or feel the implant shift within its pocket. These devices are held in place primarily by the surrounding tissue capsule, which can sometimes stretch or contract.
Subdermal devices, including contraceptive rods like Nexplanon, are thin, flexible rods inserted just beneath the skin’s surface, typically in the upper arm. Although secured by a fibrous sheath, patients may feel the rod move slightly under the skin, which is often a perceived shift rather than true migration.
Skeletal and joint implants, such as hip or knee replacements, can also create a sensation of movement. This is a more serious concern, as it may indicate loosening or wear of the device components. Similarly, pacemakers, placed in a small pocket beneath the collarbone, can sometimes migrate slightly within that surgical pocket.
Causes of Perceived and Actual Displacement
The feeling of movement stems from two distinct phenomena: actual physical displacement (migration) or a perceived sensation that is not a true shift.
Actual Displacement (Migration)
Actual displacement involves the implant moving from its intended surgical site. For breast implants, this can manifest as the implant dropping too low (“bottoming out”) or shifting too far to the side (lateral displacement).
A primary cause of actual movement, particularly in breast implants, is capsular contracture. This occurs when the scar tissue capsule around the implant tightens and compresses the device, sometimes causing it to rotate or shift.
For joint replacements, actual movement is often a sign of loosening due to wear or a failure of the implant to integrate properly with the bone (osseointegration). Physical trauma, such as a severe fall or blow to the area, can also acutely dislodge a device from its stable position.
Perceived Movement
The sensation of movement can be perceived due to changes in the surrounding soft tissues rather than the implant itself. Swelling and edema near the implant site, especially in the weeks following surgery, can create pressure and a feeling of shift as the tissue settles.
Nerve regeneration or irritation in the surgical area can also cause referred sensations, tingling, or a feeling of internal motion that is misinterpreted as movement. For soft tissue implants, a certain amount of initial “settling” is a normal part of the healing process as the tissue adjusts to the device.
Immediate Patient Steps and Emergency Signs
If you feel your implant has moved, the immediate and most important step is to contact the implanting surgeon or primary care provider without delay. You should document the event by noting the exact time and date the sensation occurred, describing the movement or change in appearance, and taking photographs if the shift is visible. It is important to resist the urge to manipulate, push, or manually reposition the implant, as this can worsen displacement or cause further tissue damage.
While awaiting medical guidance, you should be acutely aware of emergency warning signs that require immediate, urgent care:
- Sudden, severe, and unrelenting pain that is not relieved by over-the-counter medication.
- Visible signs of acute infection, such as fever, spreading redness, warmth, or the presence of pus or discharge near the implant site.
- For joint implants, a sudden loss of function, an inability to bear weight, or a noticeable shortening of the limb.
- A visible rupture of the skin or the implant becoming externally palpable or exposed.
Medical Correction Procedures
Once a patient reports a sensation of movement, the medical professional will first use diagnostic imaging to confirm the location and extent of any displacement. X-rays, ultrasound, or magnetic resonance imaging (MRI) are commonly used tools to visualize the implant’s position relative to the surrounding anatomy. This imaging is essential to differentiate between a perceived feeling and actual device migration.
For confirmed displacement, the corrective procedure depends heavily on the type of implant and the underlying cause. Non-surgical management may include a period of monitoring, bracing to stabilize the area, or medication to treat infection, such as peri-implantitis around dental implants, or reduce inflammation.
If the displacement is significant or the cause is structural, surgical revision is often necessary. Surgical correction can involve repositioning the implant and securing it with internal sutures, a technique known as capsulorrhaphy, to tighten the implant pocket. In cases of severe capsular contracture or chronic infection, the procedure may require complete removal of the existing implant and its scar tissue capsule, followed by replacement. For joint replacements, a loose component may necessitate a revision surgery to re-secure or replace the failing parts, addressing the wear or lack of osseointegration that caused the mobility.