What Causes Metal Implants to Break Inside the Body

Many people know that metal is strong. So when orthopedic surgeons implant metal to fix broken bones, replace worn-out joints, or correct deformities in the skeletal system, it's understandable why people feel confident about a problem-free prognosis.

Despite metal's resilience, the fact is that metal can break, and something may need to be done about it.

This article explains why metal implants break and whether surgery is required to fix them.

An implant that is intact
praisaeng / Getty Images

Why Does Metal Break?

The strength of a metal implant depends on a number of factors, including the type of metal, how the metal was fabricated, and the size of the implant. Common metal types used in surgical procedures include stainless steel and titanium.

By way of comparison, consider a paper clip. It can often sustain a strong force. It may bend, but it usually won't break. However, if the paper clip is bent back and forth several times, it might snap in two. Metal implants can respond in a similar way to repeated cycles of stress.

Fatigue Causes Breaks

Metal implants typically break as a result of fatigue. And fatigue occurs over time. This means that the metal usually breaks not from one sudden load but from repetitive cycles of stress.

Causes of Broken Hardware

Metal implants are typically made to support the skeletal system until the body can support normal stress without the aid of the implant. So if a bone is broken, a metal implant may be used to support the healing skeleton until the bone has healed. Several factors could interfere with this process:

  • Unhealed fractures (nonunions): There are many reasons why a broken bone may not heal or heal slowly. If a broken bone supported by metal does not heal, the support provided by the metal may eventually be insufficient.
  • Loose implants: Implants that are loose are subjected to greater stress than solidly fixed implants. This can occur with loose hardware from a fracture repair or a loose joint replacement implant.
  • Insufficient strength of repair: The stress of a broken bone requires a minimum amount of support when repaired. A "loose" repair may lead the metal supporting the bone to fail.
  • Expected broken hardware: There are a few scenarios in which broken metal may be expected. For example, sometimes ligament injuries are repaired with metal. Because normal ligaments move, even very subtly, the metal used to hold the ligament in position may eventually break.

Find Your Implant Metal

Even if you learned about metals in science class, that probably was a long time ago. The 10 toughest metals are: carbon steel, steel-iron nickel alloy, stainless steel, tungsten, tungsten carbide, titanium, titanium aluminide, inconel, chromium, and iron.

Trouble Signs

Hip and knee surgeries often involve the use of metal. Five common post-surgery problems tend to trigger certain symptoms:

  • Fracture, which usually occurs after a fall or other trauma
  • Frequent or recurring dislocations, which can cause pain and make movement difficult
  • Infection, which can incite pain, redness, and swelling; a serious infection might set off diarrhea, fatigue, fever, muscle aches, or nausea or vomiting
  • Loosening or instability, which can instigate pain and swelling, a popping or clicking sound, or the feeling that the body part is "giving out" when you place weight on it
  • Metal allergy, which can spark common allergy symptoms like itching, pain, rash, skin discoloration, stiffness, and swelling

Is Surgery Required?

Often, broken metal implants require additional surgery, but not always. If the problem is still not addressed, such as a broken bone that has not healed, then the metal may need to be removed and a new repair performed. However, if the broken metal is not causing a problem, then it can often stay in the body.

There are some rare circumstances in which loose or broken metal moves within the body. This can be concerning when the metal is located around the chest or abdomen and usually less worrisome when the metal is located in the extremities. Keep your healthcare provider up-to-date so they can monitor the situation and respond appropriately.

Summary

Orthopedic surgeons implant metal to fix broken bones, replace worn-out joints, or correct deformities in the skeletal system. Although metal implants are designed to last a long time—sometimes several decades—they often don't last forever. In fact, there are several reasons why the implants fail, such as if the repair was problematic to begin with or if the patient places too much stress on the area while it's still healing.

A Word From Verywell

Broken implant hardware almost always is a sign of a problem—either with the hardware or the bone supporting it. If you suspect something is wrong, don't hesitate to contact your healthcare provider for an evaluation.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading
Cluett

By Jonathan Cluett, MD
Dr. Cluett is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the U.S. national soccer teams.