Should metal plates and screws used in orthopedic surgery be removed in children once the bone is healed? Is there any evidence for or against this practice? In this article, pediatric orthopedic surgeons gather up all the data possible to answer the question. By combining the results of smaller studies, it’s possible to gain better insight into the dilemma.
Medical decisions are driven by evidence from research. Evidence-based treatment is the current trend. Studies are rated on the basis of their evidence from one to five. Level I is a high-quality study with conclusive evidence. Level II tell us the evidence is strong but the quality of the study is not top knotch.
Both Level I and Level II studies are randomized controlled trials (RCTs). RCTs involve placing patients in different groups in no particular order and without a specific reason to be in one group or another. The RCT approach ensures that both known and unknown factors that could affect the results are evenly distributed among all the treatment groups.
Level III gives us moderate evidence from well-designed trials but the studies are not randomized. In other words, patients aren’t randomly placed in different groups. There’s usually just one group with measurements taken before and after treatment.
Level IV studies provide limited evidence from well-designed studies. Usually there’s more than one center or research group involved. Often these are case series or case-controlled studies. Everyone is intentionally placed in the group they are in, so it is considered nonrandomized.
And Level V gives intermediate evidence based on comparative studies without control subjects. Level V evidence may also come from the opinions of well-respected authorities. The opinions are the result of clinical experience or reports of expert committees.
After reviewing all the data available in the English medical database, the authors of this review report a lack of sufficient evidence to make a blanket statement to guide surgeons. Basically, there was no evidence one way or the other to support keeping or removing the implants.
They did find that there’s about a 10 per cent complication rate associated with surgery to remove implants. Problems reported included infection, fracture, and delayed wound healing. In some cases, failure to remove all of the implant was counted as a complication. Many of the cases where complications occurred were in children with slipped capital femoral epiphysis (SCFE).
In this condition, the growth center of the hip (the capital femoral epiphysis) actually slips backwards on the top of the femur (the thighbone). Surgery is usually necessary to stop the epiphysis from slipping further. A large screw is placed into the epiphysis to hold it in place. Removing the screw takes twice as long as putting it in. There is a risk of breaking or stripping the screw during the attempted removal. Titanium screws seem to have the worst results.
Most of the time, implants are left in and removal is not an issue. But what’s the evidence that problems can occur because of implant retention? The authors report there were no studies reporting the long-term results of implants left in children.
The fear that an allergic response to the implant, infections, or malignancy caused by the implant weren’t confirmed. The incidence of these complications is very, very low. And there was no real proof that the implant actually caused these problems. Fractures around the retained plate are much less likely than fractures from removing the plate. There were no reported cases of bone fracture in children from implant removal.
There’s one final thing to consider about leaving implants in children. What happens if, as an adult, that child eventually needs a joint replacement? How will having an implant left in since childhood affect the replacement surgery?
There is a general concern that the bone will grow around the implant making further surgery difficult. But there’s no real data to support or deny this theory. A few case studies have reported that bone remodeling around the implant placed the device inside the bone shaft. Such a situation could complicate bone removal and joint replacement.
The authors conclude that until further evidence is available, the decision to keep or remove hardware in children must be done on a case-by-case basis. If the child is having pain or other symptoms from the implant, then the benefits of removing it may outweigh the possible risks.
More studies are needed to understand the long-term effects of orthopedic implants. Even studies that just observe what happens over time would be helpful. The authors also point out the need for a study on joint replacements in patients with implants already in place.