SafetyFix Medical Technologies, Inc.
8637 Delmar Blvd
St. Louis, MO 63124
This report highlights a case of synovial metallosis that developed during the use of several different implant devices to help heal a femoral fracture. The report also discusses how metal debris affects the surrounding tissue in the Discussion section. Several good histological images are also provided that show the alloy debris present in the tissue.
This report discusses a case where a patient developed a calf abscess with the underlying tissue exhibiting muscle staining and metallic wear debris. A good image of the abscess is provided that show the metallic muscle staining in the calf. Histological images showing foreign body-type multi-nucleated giant cells engulfing metallic particles are also provided. The report also concludes that more research is needed on metallosis and that because of the "potentially severe effects and complications," follow-up with patients is important. Overall a good article with a lot of information.
This study compared individuals with and without visible wear to their prosthesis to "determine the extent and effects of dissemination of wear debris." Provides good images of different tissues where wear debris" was able to reach through circulation as well as tables depicting the amount of certain types of debris found in different tissues.
This article reads as an encyclopedia entry and gives good background information on the causes and symptoms of metallosis.
This study looked at concentrations of metal ions in the blood and tissue surrounding an implant intended to assist pediatric scoliosis patients as their spines grow. The results of the study found that all patients had higher levels of metal in the surroundings tissues and 5 of the 25 patients developed metallosis symptoms. A good color image showing the black metallic discoloration around the implant as well as several histological images are included. The study concludes by recommending implants be coated with wear-resistant material or using different materials.
This case report highlights the development of metallosis discovered when investigating a failed implant. The case points out that while no discoloration appeared in surrounding tissue (common in other cases of metallosis), metallic fragments were still discovered.
This report studied the histology associated with metallosis. Their data supported "the concept that metallosis is the result of a local inflammatory response. The proinflammatory environment promotes bone resorption. Loss of bone results in implant loosening, which then causes the major symptoms of metallosis, pain and reduced range of motion." This seemed to be a very thorough histological study of the condition and came to good conclusions.
This study looked at the effects metallic implants may have on male fertility. The findings tell that metal toxicity is highly effective on the male reproductive system and that intramedullary nails increase metal levels enough to cause noticeable decreases in fertility.
A brief case report about a woman with nodules on her lower leg believed to be caused by metallosis due to 2 broken titanium screws in her hip.
This study looked at hip arthroplasty patients to determine what kinds of reactions were occur to metal debris around the failed implants. To briefly summarize, the study concludes that a range of different reactions can occur including necrosis and associated chronic lymphatic immune response.
This online source provides a list of possible symptoms associated with metallosis. It is not very scientific and does not provide any sources but gives a general overview of things that could happen.
This report discusses a case where a patient developed skin ulcers believed to be caused by their implants.
This survey of patients who underwent hardware removal was seeking to uncover information regarding the necessity of hardware removal and the positive/negative effects associated with the procedures. A lot of the literature out there claims that hardware removal can often be without noticeable positive effects and surgical procedures required for removal can lead to further complications. The information obtained from this survey contradicts those ideas and cites results that indicate that patients report improvement in quality of life post hardware removal and even when complications did occur, a majority of patients would want to have the removal again.
This study looked at the human immune responses to several different metal types that are common in implants. The results showed that the in vitro metal degradation elicited a significant immune response.
This study looked to see whether removing internal hardware is a procedure that should become common practice or whether it should be avoided. The study looked at several different aspects including the potential negative side effects of removal vs. non-removal. The conclusion they arrived at was to seek removal of implants for patients exhibiting symptoms related to their implants and to discuss with removal with asymptomatic patients before removal surgery due to possible complications. (My opinion: If complications of removal were shown to be minimal, then it seems this study would support removal due to the list of possible side effects of retaining metal in the body)
This study looked at whether the removal of hardware aided in reducing pain in patients. With no surgical complications, all patients in the study were satisfied with the results of the implant removal and would opt to have the surgery again.
This is one of those articles that cites lack of information as reason to consider the risk of hypersensitivity in implant patients minimal. The article gives good information on the mechanism of metal hypersensitivity and how testing is undergone. There is also a section that looks at case studies of implant-related metal sensitivity. The overview section is very interested and tells that "cases involving implant-related metal sensitivity have been underreported because of the difficulty of diagnosis." Despite this conclusion, the article still concludes that not enough information is available and thus the risk is minimal.
This report looks at a patient who developed an increased lymphatic response in the presence of titanium, a metal that patients are rarely allergic too. The findings provide an example of how even metals believed to be biologically inert can sometimes still have effects when left in the body.
This is a case report of patient who underwent a bunionectomy fixated with stainless steel screws. She eventually developed a significant rash contributed to a nickel allergy from the implant metal.
This study examined metal hypersensitivity in total knee arthroplasty patients. This is a very thorough study with a lot of good information. Evidence from the study indicates that there is most likely a correlation between the development of metal hypersensitivities due to implants and the failure of certain implants. The longer the metal stays in, the more likely hypersensitivity is to develop which can lead to implant loosening and failure.
This is a brief article that cites a need for more research in the area of hypersensitivity as it relates to metal implants. It provides recommendations for researchers as well as for surgeons when choosing what implants/implant materials to use in certain patients.
This chapter is pulled from the book listed below, Degradation of Implant Materials. Again this article cites a lack of research and information in the field and that the symptom is a bigger issue due to failures in joint replacement surgeries.
I am providing this entire book as a possible source of good information with chapters on in degradation of titanium and its alloys, biodegradable metals, fatigue failures of materials for medical devices and several other chapters that may provide good information.
Biologic Effects of Implant Debris - (2009)
A good article that discusses the effects metal debris has on inflammatory response as well as how this response can lead to osteolysis. A good diagram of how the pathway functions is provided.
Immune Response to Implants - (2015)
A Medscape article that provides a general overview of immune response as it relates to metal implants.
This article looks at how the procedure of resurfacing hip arthroplasty effects the biomechanics of the joint. May not relate strong comparison to the biomechanics of the foot but still provides evidence that implants can produce stress.
This report examines several varieties of screws used in orthopedic procedures to determine which is best at limiting implant loosening induced by stress shielding and subsequent bone loss.
Clinical Skills in Treating the Foot - (2005)
"Complications from silastic implants have been noted and patients need to be advised of these..." from last paragraph before section on Arthodesis.
Implants made of polygloycolide, polylactide or glycolide-lactide copolymer caused joint damage due to debris particles. The osteoarthritis that developed in these patients is contributed to foreign-body reactions caused by the absorbable debris.
This study examined a range of adverse reactions to bioabsorbable implants ranging from "painful erythematous papules" to "extensive osteolytic lesions developed at the implant tracks."
This study looks at patients with bioabsorbable implants who suffered from "copiously discharging sinus on the skin" 2-4 months post-op. In 18 patients, nonbacterial inflammatory tissue responses occurred that required surgical drainage.
This study compared the effectiveness of absorbable pins vs their metal counterpoints in foot surgeries. The research found a low complication rate with the absorbable pins and that they were effective at correcting the issues. Some complications were noted, despite the low rate.
This Literature review looks at incidences of infection associated with bioabsorbable implants. Conclusions were that many factors are involved in determining infection rate including sterilization processes, method of implant manufacture and site of implantation. Several benefits of absorbable implants are also provided.
This case study highlights the difficulty of removing a locked plate implant and the associated screws.
While not every implant will fail and while most people are not allergic to the metals found in modern implants, there is no reason not to remove a piece of hardware if it can be repeatedly done safely and without further complications. If it is safely possible the lower the risk of metal implant related complications from occurring, then it makes sense that it should be done.