Recognizing and Managing Allergies to Podiatric Surgical Materials
In the realm of podiatric surgery, the materials surgeons choose for implants and sutures are crucial to ensure successful outcomes. However, an often-overlooked consideration is the potential for patients to develop hypersensitivity reactions to these materials. Metal hypersensitivity has garnered particular attention due to its association with various adverse effects following podiatric procedures. Similarly, reactions to suture materials can pose challenges in patient management.
In this article, we delve into the diagnosis, consequences, and management strategies for metal and suture hypersensitivity in podiatric surgery.
A Closer Look at Hypersensitivity Reactions
When it comes to metal and suture hypersensitivity, reactions to these materials present as either a delayed hypersensitivity reaction or, in rare cases, anaphylaxis. Delayed-type hypersensitivity (DTH) reactions are characterized by an onset typically 24 to 72 hours after exposure to the allergen. This is the most common type of hypersensitivity reaction. Unlike immediate hypersensitivity reactions, DTH involves T-cell activation and cytokine release, resulting in inflammation and tissue damage. Common allergens in podiatric settings that can trigger DTH reactions include certain metals such as nickel, cobalt, titanium, adhesives, suture material, or topical medications.1
In our experience, chronic inflammation resulting from DTH reactions can complicate podiatric interventions by prolonging healing times, increasing infection risk, and potentially causing tissue damage. Clinicians must vigilantly identify patients at risk of DTH reactions and avoid allergens whenever possible. Patch testing may be necessary to confirm suspected allergies, particularly in cases of chronic dermatitis or delayed wound healing.
In podiatric interventions, minimizing allergen by using hypoallergenic materials can help prevent DTH reactions. Proper wound care and inflammation management are essential to promote optimal healing outcomes. Post-procedure, one should monitor patients for any signs of allergic reactions, especially if they have a history of allergies. Before patients leave the clinic or hospital, it is wise to provide instructions on managing potential allergic symptoms and when to seek medical attention.
Anaphylaxis is a severe, life-threatening allergic reaction characterized by systemic symptoms such as swelling of the throat, difficulty breathing, a drop in blood pressure, rapid pulse, and loss of consciousness. In podiatric settings, anaphylaxis can occur in response to various allergens, most commonly medications such as antibiotics or local anesthetics but also, in rare cases,
metal and suture. Therefore, clinicians should prepare for these scenarios, regardless of their rarity.2
Managing anaphylaxis during podiatric procedures requires rapid recognition and immediate intervention. Clinicians should train to identify the signs and symptoms of anaphylaxis and have emergency protocols in place in all places of service. In our experience, this includes maintaining a well-equipped anaphylaxis kit containing medications such as epinephrine, antihistamines, and corticosteroids.
Prompt administration of epinephrine is the cornerstone of anaphylaxis management, as it helps reverse the systemic effects of the allergic reaction. Following the administration of epinephrine, supportive measures such as airway management, intravenous fluids, and close monitoring of vital signs are necessary to stabilize the patient.
After an episode of anaphylaxis, patients should undergo thorough allergen testing to identify the trigger and avoid future exposure. Clinicians should also provide patients with education on recognizing the signs of anaphylaxis and carrying an epinephrine auto-injector for self-administration in case of future allergic reactions.
What You Should Know About Metal Hypersensitivity
Metal hypersensitivity is relatively rare in patients with orthopedic implants. Factors such as implant type, composition, and patient-specific immune responses contribute to the variability in prevalence rates.
Cristofaro and colleagues conducted a systematic review shedding light on the prevalence of metal hypersensitivity in the realm of foot and ankle surgery.3 Their findings revealed a significant rate of metal hypersensitivity among patients with orthopedic hardware, with 42% testing positive for hypersensitivity when subjected to patch testing. What is particularly noteworthy is that a large portion of these patients were asymptomatic. This could suggest that metal hypersensitivity may be more prevalent than initially presumed. This underscores the importance of routine screening and heightened awareness among podiatric surgeons regarding the potential for such immune responses in their patient population. By recognizing the prevalence of metal hypersensitivity in podiatric surgery, health care providers can proactively address this issue, potentially preventing adverse outcomes and ensuring optimal patient care.
Metal hypersensitivity reactions can manifest in various ways following podiatric procedures. From localized symptoms such as pain, rash, or swelling to systemic effects impacting cardiac function, the consequences can be significant. Most often patients present with dermatitis, often over the area where the implant dwells, but researchers have also reported atypical presentations such as implant failure, low-grade fever, or wound dehiscence.3,4 Oftentimes a hypersensitivity response can manifest similarly to a postoperative infection. Jenkinson and colleagues underscore the potential compromise in cardiac function observed in patients with elevated blood cobalt levels secondary to metal-on-metal hip implants.5
In cases of confirmed or suspected metal sensitivity, one must consider alternative implant materials and metals. However, in our experience, one must also weigh the selection of alternative materials against factors such as biomechanical compatibility, durability, and cost-effectiveness. Titanium-, ceramic-, and polymer-based materials offer biocompatibility and durability, making them favorable options for patients prone to metal hypersensitivity.1,3
Titanium and its alloys have gained significant attention in medical applications due to their excellent biocompatibility, corrosion resistance, and mechanical properties. Titanium’s biocompatibility ensures minimal risk of allergic reactions or adverse tissue responses, making it a compelling alternative to nickel-containing materials and suitable for long-term implantation.1,3 Moreover, titanium alloys can be tailored to meet specific mechanical requirements, offering versatility in design for various podiatric procedures. Schultzel and colleagues discovered that when patch-tested, only 3% of patients exhibited a positive reaction to titanium, contrasting sharply with the 79% who tested positive for nickel sensitivity.1
Ceramic implants present an innovative solution for podiatric surgeries, offering unique properties such as high strength, biocompatibility, and wear resistance. Ceramic materials like alumina (aluminum oxide) and zirconia (zirconium oxide) exhibit excellent biocompatibility, ensuring minimal adverse reactions when implanted in the body. These materials are also inert and non-corrosive, making them suitable for long-term use in podiatric hardware.1
Polymer-based materials are gaining prominence in podiatric surgeries as viable alternatives to traditional metal implants. These materials, such as polyetheretherketone (PEEK) and polyetherketoneketone (PEKK), exhibit favorable biocompatibility, chemical inertness, and mechanical properties suitable for orthopedic applications. In podiatric hardware, polymer-based implants offer advantages such as reduced weight, flexibility, and radiolucency. These characteristics contribute to enhanced patient comfort, faster recovery, and improved postoperative outcomes. Additionally, polymer-based materials can be manufactured with porous structures to promote osseointegration, facilitating the integration of implants with surrounding bone tissue. Ongoing research aims to optimize the properties of polymer-based materials for specific podiatric surgeries, ensuring their efficacy and long-term
performance.6
In summary, titanium and its alloys, ceramic implants, and polymer-based materials represent promising nickel-free options for podiatric surgeries. Each material offers unique advantages in terms of biocompatibility, mechanical properties, and design flexibility, catering to the diverse needs of patients and surgeons in the field of podiatry. Furthermore, advancements in implant technology continue to provide alternatives that reduce the likelihood of adverse reactions, thus optimizing patient outcomes.
When Patients Have Suture Hypersensitivity
Suture materials, although essential for wound closure, can also elicit hypersensitivity reactions in some patients. Nylon and chromic gut are among the most commonly reported suture types associated with hypersensitivity reactions. Chromic gut, a type of absorbable suture made from purified connective tissue of sheep or beef intestines, is known for its biodegradability and favorable handling characteristics. However, it can provoke hypersensitivity reactions in some patients. These reactions may manifest as localized inflammation, erythema, pruritus, and even systemic symptoms such as urticaria or anaphylaxis. The sensitization to chromic gut can be attributed to residual chemicals used in its processing or to antigens present in the collagen fibers.7
Nylon, a non-absorbable synthetic suture material, is valued for its strength and durability. However, it too can induce allergic responses in susceptible individuals. Nylon consists of long chains of polyamide polymers, and while generally considered inert, some patients may develop allergic contact dermatitis or delayed hypersensitivity reactions upon exposure to nylon. The sensitization to nylon may result from breakdown products released during degradation or from impurities present in the manufacturing process.
In addition to chromic gut and nylon, other suture materials such as silk, polyglycolic acid (PGA), polyglactin (eg, Vicryl), and polydioxanone (PDS) can also elicit allergic reactions, although these occurrences are relatively rare. Silk, derived from silkworm cocoons, contains sericin proteins that may trigger sensitization in some individuals. PGA, Vicryl, and PDS are synthetic absorbable sutures, and while they are generally well-tolerated, cases of hypersensitivity have been reported, often related to impurities or degradation byproducts.8
Recognizing the signs and symptoms associated with suture hypersensitivity is crucial for prompt intervention. In a case report by Al-Qattan and Kfoury, a delayed allergic reaction to polypropylene suture used in flexor tendon repair illustrates the diverse manifestations of suture hypersensitivity.2 The study highlights that different suture types have been reported to elicit varying clinical presentations. For instance, the study found polypropylene and polyamide sutures to manifest as slowly growing solid masses and chronic skin eczema. Braided polyester sutures, on the other hand, were associated with the formation of solid or cystic masses. Moreover, stainless steel sutures and metal prostheses exhibited a spectrum of symptoms including pain, swelling, bone resorption, and overlying skin rash. In rare occurrences, patients experienced acute anaphylactic reactions.2 This diverse array of clinical presentations underscores the importance of recognizing the potential for suture hypersensitivity and the necessity of tailored management approaches to address individual patient needs.
In patients with known hypersensitivities to traditional suture materials such as polypropylene, polyamide, and stainless steel, selecting alternative suture options becomes imperative to mitigate the risk of adverse reactions. Managing allergic reactions to suture materials involves several approaches. First, clinicians should be vigilant in assessing patients for signs and symptoms of allergic responses during and after suture placement. If one suspects an allergic reaction, identify the offending suture material and remove it promptly. When comparing the hypersensitivity reactions of staples versus suture, Liu, Smith and their respective colleagues found no significant difference between the two materials.9,10 This suggests that suture and staples can therefore be substituted for one another if patients are found to have a hypersensitivity to either metal or suture. Furthermore, alternative suture options, such as polyglactin or PDS for absorbable sutures, or polypropylene for non-absorbable sutures, may also be considered based on patient characteristics and wound characteristics.
Polyglycolic acid (PGA), commonly known as Dexon, stands out as a versatile and widely used material. Composed of a homopolymer of glycolic acid, PGA holds the distinction of being the only suture classified as a drug and approved by the Food and Drug Administration (FDA). Its mechanism of action involves gradual breakdown through hydrolysis, resulting in the formation of carbon dioxide and water. This process typically spans 90 to 120 days, facilitating sufficient wound healing time. However, it is worth noting that PGA’s braided structure renders it more reactive compared to monofilament alternatives.11
Another notable synthetic absorbable suture is polyglactin 910, marketed under the trade name Vicryl. This suture comprises polyglactin 370, a copolymer consisting of 90% glycolic acid and 10% lactic acid. Polyglactin 910 undergoes complete hydrolysis within 60 days, expediting the absorption process. However, its propensity to undergo spitting before a complete breakdown can pose challenges, potentially leading to suture abscesses and complications in wound healing.11
Polydioxanone (PDS), a polyester derived from paradioxanone polymer, emerges as one of the most promising alternatives. Notably, PDS offers several advantages, including a prolonged absorption timeline of 120 days, ensuring sustained wound support. Moreover, its monofilament structure contributes to reduced tissue reactivity, mitigating the risk of adverse reactions. The breakdown mechanism of PDS primarily involves hydrolysis, ensuring compatibility with the body’s natural processes and minimizing inflammatory responses.11
Addressing Adhesive Hypersensitivities
Skin adhesive allergies in podiatric surgery and medicine can manifest in various forms, often depending on the type of adhesive used in dressings. One common type of adhesive allergy is contact dermatitis, which occurs when the skin comes into direct contact with an allergen, triggering an immune response. So and colleagues found that 2.8% of patients who received liquid skin adhesives including Dermabond Prineo (Ethicon) developed postoperative contact dermatitis.12 Adhesive materials such as acrylate-based compounds, present in many medical tapes and dressings, are frequent culprits in contact dermatitis reactions.
Patients with reactions to adhesives may exhibit symptoms ranging from mild irritation, such as redness and itching, to more severe reactions characterized by swelling, blistering, or even oozing lesions at the site of contact. These symptoms can significantly impact wound healing and patient comfort, necessitating prompt identification and management. Yagnatovsky and colleagues delineate 3 case studies detailing patients who exhibited a hypersensitivity reaction to Dermabond following knee replacement surgery and highlight the challenge of potentially misinterpreting such reactions as postoperative infections.13 Symptoms such as eczema, itching, blistering, absence of foul odor, and periwound leakage devoid of warmth or wound discharge should draw one’s attention toward a hypersensitivity reaction as opposed to a postoperative infection.12
To address adhesive allergies, podiatric surgeons and medical practitioners often explore alternative dressing options. Silicone-based dressings, for instance, are known for their gentle adhesion and hypoallergenic properties, making them suitable for patients with sensitivities to traditional adhesives.14 Additionally, non-adhesive dressings like foam or alginate dressings can provide effective wound coverage without relying on adhesives, reducing the risk of allergic reactions.
Preventing Hypersensitivities in Podiatric Surgery
Prevention remains the cornerstone in managing hypersensitivity reactions in podiatric surgery. Informed consent processes should include discussions regarding the potential for hypersensitivity reactions to implants and sutures. Documentation should also encompass details such as the types of materials proposed for use, their intended purpose, potential risks, and any alternatives considered. Health care providers play a pivotal role in identifying patients at risk and eliciting pertinent medical histories, including previous reactions to metals and suture materials. Patch allergy testing can aid in preoperative screening when indicated, allowing for the identification of sensitivities and informing material selection decisions.
According to Dordunoo and colleagues, 90% of health care workers do not routinely ask about metal hypersensitivity when evaluating allergy history and 86% were unaware of the association between metal hypersensitivity and poor patient outcomes.15
Hypersensitivities to metals, suture material, and adhesives are something that surgeons can easily work into the patient history. Doing so could potentially avoid a host of complications. Furthermore, intraoperative precautions, such as minimizing implant exposure, meticulous wound care, and the application of barrier techniques like coatings or sleeves, can help mitigate the risk of allergic reactions. Postoperative monitoring for signs of allergic responses is equally essential, enabling early detection and prompt intervention if complications arise.
In Conclusion
In navigating the multifaceted landscape of hardware and suture allergies in podiatry, practitioners have a spectrum of alternatives and strategies. By embracing a thorough understanding of allergic reactions, exploring innovative materials, prioritizing patient education, taking a thorough allergen history, and by simply adding hypersensitivity reactions to our differentials, podiatrists can navigate these challenges with precision, ultimately ensuring positive and tailored outcomes for their diverse patient population.
Dr. Starr is a first-year resident at the Ascension St. Vincent Podiatry Residency Program in Indianapolis.
Dr. Patel is a second-year resident at the Ascension St. Vincent Podiatry Residency Program in Indianapolis.
Dr. DeHeer is the Residency Director of the St. Vincent Hospital Podiatry Program in Indianapolis. He is a Fellow of the American College of Foot and Ankle Surgeons, a Fellow of the American Society of Podiatric Surgeons, a Fellow of the American College of Foot and Ankle Pediatrics, a Fellow of the Royal College of Physicians and Surgeons of Glasgow, and a Diplomate of the American Board of Podiatric Surgery.
References
1. Schultzel M, Klein CM, Demirjian M, Blout C, Itamura JM. Incidence of metal hypersensitivity in orthopedic surgical patients who self-report hypersensitivity history. Perm J. 2020;24:19.091. doi:10.7812/TPP/19.091
2. Al-Qattan MM, Kfoury H. A delayed allergic reaction to polypropylene suture used in flexor tendon repair: case report. J Hand Surg Am. 2015;40(7):1377-1381. doi:10.1016/j.jhsa.2015.03.004
3. Cristofaro C, Pinsker EB, Halai F, Wolfstadt J, Daniels TR, Halai M. Metal hypersensitivity in foot & ankle orthopaedic surgery: A systematic review. J Clin Orthop Trauma. 2023;44:102249. Published 2023 Sep 29. doi:10.1016/j.jcot.2023.102249
4. Goodwin ML, Spiker WR, Brodke DS, Lawrence BD. Failure of facet replacement system with metal-on-metal bearing surface and subsequent discovery of cobalt allergy: report of 2 cases. J Neurosurg Spine. 2018;29(1):81-84. doi:10.3171/2017.10.SPINE17862
5. Jenkinson MRJ, Meek DRM, Tate R, et al. Cardiac function may be compromised in patients with elevated blood cobalt levels secondary to metal-on-metal hip implants. Bone Joint J. 2024;106-B(3 Supple A):51-58. Published 2024 Mar 1. doi:10.1302/0301-620X.106B3.BJJ-2023-0814.R1
6. Hu X, Mei S, Wang F, Qian J, Xie D, Zhao J, Yang L, Wu Z, Wei J. Implantable PEKK/tantalum microparticles composite with improved surface performances for regulating cell behaviors, promoting bone formation and osseointegration. Bioact Mater. 2020 Oct 8;6(4):928-940. doi: 10.1016/j.bioactmat.2020.09.021. PMID: 33102936; PMCID: PMC7560583.
7. Titley-Diaz WH, De Cicco FL. Suture Hypersensitivity. In: StatPearls. Treasure Island (FL): StatPearls Publishing; September 18, 2022.
8. Kunz RI, Brancalhão RM, Ribeiro LF, Natali MR. Silkworm sericin: properties and biomedical applications. Biomed Res Int. 2016;2016:8175701. doi:10.1155/2016/8175701
9. Liu Z, Liu B, Yang H, Zhao L. Staples versus sutures for skin closure in hip arthroplasty: a meta-analysis and systematic review. J Orthop Surg Res. 2021;16(1):735. Published 2021 Dec 24. doi:10.1186/s13018-021-02870-z
10. Smith TO, Sexton D, Mann C, Donell S. Sutures versus staples for skin closure in orthopaedic surgery: meta-analysis. BMJ. 2010;340:c1199. Published 2010 Mar 16. doi:10.1136/bmj.c1199
11. Coker C. A review of suture selection for optimal skin closure. Podiatry Institute.
12. So SP, Yoon JY, Kim JW. Postoperative contact dermatitis caused by skin adhesives used in orthopedic surgery: Incidence, characteristics, and difference from surgical site infection. Medicine (Baltimore). 2021;100(20):e26053. doi:10.1097/MD.0000000000026053
13. Yagnatovsky M, Pham H, Rokito A, Jazrawi L, Strauss E. Type IV hypersensitivity reactions following Dermabond adhesive utilization in knee surgery: a report of three cases. Phys Sportsmed. 2017;45(2):195-198. doi:10.1080/00913847.2017.1283208
14. David F, Wurtz JL, Breton N, et al. A randomised, controlled, non-inferiority trial comparing the performance of a soft silicone-coated wound contact layer (Mepitel One) with a lipidocolloid wound contact layer (UrgoTul) in the treatment of acute wounds. Int Wound J. 2018;15(1):159-169. doi:10.1111/iwj.12853
15. Dordunoo D, Hass M, Smith C, et al. Metal hypersensitivity screening among frontline healthcare workers-A descriptive study. J Clin Nurs. 2021;30(3-4):541-549. doi:10.1111/jocn.15571
