AIIMS Delhi Surgeons Perform Rare Metal-Free Ceramic Knee Replacement
Knee replacement surgery has become one of the most routine procedures in India, but for Dr Sunanda Gupta, a former professor at Safdarjung Hospital, it presented a unique challenge. Years of debilitating arthritis had left her struggling to walk, yet standard metal implants posed a severe risk due to her severe allergies to metals and multiple drugs. Even everyday items like jewellery and common painkillers triggered adverse reactions in her case.
Personalized Solution for a Complex Case
To address this, surgeons at AIIMS, Delhi opted for a fully ceramic, metal-free knee implant, underscoring a growing trend towards highly personalized joint replacement solutions for select patients. While ceramic implants have been safely used in hip replacements for over two decades, they remain uncommon in knee surgery. Dr Gupta underwent the procedure in November 2025 and is now recovering well. She attributes her progress to the ceramic implant's high biocompatibility and minimal tissue reaction, which made it the safest option despite its high cost and limited availability.
Ceramic Implants: Exception, Not the Norm
However, Dr Gupta's case is the exception rather than the rule. Dr Vikrant Manhas, additional professor of orthopaedics at AIIMS, explains that completely metal-free ceramic knee implants are extremely rare and reserved for patients who cannot or will not use hypoallergenic alternatives. "Most patients concerned about metal sensitivity can safely receive standard implants with special coatings that prevent direct tissue contact," he says, noting that only a small minority requires non-standard implants.
Cost is a significant deterrent, with ceramic knee implants nearly twice as expensive as standard ones, making them impractical for routine use. Dr Manhas adds that while ceramic implants can crack after a severe fall—a risk reduced with newer designs—metal implants do not fracture. "As coated metal implants work well for the vast majority of patients, ceramic knees are not commonly done in India," he states, describing the AIIMS procedure as necessity-driven rather than trend-setting.
Scientific Evidence Supports Ceramic Efficacy
Scientific evidence, however, suggests ceramic knees can perform just as effectively in suitable patients. An eight-year prospective follow-up study published in 2024 in Nature's scientific report evaluated a completely metal-free ceramic knee implant used in total knee arthroplasty. It found outcomes on par with conventional metal implants in terms of function, patient satisfaction, activity levels, and overall quality of life.
No allergic reactions were reported among those who received ceramic implants, supporting their use for individuals with proven metal hypersensitivity. While gradual radiological changes were observed around the tibial component over time, these did not lead to clinical loosening or symptoms. Only one revision surgery occurred, due to trauma rather than implant failure. The study concluded that ceramic knee implants are a safe and effective long-term option for patients with metal allergy, provided proper surgical techniques, such as full cementation of ceramic components, are followed.
Metal Allergy in Knee Implants: Rare but Possible
Amite Pankaj Aggarwal, principal director and head of orthopaedics and joint replacement at Fortis Hospital in Delhi's Shalimar Bagh, notes that metal allergy to knee implants is rare but possible. Standard implants typically use cobalt-chromium alloys with trace nickel, the most common allergen. When allergies occur, patients may experience persistent pain, stiffness, rashes, or redness weeks to months after surgery, and in some cases, implant loosening requiring revision surgery.
He advises patients with a history of skin reactions to jewellery or watches to inform their doctors. They are usually offered alternative metals or cobalt-chromium implants coated with ceramic layers like titanium nitride or zirconium oxide, which reduce metal ion release and wear, extending implant life. Ceramic implants, he adds, are reserved for select patients only.
Modern Implants Enhance Safety
Experts emphasize that the overall risk of metal allergy is negligible with modern implant materials. Aashish Chaudhry of Aakash Healthcare points out that advanced cobalt-chromium alloys and titanium nitride-coated implants—often called gold-coated implants—are highly biocompatible and well-tolerated, even in patients reporting metal sensitivity. He adds that ceramic remains standard for hips, not knees, where advanced metal alloys continue to be the proven choice.
Key Takeaway: Personalized Care Over One-Size-Fits-All
Doctors agree on one clear insight from the AIIMS case: ceramic knee implants are not for everyone but can be life-changing for a tiny subset of patients. Dr Gupta's experience highlights a shift from one-size-fits-all surgery towards implant choices tailored to a patient's biology, risks, and lifestyle, even when this path is rarer, costlier, and more complex.
