Claims of superiority by ‘new and improved’ brands of knee implants have little basis: NPPA

Claims of superiority by ‘new and improved’ brands of knee implants have little basis: NPPA

NEW DELHI: Claims of superiority by 'new and improved' brands of knee implants over existing ones have little basis, the National Pharmaceutical Pricing Authority has concluded after examining studies published in international medical journals and consulting orthopaedic surgeons.

Based on this, it feels that there is a "need to sensitize patients about limitations of these hyped technologies" and to moderate their prices - typically much higher than those for older, established implants. This emerges from the minutes of the NPPA's deliberations into price fixation for knee implants.

It has decided to request the Indian Orthopaedic Association, Indian Medical Association and Association of Healthcare Providers (India) to sensitize orthopaedic surgeons not to push so called 'new technologies' with unproven claims of superiority over standard implants. The authority noted that even where patients could afford to pay the extra cost, they ought to be briefed about both the benefits and limitations of the 'latest' technology in comparison with the established one.

One study of five widely used device technologies, including two 'innovative' knee implants - high flexion knee replacement and gender specific knee replacement -- concluded that none of the innovations improved functional or patient-reported outcomes.

The study based on data collected from pre-market application and mandated post-market studies at the US Food and Drug Administration noted that existing devices may be safer to use in total hip or knee replacement. "Improved regulation and professional society oversight are necessary to prevent patients from being further exposed to these and future innovations introduced without proper evidence of improved clinical efficacy and safety," stated the study published in the British Medical Journal in 2014.

The NPPA examined the various types of implants based on their construction material, application and other technological aspects as the authority knew from its earlier experience with price capping for cardiac stents that hospitals, industry and surgeons would raise the issue of 'new generation technology' when it came to fixing a ceiling price.

The NPPA noted that companies were promoting 'high flexion knee' implants in India claiming they have higher flexibility in day-to-day active life and sitting postures required for performing several religious and cultural practices. However, an analysis of trials suggested that "no clinically relevant or statistically significant improvement was obtained in flexion with the high flex prostheses".

"These high flexions are being sold in India at a premium in spite of the fact that its clinical long term superiority is not yet established even after a period of 20 years," observed the NPPA.

The NPPA also looked into the comparative merits of knee implants made from alloys of cobalt chromium, titanium and zirconium. The Authority found that the oldest, most widely used and clinically proven technology is implants made from alloy of cobalt-chromium (CoCr). CoCr's limitation it that it releases tiny particles (metal ions) in the body which may cause allergic reactions in some individuals.

However, titanium alloy which has superior biocompatibility and enhanced erosion resistance, was found to have poor shear strength and resistance to wear. And though oxidised zirconium was shown to have less wear and tear compared to CoCr, there were a larger proportion of revision surgeries to replace or compensate for failed implants with oxidised zirconium than with CoCr.

The NPPA also noted that studies and senior surgeons had found that the claimed clinical edge of un-cemented implants was yet to be established.