Introduction

Osseointegration technology allows prosthetic limbs to connect directly to bone, offering better control and comfort than traditional sockets. But when this approach was applied to finger amputations using a custom implant called the intraosseous transcutaneous amputation prosthesis (ITAP), results were not what researchers hoped for.

A new study in the Journal of Prosthetics and Orthotics (2025) followed 11 patients with finger amputations who received ITAP implants. The goal was to test whether this bone-anchored prosthesis could safely integrate through the skin without infection.

Key Findings

  • Frequent infections: Every patient experienced repeated soft tissue infections around the implant site.
  • High removal rate: Except for one patient lost to follow-up, all implants were removed within nine years.
  • Design problems: The ITAP’s flanged design, inspired by deer antlers, failed to create a stable seal between skin and implant, leading to erosion and exposure.
  • Functional limitations: Few patients could use their prosthesis effectively for daily activities, and most used it only for appearance before eventually requesting removal.

Why It Matters

While osseointegrated prostheses have shown great success for major limb amputations, this study highlights that cutaneous (skin) integration remains a major challenge—especially in smaller, high-motion areas like the hand. The findings emphasize the importance of improved implant design, infection control, and multidisciplinary collaboration between surgeons, prosthetists, and engineers.

Conclusion

The ITAP concept, though innovative, failed to prevent infection and ensure stability for finger prostheses. Researchers recommend against using this design for future digital osseointegration and urge continued exploration into safer skin-implant sealing technologies.

Reference

Kang NV, Al-Ajam Y, Woollard A, Burr N. Use of an Osseointegrated Intraosseous Transcutaneous Amputation Prosthesis for Amputated Fingers Is Followed by Frequent Infection and Implant Removal. J Prosthet Orthot. 2025;37(2):81–91.