Agung Riyanto Budi Santoso, Respati Suryanto Dradjat, Edi Mustamsir, Setyawan Purnomo Sakti, Panji Sananta, Hidayat Sujuti, Heri Suroto
Purpose Rheumatoid arthritis often affects the metacarpophalangeal (MCP) joints, resulting in pain, deformity, and loss of hand function. In advanced disease, arthroplasty provides superior functional outcomes compared with arthrodesis. The development of small joint prostheses remains a challenge, particularly in terms of long-term durability, biocompatibility, and stability. Methods A novel unconstrained MCP joint prosthesis was designed with zirconia crowns on the metacarpal side and polyether-ether-ketone (PEEK) crowns on the proximal phalanx, each supported by stainless steel stems. Biocompatibility was assessed histologically, whereas durability and stability were evaluated through mechanical testing, including measurements of surface roughness, weight and volume changes, and wear resistance. Functional stability was assessed by measuring in vivo flexion–extension and abduction–adduction ranges of motion and comparing them with those of conventional AISI 316L stainless steel prostheses. Results The zirconia–PEEK prosthesis demonstrated superior biocompatibility with reduced macrophage infiltration and greater osteoblast activity. Mechanical testing revealed significantly lower wear and minimal changes in surface roughness, whereas functional testing demonstrated preserved joint mobility. Conclusions The unconstrained zirconia–PEEK MCP prosthesis demonstrated excellent biocompatibility, superior durability, and enhanced functional stability compared with stainless steel implants, supporting its potential as a promising alternative for MCP joint replacement. Clinical relevance This study demonstrates the potential of a zirconia–PEEK prosthesis for MCP joint replacement, potentially improving long-term functional outcomes for patients with advanced rheumatoid arthritis. Its superior biocompatibility and reduced wear characteristics may reduce complications, such as implant failure and the need for revision surgery, ultimately enhancing patient quality of life. © 2026 The Authors.
Doctoral Program in Medical Sciences, Faculty of Medicine, Universitas Brawijaya, Malang, Indonesia; Department of Orthopaedic and Traumatology, Faculty of Medicine, Universitas Brawijaya–Dr. Saiful Anwar General Hospital, Malang, Indonesia; Department of Physics, Faculty of Mathematics and Natural Science, Universitas Brawijaya, Malang, Indonesia; Department of Ophthalmology, Faculty of Medicine, Universitas Brawijaya–Dr. Saiful Anwar General Hospital, Malang, Indonesia; Department of Orthopaedic and Traumatology, Faculty of Medicine, Universitas Airlangga–Dr. Soetomo Academic General Hospital, Surabaya, Indonesia
