Abstract
This study evaluated a novel implant for proximal interphalangeal (PIP) joint arthroplasty that we designed according to the principles of a logarithmic spiral. The design addresses the limitations of current implants that poorly replicate natural finger kinematics. Finite element analysis and cadaver studies, including biomechanical and kinematic analyses, were conducted. Results showed that our implant had consistent sliding displacement, maintained consistent articular surface spacing, and was able to achieve a flexion arc greater than 90°, all while maintaining consistent contact throughout joint motion. In both simulation and cadaveric models, our implant demonstrates improved biomechanics by better replicating anatomical finger joint motion through its logarithmic spiral design that can potentially improve clinical outcomes for patients undergoing PIP joint arthroplasty.
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The datasets generated and analysed in the present study are available from the authors upon reasonable request.
References
Dahaghin, S. et al. Prevalence and pattern of radiographic hand osteoarthritis and association with pain and disability (the Rotterdam study). Ann. Rheum. Dis. 64, 682–687. https://doi.org/10.1136/ard.2004.023564 (2005).
Yamamoto, M. & Chung, K. C. Joint fusion and arthroplasty in the hand. Clin. Plast. Surg. 46, 479–488. https://doi.org/10.1016/j.cps.2019.03.008 (2019).
Zhu, A. F., Rahgozar, P. & Chung, K. C. Advances in proximal interphalangeal joint arthroplasty: Biomechanics and biomaterials. Hand Clin. 34, 185–194. https://doi.org/10.1016/j.hcl.2017.12.008 (2018).
Linscheid, R. L. & Dobyns, J. H. Total joint arthroplasty. The hand. Mayo Clin. Proc. 54, 516–526 (1979).
Hess, F., Fürnstahl, P., Gallo, L. M. & Schweizer, A. 3D analysis of the proximal interphalangeal joint kinematics during flexion. Comput. Math. Methods Med. 2013, 138063. https://doi.org/10.1155/2013/138063 (2013).
Herren, D. B. Current European practice in the treatment of proximal interphalangeal joint arthritis. Hand Clin. 33, 489–500. https://doi.org/10.1016/j.hcl.2017.04.002 (2017).
Holguín, P. H., Rico, A. A., Gómez, L. P. & Munuera, L. M. The coordinate movement of the interphalangeal joints. A cinematic study. Clin. Orthop. Relat. Res. 362, 117–124 (1999).
Kuczynski, K. The proximal interphalangeal joint. Anatomy and causes of stiffness in the fingers. J. Bone Jt. Surg. Br. 50, 656–663 (1968).
Landsmeer, J. M. The coordination of finger-joint motions. J. Bone Jt. Surg. Am. 45, 1654–1662 (1963).
Caravaggi, P. et al. In vitro kinematics of the proximal interphalangeal joint in the finger after progressive disruption of the main supporting structures. Hand (N Y). 10, 425–432. https://doi.org/10.1007/s11552-015-9739-x (2015).
Pang, E. Q. & Yao, J. Anatomy and biomechanics of the finger proximal interphalangeal joint. Hand Clin. 34, 121–126. https://doi.org/10.1016/j.hcl.2017.12.002 (2018).
Zhu, Y., Wei, G., Ren, L., Luo, Z. & Shang, J. Gyroscope sensor based in vivo finger axes of rotation identification using screw displacement. Appl. Bionics Biomech. 2021, 8871593. https://doi.org/10.1155/2021/8871593 (2021).
Gupta, A. et al. The motion path of the digits. J. Hand Surg. Am. 23, 1038–1042. https://doi.org/10.1016/S0363-5023(98)80012-9 (1998).
Kamper, D. G., Cruz, E. G. & Siegel, M. P. Stereotypical fingertip trajectories during grasp. J. Neurophysiol. 90, 3702–3710. https://doi.org/10.1152/jn.00546.2003 (2003).
Stillwell, J. Mathematics and its History, 3rd edn., 126–128 (Springer, 1989).
Alnaimat, F. A. The geometrical effect on the von Mises stress on ball and socket artificial disc. Eng. Technol. Appl. Sci. Res. 10, 6330–6334. https://doi.org/10.48084/etasr.3789 (2020).
Bouchard, S. M., Stewart, K. J., Pedersen, D. R., Callaghan, J. J. & Brown, T. D. Design factors influencing performance of constrained acetabular liners: finite element characterization. J. Biomech. 39, 885–893. https://doi.org/10.1016/j.jbiomech.2005.01.032 (2006).
Minamikawa, Y. et al. Lateral stability of proximal interphalangeal joint replacement. J. Hand Surg. Am. 19, 1050–1054. https://doi.org/10.1016/0363-5023(94)90116-3 (1994).
Thiel, W. Eine Arterienmasse zur Nachinjektion bei der Konservierung ganzer Leichen [An arterial substance for subsequent injection during the preservation of the whole corpse]. Ann. Anat. 174, 197–200 (1992). [German].
Iosa, M., Morone, G. & Paolucci, S. Phi in physiology, psychology and biomechanics: the golden ratio between myth and science. Biosystems 165, 31–39. https://doi.org/10.1016/j.biosystems.2018.01.001 (2018).
Littler, J. W. On the adaptability of man’s hand (with reference to the equiangular curve). Hand 5, 187–191. https://doi.org/10.1016/0072-968x(73)90027-2 (1973).
Park, A. E., Fernandez, J. J., Schmedders, K. & Cohen, M. S. The Fibonacci sequence: Relationship to the human hand. J. Hand Surg. Am. 28, 157–160. https://doi.org/10.1053/jhsu.2003.50000 (2003).
Lutter, C. et al. Dynamic study of the finger interphalangeal joint volar plate-motion analysis with magnetic resonance cinematography and histologic comparison. Skeletal Radiol. 52, 1493–1501. https://doi.org/10.1007/s00256-023-04288-6 (2023).
Allison, D. M. Anatomy of the collateral ligaments of the proximal interphalangeal joint. J. Hand Surg. Am. 30, 1026–1031. https://doi.org/10.1016/j.jhsa.2005.05.015 (2005).
Sandhu, S. S., Dreckmann, S. & Binhammer, P. A. Change in the collateral and accessory collateral ligament lengths of the proximal interphalangeal joint using cadaveric model three-dimensional laser scanning. J. Hand Surg. Eur. Vol. 41, 380–385. https://doi.org/10.1177/1753193415597845 (2016).
Chen, J., Tan, J. & Zhang, A. X. In vivo length changes of the proximal interphalangeal joint proper and accessory collateral ligaments during flexion. J. Hand Surg. Am. 40, 1130–1137. https://doi.org/10.1016/j.jhsa.2014.11.032 (2015).
Acknowledgements
The authors recognize Kazuma Nakamura (NIPRO Corporation) for technical and manufacturing advice as well as for market information. From the Nagoya University School of Medicine, we thank Professor Ryuta Saito, Director of the Clinical Anatomy Laboratory Nagoya (CALNA); Professor Michiro Yamamoto, Director of the Department of Human Enhancement and Hand Surgery; and all other members of the Department of Human Enhancement and Hand Surgery for their invaluable contribution to the cadaveric study. We also extend our gratitude to James Curley, Department of Personalized Medical Technology, for his assistance in editing and preparing the manuscript.
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This work was financially supported by NIPRO Corporation.
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H.H. conceived concept and design; acquired, analysed and interpreted data; wrote original draft; prepared line drawings and composite renderings; reviewed and edited manuscript; supervision. S.K. acquired, analysed and interpreted CT image data. H.Y. acquired, analysed and interpreted data; performed cadaveric study. Y.K. acquired and analysed data for biomechanical study. R.S. critically reviewed and revised manuscript; ensured accuracy of intellectual content. S.S. acquired, analysed and interpreted data; performed finite element analysis. All authors meet the ICMJE criteria for authorship and made substantial contributions to the work, reviewed and approved the final manuscript, and are accountable for all aspects of the work.
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Hitoshi Hirata is a consultant for NIPRO Corporation in a capacity unrelated to the subject of this research. All other authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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Hirata, H., Kurimoto, S., Yoneda, H. et al. A novel logarithmic spiral design for proximal interphalangeal joint arthroplasty. Sci Rep (2026). https://doi.org/10.1038/s41598-026-45687-8
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DOI: https://doi.org/10.1038/s41598-026-45687-8
