Hamza Özer1, Ferid Abdulaliyev1, Niymet Pelin Cavdar Yilmaz2, Asim Ahmadov1, Yigit Gungor2, Seda Nur Tosun3, Ayhan Comert2, Nil Tokgoz2, Mehmet Yilmaz2

1Department of Orthopedics and Traumatology, Gazi University Faculty of Medicine, Ankara, Türkiye
2Department of Anatomy, Ankara University Faculty of Medicine, Ankara, Türkiye
3Department of Radiology, Gazi University Faculty of Medicine, Ankara, Türkiye

Keywords: Arthroplasty, extraarticular, Gerdy’s tubercle, joint line, knee, tibia.


Objectives: This study aimed to explore the use of Gerdy’s tubercle (GT) as an innovative and dependable anatomical landmark for the proximal tibial cut in total knee arthroplasty (TKA) in cases with extensive knee degeneration.

Materials and methods: One hundred dry tibia bones and 10 formalin-fixed cadaveric knee specimens of both sexes were examined. A Zimmer NexGen tibial cutting guide and a Mitutoyo digital caliper were utilized to align the guide with the tibia's mechanical axis. The procedure was replicated on cadaver knees using a standardized medial parapatellar arthrotomy approach. Measurements included the distance from GT superior border to the resection line and the length of the tibia. A radiological study involving magnetic resonance imaging examinations of 48 patients, which were evaluated focusing on the upper border of GT and the least degenerated segment of the posterolateral part of the lateral tibial condyle, was conducted.

Results: Anatomical measurements of GT and proximal tibial areas in 110 specimens showed slight but consistent variations with cadaver measurements. Magnetic resonance imaging analysis of 48 patients revealed notable sex differences in the distance between the superior border of GT and the tibia's posterolateral surface. There was also a significant negative correlation between the distance from GT to the posterolateral corner and cartilage thickness.

Conclusion: Proper alignment in TKA is crucial for success, but identifying an extra-articular landmark for horizontal tibial resection remains challenging, particularly in severely arthritic knees. This study introduces GT as a novel anatomical landmark for TKA, offering a more reliable reference for achieving desired joint levels in knees with significant degenerative changes.

Citation: Özer H, Abdulaliyev F, Cavdar Yilmaz NP, Ahmadov A, Gungor Y, Tosun SN, et al. Gerdy’s tubercle as a novel anatomical landmark for the proximal tibial cut in total knee arthroplasty. Jt Dis Relat Surg 2024;35(2):305-314. doi: 10.52312/jdrs.2024.1531.

Ethics Committee Approval

The study protocol was approved by the Gazi University Clinical Research Ethics Committee (date: 22.05.2023, no: 437). The study was conducted in accordance with the principles of the Declaration of Helsinki.

Author Contributions

Conceived and designed the study, provided research supervision, and critically reviewed the manuscript for important intellectual content: H.Ö.; Participated in the study design, was involved in data collection and processing, conducted the literature review, wrote the initial draft of the manuscript, and contributed to subsequent revisions: F.A., A.A.; Assisted in designing the study, collected and processed data, reviewed the relevant literature, and contributed to writing and revising the manuscript: N.P.C.Y.; Helped in the study design, was responsible for data collection and processing, analyzed and interpreted the data, reviewed the literature, and participated in writing the manuscript, also contributed to the critical revision of the manuscript: A.A.; Oversaw the study control and supervision, and was involved in sourcing the materials necessary for the research: A.C.; Critically reviewed the manuscript to enhance its intellectual content and provided necessary materials for the study. NT and SNT were additionally responsible for performing the radiological measurements and handling the related data: Y.G., N.T., M.Y.; Also contributed to the radiological data collection and analysis: S.N.T.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.


This work was not supported by grant funding. The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed.

Data Sharing Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.