Atahan Durgal, Enver Kilic, Elif Naz Perdeci, Fatma Kubra Erbay Elibol, Taner Karlidag, Burak Kulakoglu, Teyfik Demir, Olgun Bingol, Guzelali Ozdemir
Joint Diseases and Related Surgery - 2026;37(2):489-500
Objectives: This study aims to biomechanically compare four fixation methods to identify the most stable construct under axial loading conditions. Material and methods: A standardized osteotomy model simulating AO/OTA 33-B2.1 fractures was created in 28 synthetic femurs. Four groups (n = 7 each) were tested: (1) three 6.5-mm cannulated screws, (2) the same with an additional centrally placed screw, (3) three screws plus a 3.5-mm buttress plate, and (4) three screws combined with a reversed anatomical proximal tibial locking plate. Constructs were subjected to cyclic and static axial loading. The prespecified primary endpoint was load at 2-mm displacement, with stiffness and maximum load to failure as secondary outcomes. Results: Group 4 exhibited the highest stiffness (802 +/- 70 N/mm), maximum load (2360 +/- 389 N), and resistance to 2-mm displacement (1138 +/- 87 N). Group 2, with a centrally placed fourth screw, showed significantly improved performance in terms of maximum load compared to the traditional three-screw construct. While Group 3 improved stiffness over screw-only constructs, it did not significantly outperform Group 2 in key load metrics. Group 2, with a centrally placed fourth screw, demonstrated comparable stability to the buttress plate and anatomical locking plate in selected metrics, but remained inferior to the locking plate construct. Conclusion: Central placement of cannulated screws to the medial femoral condyle enhanced axial stability in this synthetic model and represented a minimally invasive alternative to buttress plating in selected metrics. The highest stability was achieved with the combined use of cannulated screws and a locking plate. These results are restricted to axial loading and the tested endpoints; thus, further biomechanical, cadaveric, and clinical studies are warranted before generalizing to early weight-bearing. Given the anatomical challenges of the medial condyle, the development of anatomically contoured locking plates specifically designed for this region remains an important future direction.
