Biomechanical analysis of different lengths of distal screws in high tibial osteotomy
JIN Hong-zhen,BAI Hao-hao,SUN Lei
Abstract:
Objective To analyse the effect of different length of the two distal screws of internal fixation on the biomechanical properties in high tibial osteotomy (HTO). Methods Selecting one patient with knee osteoarthritis and perform a 64-slice spiral CT scan of the lower extremity to obtain the required data. Using finite element analysis techniques, the Tomofix-based steel plate was constructed and the distal end of the plate was fixed using screws of different lengths, and a load of three times the body weight was applied to the surface of the tibial plateau to compare the changes in stress and displacement in different models. Results Combining the stress and displacement data, the sub-distal single cortical nailing had a peak screw stress of 348.7 MPa, which was similar to the normal nailing, and a peak tibial stress of 98.7 MPa, which was the lowest among all the nailing modalities, with a displacement deformation of 15.63 mm, which was well controlled. Tibial and screw stress deformations were significantly higher with distal or subdistal non-nailing than with other modalities, with increased risk. Conclusion The subdistal single cortical nailing performed best in balancing internal fixation and bone loading, and was the optimal nailing method. Taken together, the use of single-cortical screws at the distal end of the plate during HTO surgery is feasible.
