• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.987-988
• /
• 2009

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1543-1546
• /
• 2008

The purpose of this study was to investigate factors affecting the change of tibial posterior slope and introduce a mathematical model which calculate, through 3-dimensional analysis of the proximal tibia, how the angle of the opening wedge along the anteromedial tibial cortex influences the tibial posterior slope and valgus correction when performing a medial open wedge osteotomy. This mathematical model with navigation system can be guidelines which provide surgeons on preoperative and intraoperative measurements to maintain or correct the tibial slope and to obtain the desired valgus correction of the lower limb during an opening wedge osteotomy.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1467-1470
• /
• 2008

An upper tibial opening wedge osteotomy is an operation to cure a malalignment and a degenerate arthritis. To prevent the postoperative malalignment caused by the upper tibial opening wedge osteotomy, the research to define the relationship between a Hinge Axis Angle and a Posterior Slope Angle is needed. The effect of the relationship between the hinge axis angle and the gap angle on the posterior slope angle is studied. After 3-D Compute Tomography (CT) scanning image is reconstructed, the virtual surgery is performed by the reconstructed 3-D tibia model. It was proved that the relationship between the hinge axis angle and the gap angle were constant and the simple mathematical model could be derived. To verify the suggested mathematical model, it compared with the measured data from the virtual surgery. In conclusion, while the deviation between the data from the virtual surgery and ones of the mathematical model under the gap angle<$10^{\circ}$ was less than 1%.

• Korean Journal of Applied Biomechanics
• /
• v.30 no.2
• /
• pp.145-154
• /
• 2020

Objective: The purpose of this study was to determine the relationship between impact and shear peak force, and tibia-accelerometer variables during running. Method: Twenty-five male heel strike runners (mean age: 23.5±3.6 yrs, mean height: 176.3±3.3 m/s, mean mass: 71.8±9.7 kg) were recruited in this study. The peak impact and anteroposterior shear forces during treadmill running (Bertec, USA) were collected, and impact shock variables were computed by using a triaxial accelerometer (Noraxon, USA). One-way ANOVA was used to test the influence of the running speed on the parameters. Pearson's partial correlation was used to investigate the relationship between the peak impact and shear force, and accelerometer variables. Results: The running speed affected the peak impact and posterior shear force, time, slope, and peak vertical and resultant tibial acceleration, slope at heel contact. Significant correlations were noticed between the peak impact force and peak vertical and resultant tibia acceleration, and between peak impact average slope and peak vertical and resultant tibia acceleration average slope, and between posterior peak (FyP) and peak vertical tibia acceleration, and between posterior peak instantaneous slop and peak vertical tibial acceleration during running at 3 m/s. However, it was observed that correlations between peak impact average slope and peak vertical tibia acceleration average slope, between posterior peak time and peak vertical and resultant tibia acceleration time, between posterior peak instantaneous slope and peak vertical tibial acceleration instantaneous slope during running at 4 m/s. Conclusion: Careful analysis is required when investigating the linear relationship between the impact and shear force, and tibia accelerometer components during relatively fast running speed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.955-956
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.263-264
• /
• 2008

• Korean Journal of Computational Design and Engineering
• /
• v.18 no.6
• /
• pp.385-398
• /
• 2013

Opening wedge high tibial osteotomy (OWHTO) is widely used to treat unicompartmental osteoarthritis of the knee caused by degenerative deformations of the anatomical axes of the leg. However, since it is difficult to accurately plan the surgical degrees of adjustment such as coronal correction angle and tibial posterior slope angle to align the axes before the actual procedure, a number of studies have proposed analytical models to solve this problem. While previous analytical models for OWHTO were limited to specific cases, this study proposes an analytical osteotomy model (AOM) and a surgical planning system (SPS) that are suitable for a wide range of tibial morphologies and tibia conditions. The validity and generality of the model were verified in a total of 60 OWHTO cases. Results of the test showed that, as predicted, surgical degrees are affected quite significantly by tibia shape and slope of the resected surface. Comparison of the required surgical degrees and the degrees estimated from virtual surgery simulations using AOM showed a very small average difference of $0.118^{\circ}$. SPS, based on AOM, allows the operating surgeon to easily calculate surgical parameters needed to treat a patient.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.8
• /
• pp.835-846
• /
• 2011

In medial opening wedge high tibial osteotomy (OWHTO), researchers have reported critical problems caused by unexpected changes in the tibial posterior-slope angle. This unexpected change can be analyzed, but there is no general solution for cases with an oblique hinge axis and cut plane. We propose a general analysis model for OWHTO. We first evaluate the effects according to variation in the hinge axis and tibial cut plane and then define an ideal correction axis. This ideal axis, called the virtual tibial correction axis, is not on the tibial cut plane in general. In this paper, we also present an evaluation of feasibility of the proposed analysis model.

• Knee surgery & related research
• /
• v.30 no.4
• /
• pp.303-310
• /
• 2018

Purpose: The purpose of this study was to investigate whether surgical experience could improve surgical competency in medial open wedge high tibial osteotomy (MOWHTO). Materials and Methods: One hundred consecutive cases of MOWHTO were performed with preoperative planning using the Miniaci method. Surgical errors were defined as under- or overcorrection, excessive posterior slope change, or the presence of a lateral hinge fracture. Each of these treatment failures was separately evaluated using the cumulative summation test for learning curve (LC-CUSUM). Results: The LC-CUSUM showed competency in prevention of undercorrection, excessive posterior slope change, and lateral hinge fracture after 27, 47, and 42 procedures, respectively. However, the LC-CUSUM did not signal achievement of competency in prevention of overcorrection after 100 procedures. Furthermore, the failure rate for overcorrection showed an increasing tendency as surgical experience increased. Conclusions: Surgical experience may improve the surgeon's competency in prevention of undercorrection, excessive posterior slope change, and lateral hinge fracture. However, it may not help reduce the incidence of overcorrection even after performance of 100 cases of MOWHTO over a period of 6 years.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.3
• /
• pp.351-361
• /
• 2012

The leading surgical method for correcting the misalignment of the varus and valgus in the knee joint is the high tibial osteotomy (HTO). In the opening wedge HTO (OWHTO), there is no concern about damaging the peroneal nerve on the lateral tibia of the proximal fibula. OWHTO has been the preferred choice, as the opening of the correction angle can be modulated during the operation. The correction of the varus and valgus on the coronal plane are performed adroitly. Nevertheless, there have been numerous reports of unintended changes in the medial tibial plateau and posterior slope angle (PSA). The authors have developed an HTO method using computer-assisted surgery with the aim of addressing the abovementioned problems from an engineer's perspective. CT images of the high tibia were reconstructed three-dimensionally, and a virtual osteotomy was performed on a computer. In addition, this study recommends a surgical method that does not cause changes in the PSA after OWHTO. The results of the study are expected to suggest a clear relationship between the anteromedial cortex oblique angle of each patient and the PSA, and an optimal PSA selection method for individuals.