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

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

• Journal of the Korean Orthopaedic Association
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• v.55 no.2
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• pp.127-134
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• 2020

Purpose: The aims of this study were (1) to investigate the relationship between the characteristics of allogenic bone block and the compressive strength of an allogenic bone block measured by biomechanical experiments, and (2) to compare the maximum pressure load of allogenic bone block with the gap pressure measured at the high tibial opening osteotomy. Materials and Methods: Ten patients who provided informed consent for gap pressure measurements during opening wedge high tibial osteotomy (OWHTO) were included. The gap pressures were measured at 1 mm intervals while opening the osteotomy site from 8 mm to 14 mm. Seventeen U-shaped allogenous wedge bone blocks were made from the femur, tibia, and humerus. The height, width, cross-sectional area, and cortex thickness of the bone blocks were measured, along with the maximum compressive load just before breakage. The relationship between these characteristics and the maximum pressure load of the bone blocks was evaluated. The gap pressures measured in OWHTO were compared with the maximum pressure loads of the allogenous wedge bone blocks to evaluate the possibility of inserting allogenous wedge bone blocks into the osteotomy site without a distractor in OWHTO. Results: The OWHTO gap pressure increased with increasing osteotomy site opening. The mean gap pressure, which occurred at a 14-mm opening, was 282±93 N; the maximum pressure was 427 N. The maximum pressure load of the allografts was 13,379±6,469 N (minimum, 5,868; maximum, 29,130 N) and was correlated significantly with the cortical bone thickness (correlation coefficient=0.693, p=0.002) and cross-sectional area (correlation coefficient=0.826, p<0.001). Depending on the sterilization method, the maximum pressure loads for the bone blocks were 13,406±5,928 N for freeze-dried and 13,348±7,449 N for fresh frozen. The maximum compressive load of the allogenous wedge bone blocks was 13.7-times greater than that in OWHTO opened to 14 mm (5,868 N vs. 427 N). Conclusion: The compressive strength of allogenous wedge bone blocks was sufficiently greater than the gap pressure in OWHTO. Therefore, allogenous wedge bone blocks can be inserted safely into the osteotomy site without a distractor.

• Journal of Korean Orthopaedic Sports Medicine
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• v.11 no.1
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• pp.30-36
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• 2012

Purpose: We compared the clinical and radiological results of meniscectomy with HTO or without HTO for degenerative medial meniscus posterior horn with varus deformity. Materials and Methods: Forty-two patients who had medial meniscus degenerative root tear with varus deformity more than 3 degrees were included for this study. Among them, 30 patients were performed meniscectomy combined with open wedge HTO and 12 patients were performed only meniscectomy without HTO. The mean follow-up period was 52.5 months. The clinical results were evaluated based on symptom improvement, patients' subjective satisfaction for surgery and HSS score. We also compared the osteoarthritic progression between the group on preoperative and at the final follow up radiographs. Results: Symptom improvement was achieved in 83.3% (25 cases) with HTO group and 66.7% (8 cases) without HTO group at final follow up with a significant difference. Patients' satisfaction was achieved in 83.3% (25 cases) with HTO group and 58.3% (7 cases) without HTO group which has a significant difference. The HSS score was improved in both group (90.8: with HTO group, 89.0: without HTO group) at the final follow up without significant difference. WOMAC score was improved in both groups at the final follow up without significant difference. There were no significant differences in the osteoarthritic progression between two groups. Conclusion: The good clinical result for treatment of patient who have medial meniscus degenerative root tear with varus deformity, proximal high tibial osteotomy is considered absolutely necessary. However, the progression of degenerative arthritis, its effect on long term follow up will be needed.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.44-49
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• 2013

Purpose: To compare of the results between anterior cruciate ligament (ACL) reconstruction alone and combined with high tibial osteotomy for ACL ruptured knees with varus alignment. Materials and Methods: We retrospectively reviewed 8 cases of ACL reconstruction combined with high tibial osteotomy (Group I) and 13 cases of ACL reconstruction alone (Group II) for varus angulated ACL ruptured knees (from March 2005 to February 2007). Mean age were 34.1 years (range: 20-53) in Group I, 34.9 years (range: 21-50) in Group II. Average follow up period were 22.6 months (range: 12-35) in Group I, 20 months (range: 13-33) in Group II. We analyzed clinical and radiological results. Results: There were no significant differences in clinical and radiologic results between two groups for IKDC scores, Lysholm knee scores, Lachman test, pivot shift test, KT-2000 arthrometer, $30^{\circ}$ and $90^{\circ}$ anterior drawer stress radiographs. Tegner activity scales and Cincinnati knee ligament rating scales were 4.9, 57.9 in Group I, and 5.6, 72.9 in Group II. Group I was statistically lower than Group II for Tegner activity scales and Cincinnati knee ligament rating scales (p<0.05). Conclusion: There were no significant differences in daily living between ACL reconstruction alone and combined with high tibial ostetomy for varus angulated ACL ruptured knees. However, ACL reconstruction combined with high tibial osteotomy could limit sport activity ability.

• Journal of the Korean Orthopaedic Association
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• v.54 no.2
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• pp.120-126
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• 2019

Purpose: The efficacy of periarticular multimodal drug injection and adductor canal block after a medial opening-wedge high tibial osteotomy was compared in terms of the postoperative pain level. Materials and Methods: From November 2016 to March 2017, 60 patients underwent a medial opening-wedge high tibial osteotomy under spinal anesthesia. Preemptive analgesic medication, intravenous patient controlled anesthesia were used for pain control in all patients. Thirty patients received a periarticular multimodal drug injection (group I), and 30 patients received an adductor canal block (group II). These two groups were compared regarding the postoperative pain level, frequency of additional tramadol injections, total amount of patient-controlled analgesia, and number of times that the patients pushed the patient-controlled analgesia button at each time interval. Results: The visual analogue scale scores over the two-week postoperative period showed no statistical significance. The frequency of additional tramadol hydrochloride injections was similar in the two groups over time. The mean number of times that patients pushed the patient-controlled analgesia button was similar in two groups over time. The total amount of patient-controlled analgesia was similar in the two groups over time. Conclusion: This study shows that intraoperative periarticular multimodal drug injections and adductor canal block may have a similar effect on postoperative pain control in patients who have undergone a medial opening-wedge high tibial osteotomy for unicompartmental osteoarthritis of the knee.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.2
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• pp.100-104
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• 2011

The purpose of this article is to examine correlation between femoral rotational angle and subjective satisfaction of high tibial osteotomy outcome of the range of motion of knee joint. The subjects were 15 patients (6 males, 9 females) with primary osteoarthritis undergoing high tibial osteotomy from June of 2004 to August of 2008. They were CT tested on the knee joint before and after high tibial osteotomy. TEA (Fig. 1) and Akagi's line (Fig. 2) are analyzed as percentages. The Kendall's and Spearman's nonparametric correlation coefficient were used for the statistical tests with 0.5 level of significance. The result reveals that femoral rotational angle correlates with not the range of motion of knee joint but subjective satisfaction of the patients. Therefore, this will enable patients and physicians to have better clinical outcome.

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

• 대한관절경학회:학술대회논문집
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• 2009.10a
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• pp.192-192
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• 2009

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.431-438
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• 2012

The mechanical behavior of the polymeric material, HDPE depends on both time and temperature. The study of the tensile behavior at different strain rates is important in engineering design of the orthopedics device such as X-band plate. The mechanical properties and deformation mechanisms of HDPE are strongly dependent on the applied strain rate. Generally, the deformation behavior of HDPE based on the stress-strain curve is complex because of the highly inhomogeneous nature of plastic deformation, particularly that of necking. Therefore, we attempted to determine the mechanical behavior of HDPE in this study. Normally, tensile testing under various strain rates of the HDPE has been used to determine the mechanical behavior. We performed tensile tests at various strain rates (1 to 500 %/min) to analyze the viscoelastic behavior on increasing the strain rate. A tensile stress-strain curve was plotted from the data, and the point of transition was marked to calculate the transition stress, strain, and modulus.