• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.923-926
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• 2005

To investigate the relationship between BMD, micro-structural and mechanical properties in intertrochanteric trabecular bone, the PIXI-mus2 system, micro-CT and FE model were used. The purpose of this study were (1) to apply high-resolution imaging techniques (micro-CT imaging) in combination with new computer modeling techniques (FEA) to quantify 3D microstructural and biomechanical properties of trabecular bone in the intertrochanteric region, and (2) determine if the prediction of bone elastic constant can be improved with structural index.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.1
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• pp.32-37
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• 2010

Ultrasonographic diagnosis and treatment in Orthopaedic fields had been widely used. Sonographic diagnosis and treatment of foot and ankle is convenient because of anatomical characteristics. The knowledge of the anatomy and biomechanics in foot and ankle area can help to diagnose and treat the disease around foot and ankle. 28 bone and many tendons, ligaments and muscles are consist of ankle and foot joint and the coordinative relation among these structures can allow the dual function, weight bearing and locomotion of ankle and foot during gait cycle. Foot and ankle have small room for many structures, so systemically physical examination is essential for diagnosis. Accurate understanding of foot and ankle anatomy and biomechanics could be helpful to using ultrasonograph.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.555-556
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• 2006

• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.82-89
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• 2008

Ideal rotator cuff repair is to maintain high fixation strength and minimize gap formation for optimizing the environment of biologic healing of tendon to bone. Among the current repair techniques, the suture bridge technique is superior to single- or double-row repair in ultimate load to failure, gap formation, restoring anatomical footprint and achieving pressurized contact area. The suture bridge technique also minimizes gap formation and has rotational and torsional resistances allowing early rehabilitation. However, despite superior biomechanical characteristics of the suture bridge technique, there is no evidence that these mechanical advantages result in better clinical outcomes. Furthermore, there is no difference in failure rates between the double-row repair and suture bridge techniques. An appropriate repair technique should be determined based on tear size and pattern and tendon quality.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.377-383
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• 2019

The biomechanics study of the hip is aims to understand and explore the dynamic principles of weight transfer through the hip joint. This basic science knowledge can be applied in a variety of areas, including degenerative joint diseases and hip replacement arthroplasty. In particular, understanding of the biomechanics of the hip has led to the development of materials, design and fixation of implants, and it can be applied in various areas, such as the selection of surgical methods and the location of the implant. Moreover, it is essential to have good knowledge of the biomechanics of the hip to achieve better clinical results for patients. Therefore, this paper introduces the basic knowledge and biomechanical characteristics of a normal hip and hip replacement arthroplasty, which are needed to approach the biomechanics of the hip.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.207-214
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• 2009

Purpose: In arthroscopic rotator cuff repairs there are generally weak link in tendon suture interface, arthroscopic rotator cuff repairs can have higher retear rates than open repairs. The purpose of this study was to compare the strength of UU (Ulsan University) suture than open modified MA (Mason-Allen) suture when suture anchored into bone. Materials and Methods: The human supraspinatus tendons were harvested from the shoulder of the cadaver and split in 2 times, producing four tendons per one shoulder, for a total of 24 specimens. Two suture configurations (UU, MA) were randomized and checked on each set of tendons. Specimens were cyclically loaded under force control between 5 and 30 N at 0.25 Hz for fifty cycles. Each specimen was loaded to failure under displacement control at 1 mm/sec. Cyclic elongation, peak to peak displacement, stiffness, ultimate tensile load, mode of failure were checked. Results: No significant difference was found between two suture configuration with respect to peak to peak displacement, cyclic elongation, and stiffness. With regard to ultimate failure load, there were no significant difference statistically between the UU suture and modified MA suture (109.4 N, 110.6 N). The most common mode of failure between both sutures was suture pull-out through the tendon. Conclusion: The UU suture and modified MA suture produced similar biomechanical properties.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.239-245
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• 2013

Purpose: Osteoarthritis occurs in many different joints of the body, causing pain, stiffness, and decreased function. The knee is the most frequently affected joint of the lower limb. The aim of this study was to investigate the differences of biomechanics between independent gait and anterior walker dependent gait of patients with osteoarthritis of the knee. Methods: Lower limb joint kinematics and kinetics were evaluated in 15 patients with knee osteoarthritis when walking independently and when walking with an anterior walker. Participants were evaluated in a gait laboratory, with self-selected gait speed and natural arm swing. Results: When walking with a dependent anterior walker, participants walked significantly faster (p<0.01), using a longer stride length (p<0.01), compared to independent gait. When walking with a dependent anterior walker, participants exhibited significantly greater knee flexion/extension motion (p<0.01) and lower knee flexion moment (p<0.05) compared to independent gait. When walking with a dependent anterior walker, participants showed significantly greater peak ankle motion (p<0.01), ankle dorsiflexion/plantarflexion moments (p<0.01), and ankle power generation (p<0.05) compared to independent gait. Conclusion: These biomechanical properties of gait, observed when participants walked with a dependent anterior walker, may be a compensatory response to impaired knee function to allow sufficient power generation for propulsion. Therefore, rehabilitative strategies for patients with osteoarthritis of the knee are needed in order to improve not only knee function but also hip and ankle function.

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.35-45
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• 2011

Purpose: The purpose of this study was to document the structural features of the tendinous portions within the non-pathologic subscapularis muscle by performing high resolution MR imaging of the shoulder. Materials and Methods: Between April 2007 and May 2010, we retrospectively obtained the MR scans of 88 consecutive young patients (88 shoulders) who were in their twenties. MRI and MR arthrography were performed using a 3.0-T system for the evaluation of glenohumeral instability and nonspecific shoulder pain. None of the patient in this study had any evidence of injury to the tendon or muscle belly of the subscapularis. On MR images, we recorded the transverse length of a stout tendinous band and the total tendinous portion of the subscapularis. In addition, we recorded the number of intramuscular tendinous slips of the susbscapularis. Results: The mean transverse length of the tendinous band was 15.0 mm (range: 8 to 20 mm). The mean transverse length of the total tendinous portion was 48.9 mm (range: 40 to 60 mm). The number of intramuscular tendinous slips on the base of the glenoid fossa was 3 in 20 (22.72%), 4 in 45 (51.14%) and 5 in 23 shoulders (26.14%). On the lateral portion, the intramuscular tendinous slips became gradually rounder and thicker and they gave converge in the superior direction. Conclusion: In this study, the structural features of the tendinous portions of the subscapularis on the MR scans were identified. This will in return give good justification for the lines to be pulled during biomechanical stimulation and also for the surgical approach to restore the biomechanical function.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.2
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• pp.175-182
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• 2005

Purpose: Bone tumor occurred in femur frequently involve proximal intertrochanteric region or distal metaphyseal region. Sometimes, the pathologic fracture can happen according to the size of tumor due to the substantial biomechanical stresses. Therefore, the prognosis can be improved biomechanically by the angled blade plate considering the anatomic configuration after the excision of tumor. Materials and Methods: Between October 1991 and April 2005, there were a total of 16 patients(17 cases) who were treated by the excision of tumor and internal fixation with the angled blade plate for bone tumor occurred in femur. After the excision of tumor, we filled the cavity by bone graft in 11 cases and bone cement in 6 cases. The internal fixation was used by angled blade plate in all cases. Result: The average follow-up time was 55.5 months(6-144 months) in 16 patients(17 cases). No metal failure occurred after the operation. Reoperation was performed in 4 cases due to tumor recurrence, and the internal fixation was firm until that. Conclusion: The angled blade plate can prevent the fracture until grafted bone incorporated to host bone, and protect fragile connection between cement and host bone.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.98-103
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• 2012

The repair technique of rotator cuff tear has been markedly developed in recent years. When the natural history of rotator cuff tear was followed, the size of rotator cuff tear increased with time. The fatty infiltration which would come at the later period of rotator cuff tear and the rotator cuff tear arthropathy which would be occurred after massive rotator cuff tear may be the important factors in predicting the prognosis of rotator cuff tear or determining the timing of surgery. Because moderate supraspinatus fatty infiltration appeared an average of 3 years after onset of symptoms, the repair of rotator cuff tear was recommended to be performed before that. And if there was massive rotator cuff tear with cuff tear arthropathy, it was recommended that the rotator cuff repair should be performed before the occurrence of the narrowing of acromiohumeral interval. The techniques of arthroscopic rotator cuff repair were mainly the single row repair and the double row repair. The former is good in view of time consuming and cost, but the latter is superior in view of biomechanics. To maintain the benefit in biomechanics of double row technique and reduce the time of surgery, the suture-bridge technique was invented and widely used recently. There are several modified techniques in arthroscopic suture-bridge technique according to the characteristics of rotator cuff tear.