• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2001.06a
• /
• pp.265-270
• /
• 2001

Hip joint simulator which Is an essential device for evaluating the wear of biomaterials (ultrahigh molecular weight polyethylene, Co-Cr alloy, alumina, etc.) used in total hip joint replacement was developed. This hip joint simulator mimics the joint motion and joint loading of human gait by adapting the 4 degree of freedom in kinematic motion (flexing/extension, adduction/abduction, Internal rotation/external rotation) and axial loading, Four stations are operated by 8 servo-motors and harmony drives. Joint leading was imposed by displacement control from a ball screw, LM guide, and spring system. Each kinematic link system operates separately or coupled modes. A heater and a thermocouple were installed for keeping the body temperature in each station.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1996.10a
• /
• pp.189-194
• /
• 1996

The modern orthopaedics frequently uses the total hip replacement in the artificial hip joint. The wear in this joint requires the re-replacement of the hip joint beacuse it is under the severe load and friction conditions. To solve these problems the previous studies have been mainly focused on the development of the new materials. The research of new material, however, needs much time and effort since it should be experimented for its bio-compatibility, friction, and wear characteristics. To reduce the work, in this study, the finite element analysis is applied to find the new combination of the materials in the total hip replacement which has the excellent contact characteristics. The finite element uses MARC and the 5-node aximetric element. The results show that in case of acetabulum UHMWP has good characteristics, in femoral head, the $Al_2O_3$, and in stem, Ti6Al4V.

• Journal of Veterinary Clinics
• /
• v.36 no.4
• /
• pp.229-232
• /
• 2019

Total Hip Replacement in a patient with chronic coxofemoral joint dislocation is a challenging problem because chronic coxofemoral joint dislocation causes severe morphological changes. These challenging factors make surgery more difficult and increase the possibility of postoperative complications including cup implant dislocation and prosthetic joint luxation. All patients were diagnosed having at least 2 months of coxofemoral joint dislocation. On physical examination, crepitus was noted in the coxofemoral joint. Radiographs revealed hip joint dislocation with mild to severe degenerative changes. Total hip replacement was planned for all patients. Dorsal acetabular rim deficiency in 3 cases was augmented using a locking plate and polymethylmethacrylate bone cement. All cases have shown difficulty in prosthetic joint reduction. Pectineus and rectus femoris muscle origin were released in all cases. At 12 months follow up, all patients showed satisfactory ambulation. The issues on perioperative prosthetic joint reduction and luxation due to chronic coxofemoral joint luxation with muscle contracture and dorsal acetabular rim deficiency can be resolved by muscle releasing and dorsal acetabular rim augmentation.

• Tribology and Lubricants
• /
• v.13 no.1
• /
• pp.82-87
• /
• 1997

The modern orthopaedics frequently uses the total hip replacement in the artificial hip joint. The wear in this joint requires a re-replacement of hip joints because it is under the severe load and friction conditions. To solve these problems the previous studies have been mainly focussed on the development of new materials. The research of new materials, however, needs much time and effort since it should be experimented for its bio-compatibility, friction, and wear characteristics. To reduce the work, in this study, the finite element analysis is applied to find new combinations of bio-materials in the total hip replacement which has the excellent contact characteristics. A non-linear FEM program MARC with 5-node axisymmetric element was used for analyzing the contact stresses between the hip joints. The computed results show that in case of acetabulum UHMWP has good characteristics, in femoral head, $Al_2O_3$, and in stem, Ti6Al4V.

• Hip & pelvis
• /
• v.36 no.2
• /
• pp.77-86
• /
• 2024

Knowledge of the relationship between the hip and spine is essential in the effort to minimize instability and improve outcomes following total hip arthroplasty (THA). A detailed yet straightforward preoperative imaging workup can provide valuable information on pelvic positioning, which may be helpful for optimum placement of the acetabular cup. For a streamlined preoperative assessment of THA candidates, classification systems with a capacity for providing a more personalized approach to performance of THA have been introduced. Familiarity with these systems and their clinical application is important in the effort to optimize component placement and reduce the risk of instability. Looking ahead, the principles of the hip-spine relationship are being integrated using emerging innovative technologies, promising further streamlining of the evaluation process.

• Hip & pelvis
• /
• v.36 no.2
• /
• pp.108-119
• /
• 2024

Purpose: The incidence of deep vein thrombosis (DVT) following total hip arthroplasty (THA) without chemoprophylaxis could be as high as 50% in Caucasians. However, according to several subsequent studies, the incidence of venous thromboembolic events (VTE) in Asians was much lower. The routine use of chemoprophylaxis, which could potentially cause increased bleeding, infection, and wound complications, has been questioned in low-incidence populations. The objective of this study is to determine the incidence of VTE after primary THA without chemoprophylaxis in an Asian population using a fast-track rehabilitation protocol and to verify the safety profile for use of 'mechanical prophylaxis alone' in patients with standard risk of VTE. Materials and Methods: This is a retrospective cohort study of 542 Hong Kong Chinese patients who underwent primary THA without chemoprophylaxis. All patients received intermittent pneumatic compression and graduated compression stockings as mechanical prophylaxis. Multimodal pain management was applied in order to facilitate early mobilisation. Routine duplex ultrasonography was performed between the fourth and seventh postoperative day for detection of proximal DVT. Results: All patients were Chinese (mean age, 63.0±11.9 years). Six patients developed proximal DVT (incidence rate, 1.1%). None of the patients had symptomatic or fatal pulmonary embolism. Conclusion: The incidence of VTE after primary THA without chemical prophylaxis can be low in Asian populations when following a fast-track rehabilitation protocol. Mechanical prophylaxis alone can be regarded as a reasonably safe practice in terms of a balanced benefit-to-risk ratio for Asian patients with standard risk of VTE.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.511-512
• /
• 2006

According to development of medical science and engineering, people has made efforts to solve tile discomfort of body accident as well as the life span. Many cases that reduce pain of a hip joint or limitation of motion using Revision Total Hip Replacement are getting increased. However it has not proved which material is the most appropriate. Scientists are still studying about materials of the artificial joint. In accordance with advance of science, the materials are Betting better. Recently, when Revision Total Hip Replacement is performed, typical materials are Ti-alloys Ceramics. We have studied materials of artificial joints and analyzed which one is better for human's body.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.3
• /
• pp.200-208
• /
• 2008

Total Hip Replacement(THR) is a surgical procedure that replaces a diseased hip joint with a prosthesis. A plastic or metal cup forms the socket, and the head of the femur is replaced by a metal ball on a stem placed inside the femur. Due to the various types and shapes of human hip joint of every individual, a selected commercial implant sometimes may not be the best-fit to a patient, or it cannot be applied because of its discrepancy. Hence extracting geometry parameters of hip joint is one of the most crucial processes in designing custom-made implants. This paper describes the framework of a methodology to extract the geometric parameters of the hip joint. The parameters include anatomical axis, femoral head, head offset length, femoral neck, neck shaft angle, anteversion, acetabulum, and canal flare index. The proposed system automatically recommends the size and shape of a custom-made hip implant with respect to the patient's individual anatomy from 3D models of hip structures. The proposed procedure creating these custom-made implants with some typical examples is precisely presented and discussed in this paper.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.11
• /
• pp.17-24
• /
• 2000

• Journal of Veterinary Clinics
• /
• v.31 no.2
• /
• pp.125-128
• /
• 2014

A 7-year-old, intact female Golden Retriever weighing 38 kg was referred for left coxofemoral joint luxation. On physical examination, pain and crepitus were noted atthe left hip joint during joint extension. Radiological examination revealed coxofemoral joint luxation and mild degenerative bone changes in the left hip joint. We performed minimally invasive arthroscopy-assisted reduction with TightRope$^{(R)}$ as a treatment option; however, the left coxofemoral joint was reluxated after one month postoperatively. We performed cementless total hip replacement (THR) of the luxated left coxofemoral joint. At tenmonths after surgery, the dog could sit, stand, walk normally and jump comfortably without lameness. The thigh girth measurement of the operated limb was 108.6% of the contralateral limb. Based on the present case, THR can be a successful treatment for coxofemoral joint luxation in dogs with failed coxofemoral joint reduction.