• Advances in Computational Design
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• v.4 no.3
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• pp.295-305
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• 2019

The sealing cement of total hip arthroplasty is the most widely used binder in orthopedic surgery for anchoring implants to their recipient bones. Nevertheless, this latter remains a fragile material with weak mechanical properties. Inside this material cracks initiate from cavities. These cracks propagate under the effect of fatigue and lead to the failure of this binder and consequently the loosening of the prosthesis. In this context, this work consists to predict the position of cracks initiation and their propagations path using the Extended Finite Element Method (XFEM). The results show that cracks can only be initiated from a sharp edges of an ellipsoidal cavity which the ratio of the minor axis over the major axis is equal to 0.1. A maximum crack length of 19 ?m found for a cavity situated in the proximal zone position under a static loading. All cracks propagate in same(almost) way regardless of the cavity(site of initiation) position and its inclination in the proximal zone.

• Journal of Biomedical Engineering Research
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• v.17 no.1
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• pp.61-70
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• 1996

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony inyowth and secondary long term fixation. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone stem interface. An accurate evaluation of interf'ace micromotion and stress/strain fields in the bone-implant system may be relevant for better understanding of clinical situations and improving THA design. Recently finite element method(FEM) was introduced in'orthopaedic research field due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional finite element model of proximal femur with $Multilock^{TM}$ stem of 1179 blick elements to analyse the micromotions and mechanical behaviors at the bone-stem inteface in early post-operative period for the load simulating single leg stance. The results indicates that the values of relative motion for this well fit stem were $150{\mu}m$ in maximum $82{\mu}m$ in minimum and the largest relative motion was developed in medial region of Proximal femur and in anterior-posterior direction. The motion in the proximal bone was much greater than in the distal bone and the stress pattern showed high stress concentration on the cortex near the tip of the stem. These findings indicate that the loading on the hip joint in the early postoperative situation before achieving bony ingrowth could produce large micromotion of $150{\mu}m$ and clinicaly non-cemented THA patient should not be allowed weight bearing strictly early in the postoperative period.

• Clinics in Shoulder and Elbow
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• v.17 no.4
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• pp.201-204
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• 2014

Pulmonary embolism is a serious complication, which is well known in patients undergoing total hip or total knee arthroplasty or lower extremity fracture surgery. But, there are few literatures concerning pulmonary embolism after upper extremity surgery. Pulmonary embolism after minor upper extremity fracture surgery is extremely rare. We report a case of 66-year-old female patient that developed pulmonary embolism after percutaneous cannulated screw fixation for a greater tubercle fracture of the proximal humerus with literature review.

• Journal of Trauma and Injury
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• v.31 no.3
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• pp.177-180
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• 2018

Heterotopic bone formation in abdominal incisions is a recognized but uncommon sequela of abdominal surgery. On the other hand, the formation of ectopic bone is a well-recognized complication following arthroplasty of the hip. Heterotopic ossification of midline abdominal incision scars is a subtype of myositis ossificans traumatica. Ectopic bone formation of midline abdominal incisions may cause regional pain or discomfort in the patient after surgery. If symptomatic, treatment is complete excision with primary closure. Radiologically, it is important to distinguish this benign entity from postoperative complications. We report a 69-year-old male who underwent exploratory laparotomy for traumatic small bowel perforation. A segment of abnormal hard tissue was found in the abdominal wall. Heterotopic ossification may occur at various sites and is a recognized but infrequent sequela of exploratory laparotomy. This case highlights clinical and etiological features of this finding.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.125-133
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• 2021

Purpose: The clinical outcomes were investigated to determine if arthroscopic management is a useful method for 19 hips with iliopsoas tendon impingement (IPI) after total hip arthroplasty (THA). Materials and Methods: Eighteen patients (19 hips), who complained of groin pain and flexion pain that persisted after THA from September 2013 to December 2019, were the subjects of this investigation. The mean time to manifestation after THA was four months (range, 1-9 months) in patients of an average age of 60 years (range, 50-69 years). Thirteen out of 18 patients underwent THA using the direct anterior approach and five by the lateral approach. IPI was diagnosed by the medical history, physical examination, blood test, radiographic examination using X-ray and computed tomography, and topical injection therapy. All patients underwent arthroscopic treatment and a dynamic arthroscopic physical examination after exposure to the iliopsoas tendon revealed impingement. Tenotomy was then performed on the muscle portion through the total tendon portion. Symptoms and pain levels of preoperative, postoperative and follow-up period were investigated and compared. Results: The Western Ontario and McMaster Universities Osteoarthritis Index score decreased from an average of 58.4 (range, 40-88) before surgery to an average of 35.0 (range, 15-76) after surgery. Similarly, the visual analogue scale decreased from an average of 4.0 (range, 2-6) before surgery to an average of 1.4 (range, 0-4) after surgery. Sixteen patients (88.9%) showed pain relief and improvement in the straight leg raise test, and two patients showed postoperative muscle weakness and sustained pain. In the follow-up period, muscle weakness improved. One patient underwent arthroscopic iliopsoas tenotomy at the lesser trochanteric level but the symptoms persisted. The clinical symptoms were improved after one more tenotomy at the joint level. Conclusion: Arthroscopic iliopsoas tenotomy performed in patients with IPI after THA showed good clinical results.

• Journal of Preventive Medicine and Public Health
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• v.43 no.6
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• pp.523-534
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• 2010

Objectives: We assessed impact of performance reporting information about the readmission rate, length of stay and cost of hip hemiarthroplasty. Methods: The data are from a nationwide claims database, National Quality Improvement Project database, of Health Insurance Review & Assessment Service in Korea. From January 2006 to April 2008, we received information of length of stay, readmission within 30 days, cost of 22 851 hip hemiarthroplasty episodes. Each episodes has retained the diagnoses of comorbidities and demographics. We used time-series analysis to assess the shifting of patients selections, between high volume (over 16 operations in a year) and low volume institutions, after performance reporting (December 2007). The changes of quality (readmission, length of stay) and cost were evaluated by multilevel analysis with adjustment of patient's factors and institutional factors after performance reporting. Results: As compared with the before performance reporting, the proportion of patients who choose the high volume institution, increased 3.45% and the trends continued 4 months at marginal significance (p = 0.059). After performance reporting, national average readmission rate, length of stay were decreased by 0.49 OR (95% CI=0.25 - 0.95) and 10% (${\beta}$=-0.102, p<0.01) and cost was not changed (${\beta}$=-0.01, p=0.27). The high volume institutions were more decreased than low volume in length of stay. Conclusions: After performance reporting, readmission rate, length of stay were decreased and the patient selections were marginally shifted from low volume institutions to high volume institutions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.5
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• pp.406-413
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• 2004

Progress in medical science and cell biology has resulted in the transplantation of human cells and tissues from on human into another, facilitating reproduction and the restoration of form and function, as well as enhancing the quality of life. For more than 40 years, society has recognized the medical and humanitarian value of donation and transplanting organs and tissues. The standard operating procedures of hard tissues reflect the collective expertise and conscientious efforts of tissue bank professionals to provide a foundation for the guidance of tissue banking activities. Procurement of allograft tissues from surgical bone donors is a part of tissue banking. During the past decades the use of bone allografts has become widely accepted for the filling of skelectal defects in a variety of surgical procedures. In particular in the field of orthopaedic and oral and maxillofacial surgery the demand for allografts obtained from either living or post-mortem donors has increased. Hospital-based tissue banks mainly retrieve allografts from living donors undergoing primary total hip replacement for osteoarthritis or hemi arthroplasty for hip fractures and orthgnatic surgery such as angle reduction. Although bone banks have existed for many years, the elements of organized and maintaining a hospital bone bank have not been well documented. The experience with a tissue bank at Korea Tissue Bank(KTB) between 2001 and 2004 provides a model of procurement, storage, processing, sterilization and documentation associated with such a facility. The following report describes the standard operating procedures of hard tissues such as femoral head obtained from living donors.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.71-74
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• 1994

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony ingrowth and secondary long term fixation. Bone ingrowth depends strongly on relative micromotion and stress distributions at the interface. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone-prosthesis interface, Hence an accurate evaluation of interface behavior and stress/strain fields in the bone implant system may be relevant for better understanding of clinical situations and improving THA design. However, complete evaluation of load transfer in the bone remains difficult to assess experimentally, Hence, recently finite element method (FEM) was introduced in orthopaedic research field to fill the gap due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional numerical finite element model which is composed of totally 1179 elements off and 8 node blick. We also analyzed the micromotions at the bone-stem interface and mechanical behavior of existing bone prosthesis for a loading condition simulating the single leg stance. The result indicates that the values of relative motion for this well fit Multilock stem were $150{\mu}m$ in maximum, $82{\mu}m$ in minimum, and the largest relative motion developed in medial region of proximal femur with anterior-posterior direction. The proximal region of the bone was much larger in motion than the distal region and the stress pattern shows high stress concentration on the cortex near the tip of the stem. These findings indicates that the loading in the proximal femoral bone in the early postoperative situation can produce micromotions on the interface and clinically cementless TEA patient should not be allowed weight bearing strictly early in the postoperative period.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.245-248
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• 1997

Excessive stress on the bone-stem interface may cause local micromotion that could produce midthigh pain, interface bone resorption and prevent bony ingrowth. It is important for clinician and prosthetic designer to develop an understanding of the load transfer mechanism, its associated stress pattern and its relationships with the particular mechanical characteristics of the femoral stem designs. Finite element method (FEM) is preeminently suited to provide information in this respect. The authors developed 3-dimensional numerical finite element models implanted with the straight stem which is composed of total 1170 elements of 8 nodes and with the curved stem which is composed of total 885 elements of 8 node, and analysed the relative micromotions between the straight stem and the curved stem in immediate postoperative stage of an uncemented total hip replacement in load simulating the single leg stance. The results showed that the rotational displacement was occupied over 90% of total micromotion in both types of stem and was peak at the proximal medial portion of the stem, but markedly less distally. The curved stem was more stable especially in terms of rotational stability. It is recommended that surgeons do not allow the patient weight bearing until bony ingrowth was achieved. In the future more attention should be drawn to increase initial rotational stability of the two types of femoral stem to prevent loosening from excessive micromotion.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.112-117
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• 2006

Deep vein thrombosis and pulmonary embolism are serious fatal complication after orthopedic surgery. Most of them occur after large operation such as total knee/hip arthroplasty. Some reports about deep vein thrombosis after simple arthroscopic procedure were on the Western literatures, but there was no report on the Korean literature. So we report two cases of pulmonary embolism after knee arthroscopic procedures.