• Journal of Biomedical Engineering Research
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• v.31 no.6
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• pp.449-455
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• 2010

A ceramic articulating system in total hip replacement thought to be superior to metal-on-polyethylene due to its extremely low coefficient of friction and potential for high resistance to wear. But ceramic is brittle, which makes it mechanically and theoretically susceptible to fracture under certain mechanical conditions. In the current study, nine different models of ceramic ball heads were mechanically evaluated using 3D finite element(FE) analyses. It was found that the maximum stress in all ceramic models was lower than ceramic flexural strength, and it satisfied the requirements of the FDA Gaudience for artificial hip implant. Thus, ceramic ball head models introduced in the current study could be mechanically safe for clinical applications.

• Hip & pelvis
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• v.30 no.4
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• pp.241-253
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• 2018

Purpose: This study was conducted to compare cemented and cementless bipolar hemiarthroplasty in elderly patients with unstable intertrochanteric fractures via meta-analysis and systematic review of relevant studies. Materials and Methods: Systematic review and meta-analysis were performed on 31 available clinical studies; 19 of these studies used cemented stems, 12 used cementless stems, one used both types of stems, and two studies involved a comparative analysis of both stem types. Results: There were statistically significant differences in rates of leg length discrepancy (LLD) greater than 1 cm between the cemented (event rate, 0.089) and cementless groups (event rate, 0.015 and 0.047; P=0.03). Conclusion: Cemented bipolar hemiarthroplasty and cementless bipolar hemiarthroplasty performed on elderly patients with unstable intertrochanteric fracture revealed similar mortality and complication rates; however, the rate of LLD greater than 1 cm was significantly higher in the cemented group compared with the cementless group.

• Hip & pelvis
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• v.34 no.2
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• pp.79-86
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• 2022

Purpose: The purpose of this study was to determine whether the direct anterior approach (DAA) can be applied to hemiarthroplasty for treatment of unstable femoral intertrochanteric fractures in elderly patients. Materials and Methods: We conducted a retrospective review of 34 cases (34 patients) who underwent bipolar hemiarthroplasty using a DAA from February 2019 to April 2020. The mean age of the patients was 82.68 years (range, 67-95 years). A cementless distal fixation hip system was used in all cases. Operation time, total amount of blood loss, intraoperative and postoperative fractures, infections, and reoperations were measured. The patients performed weight-bearing walking as tolerated immediately after surgery. Measurement of migration of the greater trochanter (GT) and progressive subsidence of the femoral stem was performed using follow-up radiographs. Results: The mean operative time was 83.50 minutes (range, 60-120 minutes). The mean amount of bleeding was 263.53 mL (range, 112-464 mL). Walking started a mean of 3.03 days (range, 3-4 days) after surgery. There was no case of progressive migration of the GT more than 5 mm even though it was not fixed. There were no cases of infection, dislocation, or reoperation. Conclusion: Bipolar hemiarthroplasty using the DAA for treatment of unstable femoral intertrochanteric fractures could be considered a useful option that provides many advantages in elderly patients.

• 대한예방의학회:학술대회논문집
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• 1995.10a
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• pp.97-98
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• 1995

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.703-704
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• 2007

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2451-2454
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• 2005

In recent years, the importance of the characterization of fall for a fracture prevention system keeps increasing since fracture from a fall can lead to serious health problems. Fall is one of the major sources which increase morbidity in elderly people. In terms of the cost and the influence to the quality of life, the most serious injury with hip fractures is caused by falls. The traditional methods in characterizing fall patterns have been mainly by the epidemiological surveys. With surveys, the exact data of fall patterns can not been acquired. In this paper, we measured and analyzed with the parameters related to fall pattern such as velocities and accelerations during the motion of falls using 3D motion capture program. We acquired the parameters of the fall pattern of intentional and unexpected fall. The result showed that the variation of velocity and acceleration during fall was very important in characterizing fall pattern, which of vital importance for the development of a fracture prevention system and for the safety of the elderly.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.355-361
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• 2004

Ceramic femoral heads in the total hip replacement have been developed to reduce the polyethylene liner wear, Alumina and zirconia (3Y-TZP) having the excellent tribological properties are coupled against acetabular cups of polyethylene and are used in clinical application worldwide. However, alumina has a risk of catastrophic failure, and zirconia has the low temperature degradation in spite of enhanced fracture toughness. Recently, novel zirconia/alumina composite is very attractive due to the low temperature degradation (LTD)-free character and high fracture toughness. In the present study, we focus on the wear of ceramic on ceramic, which are able to be used as femoral heads and acetabular cups. Therefore, LTD-free zirconia/alumina composites with three compositions are made in a form of disk and cylinder, and the wear of the composites is performed on pin-on-disk type wear tester. The wear is conducted with or without lubricant. All the composites fabricated with the different composition show the good wear resistance.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.91-94
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• 2003

Ceramic femoral heads in the total hip replacement have been developed to reduce the polyethylene liner wear. Alumina and zirconia (3Y-TZP) are using in clinical application worldwide and there are many good test reports. However, alumina has a risk of catastrophic failure, and zirconia has the low temperature degradation in spite of enhanced fracture toughness. Recently, novel zirconia/alumina composite having low temperature degradation-free character and high fracture tough . was developed and it leads the lower wear 3f polyethylene than alumina and zirconia. In the present study, in order to optimise the microstructure of low temperature degradation (LTD)-free zirconia/alumina composite for the best wear resistance of polyethylene, various compositions of (LTD)-free zirconia/alumina composites were fabricated, and the sliding wear of UHMWPE against these novel composites were examined and compared with that against alumina and zirconia ceramics used for total hip joint heads.

• Hip & pelvis
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• v.35 no.3
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• pp.164-174
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• 2023

Purpose: This study investigates the relationship between preoperative neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-C-reactive protein ratio (LCR), albumin, and 2-year mortality in elderly patients having hemiarthroplasty for displaced femoral neck fracture (FNF). Materials and Methods: We retrospectively reviewed 284 elderly patients who underwent hemiarthroplasty for Garden type IV FNF from September 2014 to September 2020. Using the receiver operating characteristic curve, optimal cutoff values for LCR, NLR, and albumin were established, and patients were categorized as low or high. Associations with 2-year mortality were evaluated through univariate and multivariate Cox regression analyses. Results: Of the 284 patients, 124 patients (45.9%) died within 2 years post-surgery. The optimal cutoff values were: LCR at 7.758 (specificity 58.5%, sensitivity 25.0%), NLR at 3.854 (specificity 39.2%, sensitivity 40.0%), and albumin at 3.750 (specificity 65.9%, sensitivity 21.9%). Patients with low LCR (<7.758), high NLR (≥3.854), and low albumin (<3.750) had a statistically significant reduced survival time compared to their counterparts. Conclusion: Lower preoperative LCR and albumin levels, along with higher NLR, effectively predict 2-year mortality and 30-day post-surgery complications in elderly patients with Garden type IV FNF undergoing hemiarthroplasty.

• Hip & pelvis
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• v.35 no.1
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• pp.54-61
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• 2023

Purpose: The purpose was to examine the clinical and radiological outcomes after surgical treatment of acetabular fractures with total hip arthroplasty with a dual mobility cup cemented into a porous multihole cup in the population of frail elderly patients. Materials and Methods: A retrospective review of 16 patients who underwent surgery (mean age, 76.7 years) with a mean follow-up period of 36.9 months was conducted. Following surgery, patients underwent postoperative follow-up at six weeks, three, six, and 12 months and clinical and radiological examinations were performed. Results: Classification of fractures was based on the Letournel classification. Following surgery, all patients were allowed weight-bearing as tolerated immediately postoperative. Fourteen patients showed maintenance of preoperative mobility status at one year. The mean Harris hip score was 64.8 (range, 34.7-82.8) and 80.0 (range, 60.8-93.8) at three months and one year, respectively. The mortality rate was 12.5% at one year (2/16). Complications included heterotopic ossification (2/16), deep venous thrombosis (1/16), heamatoma (1/16), and femoral revision due to a Vancouver B2 fracture (1/16). No case of deep infection, dislocation, or implant loosening was reported. Conclusion: Total hip arthroplasty using a dual mobility cup cemented into a porous multihole cup with locking screws resulted in a stable construct with a capacity for immediate weight-bearing as tolerated with rapid relief of pain. The findings of this study suggest that this procedure can be regarded as a safe method that has shown promising clinical and radiological outcomes for treatment of patients with medical frailty.