• 전자공학회논문지S
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• 제35S권2호
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• pp.79-88
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• 1998

We developed a method for the solid angle estimation of acetabular coverage of the femoral head in 3D space. The superior half of the femoral head is modeled as part of a sphere. And the tangent lines connecting from a set of points of the acetabular outline to the center of the fitted sphere are obtained. The lines passthrough the unit sphere whose center is the same as that of the femoral head. The interesecting points form a boundary on the unit sphere. With the points on the unit sphere, we calculate the covered area of the femoral headand estimate the solid angle. Solid angle is defined asthe suface area within the boundary on the unit sphere. In this measurements, the solid angle of normal subjects is on an average 4.3(rad) and the corresponding acetabular coverage is 68%. Unlinke the conventional methods, this solid angle estimation shows real 3D acetabular coverage.

• Hip & pelvis
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• 제35권4호
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• pp.277-280
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• 2023

Dislocation after a total hip arthroplasty occurs in approximately 1% of patients; however, the frequency is much higher after revision surgery. To prevent dislocation, use of a larger femoral head is recommended, and a dual mobility femoral head has been introduced. However, reducing the dual mobility femoral head to the acetabular component is difficult in cases involving contracture in the soft tissue around the joint. A 72-year-old male patient who developed a periprosthetic joint infection underwent two-stage revision surgery using MUTARS^®. Two months after the revision, the hip joint became dislocated and manual reduction was attempted; however, dislocation occurred again. During another revision using a dual mobility bearing, the soft tissue around the hip joint was too tight to reduce. The problem was overcome by first repositioning the dual mobility head into the acetabular socket, followed by assembly of the diaphyseal portion of the implant.

• 한국정밀공학회지
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• 제29권6호
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• pp.680-685
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• 2012

Ceramic femoral heads are now widely used in Total Hip Replacement (THR). Due to their high biocompatibility and low ductility, ceramic femoral heads are considered to be suitable for young and active patients. However, as in testing the mechanical stability of the femoral head, the conventional proof test (standard ISO 7206-10) has its limit of showing axisymmetric stress distribution on the contact surface, while non-uniformed stress distribution is expected after THR. Since non-uniformed stress distribution can result in the increased probability of ceramic femoral head fracture, it is considerable to evaluate the stress distribution in vivo-like conditions. Therefore, this study simulated the ceramic femoral heads under in vivo-like conditions using finite element method. The maximum stress decreased when increasing the size of the femoral head and stress distribution was concentrated on superior contact surface of the taper region.

• 한국임상수의학회지
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• 제20권1호
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• pp.104-109
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• 2003

This study was performed to evaluate the postoperative heating process according to lameness degree, swelling, and muscle atrophy after femoral head and neck ostectomy on Retriever dogs with hip dysplasia and hindleg lameness. Femoral head and neck ostectomy (FHO) was performed for the repair of hip dysplasia in 4 Retriever dogs (5 hips) referred in veterinary medical teaching hospital of college of veterinary medicine, Konkuk University. Age (Mean $\pm$ SD) of patients was 10.3 $\pm$ 3.0 months (range,7 to 16 months) and body weight (Mean $\pm$ SD) was 28.2 $\pm$ 3.4 kg (range, 25 to 34 kg). After FHO, all cases are treated with carprofen (2.2 mg/kg, PO bid, tapering at interval 1-2 weeks) and physical therapy including passive range-of-motion exercises. In all cases, lameness degree was showed V at the next day after surgery, IV at 5 to 7 days, II-III at 30 to 35 days, II at 60 days, and I at 105 to 114 days. These results suggested that femoral head and neck ostectomy was able to be performed on large breed dogs with hip dysplasia and hindleg lameness.

• Journal of Yeungnam Medical Science
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• 제16권1호
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• pp.1-9
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• 1999

대퇴골두 무혈성괴사에 대해서는 수 많은 연구가 광범위하게 진행되어왔으나 아직 병인과 최선의 치료방법은 모르고 있는 실정이다. 앞으로 더 많은 연구와 분석이 이루어져서 새로운 정보가 추가된다면 이 질환으로 인한 유병율과 이환율을 줄일 수 있을 것이다.

• 대한관절경학회지
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• 제3권2호
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• pp.142-145
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• 1999

대퇴골두의 연골 용해증은 관절 연골의 진행성 파괴로 인해, 이차적으로 발생하는 관절 간격의 감소와 강직이 특징이며, 이는 특발성으로 발생하는 경우가 가장 많고, 이차적 원인으로는 감염이나 외상 또는 장기간 고정 등이 거론되고 있다. 저자들은 45세 남자에서 화농성 고관절염 후 발생한 대퇴골두 연골 용해증을 경험하고 관절경하에서 치험하였기에 보고하는 바이다.

• 대한정형외과학회지
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• 제56권3호
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• pp.191-199
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• 2021

대퇴골두 골괴사는 젊거나 중년의 성인에서 발생하며 많은 경우에서 대퇴골두의 함몰과 관절염으로 진행된다. 이 종설에서는 이 질환의 치료에 있어 최신 지견을 기술하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.157-158
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• 1998

The purpose of this study was to test the hypothesis that even very small change of the cue direction in the treatment of the early osteonecrosis could affect the outcomes of operation. For this, the changes in stress transfer within the necrotic area of the femoral head were investigated under various directions and placements of the core utilizing finite element method. The loading of 3188N, which represents after-heel-strike, was imposed in cubic cosine pattern. All nodes on the most distal surface of the model were constrained in all directions. All materials included were assumed to have linear-elastic behavior. The result says that the critical stress, which causes collapse of the femoral head, was reduced when the core was oriented toward the posterior side of the femoral head regardless of location of the necrotic area. The same result was obtained either fibular bone grafting or cementation was adopted. As a consequence, the biomechanical study suggests that the core should be directed toward the loading point where the resultant force is applied to get more desirable treatment of the osteonecrosis of the femoral head in the early stage.

• Korean Journal of Radiology
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• 제23권2호
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• pp.264-270
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• 2022

Objective: This study aimed to investigate the usefulness of bone single-positron emission tomography/computed tomography (SPECT/CT) of the hip in predicting the later occurrence of avascular necrosis (AVN) after slipped capital femoral epiphysis (SCFE) or femoral neck fracture in pediatric patients. The quantitative parameters of SPECT/CT useful in predicting AVN were identified. Materials and Methods: Twenty-one (male:female, 10:11) consecutive patients aged < 18 years (mean age ± standard deviation [SD], 11.0 ± 2.7 years) who underwent surgery for SCFE or femoral neck fracture and postoperative bone SPECT/CT were included. The maximum standardized uptake value (SUV), mean SUV, and minimum SUV of the femoral head were measured. The ratios of the maximum SUV, mean SUV, and minimum SUV of the affected femoral head to the contralateral side were determined. Patients were followed up for > 1 year after the surgery. The SPECT/CT parameters were compared between patients who developed AVN and those who did not. The accuracy of SPECT/CT parameters for predicting AVN was assessed. Results: Six patients developed AVN. There was a significant difference in the ratio of the mean SUV among patients who developed AVN (mean ± SD, 0.8 ± 0.3) and those who did not (1.1 ± 0.2, p = 0.018). However, there were no significant differences in the ratios of the maximum and minimum SUV between the groups (all p = 0.205). For the maximum, mean, and minimum SUVs, no significant differences were observed between the groups (p = 0.519, 0.733, and 0.470, respectively). The cutoff mean SUV ratio of 0.87 yielded a 66.7% sensitivity and 93.2% specificity for predicting AVN. Conclusion: Quantitative bone SPECT/CT is useful for evaluating femoral head viability in pediatric patients with SCFE or femoral neck fractures. Clinicians should consider the high possibility of later AVN development in patients with a decreased mean SUV ratio.

• The Journal of Korean Physical Therapy
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• 제35권4호
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• pp.117-123
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• 2023

Purpose: In this study, subjects with femoral anterior glide type were examined to investigate the effects of femoral head anterior glide fixation during active straight leg raise on the strength of the hip flexor in a supine position. Methods: Fifteen subjects participated in this study. All subjects were classified through an evaluation form for femoral anterior glide type (FAGT). The strength of the hip flexor was measured during active straight leg raise test (ASLR test), and compared with and without femoral anterior glide fixation in a supine position. The fixation of the femoral head was achieved as per the therapist's manual guidelines. Paired t-test was applied to compare changes in the strength of the hip flexor according to fixation conditions. The level of statistical significance was set at α=0.05. Results: The strength of the hip flexor was lesser during the ASLR test with fixation compared to without fixation (p=0.007). Conclusion: The strength of the hip flexor decreases with fixation. Results of this study revealed a difference between hip flexor strength, with and without femoral anterior glide fixation during ASLR, in subjects with femoral anterior glide type.