• 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.

• Journal of Korean Foot and Ankle Society
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• v.15 no.3
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• pp.149-152
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• 2011

Purpose: The Akin osteotomy which is a closing wedge osteotomy of the proximal phalanx widely used for the correction of hallux valgus has several methods of fixation. we tried to report the effects of the fixation using an absorbable suture material during the Akin osteotomy for the hallux valgus. Materials and Methods: This study was based on 448 cases of 346 patients who were able for follow-up more than 12 months among the patients who had an Akin osteotomy together with the surgery of hallux valgus between March of 2006 and May of 2010. Absorbable suture material had been used in all cases. Radiologically displacement and union of osteotomy site were observed after the surgery, and clinically postoperative complication such as skin irritation, pain and satisfaction were investigated. Results: Radiologically all cases had showed complete union and no case had the loss of an correction due to loss of fixation. Also, any case had no skin irritation due to a knot. Three cases had a medial cortical breakage due to a strong knot, and the initial one case among them had additionally fixed the osteotomy site for four weeks using K-wire, and the remaining two cases had fixed a suture on an articular surface without any fixation of an additional wire. If a medial cortical bone was lost by carrying out an ostectomy due to proximal protrusion of proximal phalanx, three cases could show union through the fixation of suture on an articular surface. Conclusion: This study considers that the fixation of the osteotomy site using an absorbable suture material in an Akin osteotomy was effective method and the advantage of this procedure was unnecessity of the material removal and no skin irritation.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.163-167
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• 2006

Purpose: To evaluate the results of extracorporeal shock wave therapy (ESWT) for patients with chronic proximal plantar fascitis. Materials and Methods: Between April 2005 and April 2006, 35 cases (24 patients) who were followed more than 6 months were evaluated. By $EvoTron^{(R)}$, 2 sessions of ESWT (Group 1: 1200 and Group 2: 1500 shock waves / session of $0.12\;mJ/mm^2$) were performed at 2 weeks interval. The mean age was 40.0 (range, 15-59) years. 13 patients were male and 11 patients were female. Visual analogue scale (VAS) on daily activity and a 100-point scoring system including 70 points for pain and 30 points for function were used. The clinical outcomes were rated as follows: excellent, no pain on daily activity; good, less than 50% of previous VAS; fair, 50-75% of previous VAS; or poor, more than 75% of previous VAS. Excellent and good were graded as satisfactory results. We compare clinical results between groups and evaluate the relationships between clinical results and duration of symptom, fascial thickening and previous steroid injection were evaluated. Results: Overall satisfactory rate were 71.4%. There was no significant difference of clinical results between groups. And there were no significant difference between clinical results and duration of symtom, preoperative fascial thickening and previous steroid injection. Conclusions: ESWT for recalcitrant chronic proximal plantar fascitis is useful treatment method with high patient satisfaction and pain relief, but more long-term study must be needed.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.11-15
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• 2010

Purpose: The purpose of this study was to retrospectively analyze the clinical and radiologic results of the proximal crescentic osteotomy for moderate to severe hallux valgus deformity. Materials and Methods: Between March 2001 and March 2008, 55 patients (71 feet) who had undergone crescentic osteotomy and distal soft tissue procedure for hallux valgus were followed up for more than one year. The average follow-up period was 15.8 months (12~28 months) and the average age at the time of surgery was 49.8 years (20~69 years). We analyzed the hallux valgus angle (HVA), the first-second intermetatarsal angle (IMA), the length of 1st metatarsal bone and the position of medial sesamoid in preoperative and the last follow-up radiographs. The American Othopeaedic Foot and Ankle Society (AOFAS) score and patient satisfaction were measured by modifying Johnson's method which were used for clinical outcome assessments. Results: The HVA and the IMA were 36.2 and 15.8 degrees preoperatively, and 10.8 and 3.9 degrees at the last follow-up, respectively. The amount of shortening of 1st metatarsal bone averaged $2.3{\pm}1.1$ rum postoperatively. The medial sesamoid position improved from a preoperative average of grade 6.6 to the last follow-up average of grade 1.9. The AOFAS score improved from a preoperative average of 45.3 points to an average 90.6 points at the last follow-up. The patient's satisfaction was completely satisfied in 61 cases (85.9%), satisfied with minor reservations in 6 cases (8.5%), satisfied with major reservations in 2 cases (2.8%), and dissatisfied in 2 cases (2.8%). Conclusion: Proximal crescentic osteotomy produced satisfactory results for moderate to severe hallux valgus deformity.

• Journal of Chest Surgery
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• v.19 no.3
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• pp.443-448
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• 1986

Aortic dissection is a serious disease that mortality does not approach to zero despite of medical and surgical improvement. Recently two cases of aortic dissection were treated with good results by the two other methods. Case 1 [57-Y-0-Male]; Chief complaint was chest pain radiating to the back. Preoperatively he was controlled by Minipress, dichlotride, & sodium nitroprusside. Aortography showed DeBakey Type III aortic dissection extending from just below the Lt. subclavian artery to the proximal portion of the origin of the renal artery. Through the midline long incision Flow reversal & Thrombo-exclusion method was used, and bypass course was proximal anastomosis at the ascending aorta - through the Rt. thoracic cavity - midportion of the diaphragm - posterior to the liver, stomach, & pancreas - distal anastomosis at the abdominal aorta proximal to its bifurcation. Bypass graft was preclotted 20 mm Dacron Woven Graft, and the aortic arch between the Lt. subclavian artery & Lt. common carotid artery was divided and meticulously sutured. Control aortogram which was done at 4th postoperative month revealed obstruction of the false lumen by thrombosis, and complications were not noticed. Case 2 [53-Y-0-Male]; Chief complaint was chest pain radiating to the abdomen. DeBakey Type III aortic dissection which was similar to the case 1 was detected by the aortography, and involvement of the Lt. subclavian & common carotid arteries was suspicious. Through the Lt. posterolateral thoracotomy the Ringed Intraluminal Sutureless Graft, No. 22 mm, was inserted from just below the Lt. common carotid artery to the midportion of the descending thoracic aorta under total circulation arrest using a F-F bypass, and the Lt. subclavian artery was ligated. Postoperatively hospital course was uneventful with antihypertensive drugs, and any specific complications were not noticed.

• Journal of Haehwa Medicine
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• v.29 no.1
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• pp.18-25
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• 2020

Objective: The goal of this study is to investigate whether peripheral axonal regeneration is affected by diabetes in experimental animals. Method: Sprague Dawely rat was injected with 45~50 mg/kg of streptozotocin (STZ) to generate an animal model of diabetes. Three months after STZ injection, sciatic nerve (2 cm length) was removed and the same length of nerve segments from STZ-injected animal or from control animal (CTL) was transplanted into STZ-injected animals (STZ-STZ and STZ-CTL respectively). Similarly, sciatic nerve segments from STZ-injected animal or from control animal were grafted into the control animals (CTL-STZ and CTL-CTL respectively). All animals were sacrificed 2 weeks after transplantation. Sciatic nerve sections were prepared and subjected to immunofluorescence staining analysis. Results: Immunofluorescence staining for NF-200 showed that distal elongation of regenerating axons reached 40~80% of proximal neve in both CTL-STZ and CTL-CTL groups. However, distal elongation in both STZ-STZ and STZ-CTL groups were 20~60% of proximal nerve. Furthermore, measurement of axonal regeneration after immuno-staining with SCG10 showed that the scores of distal elongation relative to proximal nerve were 50~90% in CTL-CTL and CTL-STZ groups and 10-60% in STZ-CTL and STZ-STZ. Conclusions: Our data showed that the levels of axonal regeneration were not affected irrespective of whether they were from STZ- or CTL graft, but were greatly reduced when the nerves were transplanted into the STZ host.

• 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.22 no.1
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• pp.29-36
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• 2019

Background: The execution of fibular allograft augmentation in unstable proximal humerus fractures (PHFs) was technically demanding. In this study, the authors evaluated the clinical and radiographic outcomes after tricortical iliac allograft (TIA) augmentation in PHFs. Methods: We retrospectively assessed 38 PHF patients treated with locking-plate fixation and TIA augmentation. Insertion of a TIA was indicated when an unstable PHF showed a large cavitary defect and poor medial column support after open reduction, regardless of the presence of medial cortical comminution in preoperative images. Radiographic imaging parameters (humeral head height, HHH; humeral neck-shaft angle, HNSA; head mediolateral offset, HMLO; and status of the union), Constant score, and range of motion were evaluated. Patients were grouped according to whether the medial column support after open reduction was poor or not (groups A and B, respectively); clinical outcomes were compared for all parameters. Results: All fractures healed radiologically (average duration to complete union, 5.8 months). At final evaluation, the average Constant score was 73 points and the mean active forward flexion was $148^{\circ}$. Based on the Paavolainen assessment method, 33 patients had good results and 5 patients showed fair results. The mean loss of reduction was 1.32 mm in HHH and 5.02% in HMLO. None of the parameters evaluated showed a statistically significant difference between the two groups (poor and not poor medial column support). Conclusions: In unstable PHFs, TIA augmentation can provide good clinical and radiological results when there are poor medial column support and a large cavitary defect after open reduction.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.577-585
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• 2019

Objective : Comparing the effects of magnetically controlled growing rod (MCGR) and traditional growing rod (TGR) techniques on the sagittal plane in the treatment of early-onset scoliosis (EOS). Methods : Twelve patients were operated using dual MCGR technique in one center, while 15 patients were operated using dual TGR technique for EOS in another center. Patients' demographic characteristics, complications and radiological measurements such as cobb angle, thoracic kyphosis, lumbar lordosis, T1-S1 range (mm), proximal junctional angle, distal junctional angle, sagittal balance, coronal balance, pelvic incidence, sacral slope and pelvic tilt were assessed and compared in preoperative, postoperative and last follow-up period. Results : Age and sex distributions were similar in both groups. The mean number of lengthening in the MCGR group was 12 (8-15) and 4.8 (3-7) in the TGR group. Two techniques were shown to be effective in controlling the curvature and in the increase of T1-S1 distance. In TGR group, four patients had rod fractures, six patients had screw pull-out and four patients had an infection, whereas three patients had screw pull-out and one patient had infection complications in the MCGR group. Conclusion : There was no significant difference between the two groups in terms of cobb angle, coronal and sagittal balance and sagittal pelvic parameters. MCGR can cause hypokyphosis and proximal junctional kyphosis in a minimum 2-year follow-up period. The implant-related complications were less in the MCGR group. However, larger case groups and longer follow-up periods are required for the better understanding of the superiority of one method on other in terms of complications.

• Korean Journal of Applied Biomechanics
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• v.33 no.4
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• pp.164-174
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• 2023

Objective: The aim of this study was to quantitatively analyze the impact characteristics of the lower extremity on strike pattern during running. Method: 19 young subjects (age: 26.53 ± 5.24 yrs., height: 174.89 ± 4.75 cm, weight: 70.97 ± 5.97 kg) participated in this study. All subjects performed treadmill running with fore-foot strike (FFS), mid-foot strike (MFS), and rear-foot strike (RFS) to analyze the impact characteristics in the lower extremity. Impact variables were analyzed including vertical ground reaction force, lower extremity joint moments, impact acceleration, and impact shock. Accelerometers for measuring impact acceleration and impact shock were attached to the heel, distal tibia, proximal tibia, and 50% point of the femur. Results: The peak vertical force and loading rate in passive portion were significantly higher in MFS and FFS compared to FFS. The peak plantarflexion moment at the ankle joint was significantly higher in the FFS compared to the MFS and RFS, while the peak extension moment at the knee joint was significantly higher in the RFS compared to the MFS and FFS. The resultant impact acceleration was significantly higher in FFS and MFS than in RFS at the foot and distal tibia, and MFS was significantly higher than FFS at the proximal tibia. In impact shock, FFS and MFS were significantly higher than RFS at the foot, distal tibia, and proximal tibia. Conclusion: Running with 3 strike patterns (FFS, MFS, and RFS) show different impact characteristics which may lead to an increased risk of running-related injuries (RRI). However, through the results of this study, it is possible to understand the characteristics of impact on strike patterns, and to explore preventive measures for injuries. To reduce the incidence of RRI, it is crucial to first identify one's strike pattern and then seek appropriate alternatives (such as reducing impact force and strengthening relevant muscles) on that strike pattern.