4개의 외측 소족지 중족 족지 관절의 탈구 후 발생한 관절의 강직에서 시행한 절제 관절 성형술(1예 보고)

박철현,이우천,Park, Chul-Hyun,Lee, Woo-Chun 대한족부족관절학회 2012 대한족부족관절학회지 Vol.16 No.1

Motion of the metatarsophalangeal joints is essential for the normal gait. Therefore it is important to recover the motion of normal joint in the treatment of stiffness of the metatarsophalangeal joints. However, there have been no report about the treatment of stiffness of the four lateral lesser metatarsophalangeal joints yet. We report an experience that good clinical and radiographic results were obtained after resection arthroplasty for the post-traumatic stiffness of the four lateral lesser metatarsophalangeal joints.

Unhealed Wound of the Lower Leg due to Synovial Fistula of the Ankle Joint

박철현,류승민,박재우,Park, Chul Hyun,Ryu, Seung Min,Park, Jae Woo The Korean Foot and Ankle Society 2017 대한족부족관절학회지 Vol.21 No.3

Synovial fistula of the ankle joint is an uncommon complication from an ankle sprain. This may likely result in an unhealed wound around the ankle joint due to continuous leakage of joint fluid. However, in the event of an open wound on the lower leg, and not on the joint, it may be difficult to consider synovial fistula as a cause of the open wound. We experienced an interesting case with an unhealed open wound on the lower leg due to a synovial fistula of the ankle joint following an ankle sprain. We obtained good results after a treatment using a self-produced suction drainage device on the unhealed open wound.

고비중(高比重) 종말품(終末品) 폐(廢)플라스틱 대량처리(大量處理)를 위한 마찰하전(摩擦荷電) 정전선별(靜電選別) 기술개발(技術開發)

박철현,전호석,백상호,김병곤,Park, Chul-Hyun,Jeon, Ho-Seok,Baek, Sang-Ho,Kim, Bong-Gon 한국자원리싸이클링학회 2009 資源 리싸이클링 Vol.18 No.2

습식 비중선별에서 sink products로 회수된 종말품 고비중 폐플라스틱 산물의 재활용을 위한 마찰하전정전선별 실증화 연구를 수행하였다. 종말품 고비중 폐플라스틱의 재질분리에 있어 적합한 하전물질 선정을 위한 하전특성 연구결과, high density polyethylene (HDPE)재질이 가장 효과적인 하전물질로 규명되어, 이 재질을 이용하여 하전장치를 제작하였다. 실험결과 최적조건인 전극의 전기장 250 kV/m, 분리대의 위치 (-) 8 cm, 그리고 상대습도 40%이하에서 PET, PS and others 산물의 품위와 회수율이 각각 99.1%와 86.0%인 결과를 얻었다. 또한 300 kg/h 규모의 대량처리 기술을 개발하여 종말품 폐플라스틱을 2등급 이상의 RPF나 RDF로 재활용할 수 있는 즉, PVC를 1% 미만을 줄일 수 있는 선별기술을 개발하였다. In this research, we studied the scale-up triboelectrostatic process for separation of PVC from higher gravity fraction of plastic wastes produced from wet gravity separation process. High density polyethylene (HDPE) was found to be the most effective materials for a tribo-charger in the separation of plastic tailings. In a commercial scale triboelelctrostatic separator unit, using the HDPE pipe-line charger, a grade of 99.1% with PET, PS and others and a recovery of 86% was obtained under optimum conditions at over 250 kV/m electric field, a splitter position of -8 cm from the center, and less than 40% relative humidity. The developed unit can process the plastic wastes at a 300 kg/h, and the product can be utilized as RPF or RDF of over grade 2.

무지외반증에 대한 근위 갈매기형 절골술 시행 후 임상적 및 방사선학적 결과는 언제 안정화되는가?

박철현,이우천,박재우,문정재,Park, Chul Hyun,Lee, Woo Chun,Park, Jae Woo,Moon, Jeong Jae 대한족부족관절학회 2015 대한족부족관절학회지 Vol.1 No.2

Purpose: The purpose of this study is to evaluate the sequential changes of clinical and radiographic results after proximal chevron osteotomy in patients with moderate to severe hallux valgus. Materials and Methods: Between January 2008 and December 2009, 93 patients (117 feet) were treated with proximal chevron osteotomy and distal soft tissue procedure for symptomatic moderate to severe hallux valgus deformity. The mean age of patients was 51 years (range, 19 to 71) and the mean duration of follow-up was 27.5 months (range, 24 to 35). Clinical results were evaluated using visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) score preoperatively, at 3, 6, and 12 months after surgery, and at the last follow-up. Radiographic parameters including hallux valgus angle, intermetatarsal angle, and sesamoid position were evaluated preoperatively, immediately postoperatively, at 6 weeks, at 3, 6, and 12 months after surgery, and at the last follow-up. Results: VAS and AOFAS score showed significant improvement until 12 months after surgery. Hallux valgus angle and sesamoid position stabilized at 12 months after surgery and intermetatarsal angle stabilized at 6 months after surgery. Conclusion: Clinical and radiographic results were stabilized beyond 12 months after proximal chevron osteotomy in patients with moderate to severe hallux valgus.

부유선별법에 의한 제련용 몰리브덴 정광의 회수

박철현,전호석,김병곤,한오형,Park, Chul-Hyun,Jeon, Ho-Seok,Kim, Byoung-Gon,Han, Oh-Hyung 한국재료학회 2009 한국재료학회지 Vol.19 No.12

Froth flotation has been carried out in order to produce roasting-molybdenite concentrate from molybdenite ore in the Shin-yeomi mine. In our study, roasting-molybdenite (Mo 0.43%) from Shin-yeomi mine was recovered by varying the conditions of regrinding time, dosage of collector and alkalinity. Liberation and flotation efficiency more were effective at regrinding time of six minutes than at single grinding. Mo recovery curves increased considerably as dosage of kerosene increased, whereas Mo grade curves decreased gradually. The separation efficiency of molybdenite was effective when the dosage of collector (kerosene) was adjusted to 300 g/t. The molybdenite concentrate was agglomerated in the range of pH 5-7 and its separation efficiency increased to pH 9-10. The concentrate of 49.5% Mo grade ($MoS_2$, 82.6%) with 81.5% recovery from Shin-yeomi molybdenite ores was obtained under conditions of 20% pulp concentration, 300 g/t kerosene 325 g/t frother (AF65), 2.5 kg/t depressant ($Na_2SiO_3$), pH 9-10 and four cleaning times. In the future, a trial run that can separate up to 50% Mo grade from Shin-yeomi molybdenite ores will be performed.

근위 갈매기 절골술 시행 전과 후의 원위 중족골 관절면각의 측정에 대한 신뢰성의 변화

박철현,이동열,Park, Chul Hyun,Lee, Dong Yeol 대한족부족관절학회 2016 대한족부족관절학회지 Vol.20 No.4

Purpose: To evaluate the reliability of preoperative and postoperative distal metatarsal articular angle (DMAA) measurements and to determine whether such reliability is different in accordance with the foot and ankle fellowship and the number of years in practice. Materials and Methods: Between July 2012 and June 2014, a total of 20 patients (24 feet) were treated with proximal chevron osteotomy and distal soft tissue procedure for symptomatic hallux valgus deformity. DMAA were measured twice with an interval of two weeks between the preoperative and postoperative dorsoplantar radiographs by four observers; two of whom were foot and ankle surgeons (A and B), one knee surgeon, and one senior resident. The intraobserver reproducibility and interobserver reliability were assessed by intraclass correlation coefficients. Moreover, the limit of agreement between the preoperative and postoperative DMAA measurements were assessed using a Bland-Altman plot. Results: The intraobserver reproducibility of the foot and ankle surgeon A, knee surgeon, and senior resident improved from 0.796, 0.575, and 0.586 preoperatively to 0.968, 0.864, and 0.864 postoperatively, respectively. The interobserver reliability of foot and ankle surgeon A-B, foot and ankle surgeon A-knee surgeon, and foot and ankle surgeon A-senior resident improved from 0.874, 0.688, and 0.677 preoperatively to 0.971, 0.917, and 0.838 postoperatively, respectively. Conclusion: The intra- and interobserver reliabilities for DMAA measurement improved after proximal chevron osteotomy. Therefore, the necessity of additional procedures to correct the increased DMAA should be reevaluated after proximal chevron osteotomy in the hallux valgus with an increased DMAA.

중등도 중족골간 각을 가지는 중증도 무지외반증의 특징

박철현,이우천,김정래,임승완,Park, Chul Hyun,Lee, Woo Chun,Kim, Jung Rae,Lim, Seung Whan 대한족부족관절학회 2014 대한족부족관절학회지 Vol.18 No.4

Purpose: The purpose of this study is to evaluate the characteristics of hallux valgus with severe hallux valgus angle (HVA) and moderate intermetatarsal angle (IMA) after proximal chevron osteotomy. Materials and Methods: Between January 2008 and December 2010, 41 patients (48 feet) were treated with proximal chevron osteotomy and distal soft tissue procedure for symptomatic severe hallux valgus deformity ($HVA{\geq}40^{\circ}$). Patients were divided into two groups, group M (IMA< $18^{\circ}$) and group S ($IMA{\geq}18^{\circ}$). Mean age of patients was 55.7 years (34~70 years) in group M and 60.0 years (44~78 years) in group S. Mean duration of follow-up was 20.4 months (12~41 months) in group M and 18.5 months (12~35 months) in group S. Radiographic parameters, including HVA, IMA, sesamoid position, metatarsus adductus angle (MAA), and distal metatarsal articular angle (DMAA), were compared between groups. Clinical results were assessed using American Orthopaedic Foot and Ankle Society (AOFAS) score and visual analogue scale (VAS). Recurrence rate at the last follow-up was compared between group M and group S. Results: Preoperative HVA and grade of sesamoid position did not differ between the groups. However, immediate postoperative HVA and grade of sesamoid position were significantly larger in group M. Preoperative MAA and DMAA were significantly larger in group M. No significant difference in AOFAS score and VAS was observed between the groups at the last follow-up. Ten of the 27 feet (37.0%) in group M and two of the 21 feet (9.5%) in group S showed hallux valgus recurrence at the last follow-up. Group M showed a significantly higher recurrence rate than group S. Conclusion: Recurrence rate for severe hallux valgus with moderate IMA is higher than that of severe hallux valgus with severe IMA.

Triboelectrostatic Separation of Mixed Three Kinds of Plastics by a Two-stage Separation Process

박철현,전호석,백상호,박재구,Park, Chul-Hyun,Jeon, Ho-Seok,Baek, Sang-Ho,Park, Jai-Koo The Korean Institute of Resources Recycling 2007 資源 리싸이클링 Vol.16 No.5

유사비중의 범위에 있는 PVC, PET and PMMA 3종 혼합플라스틱의 마찰하전 정전선별이 2단계 분리공정을 통하여 수행되었다. PVC, PET and PMMA의 재질분리에 있어 효과적인 하전장치의 재질은 Polypropylene(PP) 과 high-impact polystyrene(HIPS) 임을 확인하였다. PP 싸이클론 하전장치를 이용한 1단계 분리공정에서, PVC의 품위와 회수율은 공기속도 10 m/s, 전기장의 세기 200 kV/m 이상, 분리대 위치 +2cm, 상대습도 30% 이하의 조건에서 각각 99.6%와 97.5%로 구하였으며, HIPS 싸이크론 하전장치를 이용한 2단계 분리공정으로부터, 공기속도 10 m/s, 전기장의 세기 250 kV/m, 분리대 위치 0cm, 상대습도 40% 이하의 조건에서 PMMA의 품위와 회수율을 각각 97.8%와 95.12%로 구하였다. Triboelectrostatic separation of mixed three kinds of plastics, PVC, PET and PMMA, in the range of similar gravity has been performed through a two-stage separation process. Polypropylene (PP) and high-impact polystyrene (HIPS) were found to be the most effective materials for a tribo-charger in the separation of PVC, PET and PMMA. In the 1st stage using the PP cyclone charger, PVC grade and recovery depended considerably on the air velocity (10 m/s), the relative humidity (<30%), the electric field (>200 kV/m) and the splitter position (+2 cm from the center) in the triboelelctrostatic separator unit. At an optimum condition a PVC grade of 99.6% and a recovery of 97.5% was achieved. In the 2nd stage using the HIPS cyclone charger, a PMMA grade of 98.3% and a recovery of 97.0% was obtained under the conditions of 10m/s air velocity, over 250 kV/m electric field, central splitter position and less than 40% relative humidity.

무지외반증이 있는 농구 선수에서 발생한 족무지 근위 지골의 피로 골절에 대한 치료(1예 보고)

박철현,이우천,Park, Chul-Hyun,Lee, Woo-Chun 대한족부족관절학회 2012 대한족부족관절학회지 Vol.16 No.1

Stress fractures of the proximal phalanx of the great toe are rare. This fractures have been associated with halux valgus deformity in most reports. We performed open reduction and internal fixation with distal chevron osteotomy for the stress fracture of the proximal phalanx of the great toe in a basketball player with hallux valgus, and obtained successful bony union and rapid return to sports.

최소 침습적 정복을 이용한 대퇴골 전자하부 골절의 고정술

박철현 ( Chul Hyun Park ),하철웅 ( Chul Wung Ha ),박상진 ( Sang Jin Park ),고민수 ( Min Su Ko ),손욱진 ( Oog Jin Shon ) 대한골절학회 2013 대한골절학회지 Vol.26 No.2

목 적: 대퇴골 전자하부 골절에서 최소 침습적 정복 후 고정술의 결과를 분석하였다. 대상 및 방법: 대퇴골 전자하부 골절로 최소 침습적 정복 후 고정술을 시행 받은 환자 40명(41예)을 후향적으로 분석하였다. 평균추시 기간은 32.7개월(12-66개월), 평균 연령은 61.4세(15-89세)였다. 임상적 결과는 Parker-Palmer 보행 점수와 Salvati-Wilson 고관절 기능 점수를 이용하였으며, 방사선적 결과는 골유합 시기와 대퇴 경간각의 변화를 측정하였다. 결 과: 수술 전후의 Parker-Palmer 보행 점수는 차이는 없었고, 수술 후 Salvati-Wilson 고관절 기능 점수는 37예(90%)의 환자에서 good 이상의 결과를 나타내었다. 전 예에서 평균 22.5주(18-30주)에 골유합을 얻었다. 평균 대퇴 경간각은 수술 직후 128.8도 (120-140도)였으며, 건측에 비해 2.5도(-6-13도) 내반된 정복을 얻었다. 결 론: 대퇴골 전자하부 골절에서 최소 침습적 정복술을 이용한 고정술은 우수한 임상적 및 방사선학적 결과와 낮은 합병증 발생을 보였다. Purpose: To evaluate the results of using minimally invasive reduction techniques in patients with femoral subtrochanteric fracture. Materials and Methods: We retrospectively analyzed 40 patients (41 cases) with subtrochanteric fracture who underwent using minimally invasive reduction techniques. The mean age was 61.4 years (15-89 years), and the mean follow-up period was 32.7 months (12-66 months). Clinical results were assessed using the Parker-Palmer mobility score and the Salvati-Wilson hip functional score. Radiographic results were evaluated using bone union time and femur neck-shaft angle. Results: No significant difference was observed in the pre- and postoperative Parker-Palmer mobility score. Salvati Wilson hip functional score showed more than good grade in 37 cases (90%) at the last follow-up. Union was achieved in all 41 cases at an average of 22.5 weeks (18-30 weeks). The mean femoral neck-shaft angle immediately postoperatively was 128.8 degrees (120-140 degrees), and the mean difference versus contralateral sides was 2.5 degrees varus (-6-13 degrees). Conclusion: Fixation of femoral subtrochanteric fracture using minimally invasive reduction techniques showed excellent clinical and radiographic results and low complication rate.