• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.234-237
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• 2006

Purpose: Authors analyzed and compared the treatment result of distal chevron osteotomy between with and without adductor tenotomy. Materials and Methods: 36 patients (60 feet) with a minimum follow-up of one year were involved in this retrospective study. The chevron osteotomy without adductor tenotomy was performed for 20 patients (30 feet) and chevron osteotomy with adductor tenotomy was done for 16 patients (30 feet). The first metatarsophalangeal (MTP) angle and angle between first and second metatarsal longitudinal axis (IM) was measured. The difference of these angles were measured pre-and postoperatively and compared using Student's T-test. Results: In the group of chevron osteotomy with adductor tenotomy, the mean first MTP angle corrected $29^{\circ}$ pre-operatively to $9^{\circ}$ and the mean first IM angle corrected $16^{\circ}$ pre-operatively to $12^{\circ}$. In the group of chevron osteotomy without adductor tenotomy the mean first MTP angle corrected $31^{\circ}$ pre-operatively to $11^{\circ}$ (P>0.05) and the mean first IM angle corrected $13^{\circ}$ pre-operatively to $11^{\circ}$ (P>0.05). Deep peroneal neuroma were found in 3 cases of chevron osteotomy with adductor tenotomy. Conclusions: Adductor tenotomy should be performed in selected patient with chevron osteotomy to prevent deep peroneal neuroma.

• Journal of Korean Foot and Ankle Society
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• v.18 no.2
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• pp.56-61
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• 2014

Purpose: This study was conducted among patients with moderate to severe hallux valgus who underwent distal chevron osteotomy and groups of patients with or without Akin osteotomy were compared for evaluation of the relationship between their radiological and clinical outcomes. Materials and Methods: From January 2009 to January 2012, among patients with moderate to severe hallux valgus who underwent distal chevron osteotomy at our institution, 28 cases with additional Akin osteotomy and 35 cases without Akin osteotomy available to follow up of more than one year were included in this study. For radiologic evaluation, hallux valgus angle, 1, 2 intermetatarsal angle, and hallux interphalangeal angle were measured before and after surgery. For clinical assessment, visual analogue scale score, American Orthopaedic Foot and Ankle Society score, subjective satisfaction of the patients, and passive range of motion of the first metatarsophalangeal joints were evaluated. Results: At the final follow up, correction of valgus hallux angle and 1, 2 intermetatarsal angle was obtained from radiation results of both groups and it was found that patients who underwent Akin osteotomy showed radiographically larger angle correction but less subjective satisfaction. Conclusion: Patients with moderate to severe hallux valgus who underwent distal chevron osteotomy showed not only functional but also radiographically satisfactory results, and patients who underwent additional Akin osteotomy showed decreased subjective satisfaction. Therefore, if an incongruent first metatarsophalangeal joint is not observed, distal chevron osteotomy without Akin osteotomy seems preferable.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.156-162
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• 2006

Purpose: To evaluate the results and effectiveness of distal chevron osteotomy combined with lateral soft tissue release for the correction of hallux valgus deformity. Materials and Methods: 31 patients who underwent distal chevron osteotomy with lateral soft tissue release between July 2002 and June 2003, were analyzed in terms of hallux valgus angle, intermetatarsal angle, subluxation of sesamoid, AOFAS score and the occurrence of avascular necrosis of the first metatarsal head. Results: The mean amount of the correction of hallux valgus angle was $26.3^{\circ}$. The mean amount of the correction of intermetatarsal angle was $6.6^{\circ}$. The mean amount of the correction of sesamoid subluxation was 1.2 points. The mean improvement of AOFAS score was 25.8 points. Avascular necrosis of the first metatarsal head was not found in any cases. Conclusion: For correction of hallux valgus deformity, distal chevron osteotomy with lateral soft tissue release showed improvement of hallux valgus angle, sesamoid subluxation and AOFAS score with no evidence of avascular necrosis of the first metatarsal head.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.230-233
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• 2006

Purpose: The distal chevron osteotomy has gained popularity for the mild to moderate hallux valgus, but necessity of fixation is controversy. No fixation of distal chevron osteotomy cause instability, but fixation has problem which has pin site infection and irritability, extension of operation time, discomfort of rehabilitation. So, the author was going to analyse and compare with and without in the fixation of distal chevron osteotomy. Materials and Methods: Between 2004 and 2005, a total 18 patients (20 feet) following with and without in fixation of distal chevron osteotomies. The fixation group (A) was performed for the treatment of 10 patients (10 feet) and no fixation group (B) was done to 8 patients (10 feet). Results: On group A, the mean first MTP (metatarsophalangeal) angle corrected $17^{\circ}$ pre-operatively to average $29^{\circ}$ (range; $20-37^{\circ}$) and the mean first IM (intermetatarsal) angle corrected $10^{\circ}$ pre-operatively to average $15^{\circ}$ (range; $9-18^{\circ}$). On Group B, the mean first MTP angle corrected $16^{\circ}$ pre-operatively to average $29^{\circ}$ (range; $18-33^{\circ}$) and the mean first IM angle corrected $7^{\circ}$ pre-operatively to average $13^{\circ}$ (range; $9-16^{\circ}$) (P>0.05). Clinical results, based on AOFAS score showed an improvement in the overall results. Conclusions: Comparing the clinical and radiographic results of the distal chevron osteotomies no difference in with and without fixation of distal chevron osteotomies.

• Journal of Korean Foot and Ankle Society
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• v.13 no.2
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• pp.124-128
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• 2009

Purpose: The authors intended to analyze the operative results of mild to moderate hallux valgus treated with distal chevron metatarsal osteotomy. Materials and Methods: Twenty six feet of twenty three patients were followed for more than 1 year after the distal chevron metatarsal osteotomy. Biplanar osteotomy with wedge resection was done when the distal metatarsal articular angle (DMAA) was increased. The mean age was 39 years, and the mean follow up period was 27 months. Clinically preoperative and postoperative AOFAS hallux MP-IP scale and satisfaction after the surgery were analyzed. Radiologically hallux valgus angle, the 1st intermetatarsal angle, DMAA and sesamoid position before and after the operation were analyzed. Results: Distal chevron osteotomy was done in 15 cases and biplanar osteotomy was done in 11 cases. Clinically AOFAS scale was increased from 65.3 points preoperatively to 92.2 points postoperatively. Two patients were not satisfied with the results. Radiologically hallux valgus angle was decreased from $21.9^{\circ}$ preoperatively to $8.5^{\circ}$ postoperatively. The first intermetatarsal angle was decreased from $11.8^{\circ}$ preoperatively to $6.7^{\circ}$ postoperatively. DMAA was decreased from $11.8^{\circ}$ preoperatively to $5.5^{\circ}$ postoperatively. There was one case of minor wound infection. Conclusion: Distal chevron metatarsal osteotomy appears to be safe and satisfactory procedure for mild to moderate hallux valgus.

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.64-70
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• 2004

Purpose: We compared the result of a proximal metatarsal closed wedge osteotomy and soft tissue procedure with a modified chevron osteotomy and soft tissue procedure in the treatment of hallux valgus. Materials and Methods: Between March 1999 and February 2003, we performed proximal metatarsal closed wedge osteotomy and soft tissue procedure on 17 feet (12 patients), and modified chevron osteotomy and soft tissue procedure on 12 feet (9 patients). Results: According to Mayo clinic forefoot scoring system (FFSS), group 1, with proximal metatarsal closed wedge osteotomy, shows 67.2 points postoperatively and group 2, with modified chevron osteotomy, shows 68.5 points postoperatively. In group 1, the average correction of hallux valgus angle and intermetatarsal angle was 20.8 degrees and 4.8 degrees, respectively. In group 2, the average correction of hallux valgus angle and intermetatarsal angle was 19.9 degrees and 4.7 degrees, respectively. The average shortening was 3.15 mm in group 1 and 1.38 mm in group 2. Conclusion: We obtained relatively good clinical and radiographic result in this study. The effect on shortening of the first metatarsal was greater in the proximal metatarsal closed wedge osteotomy than modified chevron osteotomy, but the metatarsal shortening did not related with metatarsalgia. So, both techniques seems optimal surgical treatment for hallux valgus deformity.

• Journal of Korean Foot and Ankle Society
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• v.12 no.1
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• pp.20-25
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• 2008

Purpose: The purpose of this study is comparison of radiological and clinical outcomes between proximal metatarsal osteotomy and distal chevron osteotomy for the correction of hallux valgus. Materials and Methods: In this retrospective study, we included subjects who underwent the correction of hallux valgus in our institution between March 2001 and August 2006, with a minimum follow-up of 12 months. The group of proximal metatarsal osteotomy was 23 patients (34 feet); the group of distal chevron osteotomy was 20 patients (26 feet). The group of proximal metatarsal osteotomy was composed of 26 severe cases (76.5%) and 8 moderate cases (23.5%); the group of distal chevron osteotomy was composed of 13 severe cases (50.0%) and 13 moderate cases (50.0%). Results: Compared to preoperative values, the hallux valgus angle, the first-second intermetatarsal angle and the distance of first-fifth metatarsal head were significantly decreased in two groups (p<0.05). In each parameter, the hallux valgus angle was decreased 66.3% (proximal metatarsal osteotomy) versus 49.6% (distal chevron osteotomy), which were significant (p=0.037). The first-second intermetatarsal angle and the distance of first-fifth metatarsal head were not significant. Mayo clinic forefoot scoring system (FFSS) score was significantly improved in two groups (p<0.05). The ratio of improvement was not significant (p=0.762). In severe group, hallux valgus angle and the first-second intermetatarsal angle was significantly decreased in proximal metatarsal osteotomy group compared to distal chevron osteotomy group (p<0.05), but the difference of the distance of first-fifth metatarsal head and FFSS score was not significant in both groups. In moderate group, the difference of all parameters was not significant in both groups. Conclusion: Although both proximal metatarsal osteotomy and distal chevron osteotomy showed satisfactory result in FFSS, proximal metatarsal osteotomy was more proper operative technique than distal chevron osteotomy in severe group, because of superiority of correction in radiological parameters.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.304-310
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• 2000

The experimental study has been conducted on heat transfer characteristics of the plate heat exchangers(PHE) by several researchers. However most of all were focused on a gasket-type plate heat exchanger. Therefore further studies are need for a brazed-type. In the present study, a brazed type plate heat exchanger was tested at a chevron angle of $70^{\circ},\;55^{\circ}$ and $45^{\circ}$ with R-22 and R-410A. Condensation temperatures were $24.5^{\circ}C$, and mass flux was ranged from 35 to $60kg/m^2s$. The inlet and exit conditions are in a superheated vapor and subcooled liquid, respectively. The heat transfer coefficient increased with the chevron angle. The heat transfer coefficient of R-22 was lamer than that of R-410A for all chevron angles.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.16-20
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• 2010

Purpose: This study analyzed the clinical and radiographic outcome of the severe hallux valgus corrected with proximal reverse chevron metatarsal osteotomy and Akin osteotomy. Materials and Methods: The study was based on 18 feet (15 patients) of severe hallux valgus (hallux valgus angle ${\geq}40^{\circ}$ or intermetatarsal angle ${\geq}18^{\circ}$) treated with proximal reverse chevron metatarsal osteotomy and followed for more than 1 year. Akin osteotmy was added in 72% of the patients. Clinically preoperative and postoperative AOFAS Hallux Metatarsophalangeal-interphalangeal score, VAS pain score and satisfaction after the surgery were analyzed. Radiologically hallux valgus angle, hallux valgus interphalangeal angle, the intermetatarsal angle and sesamoid position before and after the operation were analyzed. Results: AOFAS Hallux Metatarsophalangeal-interphalangeal score improved from 54.5 (25-78) to 87.7 (70-100) and VAS pain score decreased from 6.0 (3-8) to postoperative 1.2 (0-5). Ninety-six percents of the patients were satisfied with results. Radiologically hallux valgus angle was decreased from $43.3^{\circ}(31-58^{\circ})$ preoperatively to $6.8^{\circ}(-8-27^{\circ})$ postoperatively. The intermetatarsal angle was decreased from $18.4^{\circ}(11-24)^{\circ}$ preoperatively to $5.3^{\circ}(1-12^{\circ})$postoperatively. The sesamoid subluxation was improved from $2.8{\pm}0.4$ preoperatively to $0.4{\pm}0.6$ postoperatively. Conclusion: Proximal reverse chevron metatarsal osteotomy and lateral soft tissue release with additional Akin osteotomy is good treatment option for severe hallux valgus.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.39-44
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• 2007

Purpose: The authors intended to analyze the operative results of moderate hallux valgus with proximal chevron metatarsal osteotomy and distal soft tissue procedure. Materials and Methods: Seventy feet of fifty-seven patients were followed for more than 1 year after the proximal chevron metatarsal osteotomy. The mean age was 47.2 years, and the mean follow up period was 2 years and 3 months. Clinically preoperative and postoperative AOFAS MP-IP scale and satisfaction after the surgery were analyzed. Radiologically hallux valgus angle, hallux valgus interphalangeal angle, the intermetatarsal angle and sesamoid position before and after the operation were analyzed. Results: Additional Akin osteotomy was performed 48 out of 70 feet. Clinically AOFAS MP-IP scale was increased from 60.4 points preoperatively to 89.8 points postoperatively. Ninety-four percents of the patients were satisfied with the results. Radiologically hallux valgus angle was decreased from $34.8^{\circ}$ preoperatively to $12.8^{\circ}$ postoperatively. The intermetatarsal angle was decreased from $15.7^{\circ}$ preoperatively to $8.0^{\circ}$ postoperatively. Hallux valgus interphalangeal angle was increased from $7.4^{\circ}$ preoperatively to $9.8^{\circ}$ postoperatively. There were 3 recurrences, 1 hallux varus and 3 minor wound infections. There were no nonunion or malunion of the 1st metatarsal. Conclusion: Proximal chevron metatarsal osteotomy with distal soft tissue procedure and additional Akin osteotomy appears to be safe and satisfactory procedure.