Biomechanical Analysis of a Novel Wedge Locking Plate in a Porcine Tibial Model

Jeong-Ku Ha,Chul Hyun Yeom,Ho Su Jang,Han-Eui Song,이성재,Kang Hee Kim,정규성,Mahendar Gururaj Bhat,김진구 대한정형외과학회 2016 Clinics in Orthopedic Surgery Vol.8 No.4

Background: The purpose of this study was to analyze biomechanical properties of a novel wedge locking plate in medial open wedge high tibial osteotomy (OWHTO) in a porcine tibial model. Methods: A uniform 8-mm OWHTO was performed in 12 porcine tibiae. Six of them were subsequently fixed with the plate without a wedge, whereas the other 6 were additionally reinforced with a metal wedge of 8 mm. Biomechanical properties (stiffness, displacement of the osteotomy gap, and failure load) were evaluated under axial load. The different modes of failure were also investigated. Results: The plate showed an axial stiffness of 2,457 ± 450 N/mm with a wedge and 1,969 ± 874 N/mm without a wedge. The maximum failure load was 5,380 ± 952 N with a wedge and 4,354 ± 607 N without a wedge. The plate with a wedge had a significantly greater failure load and significantly less displacement of medial gap at failure than that without a wedge (p = 0.041 and p = 0.002, respectively). The axial stiffness was not different between the two types of fixation. Most failures were caused by lateral cortex breakage and there was no implant failure. Conclusions: The novel wedge locking plate showed excellent biomechanical properties and an additional wedge provided significant improvement. This plate can be a good fixation method for OWHTO.

경골 근위부 절골술 비교

이준엽(Jun Yub Lee),선종근(Jong Keun Seon),송은규(Eun Kyoo Song),윤택림(Taek Rim Yoon),천승영(Seung Young Cheon),임근영(Keun Young Lim) 대한정형외과학회 2004 대한정형외과학회지 Vol.39 No.7

목적: 슬관절 내측 구획에 국한된 골관절염 환자에서 경골 근위부 개방형 설상 절골술을 시행하고 그 임상적 및 방사선학적 결과를 폐쇄형 설상 절골술과 비교하였다. 대상 및 방법: 골관절염으로 경골 근위부 개방형 절골술 후 2년 이상 추시가 가능하였던 27병 29예(A군), 비교군으로는 폐쇄형 절골술을 시행했던 30명 30예의 환자(B군)를 대상으로 하였다. 방사선학적으로 Ahlback에 의한 관절염의 정도, 대퇴-경골각, 경골의 관상면 정열 및 후방 경사도와 Insall-Salvati 방법에 의한 슬개골의 높이의 변화를 측정하여 비교하였으며, 임상적으로는 HSS 점수를 측정하였다. 결과: 개방형 군에서 수술 전에 측정한 대퇴-경골각은 내반 4.2°, 경골의 정열은 5.3° 내반 및 7.9°의 후방 경사, Insall-Salvati ratio는 0.93이었으며 폐쇄형 군에서도 유사한 수치를 보였다. 개방형 군에서 2년 추시 대퇴-경골각은 외반 7.7°, 경골의 정열은 1.3°의 외반으로 수술 전에 비해 의의있는 교정을 보였으며, Insall-Salvati ratio는 0.92로 수술 전에 비해 변화가 없었다. 그러나, 경골의 후방 경사도는 2년 추시상 10.7°로 수술 전에 비해 약 3° 이상의 증가를 보였다. 폐쇄형 군의 2년 추시에서는 개방형 군과 의의 있는 차이는 없었으나, 경골의 후방 경사도는 수술 전 8.7°에서 2년 추시상 3.7°로 의의있는 감소를 보였다. HSS 점수는 개방형 군에서 수술 전 74점에서 2년 추시 93점으로 향상되었으며, 폐쇄군의 변화와 의미 있는 차이는 없었다. 합병증으로는 개방형 군에서는 자연유합 1예 외에 다른 합병증은 관찰되지 않았으나, 폐쇄형 군에서 천 비골 신경 손상 3예, 지연유합 1예가 발생하였다. 결론: 개방형 설상 절골술은 신경 혈관 합병증이 없이 폐쇄형과 비슷한 방사선학적 및 임상적 결과를 얻을 수 있는 비교적 간단하며 안전한 술식으로 생각되나 후방 경사도의 증가의 방지를 위하여 동일한 정도의 전ㆍ후방 개방에 유의해야 할 것으로 생각된다. Purpose: To evaluate the clinical and radiological results of an opening wedge osteotomy for an osteoarthritic knee, and compared these results with those of a closing wedge osteotomy. Materials and Methods: The study included 27 patients (29 cases) with an opening wedge osteotomy (Group A) and 30 patients (30 cases) with a closing wedge osteotomy (Group B). The radiological results obtained regarding the degree of osteoarthritis, femur-tibia angle, tibial alignment, posterior tibial slope and patellar height using the Insall-Salvati s method were analyzed. HSS score was used for evaluation of the clinical results. Results: Preoperatively, there were no significant differences between the two groups regarding the degree of osteoarthritis, the femur-tibia angle, tibial alignment, posterior tibial slope, and patellar height. Two years after surgery, the femur-tibia angle and tibial alignment were significantly improved to 7.7° valgus and 1.3° valgus, respectively, and the patellar height was not changed significantly in group A. Similar results were obtained in group B. The tibial posterior slope increased from 3° to 10.7° in group A and decreased from 4° to 3.7° in group B. Clinically, the HSS score was improved from 74 points preoperatively to 93 points 2 years postoperatively in the opening group, and was similar to the improvement observed in the closing group. The complications included 1 delayed union in the opening group, and 3 cases of superficial peroneal nerve palsy and 1 delayed union in the closing group. Conclusion: An opening wedge osteotomy is a relatively simple and safe procedure that gives similar radiological and clinical outcomes to a closing wedge osteotomy, without peroneal nerve palsy. However, surgeons should take care in preventing an increase in the tibial posterior slope.

Analysis of changes in tibial torsion angle on open-wedge high tibial osteotomy depending on the osteotomy level

( In-soo Song ),( Junhan Kwon ) 대한슬관절학회 2022 대한슬관절학회지 Vol.34 No.-

Purpose: This study evaluated the tibial torsional angle changes of 72 knees before and after open-wedge high tibial osteotomy (OWHTO) and compared the results according to the osteotomy level. Materials and methods: Seventy patients (72 knees) with Kellgren-Lawrence grade 3 underwent OWHTO. Demographic data, operation procedures, and measurement of mechanical tibiofemoral angle (mTFA), anatomical tibiofemoral angle (aTFA), tibial torsional angle (TTA), and pre- and postoperative Lysholm and International Knee Documentation Committee (IKDC) scores were obtained. The authors analyzed TTA changes between 30 knees with high-level osteotomy (group A) and 42 knees with low-level osteotomy (group B). Results: The changes of TTAs in the subjects of 72 knees went from 29.26 ± 5.6° preoperative mean to 25.36 ± 6.4° postoperative mean (p = 0.032). The postoperative TTAs of group A (mean 27.4 ± 4.8°) and B (mean 25.7 ± 4.9°) were statistically significant (p < 0.01). Preoperative Lysholm and IKDC scores of 72 knees had means of 49.1 ± 3.5 and 49.0 ± 15.2, respectively, and postoperative means of 85.7 ± 8.56 and 78.0 ± 17.6, respectively, which were statistically significant (p < 0.01). Conclusions: Changes of TTA with internal rotation of distal tibia were observed following OWHTO. High-level osteotomy on the proximal tibia’s lateral cortex had less internal rotation of the distal tibia than low-level osteotomy.

유한요소법 기반 개방형 고위경골 절골술 시 골절 유형에 따른 경골의 생체역학적 거동 분석

심온,이승준,이치승 대한기계학회 2023 大韓機械學會論文集B Vol.47 No.12

개방형 고위경골 절골술은 환자의 내반 변형이 동반된 슬관절의 내측 구획 관절염의 치료로 널리 사용되고 있다. 관절염으로 고통받는 환자의 인공 관절 치환술을 지연시킬 수 있고 내측 구획의 섬유 연골 재생에 좋은 치료법이다. 그러나 해당 수술법을 행할 시에 형성하는 경첩 부분에서 골절이 발생하여 골이식이 필요해질 수 있는데 이에 관한 연구는 미미하다. 그렇기에 본 연구에서는 내측 개방형 고위경골 절골술을 행할 때 발생할 수 있는 경첩 골절의 형상에 따라 경골에 작용하는 응력 변화를 분석하였다. 결과적으로 모든 골절 모델에서 피질골과 해면골에 작용하는 von Mises 등가 응력의 최댓값과 평균값이 증가하는 것을 확인하였다. 또한, 절골선 상방으로 골절된 모델보다 하방으로 골절된 모델에서 해면골에 작용하는 응력이 높게 측정된 것을 확인하였다. Opening wedge high tibial osteotomy is widely used to treat medial compartment arthritis of the knee joint with varus deformity in patients. It can delay artificial joint replacement in patients suffering from arthritis and is a good treatment for fibrocartilage regeneration of the medial compartment. However, fractures may occur in the hinge part formed when performing the osteotomy, and bone grafting may be required; however, research on this is insignificant. Therefore, in this study, the change in the stress acting on the tibia was analyzed according to the shape of the fracture that might occur during opening wedge high tibial osteotomy. Consequently, the maximum and average values of the von Mises equivalent stress acting on cortical and cancellous bones were confirmed to increase in all fracture models. In addition, the stress acting on the cancellous bones was measured higher in the model with a fracture below the inclination angle than in the model with a fracture above the inclination angle.

Analysis of radiographic factors affecting the significant differences in knee alignment between hip-to-talus and hip-to-calcaneus radiographs after opening-wedge high tibial osteotomy

( Hyung Jun Park ),( Joon Hyeok Boo ),( Dong Hun Suh ),( Jae Gyoon Kim ) 대한슬관절학회 2023 대한슬관절학회지 Vol.35 No.-

Background Optimal alignment after opening-wedge high tibial osteotomy (OWHTO) is crucial for obtaining good clinical results. A hip-to-calcaneus radiograph (HCR) appears to reflect the true mechanical axis. However, no study has been reported using the HCR in patients who underwent OWHTO. We aimed to analyze the radiographic factors affecting the significant difference in the weight-bearing line (WBL) ratio between two radiographs after openingwedge high tibial osteotomy (OWHTO). Methods This retrospective study included 51 patients who underwent both hip-to-talus radiographs (HTR) and HCR after OWHTO. The patients were divided into two groups; a consistent group (WBL ratio difference between postoperative HTR and HCR < 5%; N = 35) and an inconsistent group ( > 5%; N = 16). Radiographic variables for lower extremity alignment, knee and ankle joints, and clinical scores were evaluated. The receiver operating characteristic curve was used to determine the threshold of radiographic variables that induced inconsistencies between the two radiographs. Results The mean postoperative WBL ratio in the HCR of the inconsistent group was significantly higher than that of the consistent group (57.7 ± 13.2% and 49.1 ± 11.6%, respectively) (P = 0.02). The preoperative and postoperative ankle joint line obliquity (AJLO) and preoperative lateral distal tibia ground surface angle (LDTGA) were significantly different between the two groups (P < 0.05). The preoperative AJLO (odds ratio 0.784, confidence interval 0.655-0.939, P = 0.008) significantly affected WBL ratio inconsistency. The cutoff value of the preoperative AJLO was 3.16°. However, clinical scores did not differ significantly between the two groups. Conclusion The pre-and postoperative AJLO and the preoperative LDTGA were significantly different between the two groups. Among these variables, only preoperative AJLO negatively affected the inconsistency in WBL ratios between the two radiographs (HTT and HTC). Therefore, it should be considered to prevent postoperative overcorrection of the true mechanical axis after OWHTO, even though we corrected it properly.

How to achieve an optimal alignment in medial opening wedge high tibial osteotomy?

( Byoung Youl Kang ),( Do Kyung Lee ),( Hyeon Soo Kim ),( Joon Ho Wang ) 대한슬관절학회 2022 대한슬관절학회지 Vol.34 No.-

Medial opening wedge high tibial osteotomy (MOWHTO) is a widely used surgical treatment option for medial compartmental osteoarthritis with varus deformity. It is important that proper lower limb alignment is achieved. However, there has been no consensus about an optimal alignment in MOWHTO. Most studies suggest that achieving valgus alignment is necessary, and recent studies support slight valgus mechanical alignment of less than 3° of mechanical femorotibial angle. Overcorrection and undercorrection is not recommended for achieving good surgical outcomes. To prevent undercorrection and overcorrection in MOWHTO, the method of placing the weight-bearing line in the target range must be precise. There are several ways to place a weight-bearing line within the target range. While the most important factor for a successful MOWHTO is achieving an ideal mechanical axis correction, there are a few other factors to consider, including joint line obliquity, posterior tibial slope, ligament balancing, and patellar height. Several factors exist that lead to undercorrection and overcorrection. Preoperative amount of varus deformity, lateral hinge fracture, and fixation failure can result in undercorrection, while medial soft tissue laxity and the amount of correction angle and target point beyond hypomochlion can result in overcorrection. This study aimed to review the literature on optimal alignment in MOWHTO and report on the factors to be considered to prevent correction errors and how to achieve an optimal alignment.

Preoperative flexion contracture is a predisposing factor for cartilage degeneration at the patellofemoral joint after open wedge high tibial osteotomy

Otsuki Shuhei,Ikeda Kuniaki,Wakama Hitoshi,Okuno Nobuhiro,Okamoto Yoshinori,Okayoshi Tomohiro,Miyamoto Yuki,Neo Masashi 대한슬관절학회 2020 대한슬관절학회지 Vol.32 No.-

The purpose of the study was to determine the effect of cartilage degeneration at the patellofemoral joint on clinical outcomes after open wedge high tibial osteotomy and to investigate the predisposing factors for progressive patellofemoral cartilage degeneration.Seventy-two knees were evaluated on second-look arthroscopy in patients who opted for plate and screw removal at an average of 20.1 months after osteotomy. Cartilage degeneration at the patellofemoral joint was evaluated using the International Cartilage Repair Society grading system, with cases divided into progression and nonprogression groups. Radiographic parameters of the patellofemoral anatomy, knee range of motion, and clinical outcomes were evaluated from the preoperative baseline to the final follow up, on average 50 months after osteotomy. A contracture > 5° was considered a flexion contracture. Cartilage degeneration progressed in 31 knees, and preoperative knee flexion contracture was significantly associated with progressive degeneration ( P < 0.01). The Lysholm and Kujala scores were significantly lower in the progression group (87.9 and 85.3, respectively) than in the nonprogression group (91.6 and 93.6, respectively) ( P < 0.05). The odds ratio of the flexion contracture resulting in progression of patellofemoral cartilage degeneration was 4.63 (95% confidence interval, 1.77–12.1). No association was detected between progressive degeneration and age, sex, body mass index, Kellgren-Lawrence grade, or radiographic parameters. Flexion contracture may be associated with progression of cartilage degeneration at the patellofemoral joint and may negatively affect the clinical outcomes after open wedge, high tibial osteotomy.

개방형 근위 경골 절골술에서 골유합과 관련된 인자와 외측 피질골 골절 시 이식물에 따른 비교

서진혁(Jin-Hyeok Seo),김도훈(Do-Hun Kim),서승석(Seung-Suk Seo),김연구(Yeon-Gu Kim),김옥걸(Ok-Gul Kim),박병윤(Beyoung-Yun Park) 대한정형외과학회 2016 대한정형외과학회지 Vol.51 No.5

목적: 개방형 경골 근위부 절골술에서 환자 관련 인자들과 외측 피질골 골절이 발생한 경우에 골이식물 종류가 골유합에 미치는 영향에 대하여 연구하였다. 대상 및 방법: Kallgren-Lawrence 2단계 이하의 환자 54명, 58예를 대상으로 2012년 5월부터 2014년 6월까지 후향적 연구를 시행하였다. 평균 추시 기간은 22개월(14-38개월)이었다. 환자 관련 인자들이 골유합과 연관성이 있는지를 분석하고, 외측 피질골 골절이 발생한 하위 집단에서 골이식물 종류(동종골, n=6; beta-tricalcium phosphate [β-TCP], n=6)에 따라 두 군으로 분류하여 술 후 6주, 3개월, 6개월, 1년에 방사선적, 임상적 평가 및 garding of van Hemert를 비교하였다. 결과: 하위 집단의 두 군 간에 임상적, 방사선적 결과는 유의한 차이가 없었고, grading of van Hemert는 술 후 6개월, 1년에 동종골 이식군에서 유의하게 높은 결과를 보였다. 비흡연 환자군과 외측 피질골 손상이 없는 환자군에서 유의하게 더 높은 골유합 등급을 보였다. 결론: 개방형 경골 근위부 절골술에서 외측 피질골 손상 시에 동종골 이식이 β-TCP보다 술 후에 더 나은 골유합을 보이며, 흡연과 외측 피질골 손상이 골유합을 지연시키는 위험 인자임을 관찰하였다. Purpose: The purpose of this study was to analyze patient factors including smoking, body mass index, correction angle, graft material, presence of lateral cortex fracture, and age for the effect on bone union after open-wedge high tibial osteotomy and the effect of graft material used for lateral cortex fractures. Materials and Methods: This retrospective study was conducted on 54 patients and 58 cases with osteoarthritic change Kallgren-Lawrence grade 2 or less from May 2012 to June 2014. Average follow-up period was 22 months (14–38 months). The patients were divided into two groups according to patient related factors and graft materials (allograft, n=6; beta-tricalcium phosphate [β-TCP], n=6) used for lateral cortex fractures and were analyzed for the relationship with bone union after open-wedge high tibial osteotomy. Radiographic and clinic analyses were performed, and van Hemert grading was used for grading bone union at 6 weeks, 3 months, 6 months, and 1 year postoperatively. Results: The non-smoking group and the group without lateral cortex fracture showed significantly higher bone union rates than the control group. No significant clinical or radiological difference was observed between the two groups in 12 cases and the allograft group showed significantly higher rates of union at 6 months and 1 year postoperatively according to the van Hemert grading. Conclusion: Smoking and the presence of a lateral cortex fracture is a risk factor for nonunion in medial open-wedge high tibial osteotomy. The use of allograft material rather than β-TCP for lateral cortex fractures is thought to result in better bone union.

Navigation assisted High Tibial Open Wedge Osteotomy

Ji-Hoon Bae,Joon-Ho Wang,Dae-Hee Lee,Cheol-Woong Kim 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

The purpose of this study was to investigate factors affecting the change of tibial posterior slope and introduce a mathematical model which calculate, through 3-dimensional analysis of the proximal tibia, how the angle of the opening wedge along the anteromedial tibial cortex influences the tibial posterior slope and valgus correction when performing a medial open wedge osteotomy. This mathematical model with navigation system can be guidelines which provide surgeons on preoperative and intraoperative measurements to maintain or correct the tibial slope and to obtain the desired valgus correction of the lower limb during an opening wedge osteotomy.

First Metatarsal Proximal Opening Wedge Osteotomy for Correction of Hallux Valgus Deformity: Comparison of Straight versus Oblique Osteotomy

한승환,김용상,박의현,조준,고용곤,이진우,최우진 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.3

Purpose: The aim of this study was to compare clinical and radiographic outcomesof proximal opening wedge osteotomy using a straight versus oblique osteotomy. Materials and Methods: We retrospectively reviewed 104 consecutive first metatarsal proximal opening wedge osteotomies performed in 95 patients with hallux valgus deformity. Twenty-six feet were treated using straight metatarsalosteotomy (group A), whereas 78 feet were treated using oblique metatarsal osteotomy(group B). The hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle, and distance from the first to the second metatarsal(distance) were measured for radiographic evaluation, whereas the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score was used for clinical evaluation. Results: Significant corrections in the HVA, IMA, and distance from the first to the second metatarsal were obtained in both groups at the last follow-up (p<0.001). There was no difference in the mean IMA correction between the 2 groups (6.1±2.7° in group A and 6.0±2.1° in group B). However, a greater correctionin the HVA and distance from the first to the second metatarsal were found in group B (HVA, 13.2±8.2°; distance, 25.1±0.2 mm) compared to group A (HVA, 20.9±7.7°; distance, 28.1±0.3 mm; p<0.001). AOFAS scores were improved in both groups. However, group B demonstrated a greater improvement relative to group A (p=0.005). Conclusion: Compared with a straight first metatarsal osteotomy,an oblique first metatarsal osteotomy yielded better clinical and radiological outcomes.