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Mimata H, Matsuura Y, Yano S, Ohtori S, Todo M. Mechanical evaluation of revision surgery for femoral shaft nonunion initially treated with intramedullary nailing: Exchange nailing versus augmentation plating. Injury 2023; 54:111163. [PMID: 37939634 DOI: 10.1016/j.injury.2023.111163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/11/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023]
Abstract
INTRODUCTION Exchange nailing (EN) or augmentation plating (AP) has been employed to treat nonunions after intramedullary nailing for femoral shaft fractures. Although instability is a factor in hypertrophic nonunion, mechanical evaluations have been limited because the contribution of the callus to fracture site stability varies with healing. Our previous study illustrated the potential for evaluation using a finite element analysis (FEA) that incorporates callus material properties. This study aimed to mechanically evaluate revision surgery for nonunions using FEA. MATERIALS AND METHODS A quantitative computed tomography-based FEA was performed on virtual revision models of a patient with suspected nonunion after intramedullary nailing. In addition to the initial nailing model (IN) with an 11-mm diameter (D) and 360-mm length (L), four EN models with D12mm (EN1), D13mm (EN2), D12mm-L400mm (EN3), and D13mm-L400mm (EN4) nails and three AP models with 5- (AP1), 6- (AP2), and 7-hole (AP3) plates were created. As with bone, callus was assigned inhomogeneous material properties derived from density based on an empirical formula. The hip joint reaction force and muscle forces at maximum load during the gait cycle were applied. The volume ratio of the callus at the fracture site with a tensile failure risk of ≥1 (tensile failure ratio) and bone fragment movement were evaluated. RESULTS The tensile failure ratio was 11.6 % (IN), 10.1 % (EN1), 6.3 % (EN2), 10.9 % (EN3), 6.2 % (EN4), 6.4 % (AP1), 7.2 % (AP2), and 7.7 % (AP3), respectively. The bone fragment movement showed an opening on the lateral side with the initial intramedullary nailing. However, both revision surgeries reduced the opening, leading to compression except in the EN1 model. The proximal bone fragments were internally rotated relative to the distal fragments, and the rotational instability was more suppressed in models with lower tensile failure ratio. CONCLUSIONS For EN, the increase in diameter, not length, is important to suppress instability. AP reduces instability, comparable to a 2 mm increase in nail diameter, and screw fixation closer to the fracture site reduces instability. This study suggest that AP is mechanically equivalent to EN and could be an option for revision surgery for femoral shaft nonunions.
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Affiliation(s)
- Hideyuki Mimata
- Research Center of Computational Mechanics, Inc., 1-7-1 Togoshi, Shinagawa-ku, Tokyo 141-0041, Japan.
| | - Yusuke Matsuura
- Department of Orthopeadic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
| | - Sei Yano
- Department of Orthopeadic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
| | - Seiji Ohtori
- Department of Orthopeadic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
| | - Mitsugu Todo
- Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-Koen Kasuga-shi, Fukuoka 816-8580, Japan
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Rao J, Zhang J, Ye Z, Zhang L, Xu J. What is the stable internal fixation for the unstable and osteoporotic supracondylar femoral fractures: a finite element analysis. J Orthop Surg Res 2023; 18:759. [PMID: 37805559 PMCID: PMC10559610 DOI: 10.1186/s13018-023-04256-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/02/2023] [Indexed: 10/09/2023] Open
Abstract
BACKGROUND Osteoporotic supracondylar femoral fractures (OSFF) have historically been managed by the lateral anatomical locking plate with reasonable success. However, for some kinds of unstable and osteoporotic supracondylar femoral fractures (UOSFF), especially with bone defects, unilateral locking plate (ULLP) fixation failed or resulted in implant breakage. This paper is going to explore what is the stable internal fixation for UOSFF by adding the bilateral locking plate (BLLP) fixation. METHODS OSFF models were divided into two groups according to the fracture line type, which would be further subdivided according to their angle of fracture line, presence of bone defect, location, and degree of bone defect. Thereafter, kinds of locking plate fixation were constructed. A 2010-N load was applied to the femoral head, and a 1086-N load was applied to the greater trochanter. In this condition, the maximum von Mises stress distribution of models were investigated. RESULTS Firstly, it was obviously found that the stress concentration in the BLLP group was more dispersed than that in the ULLP group. Secondly, according to the fracture line analysis, the stress value of fracture line type in "\" model group was higher than that of "/" model group. Moreover, with the increase in fracture line angle, the stress value of the model increased. Thirdly, from the bone defect analysis, the stress value of the medial bone defect (MBD) model group was higher than that of the lateral bone defect (LBD) model group. And as the degree of bone defect increased, the stress value increased gradually in the model group. CONCLUSION In the following four cases, lateral unilateral locking plate fixation cannot effectively stabilize the fracture end, and double locking plate internal fixation is a necessary choice. First, when the angle of the fracture line is large (30, 45). Second, when the fracture line type is "/." Third, when the bone defect is large. Fourth, when the bone defect is medial.
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Affiliation(s)
- Jianwei Rao
- Jiangshan People's Hospital, Jiangshan, 324100, China
| | - Junchao Zhang
- The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, People's Hospital, Quzhou, 324000, China
| | - Zhou Ye
- The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, People's Hospital, Quzhou, 324000, China
| | - Liguang Zhang
- The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, People's Hospital, Quzhou, 324000, China
| | - Jiangbao Xu
- The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, People's Hospital, Quzhou, 324000, China.
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Yoon YC, Park KC, Oh CW, Kim JW, Kim JW, Park KH, Kim TS, Song HK, Abdel Baki SW. Intramedullary nailing of subtrochanteric fractures in elderly patients: Comparative study of helical blade cephalomedullary nail versus reconstruction nail. Injury 2022; 53:1477-1483. [PMID: 35120730 DOI: 10.1016/j.injury.2022.01.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 01/23/2022] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Intramedullary nailing (IMN), which is a common method for treating subtrochanteric fractures, is conducted as cephalomedullary (CMN) or reconstruction (RCN) nailing. Numerous studies have reported the effectiveness of CMN, which requires a shorter surgery time and provides stronger fixation strength with blade-type devices. However, the radiographic and clinical outcomes of the use of CMN and RCN in elderly patients aged ≥65 years have not been compared yet. This study aimed to investigate whether CMN offers superior outcomes over RCN in the treatment of subtrochanteric fractures in elderly patients. MATERIALS AND METHODS This retrospective study included 60 elderly patients (17 men and 43 women; mean age: 74.9 years) diagnosed with subtrochanteric fractures and treated with IMN with helical blade CMN (CMN group: 30 patients) or RCN (RCN group: 30 patients) between January 2013 and December 2018 with at least 1 year of follow-up period. Radiologic outcomes were evaluated based on the postoperative state of alignment and the achievement and timing of bony union at the final follow-up. Clinical outcomes were evaluated using the Merle d'Aubigné-Postel score. Radiologic and clinical outcomes in the two groups were compared and analyzed, and the occurrence of complications was examined. RESULTS The difference in malalignment between the two groups was not significant; however, the RCN group achieved more effective reduction. At the final follow-up, bony union was achieved within 18.9 weeks, on average, in 28 patients in the CMN group and within 21.6 weeks, on average, in 27 patients in the RCN group. Twenty patients in the CMN group and 26 in the RCN group showed good or better results according to the Merle d'Aubigné-Postel score. No significant differences were found for any of the parameters. CONCLUSIONS In the treatment of difficult subtrochanteric fractures in elderly patients, RCN can provide excellent reduction and strong fixation similar to CMN and can result in outstanding clinical and radiologic outcomes.
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Affiliation(s)
- Yong-Cheol Yoon
- Orthopedic Trauma Division, Trauma Center, Gachon University College of Medicine, Namdong-gu, Incheon, Republic of Korea
| | - Ki-Chul Park
- Department of Orthopedic Surgery, School of Medicine, Hanyang University Guri Hospital, Guri-si, Gyeonggi-do Province, Republic of Korea
| | - Chang-Wug Oh
- Department of Orthopedic Surgery, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Chung-gu, Daegu, Republic of Korea.
| | - Joon-Woo Kim
- Department of Orthopedic Surgery, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Chung-gu, Daegu, Republic of Korea
| | - Ji Wan Kim
- Department of Orthopaedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Kyeong-Hyeon Park
- Department of Orthopedic Surgery, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Chung-gu, Daegu, Republic of Korea
| | - Tae-Seong Kim
- Department of Orthopedic Surgery, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Chung-gu, Daegu, Republic of Korea
| | - Hyung Keun Song
- Department of Orthopedic Surgery, Ajou University School of Medicine, Suwon-si, Gyeonggi-do Province, Republic of Korea
| | - Sharkawy Wagih Abdel Baki
- Department of Orthopaedic Surgery, Aswan University Hospital, Aswan University Faculty of Medicine, Aswan, Egypt
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Shin WC, Lee SM, Jang JH, Kang JH, Moon NH. Importance of firm isthmic fixation in high-energy induced subtrochanteric fracture of the femur: retrospective observational study in a level I trauma center. Eur J Trauma Emerg Surg 2021; 48:1807-1815. [PMID: 34137910 DOI: 10.1007/s00068-021-01709-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/17/2021] [Indexed: 11/25/2022]
Abstract
INTRODUCTION This study aimed to report the surgical outcomes in patients with high-energy induced subtrochanteric fracture and determine the risk factors for nonunion using statistical analysis. METHODS This study evaluated 88 patients with high-energy induced subtrochanteric fractures who underwent surgeries with indirect reduction technique and intramedullary nailing between March 2015 and December 2020. Outcome measures, including union time and nonunion incidence, were assessed by radiologic evaluation. Multiple logistic regression analyses were performed to identify the risk factors for nonunion, using age, sex, injury severity score, body mass index, preoperative mobility score, implant, and isthmic fixation as covariates. RESULTS Five nonunions and two delayed unions were identified. The average union time was 17.4 weeks. Multiple logistic regression analyses showed that poor isthmic fixation was the only risk factor for nonunion (odds ratio 15.294, 95% confidence interval 1.603-145.894, P value 0.018). Out of five nonunion cases, four were confirmed as hypertrophic, and one was confirmed as atrophic. CONCLUSION Although surgical treatment using an indirect reduction technique and intramedullary nailing showed good outcomes, hypertrophic nonunion due to distal instability could occur if a firm fixation at the level of the isthmus cannot be achieved. LEVEL OF EVIDENCE Level III, retrospective cohort study.
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Affiliation(s)
- Won Chul Shin
- Department of Orthopaedic Surgery, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Busan, South Korea
| | - Sang Min Lee
- Department of Orthopaedic Surgery, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Busan, South Korea
| | - Jae Hoon Jang
- Department of Orthopaedic Surgery, Trauma center, Pusan National University Hospital, Busan, South Korea
| | - Jun Ho Kang
- Department of Orthopaedic Surgery, Trauma center, Pusan National University Hospital, Busan, South Korea
| | - Nam Hoon Moon
- Department of Orthopaedic Surgery, Bio-Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, 179 Gudeok-Ro Seo-Gu, Busan, 49241, South Korea.
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Hamidi S, Khosravifard A, Hematiyan MR, Dehghani J. A comparative mechanical study of two types of femur bone implant using the finite element method. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3459. [PMID: 33773056 DOI: 10.1002/cnm.3459] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 01/27/2021] [Accepted: 03/20/2021] [Indexed: 06/12/2023]
Abstract
The femoral bone fracture is one of the most common fractures that orthopedic surgeons deal with. These fractures are associated with a significant percentage of death due to non-orthopedic complications. For this reason, it is necessary that the surgeon be well-aware of the condition of the patient and also of the biomechanical conditions of the bone and implant before surgery, in order to use the best surgical technique. Nowadays, the use of implants is a popular technique among the available methods for the treatment of femoral fractures. In the present study, two patients with different ages, three types of femoral bone fractures, that is, oblique, reverse oblique, and neck fracture, and two types of implants, namely, the dynamic hip screw (DHS) and the Gamma nail have been investigated. The behavior of the implants has been investigated at the two stages of treatment, that is, before and after bone union. The analysis of implants was based on the amount of stress and displacement induced in different parts of the bone and the implant. From the viewpoint of the stresses induced in the bone, all models are quite similar and in terms of the implant stresses, the Gamma nail is more reliable than the DHS. Additionally, the relative displacement of the fractured bone segments at the fracture planes was calculated. According to the obtained results, it can be concluded that the relative displacement of the fracture planes with the use of Gamma nail is somewhat less than the DHS, but this difference is not significant.
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Affiliation(s)
- Saeideh Hamidi
- Department of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | - Amir Khosravifard
- Department of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | | | - Javad Dehghani
- Bone and Joint Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Effect of fracture levels on the strength of bone-implant constructs in subtrochanteric fracture models fixed using short cephalomedullary nails: A finite element analysis. Injury 2019; 50:1883-1888. [PMID: 31431331 DOI: 10.1016/j.injury.2019.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 07/31/2019] [Accepted: 08/10/2019] [Indexed: 02/02/2023]
Abstract
OBJECTIVES This study was conducted to investigate the stress around nails and cortical bones in subtrochanteric (ST) fractures fixed using short cephalomedullary nails (CMNs) in finite element models (FEMs) and to determine the appropriate short CMN type for different fracture levels. METHODS The following three types of short CMNs were used: type A, which is 170 mm in length and has 1 distal locking screw; type B, 200 mm in length and 1 distal screw; and type C, 200 mm in length and 2 distal screws. A total of 24 FEMs were tested on a transverse ST fracture at 8 levels [0, 10, 20, 25, 30, 35, 40 and 50 mm below the lower margin of lesser trochanter (LT)], and were fixed using 3 different CMN types. Finite element analysis was then performed to evaluate the stress around the cortical bones and the CMNs under the assumption of anatomical reduction and fracture gap of 1 mm. RESULTS Peak von Mises stress (PVMS) was greatest on the cortical bone around the distal screw hole and was greater than the yield strength at fracture levels ≥ 35 mm below the LT in FEMs fixed with type A and B. In contrast, FEMs fixed with type C showed PVMS less than the yield strength at all fracture levels. The PVMS within the implant was greater than the yield strength at the junction of the nail with the distal screw and distal screw itself at fracture levels ≥ 35 mm below the LT in FEMs fixed using type A. Conversely, in FEMs fixed using type B and C, all PVMSs within the implant were less than the yield strength, regardless of the fracture level. CONCLUSION Short CMNs 170 or 200 mm in length with 1 distal screw may be used in a limited manner in high ST transverse fractures under the assumptions of anatomical reduction and fracture gap ≤ 1 mm. Meanwhile, short CMN 200 mm in length with 2 distal screws may be an available treatment option in most of ST transverse fractures regardless of the fracture level under the same set of assumptions.
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Yoo JI, Jeong H, Na J, Song SY, Kim JT, Cha YH, Park CH. Comparison of intraoperative radiation exposure with and without use of distal targeting device: a randomized control study. Arch Orthop Trauma Surg 2019; 139:1579-1586. [PMID: 31278509 DOI: 10.1007/s00402-019-03238-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Indexed: 11/30/2022]
Abstract
INTRODUCTION When locking intramedullary nails, inserting the distal interlocking screw accurately and quickly with less radiation exposure is very important. The purpose of this randomized control study was to compare radiation exposure and accuracy of distal locking screws between free-hand fluoroscopic guidance and the use of a distal targeting system (DTS). MATERIALS AND METHODS Inclusion criteria of this study were patients older than 60 years who need an intramedullary nailing due to unstable intertrochanteric and subtrochanteric fracture. The primary outcome was the attempt numbers of image intensifier during the insertion of distal locking screws. Secondary outcomes were operative time and angles between distal locking screws and nail. RESULTS A total of 36 patients participated in the study. Eighteen patients using free-hand fluoroscopic guidance were assigned to Group I while 18 patients using DTS were assigned to Group II. The number of attempts of image intensifier during distal screw insertion (57.3 ± 31.42 vs. 11.5 ± 7.41, p < 0.001), ratio of attempt number for distal screws to the total attempts (0.33 ± 0.21 vs. 0.12 ± 0.08, p = 0.001), the number of hand exposure to image intensifier directly (75.0 ± 29.55 vs. 13.5 ± 19.07, p < 0.001), and the time of radiation exposure during distal screws insertion (42.57 ± 2.42 s vs. 12.72 ± 8.10 s, p < 0.001) were significantly lower in Group II compared to those in Group I. And, operation time (96.3 min ± 18.94 vs. 76.1 min ± 14.10, p < 0.001) was also statistically significantly lower in Group II. Both distal locking screws were significantly closer to perpendicular direction to the nail in Group II. CONCLUSION The attempt number of image intensifier during the insertion of two distal locking screws was significantly reduced with DTS compared with that with free hand fluoroscopic guidance. Angle between distal locking screws and nail was also more accurate using DTS.
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Affiliation(s)
- Jun-Il Yoo
- Department of Orthopedic Surgery, Gyeongsang National University Hospital, Jinju, Republic of Korea
| | - Hojin Jeong
- Department of Radiation Oncology, Gyeongsang National University School of Medicine, Gyeongsang National University Hospital, Jinju, Republic of Korea
| | - Jaeboem Na
- Department of Radiology, Gyeongsang National University School of Medicine, Gyeongsang National University Hospital, Jinju, Republic of Korea
| | - Sang-Youn Song
- Department of Orthopedic Surgery, Gyeongsang National University Hospital, Jinju, Republic of Korea
| | - Jung-Taek Kim
- Department of Orthopedic Surgery, Ajou University School of Medicine, Ajou Medical Center, Suwon, Korea
| | - Yong-Han Cha
- Department of Orthopaedic Surgery, Eulji University Hospital, Daejeon, South Korea
| | - Chan Ho Park
- Department of Orthopedic Surgery, Yeungnam University Medical Center, 170, Hyeonchung-ro, Nam-gu, Daegu, 42415, South Korea.
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In Silico Optimization of Femoral Fixator Position and Configuration by Parametric CAD Model. MATERIALS 2019; 12:ma12142326. [PMID: 31336577 PMCID: PMC6679040 DOI: 10.3390/ma12142326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/11/2019] [Accepted: 07/19/2019] [Indexed: 11/17/2022]
Abstract
Structural analysis, based on the finite element method, and structural optimization, can help surgery planning or decrease the probability of fixator failure during bone healing. Structural optimization implies the creation of many finite element model instances, usually built using a computer-aided design (CAD) model of the bone-fixator assembly. The three most important features of such CAD models are: parameterization, robustness and bidirectional associativity with finite elements (FE) models. Their significance increases with the increase in the complexity of the modeled fixator. The aim of this study was to define an automated procedure for the configuration and placement of fixators used in the treatment of long bone fractures. Automated and robust positioning of the selfdynamisable internal fixator on the femur was achieved and sensitivity analysis of fixator stress on the change of major design parameters was performed. The application of the proposed methodology is considered to be beneficial in the preparation of CAD models for automated structural optimization procedures used in long bone fixation.
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Hou Y, Yao Q, Zhang G, Ding L. [Comparative study of proximal femoral shortening after the third generation of Gamma nail versus proximal femoral nail anti-rotation in treatment of intertrochanteric fracture]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2018; 32:338-345. [PMID: 29806285 DOI: 10.7507/1002-1892.201710065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Objective To explore the difference of the proximal femoral shortening (PFS) between the third generation of Gamma nail (TGN) and the proximal femoral nail anti-rotation (PFNA) in treating intertrochanteric fracture of femur. Methods The clinical data of 158 patients with intertrochanteric fracture of femur who were treated with TGN internal fixation or PFNA internal fixation between January 2014 and December 2015 were retrospectively analysed. The patients were divided into TGN group (69 cases) and PFNA group (89 cases) according to surgical operation. There was no significant difference in gender, age, bone mineral density, causes of injury, AO/Association for the Study of Internal Fixation (AO/ASIF) classification, accompanied disease, and the time from injury to operation between 2 groups ( P>0.05). The result of fracture reduction was divided into 3 types: positive medial cortex support, neutral position cortex support, and negative medial cortex support according to the method of Chang et al. At 18 months postoperatively, bilateral hip anteroposterior X-ray films were taken to measure horizontal PFS values (marked as X), vertical PFS values (marked as Y), and calculate the total PFS values (marked as Z). The PFS values were divided into 4 grades according to the criteria (≤1.0 mm, 1.0-4.9 mm, 5.0-9.9 mm, and ≥10.0 mm), and the constituent ratio was calculated and compared between 2 groups. The X, Y, and Z values and the collodiaphyseal angles of 2 groups at 18 months postoperatively were compared. The X, Y, and Z values of 2 groups of patients with failed fixation and normal healing within 18 months after operation were recorded and compared. The X, Y, and Z values of 2 groups of the patients with different cortex support types were also compared. Results There were 34 cases of positive medial cortex support, 30 cases of neutral position cortex support, and 5 cases of negative medial cortex support in TGN group, and there were 45, 33, and 11 cases in PFNA group respectively, showing no significant difference between 2 groups ( Z=-1.06, P=0.29). All patients were followed up 18 months after operation. At 18 months after operation, the constituent ratios of PFS values (X, Y, Z) had significant differences between 2 groups ( P<0.05). The patients of shortening of 1.0-4.9 mm and 5.0-9.9 mm were obviously more in TGN group than in PFNA group; the patients of shortening of ≥10.0 mm were obviously more in PFNA group than in TGN group. There were significant differences in X, Y, and Z values between 2 groups ( P<0.05), but no significant difference of the collodiaphysial angle was found between 2 groups ( t=0.47, P=0.64). Six cases of internal fixation failed in TGN group and PFNA group respectively within 3 months after operation, and there was no significant difference of X, Y, and Z values between failed fixation and normal healing patients within 2 groups ( P>0.05). When the reposition effect was the positive medial cortex support, the X, Y, and Z values were significantly lower in TGN group than in PFNA group ( P<0.05); but no significant difference was found between 2 groups when the reposition effect was the neutral position cortex support or negative medial cortex support ( P>0.05). At 18 months after operation, the X, Y, and Z values of the negative medial cortex support patients were significantly higher than those of the positive medial cortex support or the neutral position cortex support patients within 2 groups ( P<0.05). Conclusion PFS is a common complication of the intertrochanteric fracture of the femur after internal fixation. During operation, the selection of internal fixation should be based on the results of intraoperative reduction. TGN should be applied to reduce PFS if positive medial cortex support happened.
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Affiliation(s)
- Yu Hou
- Department of Spinal Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038,
| | - Qi Yao
- Department of Spinal Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, P.R.China
| | - Gen'ai Zhang
- Department of Spinal Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, P.R.China
| | - Lixiang Ding
- Department of Spinal Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, P.R.China
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Hong JB, Dan Y, Ouyang L, Liu Y, Xiong LM, Li S, Feng XB, Shao ZW, Yan C, Yang SH, Liu P. Biomechanical study on different lengths of PFNA fixation for unstable intertrochanteric femoral fractures. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2017; 17:299-302. [PMID: 29199189 PMCID: PMC5749036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
OBJECTIVE The aim of our study was to compare the biomechanical stability of the Proximal Femoral Nail Antirotation (PFNA) (with 200 mm, 240 mm and 280 mm-long main nails) for the management of unstable intertrochanteric femoral fractures. METHODS Tronzo-Evans Type IV and V fractures were built by applying a three-dimensional finite element model. Further, PFNA-II with 200 mm, 240 mm and 280 mm-long main nails were applied for fixation. The above model is the creation of 3 researchers designed in order to obtain average values of numerical stress. Von Mises stress distribution and medial and lateral stress peak of the femur and PFNA were compared. RESULTS 240 mm and 280 mm PFNA medial stress peak was reduced significantly in comparison to 200 mm PFNA (p⟨0.05). However, there was no difference between 240 mm and 280 mm PFN. Also, no statistical difference was observed with any of 3 lengths in both medial and lateral stress peak for Evans Type IV and V PFNA. CONCLUSION 240 mm and 280 mm PFNA could reduce femur fixation medial stress peak. Further, they were more efficient in comparison to the 200 mm PFNA, and their biomechanical stability was similar to that of the 280 mm nail.
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Affiliation(s)
- Ji-Bo Hong
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yang Dan
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Liu Ouyang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yong Liu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Li-Ming Xiong
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Shuai Li
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xiao-Bo Feng
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Zeng-Wu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Cao Yan
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Shu-Hua Yang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Pei Liu
- Department of Orthopaedic Surgery, Wuhan First Hospital, Wuhan 430022, China,Corresponding author: Pei Liu, Department of Orthopaedic Surgery, Wuhan, First Hospital, 215 Zhongshan Avenue, Wuhan 430022, China E-mail:
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11
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Rosa N, Marta M, Vaz M, Tavares S, Simoes R, Magalhães FD, Marques AT. Recent developments on intramedullary nailing: a biomechanical perspective. Ann N Y Acad Sci 2017; 1408:20-31. [DOI: 10.1111/nyas.13524] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Natacha Rosa
- DEMec, Faculty of Engineering; University of Porto; Porto Portugal
| | - Miguel Marta
- Department of Orthopedics; Centro Hospitalar de São João; Porto Portugal
| | - Mário Vaz
- DEMec, Faculty of Engineering; University of Porto; Porto Portugal
- INEGI, Faculty of Engineering; University of Porto; Porto Portugal
| | - S.M.O. Tavares
- DEMec, Faculty of Engineering; University of Porto; Porto Portugal
| | - Ricardo Simoes
- Polytechnic Institute of Cávado and Ave; Barcelos Portugal
- Institute for Polymers and Composites IPC/I3N; University of Minho; Guimarães Portugal
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Konya MN, Verim Ö. Numerical Optimization of the Position in Femoral Head of Proximal Locking Screws of Proximal Femoral Nail System; Biomechanical Study. Balkan Med J 2017; 34:425-431. [PMID: 28443571 PMCID: PMC5635629 DOI: 10.4274/balkanmedj.2016.0732] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Background: Proximal femoral fracture rates are increasing due to osteoporosis and traffic accidents. Proximal femoral nails are routinely used in the treatment of these fractures in the proximal femur. Aims: To compare various combinations and to determine the ideal proximal lag screw position in pertrochanteric fractures (Arbeitsgemeinschaft für Osteosynthesefragen classification 31-A1) of the femur by using optimized finite element analysis. Study Design: Biomechanical study. Methods: Computed tomography images of patients’ right femurs were processed with Mimics. Afterwards a solid femur model was created with SolidWorks 2015 and transferred to ANSYS Workbench 16.0 for response surface optimization analysis which was carried out according to anterior-posterior (-10°<anterior-posterior<10°), inferior-superior (-6°<inferior-superior<7°) and tip-apex distance (10 mm<tip-apex distance<30 mm) proximal lag screw positions in the fracture region. The optimum position of the proximal lag screw was determined based on the von Mises stress values occurring on the fracture line. Initial analysis of the system was realized under the surgeon’s normal positioning conditions (anterior-posterior, inferior-superior=0°; tip-apex distance=12 mm). Results: The maximum and minimum (compression) von Mises stresses were found to be 438 MPa and 0.003 MPa, respectively, and risky stresses for the system occurred in the regions where the proximal lag screw passes through the proximal femoral nail hole, the small diameter portion of stem joints with a large diameter and lag screw mounts to the stem. The most suitable position of the proximal lag screw was found at the middle position of the tip-apex distance (20 mm) and femoral neck (anterior-posterior, inferior-superior=0°), according to von Mises compression stress values occurring on the fracture line. Conclusion: In our study, we couldn’t find any correlation between proximal lag screw movement and tip-apex distance on stresses of the fracture surfaces, but the proximal lag screw position in the inferior (inferior-superior<0)-superior (inferior-superior>0) and posterior-anterior directions of the femur neck significantly increased these stresses. The most suitable position of the proximal lag screw was confirmed as the middle of the femoral neck by using optimized finite element analysis.
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Affiliation(s)
- Mehmet Nuri Konya
- Department of Orthopeadics and Traumatology, Afyon Kocatepe University School of Medicine, Afyon, Turkey
| | - Özgür Verim
- Department of Mechanics, Afyon Kocatepe University School of Engineering, Afyon, Turkey
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Design and Analysis of Bionic Cutting Blades Using Finite Element Method. Appl Bionics Biomech 2015; 2015:471347. [PMID: 27019583 PMCID: PMC4745428 DOI: 10.1155/2015/471347] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 09/27/2015] [Accepted: 10/20/2015] [Indexed: 11/26/2022] Open
Abstract
Praying mantis is one of the most efficient predators in insect world, which has a pair of powerful tools, two sharp and strong forelegs. Its femur and tibia are both armed with a double row of strong spines along their posterior edges which can firmly grasp the prey, when the femur and tibia fold on each other in capturing. These spines are so sharp that they can easily and quickly cut into the prey. The geometrical characteristic of the praying mantis's foreleg, especially its tibia, has important reference value for the design of agricultural soil-cutting tools. Learning from the profile and arrangement of these spines, cutting blades with tooth profile were designed in this work. Two different sizes of tooth structure and arrangement were utilized in the design on the cutting edge. A conventional smooth-edge blade was used to compare with the bionic serrate-edge blades. To compare the working efficiency of conventional blade and bionic blades, 3D finite element simulation analysis and experimental measurement were operated in present work. Both the simulation and experimental results indicated that the bionic serrate-edge blades showed better performance in cutting efficiency.
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