Selfdynamisable Internal Fixator Research Articles

Comparative analysis of operation time and intraoperative fluoroscopy time in intramedullary and extramedullary fixation of trochanteric fractures

Background/Aim. Cephalomedullary and extramedullary methods are used for the internal fixation of trochanteric fractures. The usage of the third generation Gamma Nail (GN) is a gold standard in this kind of treatments. Self-dynamisable Internal Fixator (SIF) is an extramedullary implant for trochanteric fractures? treatment. The aim of this study was to compare these two methods regarding operation time and intraoperative fluoroscopy time. Methods. A total of 89 patients with a surgical treatment of a trochanteric fracture were included in this study. There were two groups of patients ? GN group (43 patients) and SIF group (46 patients). Results. Average operation times were 67.5 min (GN group) and 56.0 min (SIF group). Average intraoperative fluoroscopy times were 84.8 s (GN group) and 36.7 s (SIF group). The difference between the groups was statistically significant for both of the given parameters (p < 0.05). The correlation between operation time and intraoperative fluoroscopy time was confirmed in the SIF group (p < 0.05; r = 0.405), while it was not confirmed in the GN group (p > 0.05). There was a higher variability in the GN method than in the SIF method regarding the duration and type of repeated surgical maneuvers followed by X-ray checks. Conclusion. The number of planned surgical interventions per day could depend on the type of trochanteric fracture internal fixation (intramedullary or extramedullary). Certain additional analyses including radiation dose assessment are desirable to clarify if shorter intraoperative fluoroscopy time in the SIF method can have the influence regarding intraoperative X-ray protection clothing. If there is the need to activate dynamization in long femoral axis after initial static fixation in that axis, the SIF method provides its spontaneous activation several weeks after the surgery without the need neither for additional surgery nor for additional intraoperative fluoroscopy

Hip function and health-related quality of life in intramedullary and extramedullary internal fixation of trochanteric fractures

Introduction/Objective. There are extramedullary and intramedullary methods of trochanteric fractures? internal fixation with implants having a lag screw. The objective of this study was to examine the difference in impact of these fixation types on final hip function and health-related quality of life. Method. There were 75 patients treated for a trochanteric fracture, using self-dynamisable internal fixator (SIF group), as an extramedullary method, or gamma nail (GN group), as an intramedullary method. These patients were called for the evaluation of Harris Hip Score (HHS) and SF-12 questionnaire at least two years after surgery. The SF-12 questionnaire has dual expression ? physical component score (PCS) and mental component score (MCS). Results. There were no significant differences between the SIF group and the GN group regarding HHS, PCS, and MCS. Positive correlation was confirmed between HHS, PCS, and MCS, with the strongest relation between HHS and PCS. Negative correlation was confirmed between age and HHS. Conclusion. There was no difference in final hip function and health-related quality of life between SIF and GN methods in trochanteric fractures treatment (p > 0.05). These parameters of outcome were confirmed to have positive interrelation (p < 0.05). Both submuscular presence of extramedullary implant with dimensions of SIF and the need for bone reaming in cephalomedullary fixation were considered not to have significant impact in HHS and SF-12 scores after trochanteric fractures treatment by internal fixation.

In Silico Optimization of Femoral Fixator Position and Configuration by Parametric CAD Model.

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.

Operation time and intraoperative fluoroscopy time in different internal fixation methods for subtrochanteric fractures treatment

Introduction/Objective. Subtrochanteric fractures are unstable, tending to a varus, antecurvatum, and shortening deformity. The aim of this paper was to compare operation time and fluoroscopy time between different internal fixation methods in the treatment of subtrochanteric fractures. Method. The prospective study of the group of 27 patients with a subtrochanteric fracture treated by the SIF (selfdynamisable internal fixator with a trochanteric unit) method had been done. Operation time and fluoroscopy time values from this group were compared to the same parameters data from the literature for intramedullary (IM) nails, proximal femur locking plates (PF-LCP), dynamic condylar screws (DCS), and the 95?-angled blade plate. Results. In the SIF group, operation time was 62.2 (25?140) minutes and fluoroscopy time was 43 (20?95) s. Average operation time from the literature data was: 102.1 (43?181) minutes for IM nail, 94.2 (75?129) minutes for PF-LCP, 105.3 (70?166) minutes for DCS and 221.5 (171?272) minutes for blade plate. Average fluoroscopy time from the literature data was: 109.6 (34?250) seconds for IM nail, 102.3 (47?180) seconds for PF-LCP, 238 seconds for DCS. Operation time and intraoperative fluoroscopy time were higher in IM nail, PF-LCP, DCS and blade plate comparing to SIF method (p < 0.05). Conclusion. The above mentioned difference could be explained by a degree of required accuracy in the initial operative technique maneuvers, by used number of screws and by the type of the fracture reduction performance in different fixation methods. Operation time during IM nailing of subtrochanteric fractures sometimes can be shorter than average operation time in SIF method, what could be explained by the skill of the surgeon to perform as fast closed reduction for insertion of guide wire.

Application of the New Self-dynamisable Internal Fixator in the Treatment of Femoral Shaft Fractures

Summary The aim of this study was to present the results of one original method application in internal fixation of long bones. The series of 27 patients with unilateral fractures of femoral shaft was analyzed. According to AO classification, 21 fractures were classified as 32A, five as 32B, and one as 32C type. Original diaphyseal self-dynamisable internal fixator (model 1) was used as a fixation implant, consisting of three components: specially designed extramedullary bar, clamps and screws. The main feature of this implant is a possibility to become dynamic in the axial direction spontaneously if there is no sufficient fracture healing. Because of that, this implant is known as an „intelligent implant“. Surgical method included a standard surgical approach and minimally invasive surgical approach. Minimally invasive technique of application required less blood transfusion and shorter surgery time when compared to the standard surgical approach. The duration of used intraoperative fluoroscopy control was 7(3-18) seconds. The average healing time was 4.3 (3.5-9.5) months. There were neither intra operative nor postoperative complications. In comparison to intramedullary nails, self-dynamisable internal fixator provides a similar treatment results, while in comparison to plates it provides fewer mechanical complications. Self-dynamisable internal fixator method preserves periosteal and intramedullary blood circulation, and it is the first fixation implant with a possibility of spontaneous axial dynamising activation when needed. This implant has been proven as suitable for routine use in the treatment of femoral shaft fractures.

Treatment of stable and unstable intertrochanteric fractures with selfdynamisable internal fixator (concept of double dynamisation).

BACGROUND/AIM. Intertrochanteric fractures of the femur are the third most common fractures among all bone fractures. Today in everyday orthopedic practice a number of different methods of treatment of trochanteric fractures of the femur are applied. Despite the improvement in the development of new implants, the percentage of serious complications of the treatment of these fractures remains very high, varying from 10% to 20%. One of the most serious complications of internal fixation of intertrochanteric fractures is nonunion of fractures due to the lack of additional axial dynamisation of implants. The aim of this study was to determine the efficacy of double dynamisation in stable and unstable intertrochanteric fractures treatment using the self dynamisable internal fixator. During the period from 2000 to 2009 we analyzed the use of selfdynamisable internal fixator (SIF implant) in the treatment of 247 patients with stable and unstable intertrochanteric fractures. Fracture types were classified according to the AO Fracture Classification/Orthopaedic Trauma Association Scheme. Salvati and Wilson scoring systems were used for functional assessment considering pain, walking ability and hip movements of operated patients. Of the total number of treated patients, 134 were males and 113 females, aged 19 to 90 (average 49.6) years. More than a half of the patients were older than 50 years. Monitoring of the patients after the operation was carried out clinically and radiographically for a period of three to six months in all the patients, whereas a 2-year follow-up was conducted in 176 (71.2%) patients. The average duration of surgery was 47 min, the average blood loss 145 mL, and the average fluoroscopy time was 16 sec (8-97 sec). The average time for union was 3.7 months (3-6.6 months). Double dynamisation (dynamisation along the neck and shaft of the femur) was observed in 85 (34.4%) patients, and was on average 4.3 mm (1.5-8 mm). All fractures managed with dynamisation implants healed completely within no later than six months after the surgery. In 17 cases there was a cut-out phenomenon of implant, while in seven cases there was mechanical implant failure. Complications were detected within 3 to 6 weeks after surgery, and treated by the method of intramedullary fixation. During the study, there were no cases of infection and thromboembolic complications detected. The concept of double dynamisation improves the fracture healing in the stable and unstable intertrochangeric fractures using the selfdynamisable internal fixator. This biological method of fixation provides healing of intertrochanteric fracture in the optimum period of time, significantly reducing the risk for mechanical failure.

Internal fixator "Mitkovic" in the treatment of fractures of femoral shaft: A possible solution for fractures in heavier children and adolescents

Background: Management of femoral shaft fractures in older and heavier children and adolescents is still challenging and controversial and includes several modalities of fixation. Aim of this study was to analyze single center experience in application of selfdynamisable internal fixator Mitkovic (SIF) for the treatment of fractures of femoral shaft in children and adolescents. Methods: Retrospective analysis of data of pediatric and adolescent patients treated for diaphyseal fracture in single center has been conducted. Results: Eleven patients, with 12 femoral shaft fractures were treated in ten-year-period with internal fixator ?Mitkovic?. Time to fracture healing ranged from 4-12 weeks (average 8.9 weeks). All fractures healed without complications. No rotational or angular mall-alignment was noticed. No external cast immobilization was applied in any patient. Conclusion: Selfdynamisable internal fixator Mitkovic may be considered as viable option for treatment of femoral fractures in older/heavier children and adolescents particularly with unstable fracture patterns.

Selfdynamisable internal fixator Mitkovic in treatment of periprosthetic supracondylar femoral fracture after total knee arthroplasty

Supracondylar periprosthetic femoral fractures after total knee arthroplasty are very rare, but very difficult to treat. They occur most often as a result of low energy trauma (slips and fall) in older patients with present osteoporosis and periprosthetic osteolysis. The treatment of these fractures is very difficult due to reduced biological capacity for healing in most cases. Surgical treatment of these fractures is accompanied by severe complications (prolonged healing, nonunion and disintegration osteosintets material) in 25 to 70% of the cases. The aim of this paper is to present the treatment of supracondylar femur fractures after total knee arthroplasty in men aged 72 with selfdynamisable internal fixator Mitkovic. Surgical treatment of fracture performed on the six day after the injury with minimally invasive surgical technique through two incisions. Verticalization and walking with crutches with non-weight-bearing started the first postoperative day. Patient discharged from hospital fifth postoperative day. Full weight-bearing on the operated leg is allowed after 6 weeks. The patient started a stationary physical therapy 6 weeks after surgery. Postoperative follow-up was 10 months. The fractures healed with an excellent functional result. Application of selfdynamisable internal fixator Mitkovic with minimally invasive technique in the treatment of these complex fractures provides excellent biomechanical conditions for healing.

Influence of different methods of internal bone fixation on characteristics of bone callus in experimental animals

Correct choice of osteosynthesis method is a very important factor in providing the optimal conditions for appropriate healing of the fracture. There are still disagreements about the method of stabilization of some long bone fractures. Critically observed, no method of fracture fixation is ideal. Each osteosynthesis method has both advantages and weaknesses. The objective of this study was to compare the results of the experimental application of three different internal fixation methods: plate fixation, intramedullary nail fixation and self-dynamisable internal fixator (SIF). A series of 30 animals were used (Lepus cuniculus) as experimental animals, divided into three groups of ten animals each. Femoral diaphysis of each animal was osteotomized and fixed with one of three implants. Ten weeks later all animals were sacrificed and each specimen underwent histological and biomechanical testing. Histology showed that the healing process with SIF was more complete and bone callus was more mature in comparison to other two methods. During biomechanical investigation (computerized bending stress test), it was documented with high statistical significance that using SIF led to stronger healing ten weeks after the operation. According to the results obtained in this study, it can be concluded that SIF is a suitable method for fracture treatment.

Minimally invasive treatment of bilateral femoral shaft fractures in polytrauma patient using selfdinamisibile internal fixator: A case report

Proper timing and surgical method in management of femur fractures in polytrauma patients can greatly reduce the mortality, morbidity and disability. The aim of this paper is to present the treatment of bilateral femoral fractures in polytrauma patient with dominant chest trauma by selfdynamisable internal fixator Mitkovic (SIF) as a definitive method of fractures treatment. A 23 years old female was injured in a traffic accident. After resuscitation and treatment of the dominant chest injuries, surgical treatment of bilateral femur fractures performed on the fourth day after the injury. Length of surgery was 65 minutes. There was not blood substitution during the intervention and blood loss through the operative wounds drainage. There was no worsening of the pulmonary function after orthopaedic surgery. The patient discharged from hospital postoperative day ten. Postoperative follow-up was 9 months. The fractures healed with an excellent functional result. Application of selfdynamisable internal fixator (SIF) with minimally invasive technique for the treatment of bilateral femoral fractures in polytrauma patients is a good operative method because poses minimally additional operative trauma and provides excellent biomechanical conditions for fracture healing.

Results of the femur fractures treated with the new selfdynamisable internal fixator (SIF)

PurposeAs axial dynamisation is a recognised method, many authors using interlocking femoral nail perform an additional small operation two months after the primary operation in order to remove one screw so as to provide axial dynamisation. According to the literature, dynamisation happens in about 15–25% of cases, but it cannot be predicted which patient or fracture will need dynamisation. The aim of this study is to present a new selfdynamisable implant and a minimally invasive method for the internal fixation of different femoral fractures.Materials and methodsThe study was conducted between 2000 and 2008 and included 849 patients with 871 fractures receiving the selfdynamisable internal fixator (SIF) for proximal, diaphyseal and distal femur fractures.ResultsThe average operative time was 44 min (23–119 min) and the average fluoroscopy time was 12 s (6–92 s), while the average blood loss was 90 ml (60–250 ml) when a minimally invasive technique was used. None of the patients developed complications during the intra-operative period. Complete follow-up was available in 726 patients with 738 fractures. The healing time was 3.9 months (3–9 months). Healing was achieved in 99.1% of patients. Superficial infection developed in seven fixations (0.9%), while deep infection developed in four patients (0.5%). Screw-breaking occurred within 6–18 weeks in 19 fixations (2.6%). Cut-out phenomenon happened in 24 cases. Spontaneous axial dynamisation was observed in 71 (23.8%) out of 738 fractures, being 5 mm on average (2–12 mm).ConclusionThe SIF is an effective method for the treatment of femoral fractures. This method is particularly valuable in the treatment of comminuted fractures with regard to minimally invasive surgery.Electronic supplementary materialThe online version of this article (doi:10.1007/s00068-011-0157-7) contains supplementary material, which is available to authorized users.

Fractures of the upper part of the femur treated with Mitkovic selfdynamisable internal fixator (SIF)

Complex transtrochanteric and subtrochanteric fractures need dynamisation in two axis: in neck axis and in the long axis of the femur. In this study is present one new concept of the surgical treatment of the fractures of proximal femur using new double dynamic selfdynamisable internal fixator (SIF). Dynamisation along the femoral neck axis is available immediately after the fixation, while dynamisation in the long axis of the femur is activated spontaneously 4-6 weeks after the fixation. It is shown seris of 30 consecutive fractures of the upper femur. The average operative time was 42 minutes and average blood loss was 70 (seventy) milliliters. All fractures healed within an average period of sixteen weeks (ranging from 12 to 24 weeks). There were no serious complications. SIF is one effective minimally invasive method for the treatment of complex trochanteric and subtrochanteric femoral fractures.

Treatment of Subtrochanteric Femoral Fractures Using Selfdynamisable Internal Fixator

BackgroundSurgical treatment is the preferred method for treating subtrochanteric femoral fractures and the variety of extramedullary and intramedullary implants continues to evolve. The purpose of our study was to retrospectively evaluate the clinical and radiological results of subtrochanteric fractures that are treated with the Selfdynamisable internal fixator.MethodsFrom January 2000 to January 2004, we treated 49 consecutive patients who had subtrochanteric fractures. According to the AO classification, 8 (16.3%) fractures were type 32-A, 16 (32.7%) were type 32-B and 25 (51%) fractures were type 32-C. The mean follow-up time was 22.3 months.ResultsThe average operating time was 45 minutes (range, 32 to 90 minutes). The average blood loss was 250 mL (range, 125 to 350 mL). The average hospital stay was 10 days (range, 7 to 59 days). Implant failure was not observed and union was achieved in all the patients. Deep infection occurred in one (2%) patient in the early postoperative period. Fracture union was achieved at a mean of 14 weeks. Varus malalignment less then 10 degree was noted in three (6.1%) patients at the end of follow-up. Thirty-five patients were pain-free and 14 had mild pain.ConclusionsThe selfdynamisable internal fixator was successfully used for subtrochanteric fracture. It provides a short operative time, low blood loss, spontaneous biaxial dynamisation and healing in an optimal period of time without the need for secondary intervention.

Treatment of the humeral shaft nonunion after surgical failure using the Selfdynamisable internal fixator

A nonunion of the humeral shaft is not a rare condition and is a complication of both nonoperative and operative treatment of the fracture. Several fixation options were used in the nonunion treatment, including various plate techniques, intramedullary nails and external fixator. We applied our Selfdynamisable internal fixator for the treatment of humeral shaft nonunion after surgical failure and evaluated its clinical outcome. Six patients with persistent atrophic nonunion of the humeral shaft were treated with Selfdynamisable internal fixator. The inclusion criteria were mobile, unstable resistant nonunion of the humeral diaphysis which persisted after surgical treatment for nonunion. All patients were men with a mean age of 32 (27-39) years. The initial fracture treatment was external fixator in two patients and plaster cast for four patients. All cases failed to unite after primary treatment. Plate fixation was resorted for fracture union but failed. The revision surgery consisted of removal of hardware, freshening of bone ends and bone grafting, and internal fixation with a Selfdynamisable internal fixator. The average follow-up was 33 months. All the nonunions healed after indexed operation. The average time for union was 5.5 months (range 4-9 months). There was no loosening or breakage of the fixation device. The functional results, according to the scale of Constant and Murlay modified by Ring, were excellent in five and good in one patient. There were no complications of nerve injuries or infections related to the operation. Selfdynamisable internal fixator with bone graft for the treatment of recalcitrant humeral shaft nonunion provided successful clinical outcome with minimal complications.

Treatment of trochanteric femoral fractures with double dynamic internal fixation

Trochanteric fractures are extracapsular fractures of the proximal femur. The increasing number of trochanteric fractures is a great sociomedical problem. These fractures usually occur in elderly people (older than 65 years) with osteoporosis. Lateral and frontal falls are the most frequent cause of trochanteric fractures in the elderly. The aim of this paper is to present our results of applying the Mitković selfdynamisable internal fixator (SIF). From January 2001 to December 2005, 238 patients with trochanteric femoral fractures were treated operatively using the Mitković selfdynamisable internal fixator at the Clinic of Orthopeadics and Traumatology in Nis. The average patient age was 69, 11 years (range 17 to 88). In the analyzed group there were 152 (64%) female and 86 (36%) male patients, whereas patients in the eighth 101 (43%) and seventh 65 (27%) decade of life prevailed. Excellent results in the treatment of trochanteric femoral fractures with a Mitković dynamic internal fixator were achieved in 143 (60%) patients, good in 49 (21%) patients, poor in 41 (17%) and unsatisfactory in 5 (2%) patients. The treatment of trochanteric fractures may be operative and nonoperative. The aim of the operative treatment, considered to be the "gold standard" for these fractures, is to restore the patient's pretraumatic activity level and to reduce life-threatening complications. The operative stabilization is performed using various types of implants. Surgical treatment by using dynamic implants is a method of choice in the treatment of trochanteric fractures. Internal fixation using the Mitković selfdynamisable internal fixator is a method of choice in the treatment of trochanteric femoral fractures, providing dynamization and compression of the fracture site in two axes (axis of the femoral neck and femoral diaphyseal axis) and balanced biomechanical 3D.