Invasive Stabilization System Research Articles

Functional and Radiological Outcomes of Distal Femur Fractures treated with Less Invasive Stabilization System versus Dynamic Condylar Screw

Introduction: Fractures in the distal femur are quite rare, comprising around 0.4% of all fractures and 3% of femoral fractures. Managing distal femur fractures has been a subject of debate, but recent developments favor indirect reduction and minimally invasive approaches. The objective is to find a harmonious equilibrium between the mechanical stability of the fractured segments and their biological viability. Given their elevated complication rate, achieving optimal restoration of functional anatomy and ensuring stable fixation is imperative for prompt recovery from distal femoral fractures. Comparison of less invasive stabilization system versus dynamic condylar screw fixation in treatment of distal femur fractures is subject of ongoing debate as to which one is better. Aims and Objectives: To compare the functional and radiological outcomes of distal femur fractures treated with less invasive stabilization system versus dynamic condylar screw fixation. Place and Duration of study: A randomized clinical trial was conducted in the Orthopedic Department of Sheikh Zayed Hospital, Lahore, from July 2, 2020, to January 1, 2021. Material and Methods: A randomized clinical trial was conducted at Sheikh Zayed Hospital in Lahore over a six-month duration. In total 104 patients who fulfilled the inclusion criteria were admitted to the Orthopedic Department via Emergency and OPD. Demographic data and medical histories were taken. The sample size consisted of 52 patients in each group, with random allocation to either the LISS (A) or DCS (B) groups determined by a lottery method. Follow-up appointments were scheduled for all patients at one month, three months, and six months post-surgery. Radiological outcome was evaluated at each follow-up visit while functional outcome assessed at sixth monthly follow up. Data analysis was performed using the SPSS: version 22, considering p ? 0.05 as significant. Results: Frequency of functional outcome was i.e. excellent (32.7%), good (14.4%), fair (2.9%) in group A and excellent (27.9%), good (31.7%), fair (7.7%) in group B (p-value>0.05). Mean fusion time was 18.67±3.04 in group A and 19.62±4.36 in group B (p-value>0.05). Conclusion: Our findings indicate no substantial distinction between the two groups. Using DCS or LISS, both methods yield favorable outcomes with negligible complications in the management of distal femoral fractures. Both systems effectively reduce soft tissue injury.

Management of segmental defects post open distal femur fracture using a titanium cage combined with the Masquelet technique A single-centre report of 23 cases

IntroductionThe segmental bone defects post open distal femur fracture presents a reconstructive challenge, which often requires extreme solutions. The present study reviewed a new treatment strategy which used a cylindrical titanium mesh cage as an adjunct to the Masquelet technique. MethodsWe retrospectively reviewed a consecutive series of 23 patients treated for segmental bone defects post open distal femur fracture using a titanium mesh cage combined with the Masquelet technique under a 2-staged protocol in our institution from 2017 to 2021. The study group consisted of 13 men and 10 women with an average age of 44.1 years. The surgical debridement was performed with antibiotic polymethylmethacrylate (PMMA) cement spacer implanted into the bone defect combined with cement-wrapped plate stabilization, or antibiotic beads with vacuum sealing drainage (VSD) to cover the wound. The second stage of the Masquelet technique for bone defect repair began at least 4–6 weeks after the first stage, once all signs of possible infection were eliminated. After the cement spacer was removed, the definitive reconstruction was completed with exchange to a cylindrical titanium mesh cage filled with cancellous autograft within the induced membrane. The bone defect with cage was stabilized with a distal femoral Less Invasive Stabilization System (LISS). The radiological and clinical records of the enrolled patients were retrospectively analyzed. ResultsThe mean follow-up was 38.6 months. The average number of operations before the second stage was 1.3. The mean interval between the two stages was 12.7 weeks. The average length of the defect measured 8.3 cm (ranging from 6.1 to 12.4 cm). All the defects filled with autograft within the cage achieved bony union, with a mean healing time of 8.4 months. At the latest follow-up, the mean knee extension measured 6.2° (ranging from 0° to 20°), and the mean flexion measured 101.8° (ranging from 60° to 120°). Complications included two instances of superficial stitch abscess, which eventually healed. ConclusionsThe use of a titanium cage implanted into an induced membrane in a 2-staged Masquelet protocol could achieve satisfactory clinical outcomes in cases of segmental defects following open distal femur fractures.

Application of Cortical Bone Plate Allografts Combined with Less Invasive Stabilization System (LISS) Plates in Fixation of Comminuted Distal Femur Fractures.

Background and Objectives: At present, the management of comminuted distal femur fractures remains challenging for orthopedic surgeons. The aim of this study is to report a surgical treatment for comminuted distal femur fractures using supplementary medial cortical bone plate allografts in conjunction with the lateral less invasive stabilization system (LISS) plates. Materials and Methods: From January 2009 to January 2014, the records of thirty-three patients who underwent supplementary medial cortical bone plate allografts combined with lateral LISS plates fixation were reviewed. Clinical and radiographic data were collected during regular postoperative follow-up visits. Functional outcomes were determined according to the special surgery knee rating scale (HSS) used at the hospital. Results: Thirty patients were followed for 13 to 73 months after surgery, with an average follow-up time of 31.3 months. The mean time to bone union was 5.4 months (range of 3-12 months) and the mean range of knee flexion was 105.6° (range of 80-130°). Of the remaining patients, 10 had a score of "Excellent", while 10 had a score of "Good". Three patients had superficial or deep infections, one patient had nonunion that required bone grafting, and one patient had post-traumatic knee arthritis. Conclusions: Based on these promising results, we propose that supplementary medial cortical bone plate allografts combined with lateral LISS plate fixation may be a good treatment option for comminuted distal femur fractures. This treatment choice not only resulted in markedly improved stability on the medial side of the femur, but also satisfactory outcomes for distal femoral fractures.

Analysis of 101 Mechanical Failures in Distal Femur Fractures Treated with 3 Generations of Precontoured Locking Plates.

To evaluate mechanical treatment failure in a large patient cohort sustaining a distal femur fracture treated with a distal femoral locking plate (DFLP). This retrospective case-control series evaluated mechanical treatment failures of DFLPs. The study was conducted at 8 Level I trauma centers from 2010 to 2017. One hundred one patients sustaining OTA/AO 33-A and C distal femur fractures were treated with DFLPs that experienced mechanical failure. The intervention included the treatment of a distal femur fracture with a DFLP, affected by mechanical failure (implant failure by loosening or breakage). The main outcome measures included injury and DFLP details; modes and timing of failure were studied. One hundred forty-six nonunions were found overall (13.4%) including 101 mechanical failures (9.3%). Failures occurred in different manners, locations, and times depending on the DFLPs. For example, 33 of 101 stainless steel (SS) plates (33%) failed by bending or breaking in the working length, whereas no Ti plates failed here ( P < 0.05). Eleven of 12 failures with titanium-Less Invasive Stabilization System (92%) occurred by lost shaft fixation, mostly by the loosening of unicortical screws (91%). Sixteen of 44 variable -angled-LCP failures (36%) occurred at the distal plate-screw junction, whereas only 5 of 61 other DFLPs (8%) failed this way ( P < 0.05). Distal failures occurred on average at 23.7 weeks compared with others that occurred at 38.4 weeks ( P < 0.05). Variable -angled-LCP distal screw-plate junction failures occurred earlier (mean 21.4 weeks). Nonunion and mechanical failure occurred in 14% and 9% of patients, respectively, in this large series of distal femur fracture treated with a DFLP. The mode, location, presence of a prosthesis, and timing of failure varied depending on the characteristics of DFLP. This information should be used to optimize implant usage and design to prolong the period of stable fixation before potential implant failures occur in patients with a prolonged time to union. Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

104 Our Management of Distal Femoral Comminuted Fractures with Femoral Defects

Abstract Aim Distal femoral fractures account for 3–6% of all femoral fractures. Current management of distal femoral fractures involve reducing bone fragments and placing a locking plate against it. In this study, the surgeon used a ‘selective approach’, whereby only key bone fragments in the comminuted fracture were reduced and fixed whilst the rest were either removed or left unreduced/unfixed. Method All patients underwent AxSOS plate/less invasive stabilisation system (LISS) surgery after adopting the “selective approach” during pre-surgical planning. A significant proportion of patients had a degree of bone defect, and most had open fractures. Primary outcomes included post-operative functional ability, quality of life assessed using EQ-5D-5L, Oxford Hip Score (OHS), Oxford Knee Score (OKS), range of movement. Results Average OKS and OHS for our cohort (n=10) is 23 and 35, respectively, with a mean knee-flexion of 86° (45°-120°). Average EQ-5D- 5L index value is 0.551; the most common response for mobility, self-care, usual activities, pain/discomfort, and anxiety/depression was moderate. 20% developed pin site infections, 40% reported significant knee stiffness. Conclusions Despite having a complex cohort where many of the patients had bone defects, and 80% had open fractures, the “selective approach” adopted in the present study achieved comparable outcomes to other studies with less-severe fracture characteristics, with similar operation times and range of knee-flexion. These results suggest that this alternative should be considered as a potential treatment option, although more studies on a similar cohort of patient to ours is needed to allow better comparison of the surgical approaches.

SP5.2.2 Our Management of Distal Femoral Comminuted Fractures with Femoral Defects

Abstract Aim Distal femoral fractures account for 3–6% of all femoral fractures. Current management of distal femoral fractures involve reducing bone fragments and placing a locking plate against it. In this study, the surgeon used a ‘selective approach’, whereby only key bone fragments in the comminuted fracture were reduced and fixed whilst the rest were either removed or left unreduced/unfixed. Method All patients underwent AxSOS plate/less invasive stabilisation system (LISS) surgery for their comminuted femoral fracture after adopting the “selective approach” during pre-surgical planning. A significant proportion of patients had a degree of bone defect, and most had open fractures. Primary outcomes included post-operative functional ability, quality of life assessed using EQ-5D-5L, Oxford Hip Score (OHS), Oxford Knee Score (OKS), range of movement. Results Average OKS and OHS for our cohort (n=10) is 23 and 35, respectively, with a mean knee-flexion of 86° (45°-120°). Average EQ-5D- 5L index value is 0.551; the most common response for mobility, self-care, usual activities, pain/discomfort, and anxiety/depression was moderate. 20% developed pin site infections, 40% reported significant knee stiffness. Conclusions Despite a complex cohort whereby many patients had bone defects, and 80% had open fractures, the “selective approach” adopted in the present study achieved comparable outcomes to other studies with less-severe fracture characteristics, with similar operation times and range of knee-flexion. These results suggest that this alternative should be considered as a treatment option, although more studies on a similar cohort of patient to ours is needed to allow better comparison of the surgical approaches.

Failure of Distal Femoral Locking Plate: Case Report

The Less Invasive Stabilization System (LISS) and titanium distal femoral locking compression plate (DF-LCP) was designed by the AO Group to combine the advantages of both interlocked intra-medullary nailing and biological plating techniques in one system. The stiffness of the construct is similar to a 95° condylar plate, dynamic condylar screw, or condylar buttress plate.&#x0D; We report a case of the DF-LCP and screw breakage. Early weight bearing and lack of callus consolidation precipitated failure of the implant. Non-weight bearing and early autologous bone grafting may be indicated in open distal femoral fractures.

Periprosthetic knee fractures in an elderly population: open reduction and internal fixation vs distal femur megaprostheses.

The incidence of periprosthetic fractures of distal femur (PPDFFx) after primary total knee arthroplasties is described around 0.3% and 2.5% and it is increasing as the number of patients with total knee arthroplasty continues to arise. surgical options treatments for PPDFFx include fixation in the form of eather Open reduction and internal fixation (ORIF), or retrograde intramedullary nailing (RIMN), or conventional (non locked) plating, or locked plating such as the Less Invasive Stabilization System (LISS), or dynamic condylar screws. In recent years, however, the use of megaprostheses has been increasing. Patients with periprosthetic fractures of distal femur after primary total knee arthroplasties treated with ORIF or with the use of Distal femur replacement (DFR) were retrospectively analyzed in this to evaluate differences in intra-operative blood loss, need of blood trasfusion, weight bearing, range of motion, rate of complications, rate of revision surgery and functional outcome according Oxford Knee Score between two groups. Treatment of Periprosthetic distal femur fracture remains controversial. While ORIF seems to guarantee less percentage of complications and reoperation rate, those treated with megaprosthesis seem to gain better range of motion in a very short post-operative time. In the future it will be necessary to investigate with greater numbers possible advantages and disadvantages of the various treatments in periprosthetic distal femur fractures.

Evaluation of the Results of Minimally Invasive Plate Osteosynthesis Using a Locking Plate in the Treatment of Distal Femur Fractures.

IntroductionDistal femur fractures are serious injuries that can be difficult to treat, carry an unpredictable prognosis, and lead to long-term disability and morbidity. The introduction of minimally invasive plate osteosynthesis (MIPO) avoids direct exposure of the fracture site, improves fracture healing and decreases the incidence of complications. The aim of this study was to assess prospectively the early results of the treatment of supracondylar fractures of the femur using minimally invasive percutaneous osteosynthesis using a distal femoral locking plate. The study was a prospective study that included 20 adult patients who sustained distal femur fractures.Materials and methods The study was a prospective study that included 20 patients suffering from supracondylar fractures of the femur. All patients had fixation of the fracture using a distal femur locking plate (less invasive stabilization system (LISS)) in a minimally invasive technique using an anterolateral or direct lateral approach to the distal femur according to the fracture classification. The follow-up was done using the functional evaluation scale for distal femoral fractures as regards range of motion, deformation, pain, walking ability, and return to work.ResultsThe mean age was 52.80 (19-80) years. The mean body mass index of the patients was 28.50, with a range of 23-43 kg/m2. The mechanism of trauma was road traffic accidents (RTAs) in nine patients (45%) and falling from standing height in eleven patients (55%). Fractures were classified according to the Arbeitsgemeinschaft Osteosynthesefragen-Orthopedic Trauma Association (AO-OTA) classification. All patients were followed up for a period of six months and assessed in terms of knee range of motion, deformation, pain, walking ability, and return to work. The mean time of radiological union, in which bony trabeculae crossed the fracture gap, was 3.45 ± 0.79 months. The final results obtained were excellent in four patients (20%), good in nine patients (45%), fair in five patients (25%), and poor in two patients (10%). Complications encountered were knee stiffness (20%), superficial wound infection (10%), and shortening (15%).ConclusionLISS plating using the MIPO approach is useful in treating complex distal femoral fractures. Large studies from independent centers reporting long-term results are needed to further evaluate the role of LISS plating and the MIPO approach in the management of complex distal femoral fractures.

Finite element analysis of different medial fixation strategies in double-plate osteosynthesis for AO type 33-C2 Femoral fractures

ObjectivesIn this study, we evaluated the biomechanical characteristics of different locations of medial fixation strategies in double-plate osteosynthesis for fixing AO/ASIF type 33-C2 femoral fractures by means of finite element analysis. MethodsWe used 3-matic software and UG-NX software to construct AO/ASIF type 33-C2 Femoral fractures and lateral less invasive stabilization system (LISS) plates, medial plates (MPs), and medial support pads (MSPs), respectively. Then, the LISS, MP and MSP were assembled into the fracture model separately to form three fixation models: MSP+LISS, anteromedial plate (AMP+LISS), and MP+LISS. In the next procedure, we performed finite element analysis using ANSYS software after meshing the elements of the models in HyperMesh 11.0 software. Loading conditions including lateral-medial four-point bending, anterior-posterior four-point bending, axial loading, and torsional loading were applied to evaluate the biomechanical advantages among the three fixation types. We observed the peak Von Mises Stress (VMS) value, maximum displacement, bending angle in the coronal plane of the fracture, and torsional angle of the fracture to assess the degree of plate deformation and fixation stability. ResultsOur results showed that in both lateral-medial four-point bending and anterior-posterior four-point bending, the calculations of MP+LISS were marginally better than those of AMP+LISS. However, with the action of axial loading and torsional loading, the deformation of MP+LISS was distinctly smaller than that of AMP+LISS, and the fixation stability of MP+LISS was also prominently better. Under lateral-medial four-point bending, the VMS on the lateral plate of MSP+LISS (59.977 MPa) was approximately half of the two double-plate models. Under anterior and posterior four-point bending, the 38.209 MPa peak VMS of MSP+LISS was still superior to the other two double-plate models. Under torsional loading, the peak VMS (347.75 MPa), the maximum torsional angle of the femoral head (7.852 °), and the torsional angle of fracture (0.036 °) of MSP+LISS preceded those of the other two models. However, under axial loading, the peak VMS (76.376 MPa) and the maximum displacement (3.1798 mm) of MSP+LISS were slightly higher than those of MP+LISS. ConclusionThe MSP+LISS model showed better biomechanical performance than the double-plate models, which might be an effective solution for the treatment of comminuted distal femur fractures.

Treatment of peri-implant refracture after intramedullary nail fixation for intertrochanteric fractures

To investigate the occurrence, treatment, and effectiveness of peri-implant refracture after intramedullary nail fixation for intertrochanteric fractures. The clinical data of 16 patients with peri-implant refracture after intramedullary nail fixation for intertrochanteric fractures who met the inclusion criteria between April 2014 and November 2019 were retrospectively analyzed. There were 7 males and 9 females with an average age of 78.4 years (range, 65-93 years). The 14 cases of initial intertrochanteric fractures were classified according to the classification of AO/Orthopaedic Trauma Association (AO/OTA): 5 cases of type A1, 7 cases of type A2, and 2 cases of type A3; the other 2 cases were intertrochanteric combined with subtrochanteric fractures (Seinsheimer type Ⅴ). According to the classification of peri-implant refracture which was proposed by Chan et al., there were 10 cases of type 1 (6 cases of type 1A, 3 cases of type 1B, 1 case of type 1C) and 6 cases of type 2 (4 cases of type 2A and 2 cases of type 2B). The average interval between refracture and initial surgery was 14.6 months (range, 1-52 months). The incidence of peri-implant refracture in short nail group (the length of intramedullary nail used in initial surgery≤240 mm) was 1.92% (11/573), while the incidence of long nail group (the length of intramedullary nail used in initial surgery≥340 mm) was 1.66% (5/301), showing no significant difference between the two groups ( χ 2=0.073, P=0.786). The peri-implant refractures were revised with extended intramedullary nail (5 cases) or fixed with additional limited invasive stabilization system (11 cases). The average operation time was 115.8 minutes (range, 78-168 minutes) and the average intraoperative blood loss was 283.1 mL (range, 120-500 mL). One patient died of myocardial infarction at 3 months after operation, and the other 15 patients were followed up 9-46 months (mean, 16.8 months). The peri-implant refractures healed at 14-20 weeks (mean, 16.4 weeks) after operation. There was no complications such as incision infection, nonunion, internal fixator loosening and rupture, screw cutting-out, and the second refracture during the follow-up. At last follow-up, all injured limbs regained walking function, and the Hospital for Special Surgery (HSS) score was 56-92 (mean, 80.2). The results were classified as excellent in 2 cases, good in 10, fair in 2, and poor in 1, with the excellent and good rate of 80%. Stress concentration at the tip of initial intramedullary nail and distal interlocking screw aera is the main cause of peri-implant refracture after intramedullary nail fixation for intertrochanteric fractures. Revision with extended intramedullary nail or fixation with limited invasive stabilization system according to the length of initial intramedullary nail and the type of refracture can get satisfactory effectiveness.

Treatment of Periarticular Fractures of the Knee Using the Less Invasive Stabilization System: A Retrospective Clinical Trial.

IntroductionPeriarticular fractures of the knee in adults are generally treated with internal fixation. The Less Invasive Stabilization System (LISS) plate, developed by Arbeitsgemeinschaft Osteosynthesefragen (AO)/Association for the Study of Internal Fixation (ASIF) in the late 1990s, allows reduction and biological fixation through smaller incisions without violating periosteal blood supply. It offers several advantages for the treatment of complex periarticular fractures of the knee. In this study, we have aimed to report the results of a single series of these fractures.Materials and methodsForty-eight patients with AO type 33 and AO type 41 periarticular knee fractures who were operated between 2009 and 2014 at a single institution were included in this retrospective study. Patient demographics, fracture epidemiology, intraarticular extension, concomitant injuries, American Society of Anesthesiologists (ASA) score, time to union, the average time from admission to surgery, and the mean time from operation to patient discharge were noted. The effect of patient and fracture-related factors on length of hospital stay were evaluated.ResultsThe mean follow-up time was 23.7 (12-48) months. The average time from admission till surgery and from surgery till discharge was 10.2 (1-39) and 9.7 (2-35) days, respectively. The average time for union was 6.8 months. Femur fractures healed in mean 6.6 months whereas tibia fractures took 7.1 months to heal. Time from admission to surgery and postoperative hospital stay was longer in patients with higher ASA scores (p<0.01) and open fractures (p<0.001). Patients’ body mass index (BMI) and intraarticular extension of the fracture did not cause an increase in either preoperative or postoperative hospital stay (p>0.05). The presence of concomitant major injuries caused a delay in operation (p<0.05), whereas postoperative hospital stay was not different (p>0.05).ConclusionLISS plating provides good stability through a small incision, permits biological fracture healing, may be used in multifragmentary fractures and has low complication rates. It is a good alternative for the treatment of periarticular fractures of the knee.

Comparative analysis of the biomechanical behavior of anterograde/retrograde nailing in supracondylar femoral fractures

Supracondylar femoral fractures account for a noticeable percentage of the femoral shaft fractures, affecting two etiological groups: high energy trauma in young men, with good bone quality, and older women with osteoporotic femur. Surgical treatment of those kind of fractures remains controversial, with different surgical options such as plate and sliding barrel locking condylar plate, less invasive stabilization system (LISS) or intramedullary nailing, which has emerged as a new fixation choice in the treatment of that type of fractures.The present work performs a comparative study about the biomechanical behavior of anterograde and retrograde nailing in supracondylar femoral fractures type A, in order to determine the best choice of nailing and locking configuration. A three-dimensional finite element model of the femur was developed, modeling femoral supracondylar fracture and different nailing configurations, both for anterograde and retrograde nails. The study was focused on the immediately post-operative stage, verifying the appropriate stability of the osteosynthesis.The obtained results show a better biomechanical behavior for anterograde nails, providing a better stability from the point of view of global movements, lower stresses in screws, and less stress concentration in cortical bone. So, for the analyzed fractures and osteosyntheses types, anterograde nailing has demonstrated to be a better surgical option, being an excellent indication in supracondylar fractures of femur, with clear benefits compared to retrograde nailing, providing a better stabilization which enables for a more satisfactory fracture healing.

Analyse par éléments finis de trois systèmes de fixation de fractures sous trochantériennes stables ou instables

BackgroundThe optimal type of fixation implant for managing subtrochanteric fractures (STFs) is debated, as uncertainty continues to surround the comparative biomechanical performance of the proximal femoral nail antirotation (PFNA), proximal femoral locking plate (PFLP), and reverse less invasive stabilisation system (LISS). No studies have used finite element analysis (FEA) to compare these three devices. The objective of this study was to use FEA to compare the PFNA, PFLP, and LISS used to treat STFs based on the following criteria: (1) stress distribution on the femur and implant, (2) peak stress and stress on the medial side of the femur near the fracture site, and (3) smallest axial displacement of the femoral head. HypothesisOf the three implants, the PFNA has the best biomechanical performance when used for STF fixation. MethodsFEA was used to assess synthetic bone responses to the three implants used to fix three STF types, namely, Seinsheimer I, III, and IV, characterised by increasing bone loss and/or comminution with subsequent instability. Loading was with 1400N axial compression force. ResultsThe LISS and PFLP exhibited similar biomechanical properties in all three fracture types. However, with the Seinsheimer IV fracture, the triangular configuration of the PFLP resulted in stress concentration at the medial and lateral sides of the implant junction. With the Seinsheimer I and III fractures, the PFNA resulted in higher peak stress (183.85MPa and 364.58MPa, respectively) compared to the PFLP (102.90MPa and 177.52MPa) and LISS (116.55MPa and 227.97MPa). With the Seinsheimer IV fracture, peak stress was highest with LISS (2310.40MPa) and was higher with PFLP (2054.90MPa) than with PFNA (1313.30MPa). With the Seinsheimer I and III fractures, the axial femoral head displacement was greater with the PFNA (0.74mm and 1.13mm, respectively) than with the PFLP (0.48mm and 1.02mm) and LISS (0.52mm and 0.92mm). With the Seinsheimer IV fracture, in contrast, the PFNA produced less axial femoral head displacement (4.1mm) compared to the PFLP (12.03mm) and LISS (16.56mm). DiscussionWith unstable (Seinsheimer IV) STFs, fixation stability was better with the PFNA compared to the PFLP and LISS. In contrast, with stable STFs (Seinsheimer I and III), the PFLP and LISS offered greater stability, with similar biomechanical effects. However, with Seinsheimer III fractures, the stress on the implant-femur interface was greater with the LISS. Level of evidenceIV, basic science study.

Minimally invasive plate osteosynthesis of clavicular midshaft fractures under insertion guide.

The less invasive stabilization systems for the distal femur and proximal lateral tibia have been developed to simplify the surgical technique of minimally invasive plate osteosynthesis (MIPO). MIPO, however, has simply been introduced into clavicular midshaft fixation without the aid of insertion guide though the procedure for midshaft clavicular fractures was found to produce satisfactory clinical and radiologic outcomes without serious complications. The purpose of this study was to determine the outcome of MIPO of clavicular midshaft fractures using an insertion guide. A total of 15 patients with clavicular midshaft fractures treated by MIPO using insertion guide between September 2016 and September 2018 were included. We assessed bony union, shoulder function by the Constant score, and complications at a mean follow-up of 15.4 months (ranged from 12 to 24 months). The mean surgical time 55.9±9.4 min (ranged from 50 to 70 min) and the fluoroscopic time was 146.5±29.0 s (ranged from 110 to 190 s). In all patients, the bony union was achieved at 8.8±1.0 weeks (ranged from 8 to 10 weeks) with no delayed unions or nonunions. The average Constant score was 99.1±1.2 (ranged from 96 to 100) at follow-up. Postoperative complications including infections, screw pull-out, hardware prominence, and neurovascular injury were not observed, however, one patient complained of mild plate discomfort. MIPO using insertion guide is believed to be an acceptable and effective choice in the operative treatment of clavicular midshaft fractures.

Identification of the lateral femoral safe zone for drilling during LISS plate fixation of distal femur fractures

BackgroundThe incidence of arterial injury associated with femoral fractures is approximately 1%. Lateral sub-muscular plate fixation is gaining popularity for the management of distal femoral fractures. The objective of this study was to assess the iatrogenic risk to the superficial femoral artery (SFA) during Less Invasive Stabilisation System (LISS) plate fixation of distal femoral fractures by analysing the range of distances and angles between LISS plate screws and the drilling line to the SFA. Materials and methodsWe identified all patients who underwent LISS plate fixation of distal femoral fractures between 2008 and 2018 in our level-1 trauma centre. Patients who underwent postoperative computed tomography for any reason were eligible for inclusion in the study. Twenty-five patients met the inclusion criteria. The sample comprised 10 male and 15 female patients with a mean age of 55 years. The most common fracture type was a supracondylar femur fracture (56%), followed by an intercondylar fracture (36%). A 13-hole LISS plate was the most common plate length used (44%). A consultant radiologist reviewed all scans to verify the visibility and marking of the SFA. ResultsThe median distance between the screw tip and the SFA was 21 mm (range, 8–65 mm). There was a negative correlation between the LISS plate hole number and the trajectory of drilling (Pearson coefficient: −0.87, p < 0.001). Using a linear regression model, the SFA was more likely to be in the line of drilling when the 6th to 10th holes in the LISS plate were used. ConclusionExtra care is needed when drilling into the LISS plate holes from the lateral to the medial direction in order to reduce the risk of iatrogenic injury to the SFA, especially in the high-risk plate zone where the artery can be close to the drilling line.

Less Invasive Surgery is Feasible in the Management of Traumatic Thoracolumbar Fractures in Isolated and Polytrauma Injury.

Less invasive stabilization systems (LISSs) have gained popularity. However, limited quality of life (QOL) and clinical outcome data exist for trauma patients treated with LISSs. The objective of this study is to describe QOL and outcome for posterior percutaneous pedicle screw fixation in the management of traumatic thoracolumbar fractures. Between January 2006 and December 2011, data from all patients treated with a posterior percutaneous pedicle screw fixation technique for thoracolumbar fractures were collected and analyzed. Sixty-nine patients met the inclusion criteria. Additional vertebral reduction and cement augmentation was used in 25 patients, when there was more than 50% of vertebral body comminution. Mean follow up of 19 months (range = 6-49 months). Fifty-one percent of the study population consisted of polytrauma patients, with 22% having injury severity score ≥ 15. In 6 cases (8.7%) there were perioperative complications. Response rate for the follow-up health survey was 78%, with a satisfactory overall median EuroQuol score of 0.811 (Q1-Q3 95% confidence interval = 0.709-0.897). Posterior percutaneous pedicle screw fixation proves to be effective in the management of traumatic thoracolumbar fractures, with a good overall functional outcome. Percutaneous techniques that reduce perioperative morbidity are an alternative approach well suited for damage control orthopaedics, as long as there are no neurological deficits. Especially in polytrauma patients with spine fractures, the spinal column can be stabilized in an emergency setting, while limiting the risks of "a second hit" at the patients' already frail condition. 3.

Early effectiveness of mini-Swashbuckler approach for distal femoral type C fractures

To explore the early effectiveness and advantages of mini-Swashbuckler approach in treatment of distal femoral type C fractures by comparing with Swashbuckler approach. A retrospective analysis was made on 43 patients with distal femoral type C fractures between January 2014 and June 2018. Twenty-two patients were treated with open reduction via mini-Swashbuckler approach and internal fixation with less invasive stabilization system (LISS) plate in modified group; and 21 patients were treated with open reduction via Swashbuckler approach and internal fixation with LISS plate in traditional group. There was no significant difference in age, gender, cause of trauma, fracture classification, fracture side, interval between injury and operation, and complications between the two groups ( P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy times, hospitalization time, fracture healing time, Hospital for Special Surgery (HSS) scores of the knee, and postoperative complications were recorded and compared between the two groups. The operation successfully completed in both groups. The operation time of the modified group was significantly longer than that of the traditional group, the fluoroscopy times was increased and the blood loss was reduced, the differences were significant ( P<0.05). There was no significant difference in hospitalization time between the two groups ( t=0.277, P=0.783). All patients in the two groups were followed up 6-8 months, with an average of 7.2 months. Fractures healed in both groups, there was no significant difference in healing time between the two groups ( t=0.861, P=0.394). The HSS scores of the modified group were 82.91±2.88 and 89.28±3.63 at 3 and 6 months after operation, respectively, which were superior to those of the traditional group (74.62±3.64) and (81.48±4.55) ( t=8.306, P=0.000; t=6.231, P=0.000). There was 1 case of incision infection, 1 case of deep vein thrombosis, and 2 cases of knee flexion and extension dysfunction in traditional group, and 1 case of deep vein thrombosis, 1 case of varus deformity, and 1 case of internal fixation loosening in modified group. There was no significant difference in the incidences of complications between the two groups ( P>0.05). Compared with Swashbuckler approach, mini-Swashbuckler approach has limited visual field exposure, which leads to prolonged operation time and increased fluoroscopy times, but the risks of complications do not increase. Because of its small soft tissue injury and less blood loss, it is conducive to the recovery of knee joint function after operation.

A Virtual Reality Enhanced Cyber-Human Framework for Orthopedic Surgical Training

This paper discusses the adoption of information-centric systems engineering (ICSE) principles to design a cyber-human systems-based simulator framework to train orthopedic surgery medical residents using haptic and immersive virtual reality platforms; the surgical procedure of interest is a less invasive stabilization system plating surgery that is used to treat fractures of the femur. Developing such training systems is a complex task involving multiple systems, technologies, and human experts. The information-centric approach proposed provides a structured foundation to plan, design, and build the simulators using the ICSE approach; in addition, the information models of the surgical processes were built to capture the surgical complexities and relationships between the various systems/components in the simulator framework, along with the controlling factors, performing mechanisms, and decision outcomes at various levels of abstraction. The simulator platforms include a haptic-based training system and a fully immersive training system for six training environments. Next-generation networking principles were adopted to support the collaborative training activities within this framework. As part of the proposed approach, expert surgeons played an important role in the design of the training environments. The outcomes of the learning assessment conducted demonstrate the effectiveness of using such simulator-based cyber-human training frameworks.

Comparative finite element analysis of three implants fixing stable and unstable subtrochanteric femoral fractures: Proximal Femoral Nail Antirotation (PFNA), Proximal Femoral Locking Plate (PFLP), and Reverse Less Invasive Stabilization System (LISS)

BackgroundThe optimal type of fixation implant for managing subtrochanteric fractures (STFs) is debated, as uncertainty continues to surround the comparative biomechanical performance of the proximal femoral nail antirotation (PFNA), proximal femoral locking plate (PFLP), and reverse less invasive stabilisation system (LISS). No studies have used finite element analysis (FEA) to compare these three devices. The objective of this study was to use FEA to compare the PFNA, PFLP, and LISS used to treat STFs based on the following criteria: (1) stress distribution on the femur and implant, (2) peak stress and stress on the medial side of the femur near the fracture site, and (3) smallest axial displacement of the femoral head. HypothesisOf the three implants, the PFNA has the best biomechanical performance when used for STF fixation. MethodsFEA was used to assess synthetic bone responses to the three implants used to fix three STF types, namely, Seinsheimer I, III, and IV, characterised by increasing bone loss and/or comminution with subsequent instability. Loading was with 1400N axial compression force. ResultsThe LISS and PFLP exhibited similar biomechanical properties in all three fracture types. However, with the Seinsheimer IV fracture, the triangular configuration of the PFLP resulted in stress concentration at the medial and lateral sides of the implant junction. With the Seinsheimer I and III fractures, the PFNA resulted in higher peak stress (183.85MPa and 364.58MPa, respectively) compared to the PFLP (102.90MPa and 177.52MPa) and LISS (116.55MPa and 227.97MPa). With the Seinsheimer IV fracture, peak stress was highest with LISS (2310.40MPa) and was higher with PFLP (2054.90MPa) than with PFNA (1313.30MPa). With the Seinsheimer I and III fractures, the axial femoral head displacement was greater with the PFNA (0.74mm and 1.13mm, respectively) than with the PFLP (0.48mm and 1.02mm) and LISS (0.52mm and 0.92mm). With the Seinsheimer IV fracture, in contrast, the PFNA produced less axial femoral head displacement (4.1mm) compared to the PFLP (12.03mm) and LISS (16.56mm). DiscussionWith unstable (Seinsheimer IV) STFs, fixation stability was better with the PFNA compared to the PFLP and LISS. In contrast, with stable STFs (Seinsheimer I and III), the PFLP and LISS offered greater stability, with similar biomechanical effects. However, with Seinsheimer III fractures, the stress on the implant-femur interface was greater with the LISS. Level of evidenceIV, basic science study.