Femoral Plate Research Articles

Design and surface characterization of micropatterned silica coatings for zirconia dental implants

The use of zirconia as an alternative biomaterial for titanium implants has been increasing due to its biocompatibility, favorable aesthetic features, less potential for early plaque accumulation and mechanical properties. Despite the developed efforts, strategies to promote an effective osseointegration are still enough. In this sense and combining the silica properties to improve bone formation with the micropatterning guidance characteristics, silica coatings with micropatterns were designed and evaluated regarding their hydrophilicity and integrity through resistance to scratch and friction tests against femoral bone plates (simulating implant insertion). A combined sol-gel and soft-lithography techniques were used to produce silica coatings onto zirconia substrates and different techniques were used to characterize the micropatterned silica coatings. The results revealed that the production of lines and pillars micropatterns increases the surface roughness (Ra values) and improves the surface strength adhesion. Through the scratch test, it was possible to verify that the integrity and topography characteristics of all micropatterned coatings were not significantly affected after the friction test meaning that their function is not compromised after implant insertion. Additionally, the lines micropattern was the one that presented the highest hydrophilicity for distilled water, thus being a promising surface to promote improved osseointegration. The combined use of different surface micropatterns could potentially be used to guide bone apposition and avoiding peri-implantitis.

Clinical and Biomechanical Effects of Femoral Neck Buttress Plate used for Vertical Femoral Neck Fractures

PurposeTo investigate both the biomechanical and clinical effect of an inferomedial femoral neck buttress plate (FNBP) used to augment a sliding hip screw (SHS) and anti-rotational screw (ARS) in the treatment of traumatic vertical femoral neck fractures. MethodsPart 1: Clinical - Retrospective review of patients under age 65 treated with open reduction of a vertical femoral neck fracture. Patients were divided into two groups: Group 1 patients (18 patients) had SHS/ARS fixation augmented with a FNBP, while Group 2 patients (18 patients) had SHS/ARS fixation alone and were matched for age and sex. Demographic data, OTA fracture classification, immediate post-operative and follow-up radiographs were analyzed for quality of reduction, femoral neck shortening (FNS), neck-shaft angle (NSA), avascular necrosis (AVN) and union.Part 2: Biomechanical - Pauwels III femoral neck osteotomy was created in five pairs of cadaveric specimens, then each fracture was reduced and stabilized with a SHS/ARS construct. Specimens were matched and split into Groups 1 and 2, similar to Part 1. Cadaveric specimens were axially loaded in cyclical fashion to analyze for construct stiffness, fracture displacement femoral neck shortening and changes in the neck shaft angle. ResultsPart 1: There were 18 matched patients (14 males and 4 females) in both Group 1 and Group 2. There were no statistically significant differences between the two groups with respect to Pauwels angle, femoral neck shortening, changes in neck-shaft angle, AVN or nonunion. One reoperation in Group 1 and four in Group 2.Part 2: All five cadaveric specimens in both groups survived the 10,000-cycle loading regimen. We were unable to detect any significant differences between the two groups with respect to construct stiffness, change in neck-shaft angle or amount of femoral neck shortening. ConclusionBased on the results of both clinical case series and biomechanical testing, an inferomedial neck buttress plate does not appear to offer long-term benefits with respect to maintenance of alignment or achieving union but may potentially help in obtaining the reduction.

Extension osteotomy of the lateral distal femur using the contralateral TomoFix® plate

Supracondylar distal femoral osteotomy. Fixation with the contralateral TomoFix® (Fa. DePuy Synthes, Oberdorf, Switzerland) lateral distal femur plate. Use of the laterally reversed plate to improve the reconstruction of the sagittal anatomical axis of the leg. To correct knee flexion contractures with adeficiency of extension >20° at the age of 10years. Surgical site infections or tumors. Ventral closed wedge osteotomy of the distal femur. Implantation of the locking compression TomoFix® lateral distal femur plate. Full weight bearing. In all, 16 distal femoral osteotomies were performed in 9patients. All patients had knee flexion contraction due to neurological disease. Patients with cerebral palsy showed abetter GMFCS (gross motor function classification scale) level after surgery. Hardware was removed after 11.5months (range: 9-18months).

Impact of periprosthetic femoral fracture fixation plating constructs on local stiffness, load transfer, and bone strains

Secondary femoral fractures after the successful plate-screw fixation of a primary Vancouver type B1 periprosthetic femoral fracture (PFF) have been associated with the altered state of stress/strain in the femur as the result of plating. The laterally implanted condyle-spanning plate-screw constructs have shown promises clinically in avoiding secondary bone and implant failures as compared with shorter diaphyseal plates. Though the condyle-spanning plating has been hypothesized to avoid stress concentration in the femoral diaphysis through increasing the working length of the plate, biomechanical evidence is lacking on how plate length may impact the stress/strain state of the implanted femur. Through developing and experimentally validating finite element (FE) models of 3 cadaveric femurs, this study investigated the impact of plating on bone strains, load transfer and local stiffness, which were compared between FE models of 2 different plating systems that each had a diaphyseal configuration and a condyle-spanning configuration. Under simulated gait-loading, the condyle-spanning constructs of both plating systems were shown to lower the bone strains around the distal fixation screws (up to 24.8% reduction in maximum principal strain and 26.6% reduction in minimum principal strain) and in the distal metaphyseal shaft of the femur (up to 15.9% and 25.7% reductions in maximum and minimum principal strains, respectively), where secondary bone fractures have been typically reported. In the distal diaphyseal and metaphyseal shaft of femur, FE models of the condyle-spanning constructs were shown to increase the local compressive stiffness (up to 152.9% increases under simulated gait-loading) and decrease the transfer of compressive load (37.1% decreases under simulated gait-loading), which may be indicative of the lowered risks of bone damage.

Effects of bisphosphonates on different zones of the epiphyseal growth plate of rats

Bisphosphonates (BIS) are indicated for several clinical disorders (e.g., osteoporosis). However, BIS has been associated with osteonecrosis and alterations in osteoclastogenesis and skeletal development. This study aimed to evaluate the effects of BIS (zoledronic acid - ZA and alendronate sodium - AS) on zones of the growth plate of rat femur. Animals (Wistar rats, n = 19) were divided into groups: 1) AS Group: animals received alendronate sodium orally (3 mg/kg per day); 2) ZA Group: ZA was administered intraperitoneally (0.2 mg/kg per week); and 3) Control Group (CG): a vehicle was administered. Animals were euthanized 21 days after the treatment, and femurs were collected for histological analysis. The images of all zones (resting, proliferative, hypertrophic, and calcified) were processed by the Qcapture® software providing a 40 and 400-fold increase. ZA decreased epiphyseal growth plate cell zones (ZA Group vs. CG) in most cases. Likewise, AS diminished the proliferative zone (AS Group vs. CG). Furthermore, ZA increased the calcified zone (ZA Group vs. CG). Previous works demonstrated that BIS decrease the epiphyseal disc. This reduction is probably due to the shortening of the cellular zones that undergoes calcification/ossification. The present results suggest that BIS should be carefully indicated because these drugs might accelerate epiphyseal closure.

Distal femoral fractures: A comparison between single lateral plate fixation and a combined femoral nail and plate fixation

ObjectivesDistal femoral fractures occur in patients with osteoporotic bone and also as a consequence of high energy trauma. The recognised treatment options include closed or open reduction of the fracture and fixation using a locking plate or a femoral nail. Both these fixation modalities have some drawbacks. There is a risk of metalwork failure with single lateral locking plates and limited distal fixation with intramedullary nails. Since January 2018, we started using augmented fixation of distal femoral fractures using a combination of a retrograde femoral nail and a lateral locking plate. This study compares the outcomes of single lateral femoral plating (SLP) and combined nail-plate fixation (NPF). MethodsThis is a single centre retrospective case control study including all patients who sustained distal femoral fractures (OTA 33-A2, 33-A3, 33-C, 33-V3B and 33-V3D) over the study period. Outcomes for SLP were compared to NPF. The principal outcome measure was fracture union. Secondary outcome measures were reoperation rate, mortality and post-operative weight bearing status. Results67 distal femoral fractures were included in the study. 19 patients had peri‑prosthetic fractures. 40 were treated by SLP, 27 were managed with NPF. 23 (58%) patients in the SLP group were given instructions to non-weight bear or Toe touch weight bear for 6 weeks post-surgery compared to 1 (4%) in the NPF group (p = 0.000004). 7 (18%) patients treated with SLP had metalwork failure due to a non-union compared to none treated with NPF (p = 0.04). 11 fractures in the SLP group failed to unite compared to no non-unions in the NPF group (p = 0.01). These differences were magnified when assessing older (>50 years old) patients. ConclusionsAugmented fixation of distal femoral fractures using a nail plate fixation provided significantly higher union and enabled early weightbearing compared to single plate fixation. We recommend nail plate fixation for the treatment of distal femoral fractures, particularly in osteoporotic fractures.

Acute Femoral Lengthening in Adults Using Step-Cut Osteotomy, Traction Table, and Proximal Femoral Locking Plate Fixation: Surgical Technique and Report of Three Cases.

Leg-length discrepancy (LLD) can cause distinct gait and posture disorders that may lead to lifestyle-limiting disability and premature joint degeneration. The purpose of this study was to describe a novel surgical method for acute femoral lengthening in adults with symptomatic structural LLD using step-cut osteotomy, traction table, and proximal femoral locking plate fixation. We retrospectively evaluated three consecutive adult patients that underwent the procedure at our institution between 2011 and 2019, describing the surgical technique and presenting a report of three cases, including complications assessment. The average age was 47years (range 38-58), average BMI was 28.1kg/m2 (range 26.8-29.9), average ASA score was 2 (range 1-3). The mean pre-operative shortening (2 congenital, 1 posttraumatic) was 21mm (range 20-23). The average elongation achieved was 18mm (range 15-20). The average surgery duration was 142min (range 120-165) and the average estimated blood loss was 558mL (range 375-900). Symptoms were relieved after the lengthening in all three cases. We observed no complications after the mean 68months (range 22-125) of follow-up. Successful correction of structural LLD is challenging, depends on patient selection, meticulous planning, surgical technique and experience. Therefore, it should be considered case-by-case. In the hands of an experienced surgeon, our method of acute femoral lengthening seems safe and suitable for carefully selected cases of structural LLD correction, where the final lengthening goal remains within the critical limits of one-stage leg lengthening and principles of traction table use.

A New Surgical Technique and Clinical Outcomes of Operated Proximal Metadiaphyseal Humeral Fractures and Nonunions With the Use of Reversed Anatomic Distal Femoral Locking Plate.

IntroductionProximal humeral fractures complicated with metaphyseal and diaphyseal extension are usually treated operatively with 3.5 mm long anatomic proximal humerus plates. However, frequently these comminuted and segmental fracture types may be associated with delayed union, nonunion, and/or plate failure. We present a technique for addressing this fracture pattern by using an anatomic contralateral 4.5 mm distal femoral plate in a reversed fashion.MethodsEleven patients (eight women and three men) with a mean age of 70 years (range, 52 to 84 years) were operated on with the described technique. The dominant hand was involved in seven out of 11 patients. There were seven acute metadiaphyseal fractures and four nonunions. In one patient, humeral shaft nonunion was associated with segmental metadiaphyseal defect and a free fibular graft was applied.ResultsAll fractures healed and patients regained almost normal function of the affected shoulder and upper limb. Shoulder abduction and forward elevation ranged from 80 to 110 degrees (mean, 97 degrees) and 90 to 120 degrees (mean, 102 degrees), respectively. The disabilities of the arm, shoulder and hand (DASH) score varied from 6 to 11 points (median 8). No major trauma or systemic complications were recorded.ConclusionThe morphology, strength, and characteristics of the plate could effectively conform to the anatomy of the proximal humerus and offer adequate stability for fracture union. The described technique is more useful in case of osteoporosis and/or presence of previous failed internal fixation that further compromise the vascularization and the mechanical properties of the bone.

Bone morphological feature extraction for customized bone plate design

Fractures are difficult to treat because of individual differences in bone morphology and fracture types. Compared to serialized bone plates, the use of customized plates significantly improves the fracture healing process. However, designing custom plates often requires the extraction of skeletal morphology, which is a complex and time-consuming procedure. This study proposes a method for extracting bone morphological features to facilitate customized plate designs. The customized plate design involves three major steps: extracting the morphological features of the bone, representing the undersurface features of the plate, and constructing the customized plate. Among these steps, constructing the undersurface feature involves integrating a group of bone features with different anatomical morphologies into a semantic feature parameter set of the plate feature. The undersurface feature encapsulates the plate and bone features into a highly cohesive generic feature and then establishes an internal correlation between the plate and bone features. Using the femoral plate as an example, we further examined the validity and feasibility of the proposed method. The experimental results demonstrate that the proposed method improves the convenience of redesign through the intuitive editing of semantic parameters. In addition, the proposed method significantly improves the design efficiency and reduces the required design time.

The effect of calcar femoral neck plating on vascularity of the femoral head and neck.

AimsSurgical treatment of young femoral neck fractures often requires an open approach to achieve an anatomical reduction. The application of a calcar plate has recently been described to aid in femoral neck fracture reduction and to augment fixation. However, application of a plate may potentially compromise the regional vascularity of the femoral head and neck. The purpose of this study was to investigate the effect of calcar femoral neck plating on the vascularity of the femoral head and neck.MethodsA Hueter approach and capsulotomy were performed bilaterally in six cadaveric hips. In the experimental group, a one-third tubular plate was secured to the inferomedial femoral neck at 6:00 on the clockface. The contralateral hip served as a control with surgical approach and capsulotomy without fixation. Pre- and post-contrast MRI was then performed to quantify signal intensity in the femoral head and neck. Qualitative assessment of the terminal arterial branches to the femoral head, specifically the inferior retinacular artery (IRA), was also performed.ResultsQuantitative MRI revealed a mean reduction of 1.8% (SD 3.1%) of arterial contribution in the femoral head and a mean reduction of 7.1% (SD 10.6%) in the femoral neck in the plating group compared to non-plated controls. Based on femoral head quadrant analysis, the largest mean decrease in arterial contribution was in the inferomedial quadrant (4.0%, SD 6.6%). No significant differences were found between control and experimental hips for any femoral neck or femoral head regions. The inferior retinaculum of Weitbrecht (containing the IRA) was directly visualized in six of 12 specimens. Qualitative MRI assessment confirmed IRA integrity in all specimens.ConclusionCalcar femoral neck plating at the 6:00 position on the clockface resulted in minimal decrease in femoral head and neck vascularity, and therefore it may be considered as an adjunct to laterally-based fixation for reduction and fixation of femoral neck fractures, especially in younger patients.Cite this article: Bone Jt Open 2021;2(8):611–617.

Long Low-profile Proximal Tibial Locking Plate for the Fixation of Periprosthetic Femoral Fractures Above the Prosthesis: A Pilot Study

Background: Anatomic distal femoral plates locking compression plate (LCP) are generally used for the fixation of distal femoral fractures. However, they are not suitable for periprosthetic femoral fracture after total knee arthroplasty (TKA), mainly owing to the impingement with prosthesis. Objectives: In this case series, we report the outcome of proximal tibial LCP fixation in the treatment of periprosthetic femoral fracture after TKA. Patients and Methods: Twelve patients with a periprosthetic femoral fracture who underwent surgical treatment were included. According to Su et al. classification, all fractures were type II, originating from the femoral component with proximal extending. Fractures were managed with open reduction and plate fixation. The plate choice was either a long low-profile proximal tibial LCP (n=9) or a short anatomic distal femoral LCP (n=3). Results: The study population included one male and 11 females with a mean age of 74.5±9.3 years and a mean follow-up of 2.8±1.3 years. Union of fracture was observed in all fractures that were fixed with a long locking plate during a mean period of 3.1±2.1 months. Fixation failed in all three patients who were managed with a short plate. These patients underwent revision surgery with a long low-profile proximal tibial LCP. In one of them, the fixation failed again and finally fixed with tumor prosthesis. The other two fractures were united with no complications. Conclusion: Long low-profile proximal tibial LCP omits the problem of impingement by prosthesis, which is caused by short anatomic distal femoral LCP in the treatment of periprosthetic femoral fractures above the prosthesis. However, future large-scale comparative studies are required before we can recommend it for routine implications in these fractures.

RADIOLOGICAL AND FUNCTIONAL OUTCOME OF DUAL PLATING IN DISTAL FEMUR MULTIFRAGMENTARY ARTICULAR FRACTURES: A SHORT TERM STUDY

Introduction: In this prospective cases series, we are reporting a mean 12-month follow up of the utilisation of dual plating technique for multi fragmentary articular distal femur fractures. Our technique consists of a lateral distal femoral locked plate and a low prole locked medial plate through a modied anterior (Swashbuckler) approach for the xation of C2, C3 fractures. Patients and Methods: 15 patients (9 males and 6 females) presented with supra condylar femoral fractures type C2/C3, according to Müller long bone classication and its revision, OA/OTA classication. These fractures were treated using dual plating through swashbuckler approach. They were followed up for clinical and radiological outcomes. Secondary outcomes included post-operative complications. Results: Mean time of radiological union in studied population was 18 weeks with a range of 14-24 weeks. We did not observe any post-operative varus angulation.12 out of 14 patients had good to excellent functional outcome. Fair outcome was reported in only two patients Conclusion: The technique of Dual plating xation using modied anterior approach (swashbuckler) for type C2,C3 distal femoral fractures is an efcient method of management. It has several advantages such as precise exposure, easy manipulation, anatomical reduction and stable xation. However, operative indications and principles should be strictly followed. The surgical technique must be perfect and the biomechanical qualities of the implants must be understood to prevent the development of major complications

Radiological and Functional Outcome of Dual Plating in Distal Femur Multifragmentary Articular Fractures

Introduction: In this prospective case series, we are reporting a mean 12-month follow up of the utilization of dual plating technique for multi fragmentary articular distal femur fractures. Our technique consists of a lateral distal femoral locked plate and a low profile locked medial plate through a modified anterior (Swashbuckler) approach for the fixation of C2, C3 fractures. Materials and Methods: Fifteen patients (9 males and 6 females) presented with supracondylar femoral fractures type C2/C3, according to Müller long bone classification and its revision, OA/orthopedic trauma association classification. These fractures were treated using dual plating through the swashbuckler approach. They were followed up for clinical and radiological outcomes. Secondary outcomes included postoperative complications. Results: The mean time of radiological union in the studied population was 18 weeks with a range of 14–24 weeks. We did not observe any postoperative varus angulation. 12 out of 14 patients had good to excellent functional outcomes. Fair outcome was reported in only two patients. Conclusion: The technique of Dual plating fixation using modified anterior approach (swashbuckler) for type C2, C3 distal femoral fractures is an efficient method of management. It has several advantages such as precise exposure, easy manipulation, anatomical reduction, and stable fixation. However, surgical indications and principles should be strictly followed. The surgical technique must be perfect, and the biomechanical qualities of the implants must be understood to prevent the development of major complications.

Proximal Femoral Plate, Intramedullary Nail Fixation Versus Hip Arthroplasty for Unstable Intertrochanteric Femoral Fracture in the Elderly: A Meta-analysis.

Multiple operative modalities are available for management of unstable intertrochanteric femoral fractures. This meta-analysis was conducted to find out if there is superiority of surgical fixation by proximal femoral plate or surgical fixation by intramedullary nail over hip arthroplasty for management of unstable intertrochanteric femoral fractures in the elderly. A search for relevant studies that published from January 2000 to November 2018 through the electronic literature database of Cochrane library, Medline, Trip Database and Wiley online library. A total of 19 studies including 14 prospective RCTs, and five retrospective studies. This meta-analysis showed that nail group had shorter operative time than plate group (P < 0.0001), and less blood loss than the plate and arthroplasty groups (P < 0.0001), cut-out was higher in nail group than the plate group (P < 0.0001), mortality rate was higher in hip arthroplasty compared to other groups (P < 0.0001), Harris hip score within 6months of the operation was higher in the arthroplasty group compared with the nail and plate groups, while within 1 year of the operation, nail group had higher Harris hip score than arthroplasty group (P < 0.0001). This meta-analysis suggested that the intramedullary nail fixation method is a preferred method for management of unstable intertrochanteric femoral fractures in the elderly over hip arthroplasty and proximal femoral plate fixation. The online version contains supplementary material available at 10.1007/s43465-021-00426-1.

Impact on periosteal vasculature after dual plating of the distal femur: a cadaveric study.

Objectives:Although dual plating of distal femur fractures has been described for injuries at risk of varus displacement, the vascular insult to the medial distal femur utilizing this technique is unknown. The aim of this study was to evaluate the perfusion of the medial distal femoral periosteal arteries after supplemental medial plating of the distal femur.Methods:Fifteen human fresh-frozen cadaveric femora were thawed and randomized to lateral locked plating alone or with supplemental medial plate fixation. Conventional submuscular medial plating was performed using a 12-hole small fragment plate and multiple cortical screws. The superficial femoral artery was injected with latex dye. Specimens were dissected. The patency of the medial distal femoral periosteal vessels was evaluated.Results:Four vessels were consistently observed traversing the distal medial femur: the transverse and descending (d-MMPA) branches of the medial metaphyseal periosteal artery, and the transverse and longitudinal branches of the descending geniculate artery. The anterior longitudinal arch (ALA) was present in 13 of 15 specimens and was fed by the d-MMPA. The median number of periosteal arteries occluded by the medial plate was 2 (6 out of 8 specimens). The d-MMPA was occluded in 6 of 8 medially plated femurs, resulting in a complete lack of perfusion of the ALA.Conclusions:Submuscular medial plating of the distal femur compressed the d-MMPA in the majority of specimens. This vessel gives rise to the ALA, which lacked perfusion in these specimens. This vascular insult could affect the healing of metaphyseal distal femur fractures treated with dual plating.

Clinicoradiological Outcome of Concomitant Fractures of Proximal Femur and Femoral Shaft Treated With Second-Generation Cephalomedullary Nailing

BackgroundThe ideal modality of treatment of concomitant fractures of the hip (intertrochanteric/femoral neck) and the femoral shaft is still evolving. The aim of our retrospective study was to assess the clinicoradiological outcome of such fractures managed by closed second-generation cephalomedullary nailing.MethodologyThe study was conducted among skeletally mature patients presenting within one week of injury who underwent closed second-generation cephalomedullary nailing (proximal femoral nail). Those presenting beyond one week or those who had pathological fractures, incomplete follow-ups, or other modes of fixation were excluded. Functional results were evaluated according to Friedman and Wyman’s clinical assessment system. Time required for fracture healing and the presence of any complications were also noted.ResultsA total of 10 patients with the ipsilateral hip (five intertrochanteric and five femoral neck) and femoral shaft fractures were included in the study. Associated injuries found included fractures of the ipsilateral tibia/fibula at varying levels in three patients; hand and wrist injuries in two patients; and contralateral femoral shaft fracture, ipsilateral patella, bilateral crush injury of the foot, and head and chest injury with brachial plexus injury in one patient each. Four patients were diagnosed with intra-articular knee injuries (ligamentous and meniscal injuries) postoperatively. At the final follow-up, the functional outcome results were good in four, fair in one, and poor in five patients. All femoral neck fractures united at a mean of 15.2 weeks (range: 12.0-18.0 weeks) and intertrochanteric fractures at a mean of 14.0 weeks (range: 12.0-22.0 weeks). However, there was residual varus malunion in two intertrochanteric fractures. Eight femoral shaft fractures were infra-isthmic; of these, four resulted in nonunion (two of hypertrophic and two of atrophic type) and two were found to be in the delayed union, which eventually united by 24 weeks.ConclusionsSecond-generation cephalomedullary nail is an acceptable, cost-effective, and minimally invasive alternative for the management of concomitant ipsilateral fractures of the hip and supra-isthmic or isthmic femoral shaft fractures. For infra-isthmic fractures, retrograde femoral nail or distal femoral plate along with a separate implant for addressing the hip fracture (either cannulated cancellous screw or dynamic hip screw, preferably in a rendezvous/overlapping manner) are better options.

Anterior positioning screw in proximal femoral plating restricts posterior tilt of retroverted femoral neck fractures: a retrospective cohort study

BackgroundPreoperative posterior tilt is a risk factor for fixation failure in femoral neck fractures. This study aimed to evaluate the configuration of anterior positioning screw in proximal femoral plating in the treatment of retroverted femoral neck fractures in terms of resisting posterior tilt.MethodsWe retrospectively analyzed patients with retroverted femoral neck fractures who were fixed by proximal femoral plating from January 2014 to August 2019. All patients were divided into two groups according to screw configuration: anterior long-threaded screw (ALTS, n = 36) and normally short-threaded screws (NTS, n = 46). Baseline characteristics were reviewed and radiological and clinical outcomes were analyzed. Logistic regression analysis was used to identify risk factors for developing posterior tilt.ResultsAge, gender, Garden classification, posterior comminution, and reduction quality showed no significant difference between the groups. Increased posterior tilt was lower in the ALTS group (3.2°, 2.1–4.3°) than that in the NTS group (5.3°, 4.2–8.3°) (p < 0.001), and the percentage of people with > 5° of posterior tilt was also lower in the ALTS group (5, 13.9% vs. 24, 52.2%; p < 0.001). Femoral neck shortening (FNS) was lower in the ALTS group (3.1 (2.1–4.7) mm vs. 4.3 (3.1–6.3) mm, p = 0.003), though not statistically significant when using 5 mm as the cut-off value. Harris Hip Score in the ALTS group was higher than that in the NTS group (87.0, 84.0–90.0 vs. 82.0, 76.0–84.5; p < 0.001). Postoperative complications including delayed union, nonunion, and avascular necrosis were comparable between the groups. Multivariable analysis identified posterior comminution (OR 15.9, 95% CI 3.6–70.3, p < 0.001), suboptimal reduction quality (OR 12.0, 95% CI 2.6–56.1, p = 0.002), and NTS configuration (reference: ALTS configuration) (OR 21.9, 95% CI 4.1–116.4, p < 0.001) as risk factors for developing posterior tilt.ConclusionsConfiguration of anterior positioning screw in proximal femoral plating provides better resistance against posterior tilt in the fixation of retroverted femoral neck fractures. Also, posterior comminution, suboptimal reduction, and NTS configuration (reference: ALTS) are risk factors for developing posterior tilt.Trial registrationThe trial registration number was ChiCTR2000039482.

Ideal plate screw configuration in femoral shaft fractures: 3D finite element analysis

Background/Aim: Plate screw fixation is an important method in femoral shaft fractures. Although there are many studies on plate screw fixation, the ideal plate screw configuration has not yet been determined. In our study, we investigated the optimal plate-screw configuration in femoral shaft fractures using the 3D finite element analysis method. Methods: A fracture model was created by removing the segment from the femur model obtained from 3D computed tomography scanning. Five different fixation models were designed using a 4.5 mm diameter steel locked femoral shaft plate and different screw configurations. Screws with double cortex locks of 4.5 mm in width were used in different configurations. To evaluate the effect of screw diameter, a 5.5 mm diameter screw with a double cortex lock was used in one model. Static linear analyses of these prepared Finite Element models were performed using Ansys Workbench 2020 R2 Finite Elements software. Results: The maximum stresses on the plate at the fracture sites were 156 MPa at 200 N, and 546 MPa at 700 N in model 1, 274 MPa at 200 N, and 784 MPa at 700 N in Model 2, 274 MPa at 200 N, and 959 MPa at 700 N in Model 3, 389 MPa at 200 N, and 1118 MPa at 700 N in Model 4, and 200 N is 274 MPa, and 961 MPa at 700 N in Model 5. Conclusion: The stress on the plate in the fracture area increases in parallel with the increase in screw diameter, plate length and plate working distance. Filling all screw holes does not alter the stress on the plate at the fracture line level.

Comparative study of distal femoral locking compression plate and tens nail versus lateral distal femur plate in management of distal femur fracture cases

Background: The fracture of distal femur are often unstable and comminuted and as difficult to treat. The incidence of complications in these fracture are relatively high .The purpose of our study was aimed to compare functional outcome between both column fixations by using distal femoral locking compression pate on lateral side and then using TENS nail on medial side to obtain support of medial column versus lateral distal femoral plate.Methods: We have included 80 patients with distal femur fracture with intercondylar extension in our study. We have treated 40 patients with distal femoral locking compression plate and support of medial wall with TENS nail and 40 patients with distal femoral locking compression plate. There were sixty six males and fourteen females. The average age of the patients was 39.08 ± 11.95 years. All the patients were operated between 3 to 9 days. All patients were followed up at 2th, 6th, 10th weeks, 3 month and 6 month regularly and evaluated for fracture healing, Clinical union was defined as a painless fracture site during full weight bearing. Radiological union was defined as bridging trabeculation across the fracture site on three of four cortices. The final outcome was assessed according to schatzker and Lambert scoring system.Results: The result was excellent in twelve, good in fifteen, fair in ten and poor in one in DFLCP with TENS nail group according to schatzker and Lambert scoring system. The result was excellent in eight, good in twelve, fair in twelve and poor in five in DFLCP group according to schatzker and Lambert scoring system. The average time to Union was 17.7 weeks in DFLCP with TENS nail group and 19.9 weeks in DFLCP group. Complications include superficial wound infection in three patients, secondary osteoarthritis in 17 patients and varus angulation in three patients in DFLCP with TENS nail group. In DFLCP group varus angulation was in eleven patients.Conclusions: The use of TENS nail for medial femoral defect along with distal femoral locking compression plate may eliminate the need of plate on medial side. The varus angulation that occurs with defect is decreased and additional long incision and operative time is avoided.

Finite element analysis of double\u2010plate fixation using reversed locking compression\u2010distal femoral plates for Vancouver B1 periprosthetic femoral fractures

BackgroundInternal fixation is recommended for treating Vancouver B1 periprosthetic femoral fractures. Although several fixation procedures have been developed with high fixation stability and union rates, long-term weight-bearing constructs are still lacking. Therefore, the aim of the present study was to evaluate the stability of a double-plate procedure using reversed contralateral locking compression-distal femoral plates for fixation of Vancouver B1 periprosthetic femoral fractures under full weight-bearing.MethodsSingle- and double-plate fixation procedures for locking compression-distal femoral plates were analysed under an axial load of 1,500 N by finite element analysis and biomechanical loading tests. A vertical loading test was performed to the prosthetic head, and the displacements and strains were calculated based on load-displacement and load-strain curves generated by the static compression tests.ResultsThe finite element analysis revealed that double-plate fixation significantly reduced stress concentration at the lateral plate place on the fracture site. Under full weight-bearing, the maximum von Mises stress in the lateral plate was 268 MPa. On the other hand, the maximum stress in the single-plating method occurred at the defect level of the femur with a maximum stress value of 1,303 MPa. The principal strains of single- and double-plate fixation were 0.63 % and 0.058 %, respectively. Consistently, in the axial loading test, the strain values at a 1,500 N loading of the single- and double-plate fixation methods were 1,274.60 ± 11.53 and 317.33 ± 8.03 (× 10− 6), respectively.ConclusionsThe present study suggests that dual-plate fixation with reversed locking compression-distal femoral plates may be an excellent treatment procedure for patients with Vancouver B1 fractures, allowing for full weight-bearing in the early postoperative period.