Effect of intramedullary nail stiffness on load-sharing in tibiotalocalcaneal arthrodesis: A patient-specific finite element study
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SUBMITTER: Terrill P
PROVIDER: S-EPMC10653524 | biostudies-literature | 2023 Jan
REPOSITORIES: biostudies-literature
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Project description:ObjectiveMany different techniques have been described for performing tibiotalocalcaneal arthrodesis (TTCA) in patients with severe hindfoot disorders such as failed ankle arthroplasty and failed ankle joint arthrodesis with subsequent subtalar arthritis. The use of straight retrograde intramedullary nails is extremely limited because they may interfere with normal heel valgus position and risk damaging the lateral plantar neurovascular structures. Curved retrograde intramedullary nails have been designed to overcome these shortcomings. The purpose of this single surgeon series was to investigate the outcomes of TTCA using a curved retrograde intramedullary nail.MethodsFrom June 2009 to January 2012, 22 patients underwent TTCA using intramedullary nails with a valgus curve by the same senior surgeon. All patients were available for analysis, the mean follow-up being 22.3 months (range, 6.8-38 months). The main outcome measurements included EQ-5D functional scores, the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale, radiologic assessment and clinical examination.ResultsBony union and a plantigrade foot were achieved in 100% of subjects, the mean time to union being 3.9 months (range, 2.4 to 6.2 months). Structural bone graft was used in all patients. Postoperative radiologic results showed a good hindfoot alignment in all patients. The only complication was one case of delayed wound healing without deep infection. The mean postoperative EQ-5D functional and AOFAS ankle-hindfoot scores were 69.33 (range, 20 to 90) and 69.9 (range, 45 to 85) points, respectively. No revision surgery was necessary in our cohort.ConclusionThe results of the present study indicate that TTCA using a short, retrograde, curved intramedullary nail is an acceptable technique for obtaining solid fusion and good hindfoot alignment inpatients with severe hindfoot disorders.
| S-EPMC6583464 | biostudies-literature
Project description:BackgroundTalar body osteonecrosis can be a difficult condition to treat. Recent reports highlight a high rate of failure with the use of femoral head allograft. Additionally, higher rates of failure have been reported in diabetics and smokers. Our institution attempted a novel technique utilizing fresh allograft talus in attempt to improve on a reported 50% nonunion rate.MethodsFive patients who underwent tibiotalocalcaneal (TTC) fusion utilizing fresh talar allograft were clinically and radiographically reviewed to evaluate fusion rates and functional outcomes.ResultsOur case series of 5 patients had a 100% union rate, including 2 former smokers and 2 diabetic patients. There were no infections or complications. Functional outcomes also improved in our series of patients postoperatively as noted by their FAAM and SF-36 scores.ConclusionTTC fusion using fresh allograft talus has a higher union rate than reported with femoral head allograft. This case series requires further study to evaluate whether this technique can be used beyond patients with osteonecrosis of the talus.Level of evidenceLevel IV, case series.
| S-EPMC8696819 | biostudies-literature
Project description:High-resolution peripheral quantitative computed tomography (HR-pQCT) derived micro-finite element (FE) modeling is used to evaluate mechanical behavior at the distal radius microstructure. However, these analyses typically simulate non-physiologic simplified platen-compression boundary conditions on a small section of the distal radius. Cortical and trabecular regions contribute uniquely to distal radius mechanical behavior, and various factors affect these regions distinctly. Generalized strength predictions from standardized platen-compression analyses may not adequately capture region specific responses in bone. Our goal was to compare load sharing within the cortical-trabecular compartments between the standardized platen-compression BC simulations, and physiologic BC simulations using a validated multiscale approach. Clinical- and high-resolution images were acquired from nine cadaveric forearm specimens using an HR-pQCT scanner. Multiscale FE models simulating physiologic BCs, and micro-FE only models simulating platen-compression BCs were created for each specimen. Cortical and trabecular loads (N) along the length of the distal radius micro-FE section were compared between BCs using correlations. Principal strain distributions were also compared quantitatively. Cortical and trabecular loads from the platen-compression BC simulations were strongly correlated to the physiologic BC simulations. However, a 30% difference in cortical loads distally, and a 53% difference in trabecular loads proximally was observed under platen BC simulations. Also, distribution of principal strains was clearly different. Our data indicated that platen-compression BC simulations alter cortical-trabecular load sharing. Therefore, results from these analyses should be interpreted in the appropriate mechanical context for clinical evaluations of normal and pathologic mechanical behavior at the distal radius.
| S-EPMC5767139 | biostudies-literature
Project description:BackgroundTibiotalocalcaneal (TTC) intramedullary nailing has been suggested as an alternative to open reduction and internal fixation (ORIF) for the primary treatment of unstable fragility ankle fractures with a poor soft tissue envelope. This study aims to investigate the clinical efficacy of TTC intramedullary nail fixation for the primary treatment of unstable ankle fractures in frail elderly patients with poor soft tissue condition, by assessing the number of postoperative complications and the patient-reported functional outcomes.MethodsA retrospective cohort study was performed including patients with an unstable ankle fracture treated between 2015 and 2019 with TTC stabilization using a retrograde intramedullary hindfoot nail that was inserted without joint preparation and allowing immediate weight-bearing postoperatively. The primary outcome was the total number of postoperative complications.ResultsA total of 10 patients were included out of 365 operatively treated ankle fractures. The mean age was 85.2 years (range 66-92) with a mean follow-up of 11.2 months (range 6-16). Fracture types included AO/OTA 44-B2 (n = 1), 44-B3 (n = 6), 44-C1 (n = 2) and 44-C3 (n = 1). Postoperative complications were observed in 4 patients (40%), including 3 nonunions, 2 implant related complications and 1 wound infection. No wound healing disorder or below-the-knee amputation was observed. Four patients (40%) deceased between post-operative 6 to 16 months due to medical conditions unrelated to surgery. The mean Foot and Ankle Outcome Score was 52.6 (range 44.2-73.8).ConclusionHindfoot nailingis a viable treatment option in selected high-risk patients with an advanced age, unstable ankle fractures with significant bone loss, poor soft tissue condition and/or severely impaired pre-injury mobility. In a frail geriatric population, hindfoot nailing may be a safe alternative fixation method with a low risk of wound complication or major amputation. However, unprepared joint may lead to symptomatic nonunion after TTC intramedullary nailing.
| S-EPMC8216405 | biostudies-literature
Project description:The Marchetti-Vicenzi's nail is an intramedullary device where six curved nails are kept straight by a closing ring in order to allow their insertion into the medullary canal of a long bone; in a following step, these nails stabilize the fracture due to the ring withdrawal and to the consequent elastic expansion of the nails. Pre-clinical testing of this sort of device is strongly advocated in order to be able to foresee their stability inside the medullary canal and to quantify their stiffening action on a broken bone. In this numerical work, an MB (Multi Body) model of the device has been developed, with the dual purpose of evaluating forces between the bone and the system components during its progressive opening and verifying the behavior of the stabilized bone when it undergoes external loading. Different solutions, for flexible body modeling (discretization with lumped parameters, "flexible body," "FE Part"), have been analyzed and compared in terms of accuracy of results and required computational resources. Contact parameters have been identified and criteria to simplify geometries and therefore to reduce simulation times have been given. Results have allowed to demonstrate how a moderate lateral force is able to dislocate the fracture and how the final position of the retention nut can be optimized. On the whole, a tool for the pre-clinical testing of elastic intramedullary nails has been given.
| S-EPMC6258715 | biostudies-literature
Project description:Osseointegration of load-bearing orthopaedic implants, including interbody fusion devices, is critical to long-term biomechanical functionality. Mechanical loads are a key regulator of bone tissue remodeling and maintenance, and stress-shielding due to metal orthopaedic implants being much stiffer than bone has been implicated in clinical observations of long-term bone loss in tissue adjacent to implants. Porous features that accommodate bone ingrowth have improved implant fixation in the short term, but long-term retrieval studies have sometimes demonstrated limited, superficial ingrowth into the pore layer of metal implants and aseptic loosening remains a problem for a subset of patients. Polyether-ether-ketone (PEEK) is a widely used orthopaedic material with an elastic modulus more similar to bone than metals, and a manufacturing process to form porous PEEK was recently developed to allow bone ingrowth while preserving strength for load-bearing applications. To investigate the biomechanical implications of porous PEEK compared to porous metals, we analyzed finite element (FE) models of the pore structure-bone interface using two clinically available implants with high (> 60%) porosity, one being constructed from PEEK and the other from electron beam 3D-printed titanium (Ti). The objective of this study was to investigate how porous PEEK and porous Ti mechanical properties affect load sharing with bone within the porous architectures over time. Porous PEEK substantially increased the load share transferred to ingrown bone compared to porous Ti under compression (i.e. at 4 weeks: PEEK = 66%; Ti = 13%), tension (PEEK = 71%; Ti = 12%), and shear (PEEK = 68%; Ti = 9%) at all time points of simulated bone ingrowth. Applying PEEK mechanical properties to the Ti implant geometry and vice versa demonstrated that the observed increases in load sharing with PEEK were primarily due to differences in intrinsic elastic modulus and not pore architecture (i.e. 4 weeks, compression: PEEK material/Ti geometry = 53%; Ti material/PEEK geometry = 12%). Additionally, local tissue energy effective strains on bone tissue adjacent to the implant under spinal load magnitudes were over two-fold higher with porous PEEK than porous Ti (i.e. 4 weeks, compression: PEEK = 784 ± 351 microstrain; Ti = 180 ± 300 microstrain; and 12 weeks, compression: PEEK = 298 ± 88 microstrain; Ti = 121 ± 49 microstrain). The higher local strains on bone tissue in the PEEK pore structure were below previously established thresholds for bone damage but in the range necessary for physiological bone maintenance and adaptation. Placing these strain magnitudes in the context of literature on bone adaptation to mechanical loads, this study suggests that porous PEEK structures may provide a more favorable mechanical environment for bone formation and maintenance under spinal load magnitudes than currently available porous 3D-printed Ti, regardless of the level of bone ingrowth.
| S-EPMC7603939 | biostudies-literature
Project description:Tibiotalocalcaneal arthrodesis is most common and effective surgical treatment for severe hindfoot pathology, but the fusion rate is often lower than the ordinary tibiotalar arthrodesis because of the more serious joint disease associated with obvious deformity and osteoporosis. Recent literature describe tibiotalocalcaneal arthrodesis with reverse PHILOS plate with good clinical outcome result, though some patients non-union, due to eccentric force of the plate may be hidden. The purpose of this study was to evaluate clinical outcome of the lateral approach for tibiotalocalcaneal (TTC) arthrodesis with reverse PHILOS Plate and medial cannulated screw.Between Jun, 2013 to April, 2015 12 patient with hindfoot pathology had TTC arthrodesis with a reverse PHILOS plate with medial cannulated screw through a lateral approach with resection of the distal fibula and bone graft. Perioperatively observe for wound and neurovascular status. Patients were follow-up from post-operative 1, 3, 6 and12 months, to observation of wound healing, ankle pain, subtalar Joint Fusion, internal fixation and ankle function. Ankle function were scored according to the American Orthopaedic Foot and Ankle Society(AOFAS) Ankle-Hindfoot Scale system.Twelve ankle fusion all patient follow-up, with mean time to surgery 18.6 months (12-36 month). No cases infection and issue necrosis; one patient complaint of lateral foot numbness we observe and follow-up was spontaneously recovery after 3 months. After 3 months of operation, no obvious pain of ankle joint and internal fixations loose were found. Almost fusion and good axial alignment of TTC joint also were found by X-ray and CT examination. After final fellow-up of each case, no case complain of pain of ankle joint, good fusion and axial alignment of TTC joint were also all found through Terminology. The mean American Orthopaedic Foot and Ankle society (AOFAS) score average was 77.5.TTC arthrodesis with reverse PHILOS Plate and medial cannulated screw have advantages of clear incision, effective bone orthopaedic and graft fully secure, stable internal fixation, high fusion rate and less complications, can effectively correct deformities, alleviate hindfoot pain and improve function, and is an effective method of treatment of after severe hindfoot disease.This trial is registered on ClinicalTrials.gov with reference number: ID: NCT02977910 . Registered 26 Nov 2016, retrospectively registered.
| S-EPMC5525261 | biostudies-literature
Project description:This is a study of femoral fracture healing in female rats 16 weeks old at fracture to compare intramedullary nailing, screw and plate fixation, and sham surgery. The sham surgery group received a surgical exposure of the femur, but no fracture, no plate, and no nail. Samples were collected at 1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after surgery. Each sample is a pool of RNA from three rats from the same surgery group at the same time point after fracture. The middle third of the femur was collected with the cortical bone, fracture callus, and marrow elements. Mid-diaphyseal, simple, transverse fractures were induced by a Gigli saw. The no fracture sample was a time 0 control collected on the day of surgery from intact rats. Keywords = rat Keywords = fracture Keywords = plate Keywords = nail Keywords = time Keywords = femur Keywords: time-course
2005-01-01 | GSE1685 | GEO
Project description:Delayed long bone fracture healing and nonunion continue to be a significant socioeconomic burden. While mechanical stimulation is known to be an important determinant of the bone repair process, understanding how the magnitude, mode, and commencement of interfragmentary strain (IFS) affect fracture healing can guide new therapeutic strategies to prevent delayed healing or nonunion. Mouse models provide a means to investigate the molecular and cellular aspects of fracture repair, yet there is only one commercially available, clinically-relevant, locking intramedullary nail (IMN) currently available for studying long bone fractures in rodents. Having access to alternative IMNs would allow a variety of mechanical environments at the fracture site to be evaluated, and the purpose of this proof-of-concept finite element analysis study is to identify which IMN design parameters have the largest impact on IFS in a murine transverse femoral osteotomy model. Using the dimensions of the clinically relevant IMN as a guide, the nail material, distance between interlocking screws, and clearance between the nail and endosteal surface were varied between simulations. Of these parameters, changing the nail material from stainless steel (SS) to polyetheretherketone (PEEK) had the largest impact on IFS. Reducing the distance between the proximal and distal interlocking screws substantially affected IFS only when nail modulus was low. Therefore, IMNs with low modulus (e.g., PEEK) can be used alongside commercially available SS nails to investigate the effect of initial IFS or stability on fracture healing with respect to different biological conditions of repair in rodents.
| S-EPMC8822464 | biostudies-literature
Project description:PurposeThe purpose of this study was to investigate finite element biomechanical properties of the novel transpedicular transdiscal (TPTD) screw fixation with interbody arthrodesis technique in lumbar spine.MethodsAn L4-L5 finite element model was established and validated. Then, two fixation models, TPTD screw system and bilateral pedicle screw system (BPSS), were established on the validated L4-L5 finite element model. The inferior surface of the L5 vertebra was set immobilised, and moment of 7.5 Nm was applied on the L4 vertebra to test the range of motion (ROM) and stress at flexion, extension, lateral bending and axial rotation.ResultsThe intact model was validated for prediction accuracy by comparing two previously published studies. Both of TPTD and BPSS fixation models displayed decreased motion at L4-L5. The ROMs of six moments of flexion, extension, left lateral bending, right lateral bending, left axial rotation and right axial rotation in TPTD model were 1.92, 2.12, 1.10, 1.11, 0.90 and 0.87°, respectively; in BPSS model, they were 1.48, 0.42, 0.35, 0.38, 0.74 and 0.75°, respectively. The screws' peak stress of above six moments in TPTD model was 182.58, 272.75, 133.01, 137.36, 155.48 and 150.50 MPa, respectively; and in BPSS model, it was 103.16, 129.74, 120.28, 134.62, 180.84 and 169.76 MPa, respectively.ConclusionBoth BPSS and TPTD can provide stable biomechanical properties for lumbar spine. The decreased ROM of flexion, extension and lateral bending was slightly more in BPSS model than in TPTD model, but TPTD model had similar ROM of axial rotation with BPSS model. The screws' peak stress of TPTD screw focused on the L4-L5 intervertebral space region, and more caution should be put at this site for the fatigue breakage.The translational potential of this articleOur finite element study provides the biomechanical properties of novel TPTD screw fixation, and promotes this novel transpedicular transdiscal screw fixation with interbody arthrodesis technique be used clinically.
| S-EPMC6172361 | biostudies-literature