The effect of surgeon-controlled variables on construct stiffness in lateral locked plating of distal femoral fractures

Weaver, Michael J.; Chaus, George W.; Masoudi, Aidin; Momenzadeh, Kaveh; Mohamadi, Amin; Rodriguez, Edward K.; Vrahas, Mark; Nazarian, Ara

doi:10.1186/s12891-021-04341-2

Cited by 12 publications

(19 citation statements)

References 43 publications

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“…The current study also evaluated varying working lengths of fixation, due to the custom nature of the locking plates utilized. Similar to previous mechanical studies, no significant effect of working length on construct stability was noted during compressive testing to failure [ 27 , 33 ]. However, one study noted differences in yield load, specifically, between constructs of short and long working lengths, and shorter working lengths were significantly associated with greater maximum load but not overall construct stiffness during cyclic compressive testing followed immediately by compressive load to failure [ 6 ].…”

Section: Discussionsupporting

confidence: 88%

“…Due to the retrospective nature of the study, we are unable to differentiate between the effects of overall plate length and the effects of fixation working length on fracture outcomes, and this represents a major limitation of the study. Previous in vitro and in vivo analyses of the effects of working length on locking plate fixation have yielded mixed results [ 6 , 10 , 12 , 33 ]. Using in vitro FEA modeling, Giordano et al described a direct correlation between increasing working length and construct stability through effective deflection of stress, but in mechanical testing of various working lengths for LCP fixation of canine femoral gap defects, Chao et al described significantly higher strength (yield load) in short compared to long working length constructs [ 6 , 10 ].…”

Section: Discussionmentioning

confidence: 99%

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In vitro analysis and in vivo assessment of fracture complications associated with use of locking plate constructs for stabilization of caprine tibial segmental defects

et al. 2023

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Purpose Locking plate fixation of caprine tibial segmental defects is widely utilized for translational modeling of human osteopathology, and it is a useful research model in tissue engineering and orthopedic biomaterials research due to its inherent stability while maintaining unobstructed visualization of the gap defect and associated healing. However, research regarding surgical technique and long-term complications associated with this fixation method are lacking. The goal of this study was to assess the effects of surgeon-selected factors including locking plate length, plate positioning, and relative extent of tibial coverage on fixation failure, in the form of postoperative fracture. Methods In vitro, the effect of plate length was evaluated using single cycle compressive load to failure mechanical testing of locking plate fixations of caprine tibial gap defects. In vivo, effects of plate length, positioning, and relative tibial coverage were evaluated using data from a population of goats enrolled in ongoing orthopedic research which utilized locking plate fixation of 2 cm tibial diaphyseal segmental defects to evaluate bone healing over 3, 6, 9, and 12 months. Results In vitro, no significant differences in maximum compressive load or total strain were noted between fixations using 14 cm locking plates and 18 cm locking plates. In vivo, both plate length and tibial coverage ratio were significantly associated with postoperative fixation failure. The incidence of any cortical fracture in goats stabilized with a 14 cm plate was 57%, as compared with 3% in goats stabilized with an 18 cm plate. Craniocaudal and mediolateral angular positioning variables were not significantly associated with fixation failure. Decreasing distance between the gap defect and the proximal screw of the distal bone segment was associated with increased incidence of fracture, suggesting an effect on proximodistal positioning on overall fixation stability. Conclusions This study emphasizes the differences between in vitro modeling and in vivo application of surgical fixation methods, and, based on the in vivo results, maximization of plate-to-tibia coverage is recommended when using locking plate fixation of the goat tibial segmental defect as a model in orthopedic research.

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

In vitro analysis and in vivo assessment of fracture complications associated with use of locking plate constructs for stabilization of caprine tibial segmental defects

et al. 2023

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“…longer) commercial DFLPs to find that stiffness increased linearly with WL/total plate length; but, stiffness versus total plate length data were not isolated. Also, Weaver et al 53 experimentally found 15% lower axial stiffness ( p = 0.003) for a 5-hole (i.e. shorter) versus a 13-hole (i.e.…”

Section: Resultsmentioning

confidence: 96%

“…Kandemir et al 20 experimentally showed 26% lower axial stiffness ( p = 0.003), 23% reduced axial failure strength (p value not reported), and 42% fewer axial cycles to failure ( p = 0.002) for a titanium versus steel commercial DFLP fixed to an artificial femur. However, Weaver et al 53 experimentally discovered no statistical difference in axial stiffness ( p = 0.12) for a titanium versus steel commercial DFLP implanted in artificial femurs, but they did not report if bone-on-bone contact occurred during fracture gap closure to explain this unexpected result. Similarly, Beingessner et al 60 experimentally measured no statistical difference in axial stiffness ( p = 0.51), but 34% lower torsional stiffness ( p < 0.001), for a titanium versus steel commercial DFLP mounted onto an artificial femur, while neither failed during axial cyclic loads reaching 1 kN.…”

Section: Resultsmentioning

confidence: 97%

Biomechanical design optimization of distal femur locked plates: A review

Zdero

Gide

Brzozowski

et al. 2023

Proc Inst Mech Eng H

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Clinical findings, manufacturer instructions, and surgeon’s preferences often dictate the implantation of distal femur locked plates (DFLPs), but healing problems and implant failures still persist. Also, most biomechanical researchers compare a particular DFLP configuration to implants like plates and nails. However, this begs the question: Is this specific DFLP configuration biomechanically optimal to encourage early callus formation, reduce bone and implant failure, and minimize bone “stress shielding”? Consequently, it is crucial to optimize, or characterize, the biomechanical performance (stiffness, strength, fracture micro-motion, bone stress, plate stress) of DFLPs influenced by plate variables (geometry, position, material) and screw variables (distribution, size, number, angle, material). Thus, this article reviews 20 years of biomechanical design optimization studies on DFLPs. As such, Google Scholar and PubMed websites were searched for articles in English published since 2000 using the terms “distal femur plates” or “supracondylar femur plates” plus “biomechanics/biomechanical” and “locked/locking,” followed by searching article reference lists. Key numerical outcomes and common trends were identified, such as: (a) plate cross-sectional area moment of inertia can be enlarged to lower plate stress at the fracture; (b) plate material has a larger influence on plate stress than plate thickness, buttress screws, and inserts for empty plate holes; (c) screw distribution has a major influence on fracture micro-motion, etc. Recommendations for future work and clinical implications are then provided, such as: (a) simultaneously optimizing fracture micro-motion for early healing, reducing bone and implant stresses to prevent re-injury, lowering “stress shielding” to avoid bone resorption, and ensuring adequate fatigue life; (b) examining alternate non-metallic materials for plates and screws; (c) assessing the influence of condylar screw number, distribution, and angulation, etc. This information can benefit biomedical engineers in designing or evaluating DFLPs, as well as orthopedic surgeons in choosing the best DFLPs for their patients.

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“…The use of a longer plate construct is one of the factors a surgeon may choose for achieving union. 19 In this series, a careful selection of the length of the plate, screw–plate density, implant material (titanium plate was used) and appropriate reduction and compression at the site of non-union were made with the aim of avoiding failure. 20 , 21 The literature supports titanium as more of a biocompatible and flexible material with Young's modulus comparable to the bone as opposed to stainless steel.…”

Section: Discussionmentioning

confidence: 99%

The Management of Aseptic Non-unions of Distal Femur Fractures with Anatomical Lateral Locking Plates

Ranjan¹,

Mukhopadhaya²,

Sinha³

et al. 2022

Strategies in Trauma and Limb Reconstruction

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A bstract Background Distal femoral non-unions are challenging, and frequently associated with short distal fragments, poor bone stock, and with issues from previous implants. Materials and methods A retrospective study of 31 patients admitted with distal femoral non-unions treated using anatomical lateral locking plates. Non-union scores were used. The Knee Society and Neer's scores were used for the comparison of results. The mean follow-up was 39.5 months (from 24 months to 60 months). Results Stable union was accomplished in all. There was a significant improvement in the average Neer's score (24 preoperative to 82 post-operatively at final follow-up), the Part 1 Knee Society score from an average of 46 preoperatively to 84 post-operatively, and Part 2 Knee Society score from 36 preoperatively to 80 post-operatively. Conclusion Optimal stability, good compression at the non-union site (either by lag screws or a compression device or both), maintaining the axial alignment strictly, freshening of bone ends, using an adequate amount of cortico-cancellous bone graft, respecting the biology along with the correct choice of the implant (including the size) are essential to achieve union at the fracture site. Clinical significance Paying attention to the basic principles of management, good contact, stability and maintaining biology is essential in the treatment of non-union. How to cite this article Mukhopadhaya J, Ranjan R, Sinha AK, et al . The Management of Aseptic Non-unions of Distal Femur Fractures with Anatomical Lateral Locking Plates. Strategies Trauma Limb Reconstr 2022;17(3):137–143.

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The effect of surgeon-controlled variables on construct stiffness in lateral locked plating of distal femoral fractures

Cited by 12 publications

References 43 publications

In vitro analysis and in vivo assessment of fracture complications associated with use of locking plate constructs for stabilization of caprine tibial segmental defects

In vitro analysis and in vivo assessment of fracture complications associated with use of locking plate constructs for stabilization of caprine tibial segmental defects

Biomechanical design optimization of distal femur locked plates: A review

The Management of Aseptic Non-unions of Distal Femur Fractures with Anatomical Lateral Locking Plates

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