The April 2024 Trauma Roundup³⁶⁰ looks at: The infra-acetabular screw in acetabular fracture surgery; Is skin traction helpful in patients with intertrochanteric hip fractures?; Reducing pain and improving function following hip fracture surgery; Are postoperative splints helpful following ankle fracture fixation?; Biomechanics of internal fixation in Hoffa fractures: a comparison of four different constructs; Dual-plate fixation of periprosthetic distal femur fractures; Do direct oral anticoagulants necessarily mean a delay to hip fracture surgery?; Plate or retrograde nail for low distal femur fractures?.

The October 2023 Trauma Roundup³⁶⁰ looks at: Intramedullary nailing versus sliding hip screw in trochanteric fracture management: the INSITE randomized clinical trial; Five-year outcomes for patients with a displaced fracture of the distal tibia; Direct anterior versus anterolateral approach in hip joint hemiarthroplasty; Proximal humerus fractures: treat them all nonoperatively?; Tranexamic acid administration by prehospital personnel; Locked plating versus nailing for proximal tibia fractures: a multicentre randomized controlled trial; A retrospective review of the rate of septic knee arthritis after retrograde femoral nailing for traumatic femoral fractures at a single academic institution.

The August 2023 Trauma Roundup³⁶⁰ looks at: A comparison of functional cast and volar-flexion ulnar deviation for dorsally displaced distal radius fractures; Give your stable ankle fractures some AIR!; Early stabilization of rib fractures – an effective thing to do?; Locked plating versus nailing for proximal tibia fractures: A multicentre randomized controlled trial; Time to flap coverage in open tibia fractures; Does tranexamic acid affect the incidence of heterotropic ossification around the elbow?; High BMI – good or bad in surgical fixation of hip fractures?

The June 2023 Trauma Roundup. 360. looks at: Aspirin or low-molecular-weight heparin for thromboprophylaxis?; Lateral plating or retrograde nailing for distal femur fractures?; Sciatic nerve palsy after acetabular fixation: what about patient position?; How reliable is the new OTA/AO classification for trochanteric hip fractures?; Young hip fractures: is a medial buttress the answer?; When is the best time to ‘flap’ an open fracture?; The mortality burden of nonoperatively managed hip fractures

The objective of this study was to use patient-specific finite element modeling to measure the 3D interfragmentary strain environment in clinically realistic fractures. The hypothesis was that in the early post-operative period, the tissues in and around the fracture gap can tolerate a state of strain in excess of 10%, the classical limit proposed in the Perren strain theory. Eight patients (6 males, 2 females; ages 22–95 years) with distal femur fractures (OTA/AO 33-A/B/C) treated in a Level I trauma center were retrospectively identified. All were treated with lateral bridge plating. Preoperative computed tomography scans and post-operative X-rays were used to create the reduced fracture models. Patient-specific materials properties and loading conditions (20%, 60%, and 100% body weight (BW)) were applied following our published method.[1]. Elements with von Mises strains >10% are shown in the 100% BW loading condition. For all three loading scenarios, as the bridge span increased, so did the maximum von Mises strain within the strain visualization region. The average gap closing (Perren) strain (mean ± SD) for all patient-specific models at each body weight (20%, 60%, and 100%) was 8.6% ± 3.9%, 25.8% ± 33.9%, and 39.3% ± 33.9%, while the corresponding max von Mises strains were 42.0% ± 29%, 110.7% ± 32.7%, and 168.4% ± 31.9%. Strains in and around the fracture gap stayed in the 2–10% range only for the lowest load application level (20% BW). Moderate loading of 60% BW and above caused gap strains that far exceeded the upper limit of the classical strain rule (<10% strain for bone healing). Since all of the included patients achieved successful unions, these findings suggest that healing of distal femur fractures may be robust to localized strains greater than 10%

The April 2023 Trauma Roundup³⁶⁰ looks at: Displaced femoral neck fractures in patients aged 55 to 70 years: internal fixation or total hip arthroplasty?; Tibial plateau fractures: continuous passive motion approves range of motion; Lisfranc fractures: to fuse or not to fuse, that is the question; Is hardware removal after clavicle fracture plate fixation beneficial?; Fixation to coverage in Grade IIIB open fractures – what’s the time window?; Nonoperative versus locking plate fixation in the proximal humerus; Retrograde knee nailing or lateral plate for distal femur fractures?

Introduction and Objective. Distal femoral fractures are commonly treated with a straight plate fixed to the lateral aspects of both proximal and distal fragments. However, the lateral approach may not always be desirable due to persisting soft-tissue or additional vascular injury necessitating a medial approach. These problems may be overcome by pre-contouring the plate in helically shaped fashion, allowing its distal part to be fixed to the medial aspect of the femoral condyle. The objective of this study was to investigate the biomechanical competence of medial femoral helical plating versus conventional straight lateral plating in an artificial distal femoral fracture model. Materials and Methods. Twelve left artificial femora were instrumented with a 15-hole Locking Compression Plate – Distal Femur (LCP-DF) plate, using either conventional lateral plating technique with the plate left non-contoured, or the medial helical plating technique by pre-contouring the plate to a 180° helical shape and fixing its distal end to the medial femoral condyle (n=6). An unstable extraarticular distal femoral fracture was subsequently simulated by means of an osteotomy gap. All specimens were tested under quasi-static and progressively increasing cyclic axial und torsional loading until failure. Interfragmentary movements were monitored by means of optical motion tracking. Results. Initial axial stiffness was significantly higher for helical (185.6±50.1 N/mm) versus straight (56.0±14.4) plating, p<0.01. However, initial torsional stiffness in internal and external rotation remained not significantly different between the two fixation techniques (helical plating:1.59±0.17 Nm/° and 1.52±0.13 Nm/°; straight plating: 1.50±0.12 Nm/° and 1.43±0.13Nm/°), p≥0.21. Helical plating was associated with significantly higher initial interfragmentary movements under 500 N static compression compared to straight plating in terms of flexion (2.76±1.02° versus 0.87±0.77°) and shear displacement under 6 Nm static rotation in internal (1.23±0.28° versus 0.40±0.42°) and external (1.21±0.40° versus 0.57±0.33°) rotation, p≤0.01. In addition, helical plating demonstrated significantly lower initial varus/valgus deformation than straight plating (4.08±1.49° versus 6.60±0.47°), p<0.01. Within the first 10000 cycles of dynamic loading, helical plating revealed significantly bigger flexural movements and significantly lower varus/valgus deformation versus straight plating, p=0.02. No significant differences were observed between the two fixation techniques in terms of axial and shear displacement, p≥0.76. Cycles to failure was significantly higher for helical plating (13752±1518) compared to straight plating (9727±836), p<0.01. Conclusions. Although helical plating using a pre-contoured LCP-DF was associated with higher shear and flexion movements, it demonstrated improved initial axial stability and resistance against varus/valgus deformation compared to straight lateral plating. Moreover, helical plate constructs demonstrated significantly improved endurance to failure, which may be attributed to the less progressively increasing lever bending moment arm inherent to this novel fixation technique. From a biomechanical perspective, helical plating may be considered as a valid alternative fixation technique to standard straight lateral plating of unstable distal femoral fractures

Introduction and Objective. Plating of geriatric distal femoral fractures with Locking Compression Plate Distal Femur (LCP–DF) often requires augmentation with a supplemental medial plate to achieve sufficient stability allowing early mobilization. However, medial vital structures may be impaired by supplemental medial plating using a straight plate. Therefore, a helically shaped medial plate may be used to avoid damage of these structures. Aim of the current study was to investigate the biomechanical competence of augmented LCP–DF plating using a supplemental straight versus helically shaped medial plate. Materials and Methods. Ten pairs of human cadaveric femora with poor bone quality were assigned pairwise for instrumentation using a lateral anatomical 15-hole LCP–DF combined with a medial 14-hole LCP, the latter being either straight or manually pre-contoured to a 90-degree helical shape. An unstable distal femoral fracture AO/OTA 33–A3 was simulated by means of osteotomies. All specimens were biomechanically tested under non-destructive quasi-static and destructive progressively increasing combined cyclic axial and torsional loading in internal rotation, with monitoring by means of optical motion tracking. Results. Initial axial stiffness and torsional stiffness in internal and external rotation for straight double plating (548.1 ± 134.2 N/mm, 2.69 ± 0.52 Nm/° and 2.69 ± 0.50 Nm/°) was significantly higher versus helical double plating (442.9 ± 133.7 N/mm, 2.07 ± 0.32 Nm/° and 2.16 ± 0.22 Nm/°), p≤0.04. Initial interfragmentary axial displacement and flexural rotation under 500 N static loading were significantly smaller for straight plating (0.11 ± 0.14 mm and 0.21 ± 0.10°) versus helical plating (0.31 ± 0.14 mm and 0.68 ± 0.16°), p<0.01. However, initial varus deformation under this loading remained not significantly different between the two fixation methods (straight: 0.57 ± 0.23°, helical: 0.75 ± 0.34°), p=0.08. During dynamic loading, within the course of the first 4000 cycles the movements of the distal fragment in flexion were significantly bigger for helical over straight plating (1.03 ± 0.33° versus 0.40 ± 0.20°), p<0.01. However, no significant differences were observed between the two fixation methods in terms of varus, internal rotation, axial and shear displacements at the fracture site, and number of cycles to failure. Conclusions. Augmented lateral plating of unstable distal femoral fractures with use of supplemental helically shaped medial plate was associated with more elastic bone-implant construct behavior under static and dynamic loading compared to straight double plating. Both fixation methods resulted in comparable number of cycles to failure. From a biomechanical perspective, the more elastic helical double plating may be considered as useful alternative to straight plating, potentially reducing stress risers at the distal bone-implant interface due to its ameliorated damping capacities

Dual plating of the medial and lateral distal femur has been proposed to reduce angular malunion and hardware failure secondary to delayed union or nonunion. This strategy improves the strength and alignment of the construct, but it may compromise the vascularity of the distal femur paradoxically impairing healing. This study investigates the effect of dual plating versus single plating on the perfusion of the distal femur. Ten matched pairs of fresh-frozen cadaveric lower extremities were assigned to either isolated lateral plating or dual plating of a single limb. The contralateral lower extremity was used as a matched control. A distal femoral locking plate was applied to the lateral side of ten legs using a standard sub-vastus approach. Five femurs had an additional 3.5mm reconstruction plate applied to the medial aspect of the distal femur using a medial sub-vastus approach. The superficial femoral artery and the profunda femoris were cannulated at the level of the femoral head. Gadolinium MRI contrast solution (3:1 gadolinium to saline ration) was injected through the arterial cannula. High resolution fat-suppressed 3D gradient echo sequences were completed both with and without gadolinium contrast. Intra-osseous contributions were quantified within a standardized region of interest (ROI) using customized IDL 6.4 software (Exelis, Boulder, CO). Perfusion of the distal femur was assessed in six different zones. The signal intensity on MRI was then quantified in the distal femur and comparison was made between the experimental plated limb and the contralateral, control limb. Following completion of the MRI protocol, the specimens were injected with latex medium and the extra-osseous vasculature was dissected. Quantitative MRI revealed that application of the lateral distal femoral locking plate reduced the perfusion of the distal femur by 21.7%. Within the dual plating group there was a reduction in perfusion by 24%. There was no significant difference in the perfusion between the isolated lateral plate and the dual plating groups. There were no regional differences in perfusion between the epiphyseal, metaphyseal or meta-diaphyseal regions. Specimen dissection in both plating groups revealed complete destruction of any periosteal vessels that ran underneath either the medial or lateral plates. Multiple small vessels enter the posterior condyles off both superior medial and lateral geniculate arteries and were preserved in all specimens. Furthermore, there was retrograde flow to the distal most aspect of the condyles medially and laterally via the inferior geniculate arteries. The medial vascular pedicle was proximal to the medial plate in all the dual plated specimens and was not disrupted by the medial sub-vastus approach in any specimens. Fixation of the distal femur via a lateral sub-vastus approach and application of a lateral locking plate results in a 21% reduction in perfusion to the distal femur. The addition of a medial 3.5mm reconstruction plate does not significantly compromise the vascularity of the distal femur. The majority of the vascular insult secondary to open reduction, internal fixation of the distal femur occurs with application of the lateral locking plate

Aims

Tibial plateau fractures are serious injuries about the knee that have the potential to affect patients’ long-term function. To our knowledge, this is the first study to use patient-reported outcomes (PROs) with a musculoskeletal focus to assess the long-term outcome, as compared to a short-term outcome baseline, of tibial plateau fractures treated using modern techniques.

Aims. Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity. Methods. A total of eight cadaveric lower limb pairs were arbitrarily assigned to either 1) isolated lateral plating, or 2) lateral and medial plating of the distal femur, with four specimens per group. Contralateral limbs served as matched controls. Pre- and post-contrast MRI was performed to quantify signal intensity enhancement in the distal femur. Further evaluation of intraosseous vascularity was done with barium sulphate infusion with CT scan imaging. Specimens were then injected with latex medium and dissection was completed to assess extraosseous vasculature. Results. Quantitative MRI revealed a mean reduction of 21.2% (SD 1.3%) of arterial contribution in the lateral plating group and 25.4% (SD 3.2%) in the dual plating group (p = 0.051); representing a mean decrease in arterial contribution of 4.2%. The only significant difference found between both experimental groups was regionally, at the lateral aspect of the distal femur with a mean drop in arterial contribution in the lateral plating group of 18.9% (SD 2.6%) versus 24.0% (SD 3.2%) in the dual plating group (p = 0.048), representing a mean decrease in arterial contribution of 5.1%. Gross dissection revealed complete destruction of periosteal vessels underneath either medial or lateral plates in both groups. The network of genicular branches contributing to the posterior and distal femoral condyles was preserved in all specimens. A medial vascular pedicle was found dividing from the superficial femoral artery at a mean 12.7 cm (SD 1.7) proximal to the medial epicondyle and was undisrupted in the dual plating group. Conclusion. Lateral locking-plate application resulted in mean 21.2% reduction in distal femur vascularity. Addition of medial plates did not further markedly decrease vascularity. As such, the majority of the vascular insult occurred with lateral plating alone. Supplemental medially based fixation did not lead to marked devascularization of the distal femur, and should therefore be considered in the setting of comminution and poor bone stock in distal femoral fractures. Further clinical research is required to confirm the results of this study. Cite this article: Bone Joint J 2020;102-B(4):530–538

Peri-prosthetic fractures above a TKA are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases, the TKA is well fixed and has been functioning well prior to fracture. For fractures above well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating and nailing techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension. For certain fractures, distal femoral replacement (DFR) is a wise choice. The author reserves DFR for situations where internal fixation is likely to fail (severe distal osteolysis, severe osteopenia) or for cases where it has already failed (nonunion). Obviously, if the implant is loose, revision is indicated, and typically the distal bone loss is so severe that a distal femoral replacement is indicated. The author prefers cemented constructs and routinely adds antibiotics to the cement mixture. Careful attention to posterior dissection of the distal fragment is recommended to avoid neurovascular injury. Cementing the femoral component in the proper amount of external rotation is important to allow central patellar tracking. The available literature demonstrates excellent functional results with these reconstructions, however, complications are not uncommon. Infection and extensor mechanism complications are the most frequent complications and are best avoided. In summary, ORIF remains the treatment of choice for these fractures, however, for cases where ORIF is likely to fail, or has failed, DFR remains a predictable salvage option

Peri-prosthetic fractures above a TKA are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases the TKA is well fixed and has been functioning well prior to fracture. For loose components, revision is typically indicated. Typically a megaprosthesis is required. Well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. More recent developments with polyaxial locked screws (that allow angulation prior to end-point locking) may offer even more versatility when distal fragment fixation is challenging. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension

Aims

Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques.

The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate.

Peri-prosthetic fractures above a TKA are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases the TKA is well fixed and has been functioning well prior to fracture. For loose components, revision is typically indicated. Often, distal femoral mega prostheses are required to deal with metaphyseal bone loss. Good results have been reported in small series, however, complications, including infection remain concerning, and these implants are incredibly expensive. Although performing a mega prosthesis in the setting of a well fixed TKA is not unreasonable due to immediate full weight bearing, in my opinion, prosthetic replacement should be limited to cases of failed ORIF (rare), or in cases where fixation is likely to fail (i.e., severe osteolysis distally). For the majority of fractures above well fixed components, internal fixation is preferred for the main reason that the overwhelming majority of these fractures will heal. Fixation options include retrograde nailing or lateral locked plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. More recent developments with polyaxial locked screws (that allow angulation prior to end-point locking) may offer even more versatility when distal fragment fixation is challenging. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension

Periprosthetic femoral shaft fractures are a significant complication of total hip arthroplasty. Plate osteosynthesis with or without onlay strut allograft has been the mainstay of treatment around well-fixed stems. Nonunions are a rare, challenging complication of this fixation method. The number of published treatment strategies for periprosthetic femoral nonunions are limited. In this series, we report the outcomes of a novel orthogonal plating surgical technique for addressing nonunions in the setting of Vancouver B1 and C-type periprosthetic fractures that previously failed open reduction internal fixation (ORIF). A retrospective chart review of all patients from 2010 to 2014 with Vancouver B1/C total hip arthroplasty periprosthetic femoral nonunions was performed. All patients were treated primarily with ORIF. Nonunion was defined as no radiographic signs of fracture healing nine months post-operatively, with or without hardware failure. Exclusion criteria included open fractures and periprosthetic infections. The technique utilised a mechanobiologic strategy of atraumatic exposure, resection of necrotic tissue, bone grafting with adjuvant recombinant growth factor and revision open reduction internal fixation. Initially, compression was achieved using an articulated tensioning device and application of an anterior plate. This was followed by locked lateral plating. Patients remained non-weight bearing for eight weeks. Six Vancouver B1/C periprosthetic femoral nonunions were treated. Five patients were female with an average age of 80.3 years (range 72–91). The fractures occurred at a mean of 5.8 years (range 1–10) from their initial arthroplasty procedure. No patients underwent further revision surgery; there were no wound dehiscence, hardware failures, infections, or surgical complications. All patients had a minimum of nine months follow up (mean 16.6, range 9–36). All fractures achieved osseous union, defined as solid bridging callus over at least two cortices and pain free, independent ambulation, at an average of 24.4 weeks (range 6.1–39.7 weeks). To our knowledge, this is the first case series describing 90–90 locked compression plating using modern implants for periprosthetic femoral nonunions. This is a rare but challenging complication of total hip arthroplasty and we present a novel solution with satisfactory preliminary outcomes. Orthogonal locked compression plating utilising an articulated tensioning device and autograft with adjuvant osteoinductive allograft should be considered in periprosthetic femur fractures around a well-fixed stem. Further biomechanical and clinical research is needed to improve our treatment strategies in this population

Peri-prosthetic fractures above a total knee arthroplasty (TKA) are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases the TKA is well-fixed and has been functioning well prior to fracture. For loose components, revision is typically indicated. Typically a megaprosthesis is required. For well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. More recent developments with polyaxial locked screws (that allow angulation prior to end-point locking) may offer even more versatility when distal fragment fixation is challenging. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension

Objectives

This study tests the biomechanical properties of adjacent locked plate constructs in a femur model using Sawbones. Previous studies have described biomechanical behaviour related to inter-device distances. We hypothesise that a smaller lateral inter-plate distance will result in a biomechanically stronger construct, and that addition of an anterior plate will increase the overall strength of the construct.