Fixation of periprosthetic femoral shaft fractures occurring at the tip of the stem: a biomechanical study of 5 techniques

This study evaluated 5 currently used periprosthetic femoral shaft fracture fixation techniques to determine which technique provided the greatest fixation stability. Periprosthetic fractures in 30 synthetic femurs were fixed with a plate with cables, plate with proximal cables and distal bicortical screws (Ogden concept), plate with proximal unicortical screws and distal bicortical screws, plate with proximal unicortical screws and cables and distal bicortical screws, or 2 allograft cortical strut grafts with cables. These specimens were then tested in 3 physiologic loading modes. The plate constructs with proximal unicortical screws and distal bicortical screws or with proximal unicortical screws, proximal cables, and distal bicortical screws were significantly more stable in axial compression, lateral bending, and torsional loading than the other fixation constructs studied.     

Biomechanical cadaver testing of a fixed-angle plate in comparison to tension wiring and screw fixation in transverse patella fractures

IntroductionOperative treatment of patella fractures is frequently associated with implant failure and secondary dislocation which can be attributed to the employed hardware. Therefore, a 2.7 mm fixed-angle plate designed for the treatment of patella fractures was tested biomechanically against the currently preferred methods of fixation. It was hypothesized that under simulated cyclic loading fixed-angle plating would be superior to modified anterior tension wiring or cannulated lag screws with anterior tension wiring.Materials and methodsEighteen human cadaver knees, matched by bone mineral density and age, were divided into three groups of six. After setting a transverse patella fracture each group received one of the osteosyntheses mentioned above. Repetitive testing over 100 cycles was performed at non-destructive loads by simulating knee motion from 90° flexion to full extension.ResultsAnterior tension wiring as well as lag screws with tension wiring showed significant fracture displacement after the initial cycle already. Both constructs, lag screws plus wiring (3.7 ± 2.7 mm) as well as tension wiring alone (7.1 ± 2.2 mm) displayed fracture displacement of >2 mm which is clinically regarded as failure. Those patellae stabilized with fixed-angle plates showed no significant fracture gap widening after completion of 100 cycles (0.7 ± 0.5 mm). The differences between the fixed-angle plate group and the other two groups were statistically significant (p < 0.05).ConclusionIn contrast to modified anterior tension wiring and cannulated lag screws with anterior tension wiring the bilateral fixed-angle plate was the only fixation device to stabilize transverse patella fractures securely and sustainably.     

Percutaneous screw fixation for the acetabular fracture with quadrilateral plate involved by three-dimensional fluoroscopy navigation: surgical technique

BackgroundThe percutaneous three-dimensional (3D)-fluoroscopic-navigated screw directing to the quadrilateral plate was attempted.Materials and methodsFive patients with acetabular fractures were treated by 3D navigated percutaneous screw. The quadrilateral plate was involved in all the patients. The Arcadis 3D (ARCADIS Orbic 3D^®; Siemens AG Healthcare Sector, Erlangen, Germany) and computer navigation system (stryker navigation system) were employed, screwing trajectory was attempted to anchor the quadrilateral plate perpendicularly to the fracture line and close to the joint cartilage as much as possible. Parameters including fracture gap closure (P1), distance to the joint cartilage (P2), angulations between the screw and the fracture line (P3), were measured with the software installed on the machine of Arcadis 3D.ResultSeven screws were inserted with the use of 3D fluoroscopic navigation. The quadrilateral plate was hold by percutaneous screws. The closure of fracture gap was achieved in 3 patients by 2–3 mm. The nearest distance from the screw to the joint cartilage was ranged from <1 mm to 6 mm. The angulations between the screw and the fracture line was 80–90° in three patients, it was 60° and 65° respectively on the rest two patients. All patients felt pain free 1 week after the operation. No complication was noted postoperatively.ConclusionThe surgical technique of percutaneous screwing for the acetabular fracture with three-dimensional fluoroscopy-based navigation was demonstrated.     

Construct failure after open reduction and plate fixation of displaced midshaft clavicular fractures

IntroductionWorldwide, implants mostly used for fixation of displaced midshaft clavicular fractures (DMCF) are the easily to bend reconstruction plate and the stiffer small fragment locking compression plate. Construct failure rates after plate fixation of DMCF are reported around 5 percent. Possible risk factors for construct failure are implant type and fracture type. However, little is known about the influence of fracture fixation method on construct failure. The aim of this study was to assess construct failure in plate fixation of DMCF and to identify possible risk factors.MethodsAll consecutive patients treated in a level 1 trauma centre with open reduction and fixation of DMCF using a 3.5-mm reconstruction plate or 3.5-mm small fragment locking compression plate between 2007 and 2015 were evaluated. Potential risk factors for construct failure were analysed using univariate analysis.ResultsTwo hundred and fifty-nine patients were analysed. Fifty DMCF (19%) were fixated with a reconstruction plate and 209 (81%) with a small fragment locking compression plate. Construct failure was seen in 18 patients (6.9%), including 5 broken plates and 13 with screw loosening. Eight percent of all reconstruction plates broke in contrast to 0.5 percent of all small fragment locking compression plates (p = 0.001). All broken implants were used as a bridging plate. Loosening of screws was seen in older patients and when the plate was fixated with less than three bicortical screws on one side of the fracture (p = 0.002).ConclusionsOverall construct failure after open reduction and plate fixation of DMCF occurred in 6.9 percent. Risk factors for plate breakage were the use of a reconstruction plate and a bridging method for fracture fixation. Risk factors for screw loosening were an increasing patient age and plate fixation with less than three bicortical screws on one side of the fracture.RecommendationsBased on the results of this study our recommendation is to use a small fragment locking compression plate for open reduction and internal fixation of DMCF. The surgeon should always strive to fixate the plate on both sides of the fracture with at least three bicortical screws.     

Locking plate fixation of humeral head fractures with a telescoping screw. A comparative biomechanical study versus a standard plate

ObjectivesLocking plate fixation of humeral head fractures bares the risk of glenohumeral screw penetration. In order to circumvent this problem it is recommended to insert shorter locking screws having at least a 6 mm distance to the humeral head cortex. This in turn may reduce fixation stability and may lead to early varus displacement. One second frequent failure mechanism is cranial displacement of the greater tubercle. The study evaluates the biomechanical properties of a locking plate employing an additional telescoping screw that may enhance resistance to varus displacement. Screw in screw fixation of the greater tubercle may reduce the rate of cranial displacement.MethodsIn four paired fresh-frozen human cadaver humeri (age > 70 years) a Neer IV/3 fracture was created with a 5 mm osteotomy gap simulating metaphyseal comminution. Limbs were randomly assigned to receive plate fixation with an additional telescoping screw (Humerus Tele Screw: HTS) and on the contralateral limb Philos plate fixation before biomechanical evaluation (MTS-Bionix 858.2). Standard locking screws were placed in both groups 6 mm below the radiological head circumference; the telescoping screw was placed in the subchondral layer. The greater tubercle was fixed with an additional screw in both techniques, in the HTS group the screw was anchored in the sleeve of the telescrew (screw in screw fixation).FindingsFixation stability with a mean stiffness of 300.9 ± 28.8 N/mm in the HTS plate group proved to be significantly higher than in the Philos plate group (184.2 ± 23.4 N/mm; p = 0.006). The HTS plate also resisted higher loads in terms of fixation failure with loss of reduction at 290 ± 58.6 N in comparison to 205 ± 8.6 N for the Philos plate (p = 0.2). Displacement of the greater tubercle occurred in no case of the HTS plate group and in two out of four cases in the Philos plate group.InterpretationThe HTS plate provides high fixation stability in an in vitro humeral head fracture model and securely prevents displacement of the greater tubercle.     

Reconstruction of a Bryan and Morrey type I capitellar fracture in a sawbone model with four different fixation devices: an experimental study

BackgroundWe evaluated 4 different fixation devices for the reconstruction of a standardised Bryan and Morrey capitellar shear fracture in a sawbone model. Outcome measurements were the quality of reduction, time for reconstruction and stability.Methods80 standardised Bryan and Morrey type I fractures were created for 5 different orthopaedic surgeons in 80 sawbones. Each surgeon reconstructed 16 fractures with 2 mm K-wires, 3 mm Herbert screws, 2.7 mm AO screws and 2.2 mm fine-threaded wires (Fragment Fixation System: FFS). 4 fractures were allocated to each method with a standardised reconstruction procedure. Quality of reduction and time for reconstruction were measured after definitive fixation. Biomechanical testing was performed using a shear loading model with the application of monocyclic or polycyclic stress to the reconstructed capitulum.ResultsThere was no difference in the quality of reduction with the different fixation devices. Herbert and AO screw fixation was slower than the other implants (p < 0.05). No difference in the time for reconstruction was observed with K-wires and FFS. Failure load was less for K-wires compared to FFS, Herbert screws and AO screws (p < 0.05). With polycyclic loading, residual deformation was higher with K-wire reconstruction compared to FFS, Herbert screws and AO screws (p < 0.05).ConclusionWhen using four different fixation devices, the fixation of standardised Bryan and Morrey type I fractures in the sawbone model differs when it comes to the time needed for reduction, but not in the quality of reduction. Stability was the same for the implants used, except for the K-wires. There is no argument in favour one of the screw implants over another in clinical use.     

Finite element analysis of the three different posterior malleolus fixation strategies in relation to different fracture sizes

PurposeAppropriate fixation method for the posterior malleolar fractures (PMF) according to the fracture size is still not clear. Aim of this study was to evaluate the outcomes of the different fixation methods used for fixation of PMF by finite element analysis (FEA) and to compare the effect of fixation constructs on the size of the fracture computationally.Materials and methodsThree dimensional model of the tibia was reconstructed from computed tomography (CT) images. PMF of 30%, 40% and 50% fragment sizes were simulated through computational processing. Two antero-posterior (AP) lag screws, two postero-anterior (PA) lag screws and posterior buttress plate were analysed for three different fracture volumes. The simulated loads of 350 N and 700 N were applied to the proximal tibial end. Models were fixed distally in all degrees of freedom.ResultsIn single limb standing condition, the posterior plate group produced the lowest relative displacement (RD) among all the groups (0.01, 0.03 and 0.06 mm). Further nodal analysis of the highest RD fracture group showed a higher mean displacement of 4.77 mm and 4.23 mm in AP and PA lag screws model (p = 0.000). The amounts of stress subjected to these implants, 134.36 MPa and 140.75 MPa were also significantly lower (p = 0.000). There was a negative correlation (p = 0.021) between implant stress and the displacement which signifies a less stable fixation using AP and PA lag screws.ConclusionProgressively increasing fracture size demands more stable fixation construct because RD increases significantly. Posterior buttress plate produces superior stability and lowest RD in PMF models irrespective of the fragment size.     

Biomechanical evaluation of fracture fixation constructs using a variable-angle locked periprosthetic femur plate system

Background

In the United States there are more than 230,000 total hip replacements annually, and periprosthetic femoral fractures occur in 0.1–4.5% of those patients. The majority of these fractures occur at the tip of the stem (Vancouver type B1). The purpose of this study was to compare the biomechanically stability and strength of three fixation constructs and identify the most desirable construct.

Methods

Fifteen medium adult synthetic femurs were implanted with a hip prosthesis and were osteotomized in an oblique plane at the level of the implant tip to simulate a Vancouver type B1 periprosthetic fracture. Fractures were fixed with a non-contact bridging periprosthetic proximal femur plate (Zimmer Inc., Warsaw, IN). Three proximal fixation methods were used: Group 1, bicortical screws; Group 2, unicortical screws and one cerclage cable; and Group 3, three cerclage cables. Distally, all groups had bicortical screws. Biomechanical testing was performed using an axial–torsional testing machine in three different loading modalities (axial compression, lateral bending, and torsional/sagittal bending), next in axial cyclic loading to 10,000 cycles, again in the three loading modalities, and finally to failure in torsional/sagittal bending.

Results

Group 1 had significantly greater load to failure and was significantly stiffer in torsional/sagittal bending than Groups 2 and 3. After cyclic loading, Group 2 had significantly greater axial stiffness than Groups 1 and 3. There was no difference between the three groups in lateral bending stiffness. The average energy absorbed during cyclic loading was significantly lower in Group 2 than in Groups 1 and 3.

Conclusions

Bicortical screw placement achieved the highest load to failure and the highest torsional/sagittal bending stiffness. Additional unicortical screws improved axial stiffness when using cable fixation. Lateral bending was not influenced by differences in proximal fixation.

Clinical relevance

To treat periprosthetic fractures, bicortical screw placement should be attempted to maximize load to failure and torsional/sagittal bending stiffness.     

Dall-miles cable-grip system for periprosthetic fractures of femur

Periprosthetic femur fractures are one of the most serious complications in hip surgery. Treatment of femoral shaft fractures complicating endoprosthesis remains controversial.Twenty-one such fractures were treated with Dall-Miles cable grip system. This modified plate allows for fixation using heavy duty circlage cable wire in conjugation with unicortical and bicortical screws throughout the length of the plate. 3 patients with type II transverse periprosthetic fracture with medial communution had primary bone grafting. 20 of the 21 fractures healed in an average of 5.5 months. One patient developed deep infection and died postoperatively. Use of Dall-Miles cable grip system provides immediate rigid fixation allowing early mobilisation.     

Biomechanical comparison of different acetabular plate systems and constructs--the role of an infra-acetabular screw placement and use of locking plates

IntroductionThe aim of this study was the direct comparison of the static fixation strength of two common plate systems: MPS (Matta Pelvic System) and LPPS (Low Profile Plate System). Furthermore the role of a modified screw placement with addressing the infra-acetabular corridor and the use of locking screws were evaluated.Materials and methodsCustom made anterior column fractures in artificial SYNBONE pelves were fixed with different acetabular plates (group I: MPS, group II: LPPS none locking and group III: LPPS locking). Each pelvis was tested twice, with the additionally placed infra-acetabular lag screw [+] first, followed by a repeated measurement without the infra-acetabular screw [?]. Six pelves per group were tested under static loading with six cycles up to 800 N, each. The fracture displacement was measured in the weight bearing dome using an ultrasound based Zebris-3D-Motion Analyzer.ResultsThe MPS-plate had a less fixation strength compared to the LPPS-plate (mean ± SD of maximum fracture displacement [mm] in group I vs. group II = 0.63 ± 0.02 vs. 0.37 ± 0.02, p < 0.05). The locking feature did not increase the fracture fixation strength (mean ± SD of maximum fracture displacement [mm] in group II vs. group III: 0.37 ± 0.02 vs. 0.37 ± 0.03; ns).The infra-acetabular screw significantly reduces the maximum fracture displacement in all groups, independent of the plate systems ([Delta%] in group I = 50; group II = 63 and group III = 40; p < 0.05 each).ConclusionThe LPPS-plate performed superior fixation strength for anterior column fractures compared to the MPS-plate. The locking plate modality did not reduce the maximum fracture displacement, whereas the additional infra-acetabular screw placement actually doubles the fracture fixation strength independent of the used plate system.     

Is there a benefit of proximal locking screws in osteoporotic distal radius fractures? – A biomechanical study

IntroductionThe distal radial fracture is a common fracture and frequently seen in geriatric patients. During the last years, volar plating has become a popular treatment option. While the application of locking screws at the distal fragment is widely accepted, there is no evidence for their use at the radial shaft.Materials and methodsIn six osteoporotic pairs of matched human cadaver radii an extra-articular model creating an AO 23-A2.1 fracture was employed. Osteosynthesis were performed using the APTUS 2.5 Adaptive TriLock Distal Radius System (Medartis AG) with locking (LS) or non-locking screws (NLS) for proximal fixation. Biomechanical testing was performed in a staircase fashion: starting with 50 cycles at 200 N, the load was continuously increased by 50 N every 80 cycles up to a maximum force of 400 N. Finally, load to failure was analyzed with failure defined as sudden loss of force measured (20%) or major deformation of the radii (10 mm).ResultsAt 200 N, 250 N, 300 N, 400 N and load to failure, the NLS group showed a higher degree of elastic modulus. In contrast, the LS group showed higher elastic modulus at 350 N. Maximum force was higher in the LS group without reaching statistical significance. Reasons for loss of fixation were longitudinal shaft fractures, horizontal peri-implant fractures and distal cutting out. No difference was seen between the two groups concerning the development of the above mentioned complications.ConclusionOur study did not show biomechanical superiority for distal radius fracture fixation by using locking screws in the proximal holes in an osteoporotic cadaver study. At load to failure, longitudinal shaft fractures and peri-implant fractures seemed to be a more relevant problem rather than failure of the proximal fixation.     

Outcome of periprosthetic distal femoral fractures following knee arthroplasty

IntroductionThe majority of periprosthetic fractures around the knee occur at the supracondylar region of the distal femur. Fixation of distal femoral fractures in osteoporotic bone with short segment remains a challenge, especially after total knee arthroplasty (TKA). Internal fixation of these fractures using locking plates has become popular. The purpose of this study was to evaluate a consecutive series of periprosthetic supracondylar femoral fractures treated with locked periarticular plate fixation with regard to surgical procedure, complications and clinical outcome.Materials and methodsFrom two academic trauma centres, 55 consecutive periprosthetic distal femoral fractures (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association, AO/OTA 33) were retrospectively identified as having been treated with locked plate fixation. Of these, 36 fractures in 35 patients (86.1% female) met the inclusion criteria. Patients had an average age of 73.2 years (range 54–95 years). Fixation constructs for plate length and working length were delineated. Nonunion, infection and implant failure were used as complication variables. Demographics were assessed. Outcome was addressed radiographically and clinically according to Kristensen et al.¹ by range of motion and pain.ResultsTwenty-five of 36 fractures (69.4%) healed after the index procedure. Eight of 36 fractures (22.2%) developed a nonunion with three fractures (8.3%) leading to hardware failure. Nine of the 36 patients (25%) were radiographically diagnosed with notching of the anterior femoral cortex. Regarding technical aspects, distance from the anterior flange of the femoral component to fracture was significantly shorter in patients with compared to without anterior notching (t = 3.68, p = 0.02). Patients who underwent submuscular plate insertion compared to an extensive lateral approach had a reduced nonunion risk (χ² = 0.05). No difference in infection rate was found for submuscular procedures compared with open procedures (χ² = 0.85). Range of motion was reduced in most of the patients and 13.5% had a persistent loss of extension of 5°. More than 77% of the patients reported no or only mild pain during the last office visit. Range of motion loss did not influence pain. Successful treatment according to Cain et al.² was achieved in 83%. Using Kristensen's¹ criteria, 56% of the knees had acceptable flexion.ConclusionOperative fixation of periprosthetic distal femoral fractures after TKA continues to be challenging. Notching of the anterior femoral cortex should be avoided. Loss of reduction and high failure rates still occur with locked plating and may be related to underlying factors. Indirect reduction and submuscular plate insertion technique reduce nonunion risk.     

Periarticular raft constructs and fracture stability in split-depression tibial plateau fractures

ObjectivesTo evaluate relative fracture stability yielded by screws placed above a lateral plate, as well as locking and non-locking screws placed through a plate in a split depression tibia plateau fracture model.MethodsCadaver tibia specimens (mean age 74.1 years) were randomised across 3 groups: Groups 1: raft-construct outside the plate, 2: non-locking raft screws through the plate, and 3: locking raft screws through the plate. Displacement of the depressed fragment was recorded with force values from 400 N to 1600 N in increasing 400 N increments. The force required to elicit lateral plateau fragment displacement of 5 mm, 10 mm, and 15 mm was also recorded.ResultsNone of the mechanical testing results demonstrated statistical significance with p-values of <0.05. Cyclic testing of Groups 1, 2, and 3 at 400 N revealed displacements of 0.54 mm, 0.64 mm, and 0.48 mm, respectively. At 800 N, displacements were 1.36 mm, 1.4 mm, and 1.4 mm, respectively. At 1200 N, displacements were 2.4 mm, 1.9 mm, and 2.1 mm, respectively. At 1600 N, displacements were 2.8 mm, 2.5 mm, and 2 mm, respectively. Resistance to displacement data demonstrated the mean force required to displace the fracture 5 mm in Groups 1, 2, and 3 were 250 N, 330 N, and 318 N, respectively. For 10 mm of displacement, forces required were 394 N, 515 N, and 556 N, respectively. For 15 mm of displacement, forces required were 681 N, 853 N, and 963 N, respectively. Compared to combined groups using screws through the plate, Group 1 demonstrated lower displacement ≤800 N, but demonstrated greater displacement >800 N. Group 2 demonstrated greatest resistance to plateau displacement of 5 mm compared to Group 1 or 3, while Group 3 was most resistant to greater displacement. The combined group using screws through the plate (Groups 2 + 3) was consistently more resistant than Group 1 at all levels of displacement.ConclusionsDesigns utilising screws through the plate trended towards statistically significant improved stability against plateau displacement relative to utilising screws outside the plate. Our study also suggests that there is no significant benefit of locking screws over non-locking screws in this unicondylar tibia plateau fracture model.     

Orthogonal plating of intra-articular distal radius fractures with an associated radial column fracture via a single volar approach

IntroductionThe purpose of this study was to investigate the radiographic and functional outcome of orthogonal plating (two plates at right angles) via a single volar approach for fixation of intra-articular distal radius fractures with an associated radial column fracture.MethodsIn a retrospective, chart-based review, we identified 14 consecutive patients with an intra-articular distal radial fracture who had been treated with locked volar plate fixation and an additional radial column plate. Radial column plates were LCP Distal Radius Plates 2.4; volar plates were LCP Distal Radius Plates 2.4 (n = 13) or LCP T-plate (n = 1). These patients were operated on using the extended volar flexor carpi radialis (FCR) approach as described by Orbay. Radiographic measurements, healing rates, time to union, complications, range of motion, the Gartland and Werley score, and the QuickDASH questionnaire were done in order to evaluate the radiographic and functional outcomes of this technique.ResultsThirteen of the 14 fractures healed within 7 weeks after surgery. Two implant removals were done. One patient had malposition of the fracture and carpal tunnel symptoms, which required a second surgery. No other complications (e.g., first dorsal compartment problems, radial plate prominence problems and radial sensory nerve problems) were observed. The average length of follow-up was 30 months (range, 12.8 months to 5.4 years). Radiographic results after healing were radial inclination 20°, radial length 11.4 mm, tilt 6° volar, ulnar variance ?0.5 mm, articular gap 0.1 mm and step-off 0.1 mm. Wrist range of motion was flexion–extension arc 93°, ulnar–radial deviation arc 49° and pronation–supination arc 152°. Nine patients scored ‘excellent’ on the Gartland and Werley score, while the remaining five patients scored ‘good’. The average QuickDASH score was 13.4.ConclusionAdditional fixation of a radial column process in an intra-articular distal radius fracture via the extended FCR approach using a standard volar plate and radial LCP resulted in good/excellent radiographic and functional outcome.Level of evidenceTherapeutic IV.     

A biomechanical study on variation of compressive force along the Acutrak 2 screw

IntroductionAcutrak 2 screws are commonly used for scaphoid fracture fixation. To our knowledge, the variation in compressive force along the screw has not been investigated before. The objectives of our study were to measure variance in compression along the length of the standard Acutrak 2 screw, to identify the region of the screw which produces the greatest compression and to discuss the clinical relevance of this to the placement of the screw for scaphoid fractures.Materials and methodsA laboratory model was set up to test the compressive force at 2 mm intervals along the screw, using solid polyurethane foam (Sawbone) blocks of varying width. The Acutrak 2 screws were introduced in the standard method. Forces were measured using a custom-made load cell washer introduced between the Sawbone blocks and were plotted as a graph along the whole length of the screw.ResultsMaximum compression was at the mid-point of the screw. Overall compressive forces were higher in the proximal half of the screw by 19% when compared with the distal half. Minimum compression was seen at 4 mm or less from either end of the screw.ConclusionsThere is variation in compression along the length of the standard Acutrak 2 screw and the maximum compression was obtained at the mid-point of the screw. From this study, we would recommend when using an Acutrak 2 screw for internal fixation of scaphoid fractures, to attain maximum compressive force, place the fracture at the mid-point of the Acutrak screw. If this is not possible, then place the fracture towards the proximal half of the screw.     

Working length and proximal screw constructs in plate osteosynthesis of distal femur fractures

BackgroundThe study purpose is to evaluate the working length, proximal screw density, and diaphyseal fixation mode and the correlation to fracture union after locking plate osteosynthesis of distal femoral fractures using bridge-plating technique.MethodsA four-year retrospective review was performed to identify patients undergoing operative fixation of distal femur fractures with a distal femoral locking plate using bridge-plating technique for the metadiaphyseal region. Primary variables included fracture union, secondary surgery for union, plate working length, and diaphyseal screw technique and configuration. Multiple secondary variables including plate metallurgy and coronal plane fracture alignment were also collected.ResultsNinety-six patients with distal femur fractures with a mean age 60 years met inclusion criteria. None of the clinical parameters were statistically significant indicators of union. Likewise, none of the following surgical technique parameters were associated with fracture union: plate metallurgy, the mean working length, screw density and number of proximal screws and screw cortices. However, diaphyseal screw technique did show statistical significance. Hybrid technique had a statistically significant higher chance of union when compared to locking (p = 0.02). All proximal locking screw constructs were 2.9 times more likely to lead to nonunion.ConclusionsPlating constructs with all locking screws used in the diaphysis when bridge-plating distal femur locking plates were 2.9 times more likely to incur a nonunion. However, other factors associated with more flexible fixation constructs such as increased working length, decreased proximal screw number, and decreased proximal screw density were not significantly associated with union in this study.     

Treatment of unstable posterior pelvic ring fracture with percutaneous reconstruction plate and percutaneous sacroiliac screws: a comparative study

ObjectiveThe aim of this study is to compare the clinical effects of percutaneous reconstruction plate and percutaneous sacroiliac screws in treatment of unstable posterior pelvic ring fracture.MethodsFifty-eight patients with unstable posterior pelvic ring fracture treated with two methods from March 2002 to October 2007 were enrolled in the study and divided into two groups according to two kinds of internal fixation: percutaneous reconstruction plate (20 males and 9 females, at mean age 37.3 ± 11.3 years) and percutaneous sacroiliac screws (21 males and 8 females, at mean age 39.3 ± 10.4 years). Causes of injury included traffic accident in 38 patients, fall from height in 17, and crush in 3. The correlative data of operation duration, number of X-ray exposures, intraoperative bleeding volume, length of incision, Majeed postoperative functional evaluation, and postoperative complications were analyzed statistically.ResultsAll 58 patients were followed up for 12–36 months (mean duration 21.3 months). There was statistical difference for operation duration, number of X-ray exposures, size of incision, and intraoperative bleeding volume between the two groups. Majeed postoperative functional evaluation indicated excellent and good rates of 86.1 % for percutaneous reconstruction plate and 88.2 % for percutaneous sacroiliac screws.ConclusionsThe clinical effect of the two methods is similar in treatment of Tile C pattern posterior pelvic ring fracture. However, the percutaneous reconstruction plate has lower risk of damaging nerves and blood vessels than the percutaneous sacroiliac screws. Moreover, intraoperative fluoroscopy is rarely performed.     

The outcome of unstable proximal femoral fracture treated with reverse LISS plates

BackgroundThe Russel-Taylor type 2B fractures compromised the trochanteric region and medial buttress of proximal femur. This fracture pattern limits the choice of implants and raises the risk of adverse outcomes. We aimed to (i) determine the outcome of Russel-Taylor type 2B fractures treated using reverse less invasive stabilization system plates (LISS-DF) and to (ii) learn what factors affected outcomes after osteosynthesis with reverse LISS plates.DesignA retrospective studySettingThe study was conducted at a Level III trauma center in Taiwan.MethodsTwenty-five consecutive patients presenting with a Russel-Taylor type 2B fracture were enrolled. All cases were treated with reverse LISS plates. A Modified Radiographic Union Scale for Femur (RUSF), Radiographic parameters, functional scores, and complications were assessed.ResultsUnion occurred in 21 cases at an average of 18.8 weeks. The average immediate postoperative neck-shaft angle was 130° (range: 122–135°) compared with 139° (range: 135–141°, p = 0.05) on the contralateral side. Two cases had complications of proximal screws cutting out and two cases had broken implants. Finally, all 4 cases required repeated surgeries (16%). Malunion occurred in 4 patients and early mechanical failure (proximal screws cut out) occurred in 2. There was a significant difference in the purchase index of the proximal screws between cases with redisplacement and those without (26.4 mm and 98.6 mm, p = 0.01).ConclusionsThe use of reverse LISS plate appeared to be an alternative procedure for the specific pattern in the present study. We recommend using this reverse locking plate to treat unstable proximal femoral fractures with meticulous techniques of placing plates. Adequate purchase of the proximal locking screws might decrease the risks of complications.     

The effects of a displaced dorsal rim fracture on outcomes after volar plate fixation of a distal radius fracture

IntroductionThe purpose of this study was to determine whether a displaced dorsal rim fracture has an adverse effect on wrist function after volar plate fixation of a dorsally displaced distal radius fracture (DRF).Materials and methodsTwo matched cohorts of 23 matched patients, one with a displaced dorsal rim fracture >2 mm (group 1), and the other without a dorsal rim fracture (group 2) were analysed in this study of volar locking plate fixation for dorsally unstable DRFs. The two cohorts were analysed for differences in wrist function and wrist pain, radiographic parameters and arthritic grades of radiocarpal joints. Displacement of dorsal rim fragments and diameters of the retained articular portions of dorsal rims in group 1 were measured.ResultsNo significant difference was found between the two groups in overall wrist function or wrist pain. Mean displacement of dorsal rims in group 1 was 3.0 mm and the mean diameter of the retained articular portion of dorsal articular wall was 2.0 mm. No significant difference was found between the two groups in terms of any radiographic parameters or the arthritic grading of radiocarpal joints.ConclusionA displaced dorsal rim fracture does not appear to affect outcomes adversely after volar locking plate fixation of dorsally displaced DRFs.     

Biomechanical analysis of a novel femoral neck locking plate for treatment of vertical shear Pauwel's type C femoral neck fractures

BackgroundThe purpose of this study is to determine the biomechanical stability of a novel prototype femoral neck locking plate (FNLP) for treatment of Pauwels type C femoral neck fractures compared with other current fixation methods.MethodsForty femur sawbones were divided into groups and a vertical femoral neck fracture was made. Each group was repaired with one of the following: (CS) three parallel cancellous screws; (XCS) two cancellous lag screws into the head and one transverse lag screw into the calcar; and (FNLP) a novel FNLP with two 5.7 mm locking, one lag screw into the calcar and two screws into the shaft; and (AMBI) a two-hole, 135° AMBI plate with a derotation screw. All groups were tested for change in axial stiffness over 20 000 cycles, and rotational stiffness was measured before and after cyclic testing. A maximum load to failure test was also conducted. Results were compared with one-way analysis of variance (ANOVA) and Fisher protected least significant difference (PLSD).ResultsResults for axial stiffness show that AMBI, CS, XCS and FNLP are 2779.0, 2207.2, 3029.9 and 3210.7 N-m mm^?1, respectively. Rotational rigidity results are 4.5, 4.1, 17.1 and 18.7 N-m mm^?1. The average cyclic displacements were 0.75, 0.88, 0.80 and 0.65 mm, respectively. Destructive failure loads for AMBI, CS, XCS and FNLP were 2.3, 1.7, 1.6 and 1.9 kN, respectively.ConclusionsThe results of this experiment show statistically significant increases in axial stiffness for the FNLP compared with three traditional fixation methods. The FNLP demonstrates increased mechanical stiffness and combines the desirable features of current fixation methods.