Introduction. Ilizarov fixators are reliant on tensioned fine wires for stability. The tension in the wires is generated using specific tensioning devices. Loss of wire tension over time may lead of loss a stability and complications. A series of in vitro experiments were undertaken to explore wire tensioner accuracy, the impact of fixation bolt torque and initial tension on loss of tension in ilizarov constructs under static and dynamic loads. Materials & Methods. Medical grade materials were applied to a synthetic bone analogue using surgical instruments in all experiments. Bolt torque was fixed at 6, 10 or 14 Nm using a torque limiting wrench. Wire tension was assessed using a strain measurement bridge. Wires were tensioned to 90, 110 and 130kg as measured by a commercial dynamometric tensioner. Static and dynamic testing was undertaken using an instron testing machine. Cyclical loads from 50–750N were applied for 5000 cycles. Results. Actual wire tension was approximately 15% less than indicated by the tensioner device. Using fixation bolt torques of 10Nm and 14Nm achieved final wire tensions of around 60% and 80% of that applied at 90 and 130kg of applied tension. Static load testing demonstrated self stiffening to similar levels in all pre-tensions. Dynamic testing demonstrated significant loss of tension, most of which occured in the first 3 cycles, inversely proportional to the tension initially applied. Conclusions. These experiments provides insight into the effect of initially applied wire tension on Illizarov mechanical performance. It is important surgeons understand how the different ways that these devices are applied affects mechanical performance. Further research examining what factors affect performance across different manufacturers equipment would therefore be relevant, alongside the development of novel fixation methods to reduce wire slippage and the further development of equipment for clinical use

Background: Tension Band wiring technique is commonly used to treat transverse patella fractures. The commonly used configuration has parallel K wires and a stainless steel wire loop oriented as a figure of 8. Use of non-metallic suture materials as reliable fixation materials have been reported. We investigated the properties of composite polyester suture (Fibre wire) when used in Tension band wiring of patella. Methods: A wooden model of a transversely fractured patella was used. The fracture was fixed using two K wires and a loop of horizontally oriented stainless steel wire or fibre wire. Two wire twists placed at corners were used for SS wire loops. For fibre wire samples a tensioning device was used and the knots placed at one corner. Interfragmentary compression at the point of wire breakage and fracture displacement on physiologic cyclic loading was measured for each fixation construct. The reliability of tensioning device (Arthrex) and the effect of using multiple strands of wire were assessed. Results: Use of the tensioning device produced interfragmentary compression that could be repeated reliably. The addition of a further strand increased the interfragmentary compression developed by 94%. There was no significant difference between interfragmentary compression developed between groups (p> 0.05). The average interfragmentary compression produced for three repetitions for the individual groups, Fibre wire (1394N), SS wire of 1.0mm diameter (1320N), SS Wire of 1.25mm diameter (1594N) were comparable. This increased significantly when a second loop of fibre wire was used (2566N). Permanent fracture displacement at physiologic loads were, Fibre wire (9.7mm, SD 2.7mm), SS wire of 1.0mm diameter (7.0mm, SD 1.0mm) and SS Wire of 1.25mm diameter (7.4mm, SD 2.3mm). The addition of the second strand of fibre wire decreased the displacement significantly (4.8mm, SD 0.6mm). The effect of second strand of fibre wire decreased the displacement by 97% while the decrease on addition of the second strand of stainless steel wire was only 14%. Discussion: Interfragmentary compression produced to failure was comparable between a single strand of fibre wire, 1.0mm SS wire and 1.25mm SS wire, the commonly used SS wire diameters in fixation of fractured patella. The standard deviations of final permanent displacement were higher with the larger diameter of SS wire, indicating that the use of a thicker wire would require some preloading before it is uniformly tensioned. Amongst the SS wire diameters tested, 1.0mm resulted in least variations (SD 1.0mm). The addition of second strand resulted in a marked improvement in displacement with Fibre wire and variations between different samples were smaller than in any other group tested (SD 0.6mm). Conclusions:. Fibre wire has similar strength to failure when compared the commonly used thickness of stainless steel wire for fixation of patella. Use of tensioning device produces interfragmentary compression in a reliable and reproducible manner. The addition of second loop of fibre wire, separately tensioned results in significant improvements in interfragmentary compression and resistance against displacement

Fine-wire fixators are a powerful tool in the management of acute fractures, non-unions, mal-unions and limb lengthening. The tension in the wires is very important in achieving stiffness of the whole fixator construct and current guidelines suggests tensioning wires to 900-1275N. There is evidence that during long term use the tension in the wires can reduce significantly. The effects of a reduction in tension on the fixator stiffness has been well characterised however the effect on the stresses imparted on the bone at the interface with the wire remain unknown. The main aim of this study was to identify any relationship between wire tension and wire-bone interface pressure. An experimental system utilizing artificial cancellous bone mounted on a tensioned 2mm wire and then loaded by a material testing machine was employed. Pressure sensitive film allowed determination of interface stresses. The experiment was repeated at wire tensions of 600, 900 and 1200N. All other variables were kept the same during testing. The highest pressures were found closest to the wire. At 1200N the peak pressures were 6-8 MPa, at 900N of tension the pressures rose to 8-10 MPa and at 600N pressures up to 14 MPa were observed. Deeper in the bone the pressures observed at 600N tension were double that seen at 1200N. This is the first characterisation of the relationship between interface pressure and wire tension in fine-wire fixators. At 1200N the highest pressures are less than the compressive yield strength of cancellous bone whereas at both 600 and 900N pressures are greater than the yield which may lead to loosening. We therefore conclude that a tension of 1200N be employed when applying fine-wire fixators and during long term treatments the tensions should be regularly monitored to prevent loss of tension

Introduction. In my paediatric Orthopaedic practice I use Kirchner wires for the fixation of the TSF on bone. I noted a significant percentage of wire loosening during the post-operative period. The aim of this project was to establish the effectiveness of the wire clamping mechanism and find ways to reduce the incidence of wire loosening when using the TSF. Materials and Methods. In the first instance wire slippage was measured intra-operatively after the tensioner was removed using an intra-operative professional camera. Following this study mechanical tests were performed in the lab measuring the pull out properties of Kirchner wires using different bolts and different torque levels in order to tighten the wire on the fixator. Results. Our clinical study confirmed wire slippage intra-operatively immediately after the tensioner was removed. Wire slippage after the tensioner was removed was found to vary from 0.01 mm to 0.51 mm (mean 0.19 mm). Our mechanical tests showed that the ideal torque for tightening the wire on the frame using a bolt was around 15 N.m. A comparison between cannulated and slotted bolts suggested that cannulated bolts are more effective as a clamping mechanism. A comparison between aluminium made Taylor Spatial frame rings and stainless steel made Ilizarov rings suggested that the Taylor Spatial frame rings are more effective as part of a clamping mechanism. Conclusions. It is important that clinicians routinely measure the torque they use to clamp wires on circular external fixators. Clinicians and manufacturers are informed that the type of bolt used is important in maintaining wire tension. Manufacturers should design the ideal bolt which effectively grips the wire without the risk of fracture. The Ilizarov frame clamping mechanism can be effectively used with the Taylor Spatial frame

Introduction. During its conception, Ilizarov advocated a fine wire tension of between 900N and 1200N for circular frame construction. Wire tension can be achieved via a tensioning device or ‘Russian tensioning’ (a fixed wire lengthening around a bolt). There is limited information on the latter technique. This study aimed to explore the tensions achieved via Russian tensioning and report the impact of a second wire on construct tension. Materials and Methods. A single 160mm stainless-steel ring was constructed, then 1.8mm stainless steel wires secured using a Russian fixation bolt and Russian tensioned with a 2nd bolt. The angle subtended by tensioning using the 2nd bolt was measured using a goniometer. Angles of 45°, 70° and 90° were repeated in triplicates, with wire tension measured using a calibrated tensiometer. A 2nd orthogonal wire was placed on the opposite side and tensioned to the same angle. Tensions of both wires were remeasured and recorded. Statistical comparison using unpaired t-tests was used to compare mean tensions. A value of p<0.05 was considered significant. Results. Russian wire tensioning at all angles was insufficient to achieve the target range of 900–1200N (range 99–110N). The addition of a second orthogonal wire changed frame dynamics such that a 90° angle resulted in both wires achieving adequate tension (mean 1143N, SD 307N). Increases were significant across all tensioning angles (p–<0.002) however only biomechanically relevant for 90°. Conclusions. Russian tensioning is insufficient with a single wire, however the addition of an orthogonal wire increases tension in both wires, which reaches the target range at 90° deflection. This phenomenon is explained by force transmission initially into ring deflection, which is then balanced out by the second wire. Further study of this phenomenon using wire tensioners is warranted, and also the impact of non-orthogonal wire constructs

Gavril Ilizarov advocated a fine wire tension of between 900N and 1200N for circular frame construction. Wire tension can be achieved via a tensioning device or ‘Russian tensioning’ (a fixed wire lengthening around a bolt). There is limited information on the latter technique. This study explored the tensions achieved via Russian tensioning and reports the impact of a second wire on construct tension. A single 160mm stainless-steel ring was constructed, then 1.8mm stainless steel wires were secured using a Russian fixation bolt and Russian tensioned with a 2nd bolt. The angle subtended by tensioning using the 2nd bolt was measured using a goniometer. Angles of 45°, 70° and 90° were repeated in triplicates, with wire tension measured using a calibrated tensiometer. A second, orthogonal wire was added and tensioned to the same angle. Tensions of both wires were remeasured and recorded. Unpaired t-tests were used to compare mean tensions. A value of p<0.05 was considered significant. Tensioning at all angles was insufficient to achieve the target range of 900–1200N (range 99–110N). A second, orthogonal wire changed frame dynamics such that a 90° angle resulted in both wires achieving adequate tension (mean 1143N, SD 307N). Increases were significant across all tensioning angles (p=<0.002) however only biomechanically relevant for 90°. Russian tensioning is insufficient with a single wire, however the addition of an orthogonal wire increases tension in both wires, reaching the target range at 90° deflection. Further study using wire tensioners is warranted, and also the impact of non-orthogonal wire constructs

Securing the osteotomized greater trochanter (GT) during total hip arthroplasty (THA) for dislocated dysplastic hips (DDH) poses a significant challenge. This study evaluates the union rate and effectiveness of a 2-strand transverse wiring technique utilizing the lesser trochanter for wire anchorage and tensioning. A digastric anterior slide trochanteric osteotomy was performed in 106 patients (118 hips) undergoing THA for DDH. Following uncemented stem insertion, the GT was transferred and fixed to the lateral cortex of the proximal femur using monofilament stainless steel wires. In 72 out of 106 patients (80 hips), the GT was fixed with 2 transverse wire cerclages threaded through 2 drill holes in the base of the lesser trochanter, spaced vertically 5–10 millimeters apart. The wires were wrapped transversely over the GT and tightened, avoiding contact with its tendinous attachments. Patients were regularly monitored, and GT union was assessed clinically and radiographically. Patient ages ranged from 20 to 57 years (mean 35.5), with a follow-up period ranging from 1.5 to 12 years (mean 6.2). The mean union time was 3.3 months (range 2–7). Among all hips, two developed stable nonunion and single wire breakage, but no fragment displacement (2.5%). Two hips exhibited delayed union, eventually healing at 6 and 7 months after surgery. Reattachment of the greater trochanter utilizing a 2-strand transverse wire cerclage anchored at the base of the lesser trochanter demonstrated a high rate of union (97.5%) following THA in dislocated DDH cases

Aims. The primary aim of this study was to report the radiological outcomes of patients with a dorsally displaced distal radius fracture who were randomized to a moulded cast or surgical fixation with wires following manipulation and closed reduction of their fracture. The secondary aim was to correlate radiological outcomes with patient-reported outcome measures (PROMs) in the year following injury. Methods. Participants were recruited as part of DRAFFT2, a UK multicentre clinical trial. Participants were aged 16 years or over with a dorsally displaced distal radius fracture, and were eligible for the trial if they needed a manipulation of their fracture, as recommended by their treating surgeon. Participants were randomly allocated on a 1:1 ratio to moulded cast or Kirschner wires after manipulation of the fracture in the operating theatre. Standard posteroanterior and lateral radiographs were performed in the radiology department of participating centres at the time of the patient’s initial assessment in the emergency department and six weeks postoperatively. Intraoperative fluoroscopic images taken at the time of fracture reduction were also assessed. Results. Patients treated with surgical fixation with wires had less dorsal angulation of the radius versus those treated in a moulded cast at six weeks after manipulation of the fracture; the mean difference of -4.13° was statistically significant (95% confidence interval 5.82 to -2.45). There was no evidence of a difference in radial shortening. However, there was no correlation between these radiological measurements and PROMs at any timepoint in the 12 months post-injury. Conclusion. For patients with a dorsally displaced distal radius fracture treated with a closed manipulation, surgical fixation with wires leads to less dorsal angulation on radiographs at six weeks compared with patients treated in a moulded plaster cast alone. However, the difference in dorsal angulation was small and did not correlate with patient-reported pain and function. Cite this article: Bone Jt Open 2024;5(2):132–138

Previous studies have highlighted differences in the risk of periprosthetic fracture between tapered slip (TS) and composite beam (CB) stems. This biomechanical study explored periprosthetic fractures around these stems and the effect of adding a 16-gauge calcar or diaphyseal wire to TS stems on their resistance to torque. A power analysis determined a sample size of 7 specimens per group, assuming a standard deviation of 14.8 Nm in peak torque, to provide 90% power to detect a difference of at least 30 Nm between groups. Twenty-one TS stems (eight alone, six with calcar wiring, seven with diaphyseal wiring placed 2 cm distal to the lesser trochanter) and seven CB stems were cemented into standard Sawbones. A servo-hydraulic test machine applied a 1000 N load with a 1-degree rotation per second until failure. The peak torque at failure was measured, and the fracture location recorded. Comparisons were performed using two-sample t-tests. CB stems exhibited a significantly higher peak torque at failure (205.3 Nm) than TS stems (159.5 Nm, p=0.020). Calcar-wire-TS (148.2 Nm, p=0.036) and diaphyseal-wire-TS (164.9 Nm, p=0.036) were both weaker than CB stems. Wired-TS stems showed no significant difference from non-wired-TS stems. Additionally, the study could not conclude that calcar wiring is stronger than diaphyseal wiring. All TS fractures occurred at the mid-stem, simulating a B-type fracture, while the addition of the diaphyseal wire shifted the fracture location more distally in four of seven stems (p=0.0699). This biomechanical study supports the clinical evidence that CB stems have stronger resistance to torque than TS stems and may explain lower risk of periprosthetic fracture. The addition of calcar or diaphyseal wires to TS stems resulted in no significant changes in peak torque to fracture. In patients at high risk of periprosthetic fracture, CB cemented stems should be considered

Introduction. Critical limb ischemia (CLI) is the reduced blood flow in the arteries of the lower extremities. It is a serious form of peripheral arterial disease, or PAD. If left untreated the complications of CLI will result in amputation of affected limb. The treatment experience of diabetic foot with transverse tibial transport was carried out by Ilizarov technique. Madura foot ulcer is not a common condition. It disturbs the daily activities of the patient. Pain swelling with multiple nodules with discharging sinus with discoloration(blackening) of the affected area is the main problem. Materials and Methods. We treated total case: 36 from Jan. 2003 – Jan. 2020 (17yrs.). Among these-. TAO- 20. Limb Ishchemia- 5. Diabetic Foot- 9. Mycetoma pedis- 2. Infected sole and dorsum of the foot- 5. Results. Transverse corticotomy and wire technique followed by distraction increases blood circulation of the lower limbs, relieving the pain. The cases reported here were posted for amputation by the vascular surgeons, who did not have any other option for treatment. Hence we, re-affirm that Academician Prof. Ilizarov's method of treatment does help some patients suffering from these diseases. Conclusions. By Ilizarov compression distraction device for TAO, modura foot ulcer, diabetic foot ulcer, mycetoma pedis ulcer, infected sole and dorsum of the foot ulcer were treated by introducing K/wires through the bones with proper vertical corticotomy. Application of this noble device will bring angeogenesis within the reach of all deserving patients

Abstract. Objectives. The aim of this work was to compare the different techniques and the different fluid permeability of the tissue following each technique through assessing the flow of radiopaque contrast agent using μCT image analysis and 3D modelling. Methods. Donated human tali specimens (n=12) were prepared through creating a 10mm diameter chondral defect in three different regions of each talus. Each region then underwent one of three surgical techniques: 1) Fine wire drilling, 2) Nanofracture or 3) Microfracture, equidistant sites in each defect to ensure even distribution. Each region then had an addition of 0.1 ml radiopaque contrast agent (Omnipaque™ 300), imaged using a clinical μCT scanner (SCANCO Medical AG, 73.6 μm resolution). Each μCT scan was segmented using Slicer 3D software (The Slicer Community, 2023 3D Slicer (5.2.2)). The segmentation package was used to segment the bone and contrast agent regions in each different surgical site of each sample. Each defect site was created into a cylinder and the ratio of segmented pixels of contrast agent against bone. Results. The μCT analysis indicated that across the 12 samples, eight nanofracture regions demonstrated flow of the contrast agent either to the depth of the fracture site or deeper. Some lateral flow was also observed in these sites. eight microfracture regions demonstrated that the flow of the contrast agent was localised to the fracture site and a preferential flow laterally. In only one sample, did a fine wire drilling region demonstrate any fluid flow. In this sample, contrast agent had permeated through the drilling site to the bottom and some sub-site permeation was observed. However, in all samples that showed no permeation of contrast agent through the fracture site, a layer of contrast agent on the chondral surface or minor permeation through to the sub-chondral surface. Segmentation of each sample site showed a significant increase (n=12, p<0.05) in fluid flow of the contrast agent in the nanofracture sites (11%) compared to microfracture (5%) and fine wire drilling (2%). Conclusions. Nanofracture showed significantly improved fluid permeability throughout the surrounding trabecular structure, when compared to microfracture and fine wire drilling. Microfracture appears to allow some fluid flow, but only confined to the immediate area around the fracture site, while fine wire drilling appears to allow a comparably small amount, if not no fluid flow through the surrounding trabecular tissue. This conclusion is reinforced by previous literature that concluded the damage to the structure of the trabecular tissue is reduced when using nanofracture, compared to the other two techniques. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Objectives: To develop a non-invasive method to assess the wire tension quantitatively which can be used in clinic. Background: Fine-wire external fixators are widely used in the fixation of fractures and limb reconstruction. A requirement of stable fixation is that the wires maintain their tension. Recent lab tests have shown that substantial reduction in wire tension occurred during the simulated operative procedures. Clinical experience also indicated that wire site discomfort might be related to loss in wire tension. It would be very helpful if the wire tension could be assessed quantitatively by a non-invasive method. Methods: An apparatus based on a LVDT (Linear Variable Differential Transformer) was developed to apply a constant transverse force to a wire and measure its deflection with respect to another parallel wire. An unstable oblique fracture was created in a Sawbones tibia and stabilized by a Sheffield Ring Fixator. The deflection of the testing wire was measured in four tests: (1) Two parallel wires fixation, tensioned reference wire, variable clamp to bone distance; (2) Two parallel wires fixation, loose reference wire, 80mm clamp-bone distance. (3) Two groups of parallel wires fixation with 70° crossing angle, tensioned reference wire, 80mm clamp-bone distance; (4) Two groups of parallel wires fixation with 70° crossing angle, tensioned reference wire, 80mm clamp-bone distance, osteotomy site fixed with a lag screw to simulate a stable fracture or a healing fracture. Fracture stiffness in the above conditions was derived from previous work. Stepwise multiple variable regression analyses were performed to determine the relationship between wire deflection and wire tension, clamp-bone distance, number of wires, reference wire tension, and fracture stiffness. Results: The reference wire tension and fracture stiffness was excluded from the regression equation, indicating that they did not affect the wire deflection. The regression equation containing only the testing wire tension had an adjusted R-square value of 0.521, while the equation containing the testing wire tension and clamp-bone distance had the R-square values of 0.854. The addition of the number of wires to the regression equation resulted in a slight increase of the R-square value (0.862). Conclusion: The wire deflection and the clamp-bone distance are the two most important factors that affect wire deflection. The measurement of wire deflection has the potential to predict wire tension and the effect of clamp-bone distance must be considered. Further work is required to refine the apparatus for clinical use

Aim. To evaluate bacterial adhesion and biofilm formation to metallic cerclage wire versus polymer cerclage system (SuperCable®). Methods. Experimental in vitro study to evaluate quantitative bacterial adherence to different cerclage wire materials. Two types of cerclage wires were compared: a metallic versus a polymer based wire (SuperCable®). A two-centimeter cerclage wire piece of each material was included in 2 mL of tryptic soy broth (TSB) culture media, inoculated with 10 microliters of a 0.5 McFarland of a Staphylococcus epidermidis strain and cultivated at 37°C during 2h for adhesion and 48h for biofilm formation. After this time, the cerclages were washed using a 1% phosphate buffered saline (PBS) and sonicated in new culture medium. After sonication, dilutions of each culture were spread in TSB agar and incubated 37°C during 24h. The number of colonies were counted and the cfu/cm2 was calculated. Results. There were no differences in the number of colonies counted at 2 hours. At 48 hours, the polymer cerclage system showed a clinically and statistically reduction of 95.2% in the biofilm formation of S. epidermidis. The highest bacterial counts were observed in metallic cerclages after 48h. Conclusion. In in vitro conditions, the polymer cerclage system may offer decreased biofilm formation compared with metallic cerclage wires. However, there are many other factors in in vivo conditions that could play a role in bacterial adhesion to cerclage wires. Further research is needed in order to recommend the use of polymer cerclage systems for septic revision surgery

Introduction: During hip stem revisions osteotomies allow to remove well-fixed components. Once removal has been done, cerclage wires should secure the osteotomy and support primary stability of the new stem. Stability is important for a bony ingrowth and therefore the longevity of a cementless revision stem. Tension wires seem to dominate revision surgery and studies only refer to the advantages of cable wires in general. This in-vitro study analyzed the infiuence of both, tension and cable wires on primary stability of cementless revision stems. We aimed to examine the effectivity of wiring a femoral osteotomy, differences achieved with each method, and whether one wire has advantages regarding the fixation concepts of revision stems (meta- and diaphyseal). Methods: We studied a Ti-tension- and a CoCrWNi-cable-wire. The Helios-stem stood for the meta- and the Wagner-SL-stem for the diaphyseal fixation concept. Each stem was implanted into 3 synthetic femurs and a standardized extended proximal femoral osteotomy was performed. Spatial movements of bones and stems at several sites were explored under axial torques using a high-resolution measuring device. Movement graphs subjected to the sites defined relative movements RM = ΔαZ/TZ [mdeg/Nm]. The osteotomies were locked consecutively with both wires and all compounds were measured again. Wiring was done by a proximal figure 8 and a diaphyseal circular loop. Results: Compared to the unlocked osteotomy the tension as well as the cable wires caused a changed RM for the stems (p=0.03). Both wires affect an increased stability within the proximal main fixation area of the Helios. Even for the Wagner-SL, usually fixating diaphyseally, a proximal fixation was reached with both wires. A significantly better stabilization could be observed for the Helios using cable wires (p=0.04). The overall RM reached with tension and cable wires was 16.6 and 11.1 mdeg/Nm. The Wagner-SL. ®. showed no difference in stability between tension and cable wire treatment (p=0.29). Discussion: Both, the tension and the cable wires support the revision stems in bridging the artificial defect of an extended proximal femoral osteotomy. Especially for the proximal fixating stem, RMs could largely be reduced, while cable wires seem to be advantageous. Preventing a circular constriction leading to an osseous malnutrition, the use of cable wires, however, should be impeded with regard to diaphyseal fixating stems and proximal osteotomies. Comparable results with both wires were reached and none of the wires showed any advantage in this situation. In conclusion, the wires should be chosen depending on the fixation concept of the revision stem

A fluoroscopic based computer enhancement system was designed for accurate insertion of guide wires for hip fracture fixation while decreasing fluoroscopy time. A saw bone model was created. The femur was imaged with fluoroscopy and a three-dimensional computer model was created. The femur, fluoroscopy drum, and drill were tracked with an optical tracking device. Guide wire position was planned on the computer model. Using a tracked drill the guide wire was inserted. The number of fluoroscopic images was decreased by 85% and the number of passes required to place the guide wire in acceptable position was decreased by 60% using computer enhanced technique. A fluoroscopic based computer enhancement system was designed for accurate insertion of guide wires for hip fracture fixation while decreasing fluoroscopy time. The number of fluoroscopic images and passes required to place the guide wire in acceptable position were decreased using computer enhanced technique. Final guide wire position was not different between the two groups. Orthopedic surgeons are exposed to radiation from fluoroscopy on a daily basis. This system allowed us to insert guide wires using substantially less fluoroscopy, without compromising accuracy. An average of 13.5 images were taken for each standard technique trial compared to two images for each computer enhanced trial, representing a reduction in fluoroscopy of 85%. One pass was used for each computer enhanced trial. An average of 2.4 trials was used for standard technique. Average final error was 3.6mm using standard technique and 3.8mm using computer technique. A saw bone model with a soft tissue sleeve was created. A DRB (dynamic referencing body) was fixed to the femur. The DRB, fluoroscopy drum, and drill were tracked with an optical tracking device. The system created a 3D model from two orthogonal fluoroscopic images. Guide wire position was then planned on the computer model. Using a tracked drill the guide wire was inserted. Computer enhanced trials were compared to standard techniques in regards to number of fluoroscopic images taken, number of trials to obtain acceptable guide wire position, and accuracy of guide wire placement. Guide wire position was measured on AP and lateral x-rays. Funding: This project was funded in part through a grant from the Canadian Foundation for Innovation

Introduction. Direct lateral approaches to the hip require detachment and repair of the anterior part of the gluteus medius and minimus tendon attachments. Limping may occur postoperatively due to nerve injury or failure of muscle re-attachment. The aim of this study was to assess the integrity of abductor muscle repairs using a braided wire suture marker. Methods. Total hip arthroplasties were inserted using a modified Freeman approach. After repair of the abductor tendons using a 1 PDS suture with interlocking Kessler stitches, a 3–0 braided wire suture marker was stitched into the lower end of the flap. The suture was easily visible on postoperative radiographs and its movement could be measured. Patients were assessed using radiographs and Oxford hip scores collected prospectively. Results. 56 joint replacements were performed in 51 patients with no major surgical complications. Mean age was 65 yr and 80% (n=41) were female. It proved possible to reproducibly classify repairs based on radiographic measurements as: no wire movement (43%); repair stretched, moving cephalad a short distance (46%); repair detached, moving cephalad a significant distance (11%). Risk of failure of the repair had no relationship with age, preoperative Oxford hip score, or postoperative Oxford hip score. The mean Oxford hip score drop in the no movement group was 36%, the stretched group 37%, and the detached group 33%. These differences were not significant. Discussion/Conclusion. The wire marker proved to be a revealing method of auditing abductor repair following hip arthroplasty. No difference was demonstrated in outcome in relation to wire movement, therefore this study did not show any advantage from a careful repair technique. Due to the small number of failed repairs there may be a type II error. This method may also be useful in assessing the integrity of other large tendon repairs, such as quadriceps tendons splits in total knee replacements

Background:. Potential injury to the common peroneal nerve at the level of the fibula head/neck junction during fine wire insertion in stabilization of proximal fibula, is a recognised complication. This study aims to relate the course of the common peroneal nerve to fibula head transfixion wire. Methods:. Standard 1.8mm Ilizarov wires were inserted percutaneously in the fibula head of cadaveric knees. The course of the common peroneal nerve was dissected calculating wire to nerve distance. Results:. The common peroneal nerve was seen to cross the neck of fibula at a mean distance of 34.8mm from the tip of fibula (range 21.5–44.3mm). Wire placement was found to be on average, 52% of the maximal AP diameter of the fibula head and 64% of the distance from tip of fibula to the point of nerve crossing fibula neck. Conclusion:. When inserting a fibula head transfixion wire, care must be taken not to place wire entry point too distal or posterior on the fibula head. Observing a safe zone in the anterior half of the proximal 20mm of the fibula head would avoid injury to the nerve. In cases where palpation of fibula is difficult, we recommend wire insertion under fluoroscopic guidance

Percutaneous wiring is a successful technique for the management of distal radial fractures. Practice differs according to surgeon preference as to whether the wires used are buried or protruding. To assess patient satisfaction with wither technique, we prospectively randomised 52 consecutive patients undergoing percutaneous wiring for distal radius fractures with regard to whether the wires were buried or not. Patients with a distal radial fracture managed with percutaneous wire fixation and casting only were randomly allocated to have the wires buried or protruding. The fractures were classified according to Frykmn’s classification of fractures of the distal radius, and there were no differences between the groups (p=0.9). The total number of patients studied was 52, with a mean age of 56.6 years (range 19–84). The female: male ratio was 38:13. Twenty-five (48%) patients had percutaneous wiring of their fracture with the Kirschner wires buried and 27 (52%) had the wires protruding. Cast and wire fixation were removed at a mean duration of 5.8 weeks in an outpatient setting. Patients recorded whether they experienced pain during the period of wire fixation or pain during the removal of wires on a visual analogue scale. Fifteen patients reported pain during the period of fixation (55.5%), the severity ranged between 2–8 (mean 3.8) with no significant difference between the groups (p=0.8). All patients with buried wires compared with 10% of those protruding wires required local anaesthesia in the operating theatre for removal (p=0.03). Superficial infection was diagnosed in 4 patients with no significant difference between groups (p=0.14). Buried wires are typically advocated to prevent pin site infections and to improve patient comfort and satisfaction. However, we found no difference between the study groups with regard to patient satisfaction, pain during the period of fixation or pin-site infections. Furthermore, all patients in the buried wire group required local anaesthesia for removal with some of these necessitating a visit to the operating theatre. We therefore feel that burying these wires confers no advantage while adding to the complexity, time and cost of removal and recommend leaving wires protruding through the skin

Introduction. Circular frame fixation has become a cornerstone of non-union and deformity management since its inception in the 1950s. As a consequence of modularity and heterogenous patient and injury factors, the prediction of the mechanobiological environment within a defect is subject to wide variations in practice. Given these wide range of confounding variables, clinical and cadaveric experimentation is close to impossible and frame constructs are based upon clinician experience. The Finite Element Analysis (FEA) method provides a powerful tool to numerically analyse mechanics. This work aims to develop an FEA model of a tibial defect and predict the mechanical response within the construct. Materials and Methods. The geometry of a tibia was acquired via CT and a series of bone defects were digitally created in the tibial diaphysis. A 4-ring, 10-wire Ilizarov fixator was constructed using 180mm stainless steel rings and 1.8mm stainless steel wires tensioned to 1200N. An axial load (800N) was applied to simulate single leg stance of an 80kg patient. The magnitude of displacement was measured for defects with varying sizes (5–40mm). A numerical analysis was performed in large-strain regime using open-source FEA library (MoFEM). Results. Defect size did not effect displacement, but significantly influenced strain. Measured displacements were 5.72–5.78mm, however strain ranged from 14.5–100%. Moreover, it was found that bone material properties also have no significant impact on the results. Conclusions. Accounting for FEA assumptions, this model predicted a strain environment which was above expected favourable range for bone healing. The addition of graft within the environment is likely to change the mechanobiological environment which warrants further investigation. We plan to develop this model to answer further research questions in the limb reconstruction discipline and validate its accuracy with mechanical data. We believe the presented approach can be a useful tool for investigating the performance circular frames

Wire crossing angle affects the stability of circular fine wire frames. Anatomical atlases document safe ‘corridors’ to avoid neurovascular structures, although this may limit crossing angle. In the distal tibia the furthest posteriolateral safe corridor described is through the fibula. The present study describes a new and safe ‘retro-fibular’ corridor for wire placement in the distal tibia that provides a greater crossing angle. Two different methods of wire insertion are considered to determine which provides greater protection to neurovascular structures. A dissection based study of 20 embalmed lower limbs divided into two groups. 1.8mm wires were inserted at increments along the tibia, from posterolateral to antero-medial, at 30–45 degrees to the sagittal plane. In the first group wires were placed against the posterior surface of the fibula and ‘stepped’ medially onto the tibia. In the second wires were inserted midway between the border of the fibula and tendoachilles. Standard dissection techniques were used to identify the path of wires and distance from neurovascular structures. In group one distal tibial wires avoided the posterior tibial neurovascular bundle (mean distance 21.7mm) although passed close to the peroneal artery (mean distance 1.2mm). In group two both the posterior tibial and peroneal structures were avoided (mean distances 15.5mm and 7.1mm respectively). Comparison of the two groups shows a significant difference (p< 0.001). Retrofibular wire placement is safe in the distal quarter of the tibia and facilitates an optimal crossing angle, although is not described in standard atlases. Insertion of wires mid-way between the posteromedial border of the fibula and the tendoachilles appears the most reliable technique