Anatomical atlases document safe corridors for placement of wires when using fine-wire circular external fixation. The furthest posterolateral corridor described in the distal tibia is through the fibula. This limits the crossing angle and stability of the frame. In this paper we describe a new, safe Retro-Fibular Wire corridor, which provides greater crossing angles and increased stability. In a cadaver study, 20 formalin-treated legs were divided into two groups. Wires were inserted into the distal quarter of the tibia using two possible corridors and standard techniques of dissection identified the distance of the wires from neurovascular structures. In both groups the posterior tibial neurovascular bundle was avoided. In group A the peroneal artery was at risk. In group B this injury was avoided. Comparison of the groups showed a significant difference (p < 0.001). We recommend the Retro-Fibular wire technique whereby wires are inserted into the tibia mid-way between the posteromedial border of the fibula and the tendo Achillis, at 30° to 45° to the sagittal plane, and introduced from a posterolateral to an anteromedial position. Subsequently, when using this technique in 30 patients, we have had no neurovascular complications or problems relating to tethering of the peroneal tendons

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

Using an osteotomy of the olecranon as a model of a transverse fracture in 22 cadaver elbows we determined the ability of three different types of suture and stainless steel wire to maintain reduction when using a tension-band technique to stabilise the bone. Physiological cyclical loading simulating passive elbow movement (15 N) and using the arms to push up from a chair (450 N) were applied using an Instron materials testing machine whilst monitoring the osteotomy site with a video extensometer. Each osteotomy was repaired by one of four materials, namely, Stainless Steel Wire (7), No 2 Ethibond (3), No 5 Ethibond (5), or No 2 FiberWire (7). There were no failures (movement of > 2 mm) with stainless steel wire or FiberWire and no significant difference in the movements measured across the site of the osteotomy (p = 0.99). The No. 2 Ethibond failed at 450 N and two of the five of No. 5 Ethibond sutures had a separation of > 2 mm at 450 N. FiberWire as the tension band in this model held the reduction as effectively as stainless steel wire and may reduce the incidence of discomfort from the hardware. On the basis of our findings we suggest that a clinical trial should be undertaken

INTRODUCTION. Growth-guidance constructs are an alternative to growing rods for the surgical treatment of early onset scoliosis (EOS). In growth-guidance systems, free-sliding anchors preserve longitudinal spinal growth, thereby eliminating the need for surgical lengthening procedures. Non-segmental constructs containing ultra-high molecular weight polyethylene (UHMWPE) sublaminar wires have been proposed as an improvement to the traditional Luque trolley. In such a construct, UHMWPE sublaminar wires, secured by means of a knot, serve as sliding anchors at the proximal and distal ends of a construct, while pedicle screws at the apex prevent rod migration and enable curve derotation. Ideally, a construct with the optimal UHMWPE sublaminar wire density, offering the best balance between providing adequate spinal fixation and minimizing surgical exposure, is designed preoperatively for each individual patient. In a previous study, we developed a parametric finite element (FE) model that potentially enables preoperative patient-specific planning of this type of spinal surgery. The objective of this study is to investigate if this model can capture the decrease in range of motion (ROM) after spinal fixation as measured in an experimental study. MATERIALS AND METHODS. In a previous in vitro study, the ROM of an 8-segment porcine spine was measured before and after instrumentation, using different instrumentation constructs with a sequentally decreasing number of wire fixation points. In the current study, the parametric FE model of the thoracolumbar spine was first validated relative to ROM values reported in the literature. The rods, screws, and sublaminar wires were implemented, and the model was subsequently used to replicate the in vitro tests. The experimental and simulated ROM”s for the different instrumentation conditions were compared. RESULTS. Good agreement between in vitro biomechanical tests and FE simulations was observed in terms of the decrease in ROM for the complete construct with wires at each level. The stepwise increase in total ROM with decreasing number of wires at the construct ends was less prominent in silico in comparison to in vitro. CONCLUSION. Important first steps in the implementation and validation of a growth-guidance construct for EOS patients in a patient-specific FE model of the spine have been made in this study. The parametric nature of the FE model allows for rapid personalization. Although further improvements to the model will be necessary to better distinguish between different spinal instrumentation constructs, we conclude that the model can well capture essential aspects of spinal motion and the overall effect of instrumentation

Introduction. The use of the dynamic hip screw is common practice for the fixation of intertrochanteric fractures of the femur. The success of this procedure requires accurate guide wire placement. This can prove difficult at times and can result in repeated attempts leading to longer operating time, multiple tracks and more importantly greater radiation exposure to both patient and operating staff. We hypothesised that rather than using the standard anterior-posterior projected image (Figure 1) of a proximal femur, rotating the intensifier image (Figure 2) so that the guide wire appears to pass vertically makes it easier to visualise the projected direction of the guide wire. Methods. Fifty Specialist Registrars, thirty participating in the London hip meeting 2009, ten from Oxford and ten from Northern deanery orthopaedic rotations were involved in the study. They were presented with standard AP and rotated images of the femoral neck on paper using 135 degree template to replicate the DHS guide. The participants were asked to mark the entry point on the intertrochanteric area of femur on the image where they would have placed the guide wire. They did this on both standard AP and rotated images aiming for the centre of the head of the femur. Fig. 1 Standard AP image Fig. 2 Rotated image. Results. Thirty-seven Specialist Registrars (74%) were able to accurately mark their entry point on rotated images on their first attempt as compared to eighteen trainees (36%) managing to place it correctly first time on the standard image. Thirteen trainees (26%) were able to mark their entry point correctly on both standard AP and rotated images with equal accuracy. Conclusion. Coren et al. 1 argue that human vision can more easily judge horizontal and vertical lines rather than oblique lines. Thus, rather than use the standard anterior-posterior projected image of the hip, we should routinely rotate the intensifier image so that the guide wire appears to be passing in a vertical direction. By rotating the image (Figure 2) in this way it becomes significantly easier to visualise the projected direction of the guide wire and in doing so ensure its accurate final placement thereby minimising possible complications

The patella is an important component of the extensor mechanism of the knee. Patellar fractures need to be fixed if displacement occurs more than 2 mm. Transverse fractures comprise the largest category. Several different techniques for internal fixation have been employed. The aim of this work was to evaluate the results of treatment of transverse patellar fractures with figure of eight wiring through cannulated screws. Twenty patients were included in the study, all suffering from displaced transverse patellar fractures. All were treated by open reduction and internal fixation with figure of eight tension band wire through 4.0 mm cannulated screws. All patients were assessed after 1 month, 3 months and 6 months according to a modified Hospital for special surgery (HSS) knee scoring system. Because varus and valgus knee alignment and stability are not affected by patellar fracture fixation, the ten points assigned to these functions are eliminated, making the highest score ninety points. Excellent results are considered with points from 75 to 90, good from 60 to 74, fair from 50 to 59 and poor with points below 50. The final results of the study showed fourteen patients (70%) had excellent results, five (25%) good result, one (5%) fair result and no patient had a poor result. There was a statistically significant improvement of the patients' score throughout the follow up period. The complications occurred included knee pain in one patient (5%), loss of terminal flexion of knee occurred in three patients (15%), one patient lost 30 degrees, another lost 20 degrees while the last lost 10 degrees. There were no cases with extension lag in this series. Treatment of patellar fractures using figure of eight wiring through cannulated screws is an easy technique which gives good stability leading to good results with a low complication rate

Our aim was to ascertain if K-wire configuration had any influence on the infection and complication rate for base of 4th and 5th metacarpal fractures. We hypothesised that in individuals whose wires crossed the 4th and 5th carpometacarpal joint (CMCJ), the rate of complications and infection would be higher. Data was retrospectively analysed from a single centre. 106 consecutive patients with a base of 5th (with or without an associated 4th metacarpal fracture) were analysed between October 2016 and May 2021. Patients were split into two groups for comparison; those who did not have K-wires crossing the CMCJ's and those in whose fixation had wires crossing the joints. Confounding factors were accounted for and Statistical analysis was performed using SPSS version 20 software. Of 106 patients, 60 (56.6%) patients did have K-wires crossing the CMCJ. Wire size ranged from 1.2-2.0 with 65 individuals (65.7%) having size 1.6 wires inserted. The majority of patients, 66 (62.9%) underwent fixation with two wires (range 1-4). The majority of infected cases (88.9%) were in patients who had k-wires crossing the CMCJ, this trended towards clinical significance (p=0.09). Infection was associated with delay to theatre (p=0.002) and longer operative time (p=0.002). In patients with a base of 4th and 5th metacarpal fractures, we have demonstrated an increased risk of post-operative infection with a K-wire configuration that crosses the CMCJ. Biomechanical studies would be of use in determining the exact amount of movement across the CMCJ, with the different K-wire configuration in common use, and this will be part of a follow-up study

Intraoperative fractures although rare are one of the complications known to occur while performing a total hip arthroplasty (THA). However, due to lower incidence rates there is currently a gap in this area of literature that systematically reviews this important issue of complications associated with THA. Method: We looked into Electronic databases including PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), the archives of meetings of orthopaedic associations and the bibliographies of included articles and asked experts to identify prospective studies, published in any language that evaluated intra-operative fractures occurring during total hip arthroplasty from the year 1950-2020. The screening, data extraction and quality assessment were carried out by two researchers and if there was any discrepancy, a third reviewer was involved. Fourteen studies were identified. The reported range of occurrence of fracture while performing hip replacement surgery was found to be 0.4-7.6%. Major risk factors identified were surgical approaches, Elderly age, less Metaphyseal-Diaphyseal Index score, change in resistance while insertion of the femur implants, inexperienced surgeons, uncemented femoral components, use of monoblock elliptical components, implantation of the acetabular components, patients with ankylosing spondylitis, female gender, uncemented stems in patients with abnormal proximal femoral anatomy and with cortices, different stem designs, heterogeneous fracture patterns and toothed design. Intraoperative fractures during THA were managed with cerclage wire, femoral revision, intramedullary nail and cerclage wires, use of internal fixation plates and screws for management of intra operative femur and acetabular fractures. The main reason for intraoperative fracture was found to be usage of cementless implants but planning and timely recognition of risk factors and evaluating them is important in management of intraoperative fractures. Adequate surgical site exposure is critical especially during dislocation of hip, reaming of acetabulum, impaction of implant and preparing the femoral canal for stem insertion. Eccentric and increased reaming of acetabulum to accommodate a larger cup is to be avoided, especially in females and elderly patients as the acetabulum is thinner. However, this area requires more research in order to obtain more evidence on effectiveness, safety and management of intraoperative fractures during THA

Abstract. Approximately 20% of primary and revision Total Knee Arthroplasty (TKA) patients require multiple revisions, which are associated with poor survivorship, with worsening outcomes for subsequent revisions. For revision surgery, either endoprosthetic replacements or metaphyseal sleeves can be used for the repair, however, in cases of severe defects that are deemed “too severe” for reconstruction, endoprosthetic replacement of the affected area is recommended. However, endoprosthetic replacements have been associated with high complication rates (high incidence rates of prosthetic joint infection), while metaphyseal sleeves have a more acceptable complication profile and are therefore preferred. Despite this, no guidance exists as to the maximal limit of bone loss, which is acceptable for the use of metaphyseal sleeves to ensure sufficient axial and rotational stability. Therefore, this study assessed the effect of increasing bone loss on the primary stability of the metaphyseal sleeve in the proximal tibia to determine the maximal bone loss that retains axial and rotational stability comparable to a no defect control. Methods. to determine the pattern of bone loss and the average defect size that corresponds to the clinically defined defect sizes of small, medium and large defects, a series of pre-operative x-rays of patients with who underwent revision TKA were retrospectively analysed. Ten tibiae sawbones were used for the experiment. To prepare the bones, the joint surface was resected the typical resection depth required during a primary TKA (10mm). Each tibia was secured distally in a metal pot with perpendicular screws to ensure rotational and axial fixation to the testing machine. Based on X-ray findings, a fine guide wire was placed 5mm below the cut joint surface in the most medial region of the plateau. Core drills (15mm, 25mm and 35mm) corresponding to small, medium and large defects were passed over the guide wire allowing to act at the centre point, before the bone defect was created. The test was carried out on a control specimen with no defect, and subsequently on a Sawbone with a small, medium or large defect. Sleeves were inserted using the published operative technique, by trained individual using standard instruments supplied by the manufacturers. Standard axial pull-out (0 – 10mm) force and torque (0 – 30°) tests were carried out, recording the force (N) vs. displacement (mm) curves. Results. A circular defect pattern was identified across all defects, with the centre of the defect located 5mm below the medial tibial base plate, and as medial as possible. Unlike with large defects, small and medium sized defects reduced the pull-out force and torque at the bone-implant interface, however, these reductions were not statistically significant when compared to no bony defect. Conclusions. This experimental study demonstrated that up to 35mm radial defects may be an acceptable “critical limit” for bone loss below which metaphyseal sleeve use may still be appropriate. Further clinical assessment may help to confirm the findings of this experimental study. This study is the first in the literature to aim to quantify “critical bone loss” limit in the tibia for revision knee arthroplasty. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Currently, between 17% of patients undergoing surgery for adult spinal deformity experience severe instrumentation related problems such as screw pullout or proximal junctional failure necessitating revision surgery. Cables may be used to reinforce pedicle screw fixation as an additive measure or may provide less rigid fixation at the construct end levels in order to prevent junctional level problems. The purpose of this study is to provide insight into the maximum expected load during flexion in UHMWPE cable in constructs intended for correction of adult spine deformity (degenerative scoliosis) in the PoSTuRe first-in-man clinical trial. Following the concept of toppinoff, a new construct is proposed with screw/cable fixation of rods at the lower levels and standalone UHMWPE cables at the upper level (T11). A parametric FE model of the instrumented thoracolumbar spine, which has been previously validated, was used to represent the construct. Pedicle screws are modeled by assigning a rigid tie constraint between the rod and the lamina of the corresponding spinal level. Cables are modeled using linear elastic line elements, fixing the rod to the lamina medially at the cranial laminar end and laterally at the caudal laminar end. A Youngs modulus was assigned such that the stiffness of the line element was the same as that of the cable. An 8 Nm flexion moment was applied to the cranial endplate. The maximum value of the force in the wire (80 N) is found at the T11 (upper) level. At the other levels, forces in the cable are very small because most of the force is carried by the screw (T12) or because the wires are force shielded by the contralateral and adjacent level pedicle screws (L2, L3). The model provides first estimates of the forces that can be expected in the UHMWPE cables in constructs for kyphosis correction during movement. It is expected that this approach can help in defining the number of wires for optimal treatment

Treatment of bone infection often includes a burdensome two-stage revision. After debridement, contaminated implants are removed and replaced with a non-absorbable cement spacer loaded with antibiotics. Weeks later, the spacer is exchanged with a bone graft aiding bone healing. However, even with this two-stage approach infection persists. In this study, we investigated whether a novel 3D-printed, antibiotic-loaded, osteoinductive calcium phosphate scaffold (CPS) is effective in single-stage revision of an infected non-union with segmental bone loss in rabbits. A 5 mm defect was created in the radius of female New Zealand White rabbits. The bone fragment was replaced, stabilized with cerclage wire and inoculated with Staphylococcus aureus (MSSA). After 4 weeks, the infected bone fragment was removed, the site debrided and a spacer implanted. Depending on group allocation, rabbits received: 1) PMMA spacer with gentamycin; 2) CPS loaded with rifampin and vancomycin and 3) Non-loaded CPS. These groups received systemic cefazolin for 4 weeks after revision. Group 4 received a loaded CPS without any adjunctive systemic therapy (n=12 group1-3, n=11 group 4). All animals were euthanized 8 weeks after revision and assessed by quantitative bacteriology or histology. Covariance analysis (ANCOVA) and multiple regression were performed. All animals were culture positive at revision surgery. Half of the animals in all groups had eliminated the infection by end of study. In a historical control group with empty defect and no systemic antibiotic treatment, all animals were infected at euthanasia. There was no significant difference in CFU counts between groups at euthanasia. Our results show that treating an osteomyelitis with segmental bone loss either with CPS or PMMA has a similar cure rate of infection. However, by not requiring a second surgery, the use of CPS may offer advantages over non-resorbable equivalents such as PMMA

Thermal osteonecrosis is a side effect when used Kirschner (K) wires and drills in orthopaedic surgeries. This osteonecrosis may endanger the fixation. Orthopaedic surgeons sometimes have to use unsharpened K-wires in emergent surgery. The thermal effect of used and unsharpened K wire is ambiguous to the bone. This experimental study aims to assess the thermal osteonecrosis while drilling bone with three different types of K-wires especially a previously used unsharpened wire and its thermographic measurements correlation. Two different speeds of rotation were chosen to investigate the effect of speed on thermal necrosis to the bone. A total of 16 New Zealand white rabbits weighing a mean of 2.90 kg (2.70 – 3.30 kg) were used. All rabbits were operated under general anaesthesia in a sterile operating room. Firstly, 4 cm longitudinal lateral approach was used to the right femur and then the femur was drilled with 1.0 mm trochar tip, spade tip and previously used unsharpened K-wires and 1.0 mm drill bit at 1450 rpm speed. Left femur was drilled with same three type K-wires and drill bit at 330 rpm speed. One cm distance was left among four penetrations on the femur. The thermal changes were recorded by Flir® E6 Thermal Camera from 50 cm distance and 30-degree angle. Thermographic measurements saved for every drilling process and recorded for the highest temperature (°C) during the drilling. All subjects were sacrificed post-operatively on the eighth day and specimens were prepared for the histological examination. The results of osteonecrosis assessment score and thermographic correlation were evaluated statistically. Histological specimens were evaluated by the scoring of osteonecrosis, osteoblastic activity, haemorrhage, microfracture and inflammation. Results were graded semi-quantitatively as none, moderate or severe for osteonecrosis, haemorrhage and inflammation. The microfracture and osteoblastic activity were evaluated as present or absent. There was no meaningful correlation between osteonecrosis and the drilling speed (p=0.108). There was less microfracture zone which was drilled with trochar tip K-wires at 1450 rpm speed (p=0.017). And the drilling temperature of trochar tip K-wires was higher than the others(p=0.001). Despite this evaluation, osteonecrosis zone of spade and unsharpened tip K-wires were more than trochar tip K-wires (p=0.039). The drill bit at 330 rpm caused the least osteonecrosis and haemorrhage and respectfully the lowest drilling temperature (p=0,001). The osteoblastic activity shows no difference between the groups. (p=0,122; 0,636;0.289). On the contrary to the literature, our experiment showed that there is no meaningful correlation between osteonecrosis score and temperature produced by drilling. The histological assessment showed the osteonecrosis during short drilling time but, not clarify the relation with drilling temperature. Eventually, the osteonecrosis showed a positive correlation with drilling time independently of drilling temperature at 330 rpm. (p=0,042) These results show that we need more studies to understand about osteonecrosis and its relationship with drilling heat temperature. Trochar tip K-wires creates higher drilling temperature but less osteonecrosis than a spade and unsharpened cut tip K-wires. Using unsharpened tip K-wire causes more osteonecrosis. Previously used and, unsharpened K-wires should be discarded

Complications after spinal fusion surgery are common, with implant loosening occurring in up to 50% of osteoporotic patients. Pedicle screw fixation strength reduces as a result of decreased trabecular bone density, whereas sublaminar wiring is less affected by these changes. Therefore, pedicle screw augmentation with radiopaque sublaminar wires (made with Dyneema Purity® Radiapque fibers, DSM Biomedical, Geleen, the Netherlands) may improve fixation strength. Furthermore, sublaminar tape could result in a gradual motion transition to distribute stress over multiple levels and thereby reduce implant loosening. The objective of this study is to test this hypothesis in a novel experimental setup in which a cantilever bending moment is applied to individual human vertebrae. Thirty-eight human cadaver vertebrae were stratified into four different groups: ultra-high molecular weight polyethylene sublaminar tape (ST), pedicle screw (PS), metal sublaminar wire (SW) and pedicle screw reinforced with sublaminar tape (PS+ST). The vertebrae were individually embedded in resin, and a cantilever bending moment was applied bilaterally through the spinal rods using a universal material testing machine. This cantilever bending setup closely resembles the loading of fixators at transitional levels of spinal instrumentation. The pull-out strength of the ST (3563 ± 476N) was not significantly different compared to PS, SW or PS+ST. The PS+ST group had a significantly higher pull-out strength (4522 ± 826N) compared to PS (2678 ± 292N) as well as SW (2931 ± 250N). The higher failure strength of PS + ST compared to PS indicates that PS augmentation with ST may be an effective measure to reduce the incidence of screw pullout, even in osteoporotic vertebrae. Moreover, the lower stiffness of sublaminar fixation techniques and the absence of damage to the cortices in the ST group suggest that ST as a stand-alone fixation technique in adult spinal deformity surgery may also be clinically feasible and offer clinical benefits

Background. Finite element (FE) models have become a standard pre-clinical tool to study biomechanics of spine and are used to simulate and evaluate different strategies in scoliosis treatment: examine their efficacy as well as the effect of different implant design parameters. The goal of this study is to investigate, in a system of rods and laminar wires, the effect of the number of wires and their pre-stress on whole spine stiffness. Methods. A generic FE model was developed to represent a full human spine, including vertebrae, intervertebral discs, ligaments, facet and costovertebral joints, and ribcage. Intervertebral discs were modeled with 3D rebar elements with linear elastic material properties. Vertebrae, ribs, sternum, facet joints, cartilage and endplates were modeled with brick elements, and costal muscles with shell elements with linear elastic properties. Furthermore, ligaments were modeled with truss elements with nonlinear hypo-elastic properties. The spine model was instrumented from T7 to T12 with rods and wires modeled as titanium. Nonlinear contact properties were defined for rib neck-vertebra, transverse processes-rib and facet joint sets. The FE model was loaded in flexion and the whole spine instantaneous stiffness was calculated for different wire pre-stressing levels (0.1 to 2 MPa). Similar analyses were performed with changed numbers of wires and whole spine stiffness was calculated. Results. The results show that with increasing the pre-stress level the whole spine instantaneous stiffness increases by up to 6%. Reducing the number of wires decreases the whole spine stiffness almost linearly by 5%. These changes also alter center of rotation of the spine. The results suggest that pre-stressing and number of wires have an effect on whole spine stiffness. Conclusions. In summary, the develop FE model can be used to simulate different treatment strategies and to improve implant designs used in surgical treatment of scoliosis. Level of evidence. FEA study

Introduction. The BOAST (British Orthopaedic Association Standards for Trauma) guidelines do advise that open pilon fractures amongst other open lower limb fractures need to be treated at a specialist centre with Orthoplastic care. The purpose of this study was to determine clinical outcomes in patients with open pilon fractures treated as per BOAST guidelines including relatively aggressive bone debridement. Methods. A retrospective analysis of a single surgeon series of open pilon fractures treated between 2014 and 2019 was conducted. Injuries were graded according to the Gustillo-Anderson classification and all patients were included for the assessment of the rate of infection and fracture healing. Functional outcome assessment was performed in all patients according to the American Orthopedic Foot and Ankle Score (AOFAS) at 6 months after definitive surgery. Initial wound with bone debridement and application of a spanning external fixator was performed within an average of 13.5 (Range: 3–24) hours. Fixation with FWF (Fine Wire Frame) was performed when the wound was healed, with the mean time from primary surgery to application of FWF being 24.5 (Range: 7–60) days. Results. There was a total of 20 patients including 16 males and 4 females. The mean age was 50.45 (Range: 16–88) years. Follow-up was for an average of 23.2 (Range: 5–51) months. There were 3 patients with Gustilo Type I injuries, 6 with Type II, 4 Type with type IIIa and 7 with Type IIIb injuries. Average time to bone union was 9.3 (Range: 2–18) months. The mean AOFAS score was 66 (Range: 15–97) points. TSF was used on 18 patients, while 2 patients had an Ilizarov frame. A corticotomy was performed on 4 patients with critical bone defect post debridement, while 2 patients had Stimulan beads with antibiotics. There was 1 case (5%) of deep infection and 9 cases (45%) of superficial infection. There were also 2 cases (10%) of non-union which required bone grafting from their femur using a RIA (Reamer Irrigation Aspirator). Other complications included 1 case of acute compartment syndrome, 1 case of pulmonary embolism, 1 case of necrotic skin and 1 case of amputation. Conclusion. Results of our study suggests that the use of staged wound debridement including relatively aggressive bone debridement in conjunction with antibiotics, external fixators and patient tailored conversion from spanning external fixator to fine wire frame achieves low rates of wound infection and complications for patients with open pilon fractures

Abstract. Objectives. Current literature on pilon fracture includes a range of different management strategies, however there is no universal treatment algorithm. We aim to determine clinical outcomes in patients with open and closed pilon fractures, managed using a treatment algorithm applied consistently over the span of this study. Methods. 135 patients over a 6-year period were included. Primary outcome was AOFAS score at 3, 6, 12-months post-injury. Secondary outcomes include time to partial weight-bear (PWB), full weight-bear (FWB), bone union time, follow-up time. AO/OTA classification was used (43A: n=23, 43B: n=30, 43C: n=82). Treatment algorithm consisted of fine wire fixator (FWF) for severely comminuted closed fractures (AO/OTA type 43C3), or open fractures with severe soft tissue injury (GA type 3). Otherwise, open reduction internal fixation (ORIF) was performed. When required, minimally invasive osteosynthesis was performed in combination with FWF to improve joint congruency. Results. Mean AOFAS score 3, 6, and 12 months post-treatment for open and closed fracture patients were 44.12 and 53.99 (p=0.007), 62.38 and 67.68 (p=0.203), 78.44 and 84.06 (p=0.256), respectively. 119 of 141 fractures healed without further intervention (84.4%). Average time to union was 51.46 and 36.48 weeks for open and closed fractures, respectively (p=0.019). On average, open, and closed fracture patients took 12.29 and 10.76 weeks to PWB (p=0.361); 24.04 and 20.31 weeks to FWB (p=0.235), respectively. Common complications for open fractures were non-union (24%), post-traumatic arthritis (16%); for closed fractures they were post-traumatic arthritis (25%), superficial infection (22%). Open fracture was a risk factor for non-union (p=0.042;OR=2.558,95% CI 1.016–6.441), bone defect (p=0.001;OR=5.973,95% CI 1.986–17.967), and superficial infection (p<0.001;OR=4.167,95% CI 1.978–8.781). Conclusions. FWF with minimally invasive osteosynthesis, where required for severely comminuted closed fractures, and FWF for open fractures with severe soft tissue injury, are safe methods achieving low complication rates and good functional recovery

A significant source of failure for external fixation devices is loosening of the fixation implant. As bone competence drops with ageing or disease such as osteoporosis, the risk of loosening is likely to increase. However it is not clear how fixator configuration should be adapted to minimise loosening in weaker bone. The aim of this study was to assess the effect of bone competence on the yielding of bone tissue surrounding fixation implants, and thereby inform the selection of fixator configuration to minimise loosening. External fixation of the tibial midshaft using half-pins and Illizarov wires was modelled using finite-element analysis. Half-pin configurations of two and three stainless steel and titanium pins pins were assessed. Illizarov wire configurations of two and four wires were studied, over a range of wire tensions. Bone competence was varied by changing the cortical thickness and elastic properties of the bone fragments to approximate: a) young, high-density bone, b) middle-aged, mid-porosity bone and c) old-aged, severely porous bone. Bone elastic properties were taken from a recent study of cortical bone conducted by the authors. The interaction between implants and bone was modelled with contact analysis, enabling realistic separation. Implant loosening was included using a bone-specific, strain-based yield criterion. Regions where bone tissue yielded were identified as likely sites of loosening. In all cases loading was applied to simulate a one-legged stance. Half-pin fixation. Increasing the number of half-pins from two to three produced an approximate 80% reduction of yielded bone volume in all age groups. The volume of yielded bone increased with ageing, approximately three times greater in old-aged bone than in young bone. In the young and middle-aged cases yielded bone never penetrated the full cortex. Contrastingly, the full cortex was yielded in the old-aged bone fragments for both two- and three-pin fixation. In all cases the volume of yielded bone was greater at the pin(s) nearest to the fracture gap. The use of titanium pins increased the volume of yielded bone around half-pins by approximately 1.7 times. These results suggest bone competence, number of half-pins, location of half-pins and half-pin material all significantly influence implant loosening. Illizarov wire fixation. Increasing the number of Illizarov wires reduced the volume of yielded bone by approximately 60% in all age groups. The volume of yielded bone increased with ageing by a factor of approximately 2.0 times from young to old bone. Bone yielding never progressed through the entire cortex; it reached a maximum of 70% of the cortical thickness in two-wire fixation of the old-aged bone fragment. This is a possible reason for the lower rate of loosening in Illizarov wire fixation as compared to half-pin fixation. Increasing wire tension reduced the volume of yielded bone. These results suggest that bone competence, number of wires, wire tension and wire arrangement significantly influence loosening

Introduction and Objective. Management of gap non-union of the tibia, the major weight bearing bone of the leg remains controversial. The different internal fixation techniques are often weighed down by relatively high complication rates that include fractures which fail to heal (non-union). Minimally invasive techniques with ring fixators and bone transport (distraction osteogenesis) have come into picture as an alternative allowing alignment and stabilization, avoiding a graduated approach. This study was focused on fractures that result in a gap non-union of > 6 cm. Ilizarov technique was employed for management of such non-unions in this case series. The Ilizarov apparatus consists of rings, rods and kirschner wires that encloses the limb as a cylinder and uses kirschner wires to create tension allowing early weight bearing and stimulating bone growth. Ilizarov technique works on the principle of distraction osteogenesis, that is, pulling apart of bone to stimulate new bone growth. Usually, 4–5 rings are used in the setup depending on fracture site and pattern for stable fixation. In this study, we demonstrate effective bone transport and formation of gap non-union more than 6 cm in 10 patients using only 3 rings construct Ilizarov apparatus. Materials and Methods. This case study was conducted at Dr. D. Y. Patil Medical Hospital, Navi Mumbai, Maharashtra, India. The study involved 10 patients with a non-union or gap > 6 cm after tibial fracture. 3 rings were used in the setup for the treatment of all the patients. Wires were passed percutaneously through the bone using a drill and the projecting ends of the wires were attached to the metal rings and tensioned to increase stability. The outcome of the study was measured using the Oxford Knee scoring system, Functional Mobility Scale, the American Foot and Ankle Score and Visual Analog Scale. Further, follow up of patients was done upto 2 years. Results. All the patients demonstrated good fixation as was assessed clinically and radiologically. 9 patients had a clinical score of > 65 which implied fair to excellent clinical rating. The patients showed good range of motion and were highly satisfied with the treatment as measured by different scoring parameters. Conclusions. In this case study, we demonstrate that the Ilizarov technique using 3 rings is equally effective in treating non-unions > 6 cm as when using 4–5 rings. Obtaining good clinical outcome and low complication rate in all 10 patients shows that this modified technique can be employed for patients with such difficulties in the future

Biomechanical studies involving all-wire and hybrid types of circular frame have shown that oblique tibial fractures remain unstable when they are loaded. We have assessed a range of techniques for enhancing the fixation of these fractures. Eight models were constructed using Sawbones tibiae and standard Sheffield ring fixators, to which six additional fixation techniques were applied sequentially. The major component of displacement was shear along the obliquity of the fracture. This was the most sensitive to any change in the method of fixation. All additional fixation systems were found to reduce shear movement significantly, the most effective being push-pull wires and arched wires with a three-hole bend. Less effective systems included an additional half pin and arched wires with a shallower arc. Angled pins were more effective at reducing shear than transverse pins. The choice of additional fixation should be made after consideration of both the amount of stability required and the practicalities of applying the method to a particular fracture

We have evaluated four different fixation techniques for the reconstruction of a standard Mason type-III fracture of the radial head in a sawbone model. The outcome measurements were the quality of the reduction, and stability. A total of 96 fractures was created. Six surgeons were involved in the study and each reconstructed 16 fractures with 1.6 mm fine-threaded wires (Fragment Fixation System (FFS)), T-miniplates, 2 mm miniscrews and 2 mm Kirschner (K-) wires; four fractures being allocated to each method using a standard reconstruction procedure. The quality of the reduction was measured after definitive fixation. Biomechanical testing was performed using a transverse plane shear load in two directions to the implants (parallel and perpendicular) with respect to ultimate failure load and displacement at 50 N. A significantly better quality of reduction was achieved using the FFS wires (Tukey’s post hoc tests, p < 0.001) than with the other devices with a mean step in the articular surface and the radial neck of 1.04 mm (. sd. 0.96) for the FFS, 4.25 mm (. sd. 1.29) for the miniplates, 2.21 mm (. sd. 1.06) for the miniscrews and 2.54 mm (. sd. 0.98) for the K-wires. The quality of reduction was similar for K-wires and miniscrews, but poor for miniplates. The ultimate failure load was similar for the FFS wires (parallel, 196.8 N (. sd. 46.8), perpendicular, 212.5 N (. sd. 25.6)), miniscrews (parallel, 211.8 N (. sd. 47.9), perpendicular, 208.0 N (. sd. 65.9)) and K-wires (parallel, 200.4 N (. sd. 54.5), perpendicular, 165.2 N (. sd. 37.9)), but significantly worse (Tukey’s post hoc tests, p < 0.001) for the miniplates (parallel, 101.6 N (. sd. 43.1), perpendicular, 122.7 N (. sd. 40.7)). There was a significant difference in the displacement at 50 N for the miniplate (parallel, 4.8 mm (. sd. 2.8), perpendicular, 4.8 mm (. sd. 1.7)) vs FFS (parallel, 2.1 mm (. sd. 0.8), perpendicular, 1.9 mm (. sd. 0.7)), miniscrews (parallel, 1.8 mm (. sd. 0.5), perpendicular, 2.3 mm (. sd. 0.8)) and K-wires (parallel, 2.2 mm (. sd. 1.8), perpendicular, 2.4 mm (. sd. 0.7; Tukey’s post hoc tests, p < 0.001)). The fixation of a standard Mason type-III fracture in a sawbone model using the FFS system provides a better quality of reduction than that when using conventional techniques. There was a significantly better stability using FFS implants, miniscrews and K-wires than when using miniplates