Abstract. Introduction. There is little literature exploring clinical outcomes of secondarily displaced proximal humerus fractures. The aim of this study was to assess the rate of secondary displacement in undisplaced proximal humeral fractures (PHF) and their clinical outcomes. Methods. This was a retrospective cohort study of undisplaced PHFs at Royal Derby Hospital, UK, between January 2018-December 2019. Radiographs were reviewed for displacement and classified according to Neer's classification. Displacement was defined as translation of fracture fragments by greater than 1cm or 20° of angulation. Patients with pathological, periprosthetic, bilateral, fracture dislocations and head-split fractures were excluded along with those without adequate radiological follow-up. Results. In total, 681 patients were treated with PHFs within the study period and out of those 155 were excluded as above. There were 385 undisplaced PHFs with mean age 70 years (range, 21–97years) and female to male ratio of 3.3:1. There were 88 isolated greater tuberosity fractures, 182 comminuted PHFs and 115 surgical neck fractures. Secondary displacement occurred in 33 patients (8.6%). Mean time to displacement was 14.8 days (range, 5–45days) with surgical intervention required in only 5 patients. In those managed nonoperatively, three had malunion and one had nonunion. No significant differences were noted in ROM between undisplaced and secondarily displaced PHFs. Conclusion. Undisplaced fractures are the most common type of PHF. Rate of secondary displacement is low at 8.6% and can occur up to 7 weeks after injury. Displacement can lead to surgery, but those managed conservatively maintain their ROM at final follow up

Distal radius fractures (DRFs) are common injuries that represent 17% of all adult upper extremity fractures. Some fractures deemed appropriate for nonsurgical management following closed reduction and casting exhibit delayed secondary displacement (greater than two weeks from injury) and require late surgical intervention. This can lead to delayed rehabilitation and functional outcomes. This study aimed to determine which demographic and radiographic features can be used to predict delayed fracture displacement. This is a multicentre retrospective case-control study using radiographs extracted from our Analytics Data Integration, Measurement and Reporting (DIMR) database, using diagnostic and therapeutic codes. Skeletally mature patients aged 18 years of age or older with an isolated DRF treated with surgical intervention between two and four weeks from initial injury, with two or more follow-up visits prior to surgical intervention, were included. Exclusion criteria were patients with multiple injuries, surgical treatment with fewer than two clinical assessments prior to surgical treatment, or surgical treatment within two weeks of injury. The proportion of patients with delayed fracture displacement requiring surgical treatment will be reported as a percentage of all identified DRFs within the study period. A multivariable conditional logistic regression analysis was used to assess case-control comparisons, in order to determine the parameters that are mostly likely to predict delayed fracture displacement leading to surgical management. Intra- and inter-rater reliability for each radiographic parameter will also be calculated. A total of 84 age- and sex-matched pairs were identified (n=168) over a 5-year period, with 87% being female and a mean age of 48.9 (SD=14.5) years. Variables assessed in the model included pre-reduction and post-reduction radial height, radial inclination, radial tilt, volar cortical displacement, injury classification, intra-articular step or gap, ulnar variance, radiocarpal alignment, and cast index, as well as the difference between pre- and post-reduction parameters. Decreased pre-reduction radial inclination (Odds Ratio [OR] = 0.54; Confidence Interval [CI] = 0.43 – 0.64) and increased pre-reduction volar cortical displacement (OR = 1.31; CI = 1.10 – 1.60) were significant predictors of delayed fracture displacement beyond a minimum of 2-week follow-up. Similarly, an increased difference between pre-reduction and immediate post reduction radial height (OR = 1.67; CI = 1.31 – 2.18) and ulnar variance (OR = 1.48; CI = 1.24 – 1.81) were also significant predictors of delayed fracture displacement. Cast immobilization is not without risks and delayed surgical treatment can result in a prolong recovery. Therefore, if reliable and reproducible radiographic parameters can be identified that predict delayed fracture displacement, this information will aid in earlier identification of patients with DRFs at risk of late displacement. This could lead to earlier, appropriate surgical management, rehabilitation, and return to work and function

INTRODUCTION. Ceramic heads are used in hip revision surgery to mitigate corrosion concerns. Manufacturers recommend using a pristine titanium sleeve in conjunction with a well-fixed metal stem to prevent early failure of the ceramic head. However, the influence of impact force, head size, and sleeve offset on pull-off strength and seating displacement of a revision head assembly is not fully understood. Therefore, the purpose of this study was to investigate the pull-off strength and displacement of commercially available revision ceramic heads and titanium taper sleeve offsets (BIOLOX OPTION, CeramTec GmbH, Plochingen, Germany) while covering a range of clinically relevant impaction forces. METHODS. Two head sizes (28 mm, n = 12 and 36 mm, n = 12) and two taper adapter sleeve offsets (small, n = 12 and extra-large, n =12) were tested in this study. A dynamic impaction rig was constructed to seat the head, sleeve, and stem assembly. Consistent impaction forces were achieved by a dropping a hammer fixed to a lever arm from a pre-determined height onto a standard impactor instrumented with a piezoelectric force sensor (PCB Piezotronics Inc.). Axially applied forces of 2 kN and 6 kN were used to cover a range of typical impaction forces. Three non-contact differential variable reluctance transducers (LORD Sensing Systems) were used to track the displacement of the head relative to the stem. Subsequently, samples were transferred a servo hydraulic testing machine, and a pull-off test was carried out per ISO 7206- 10 to measure the disassembly force. RESULTS. For all head and sleeve combinations assembled at 6 kN, pull-off forces and assembly displacements were over two times the values measured at 2 kN. As expected, an increased assembly force resulted in increased pull-offs and displacements. Head size did not play a significant role on measured outcomes. Regarding sleeve offsets, at assembly of 6 kN mean pull-off forces for extra-large sleeves were reduced by approximately 25% relative to small sleeves. However, at a 2 kN assembly, sleeve offsets did not appear to influence pull-off forces. DISCUSSION. This study assessed the effect of impact assembly force, head size, and sleeve offset on pull-off strength and seating displacement of revision ceramic heads. The data suggests assembly force and sleeve offset may influence the pull-off strength and seating displacement of modular heads used in revision hip arthroplasty. Mean pull-off forces for revision heads were comparable in magnitude and trend to previous studies assessing the linear relationship between assembly force and pull-off force in primary heads (Krull et al., 2017, Rehmer et al., 2012). Lower pull-off forces were observed for extra-large sleeves when compared to small sleeves, indicating, decreased contact at the sleeve and stem interface for extra-large offsets may play a role in reducing pull-off forces

Fractures of the clavicle are relatively common, occurring mostly in younger patients and have historically been managed non-operatively. Recent studies have shown an advantage to surgical reduction and stabilisation of clavicle fractures with significant displacement. Currently, fracture displacement is measured using simple anterior-posterior two-dimensional x-rays of the clavicle. Since displacement can occur in all three-dimensions, however, evaluation of the amount displacement can be difficult and inaccurate. The purpose of this study was to determine the view that provides the most accurate assessment. Nine CT scans of acute displaced clavicle fractures were analysed with AmiraDEV5.2.2 Imaging software. Measurements for degrees of shortening and fracture displacement of the fracture clavicle were taken. Using a segmentation and manipulation module (ITK toolkit), five digitally reconstructed radiographs (DRRs) mimicking antero-posterior x-rays were created for every CT, with each differing by projection angle (ranging from 20° upwards tilt to 20° downwards tilt). Measurements were taken on each DRR using landmarks of entire clavicle length, distance from vertebrae to fracture (medial fragment length), distance from fracture to acromium (lateral fragment length), and horizontal shortening, and then compared to the true measurement obtained from the original CT. For all 9 samples, after comparing the measurements of clavicle fracture displacement in each 2D image, we found that an AP view with a 20° downward tilt yielded displacement measurements closest to the 3D (“gold standard”) measurements. The results agree with previous data collected from cadaveric specimens using physical X-ray film images. DDRs enable creation of multiple standard AP radiographs from which accurate tilt can be measured. The large deviation in measurements on different DRR projections motivates consideration of standardising X-ray projections. A uniform procedure would allow one to correctly evaluate the displacement of clavicular fractures if fracture displacement information is to be utilized in motivating surgical decision-making

Introduction. Stress shielding is one of the major concerns of load bearing implants (e.g. hip prostheses). Stiff implants cause stress shielding, which is thought to contribute to bone resorption1. On the contrary, low-stiffness implants generate high interfacial stresses that have been related to pain and interfacial micro-movements². Different attempts have been made to reduce these problems by optimizing either the stem design3 or using functionally graded implants (FGI) where the stem's mechanical properties are optimized4. In this way, new additive manufacturing technologies allow fabricating porous materials with well-controlled mesostructure, which allows tailoring their mechanical properties. In this work, Finite Element (FE) simulations are used to develop an optimization methodology for the shape and material properties of a FGI hip stem. The resorbed bone mass fraction and the stem head displacement are used as objective functions. Methodology. The 2D-geometry of a femur model (Sawbones®) with an implanted Profemur-TL stem (Wright Medical Technology Inc.) was used for FE simulations. The stem geometry was parameterized using a set of 8 variables (Figure 1-a). To optimize the stem's material properties, a grid was generated with equally spaced points for a total of 96 points (Figure 1-b). Purely elastic materials were used for the stem and the bone. Two bone qualities were considered: good (Ecortical=20 GPa, Etrabecular=1.5 GPa) and medium (Ecortical=15 GPa, Etrabecular=1 GPa). Poisson ratio was fixed to v=0.3. Loading corresponded to stair climbing. Hip contact force along with abductors, vastus lateralis and vastus medialis muscles were considered5 for a bodyweight of 847 N. The resorbed bone mass fraction was evaluated from the differences in strain energy densities between the intact bone and the implanted bone2. The displacement of the load point on the femoral head was computed. The optimization problem was formulated as the minimization of the resorbed bone mass fraction and the head displacement. It was solved using a genetic algorithm. Results. For the Profemur-TL design, bone resorption was around 36% and 56% for good and medium bone qualities, respectively (Fig. 2). The corresponding head displacements were 11.75 mm and 21.19 mm. Optimized solutions showed bone resorption from 15% to 26% and from 44% to 65% for good and medium bone qualities, respectively. Corresponding head displacements ranged from 11.85 mm to 12.25 mm and from 16.9 mm to 22.6 mm. Conclusion. The obtained set of solutions constitutes an improvement of the implant performance for this functionally graded implant (FGI) compared to the original implant for both bone qualities. From these simulations, the final solution for the FGI could be chosen based on manufacturing restrictions or another performance indicator

Aim. To delineate which of four common and easily constructed Ilizarov frame configurations is best at resisting shear displacement. Methods. Four Ilizarov frames were constructed on Sawbones™ Tibiae taking into account soft tissue and neuro-vascular limitations in frame design. The designs consisted of a standard all wire frame, an opposing olive wire standard frame, a perpendicular trans-fracture opposing olive wire frame and a perpendicular half pin frame. These were tested over three cycles in compression on a load-testing machine with movement in the plane of the fracture measured using a clip gauge. Each frame was tested to the maximum displacement of the clip gauge or a total single cycle compressive load of 700N, whichever limit occurred first. Results. The perpendicular trans-fracture olive wire frame showed the least displacement in shear. The half pin frame, followed by the opposing olive standard frame and finally the all wire frame were least stable to shear displacement. Conclusion. For this fracture pattern, this study recommends the use of the perpendicular trans-fracture olive wire frame. Further investigation of immediate post-operative limb loading in patients will allow practical application of this data. Further frame motion analysis and bending analysis will allow validation of these results and allow for future frame design. The next steps in this project involve validation against FE Analysis in order to create a design software to allow mechanical templating of frame designs pre-operatively

Purpose. The purpose of this study was to assess the biomechanical stability of the a total ankle arthroplasty system using longitudinal migration (LM) and inducible displacement (ID) measures. This study is the first study of its kind to assess total ankle arthroplasty (TAA) implant micromotion using model-based radiostereometric analysis (MBRSA). Method. Twenty patients underwent TAA that implanted the Mobility(TM) (DePuy, Warsaw IN). The mean (SD) age was 60.4 (12.5) and BMI was 29.1 (2.8) kg/m. 2. One surgeon performed all surgeries. All patients included in this study had given informed consent. Capital Health Research Ethics Board had approved this study. Uniplanar medial-lateral RSA X-ray exams were taken postop (double exam), at six wk, three mth, six mth, one yr and two yr followup times using a supine, unloaded position. Standing medial-lateral exams were taken at three mth, six mth, one yr and two yr followup intervals. LM and ID micromotions were assessed using Model-based RSA 3.2 software (Medis specials, Leiden, The Netherlands). Implant micromotions (x, y, z, Rx, Ry, Rz, MTPM) were determined and assessed for each subject using model-based pose estimation, and the implant-based coordinate system. The Elementary Geometric Shapes module from the Model-based RSA 3.2 software was used to assess the micromotion of the tibial component spherical tip due to implant symmetry. Results. The median (range) maximum total point motion (MTPM) for the implants at 2 year followup were 1.23 mm (0.39–1.95 mm) for the talar implant and 0.96 mm (0.17–2.28 mm) for the spherical tip of the tibia implant. Generally for each subject and implant component, the slopes of the migration curves decreased over time. The talar and tibial implants mean LM showed initial subsidence in the y-direction (migration into the bone) followed by stabilization patterns at one year followup. The median (range) of two year MTPM ID for the talar component was 0.39 (0.27–1.06) mm. At the one year and two year followup times the ID were almost all below the detection limit of 0.85 mm. The highest measured displacement for any one talar component at either of these times was 1.06 mm. Hence, the implant was displaced at least 0.21 mm under loading. The median (range) of one year and two year MTPM ID for the tibial component spherical tip was 0.08 (0.03–0.19) mm. The tibial component spherical tip demonstrates no ID in terms of MTPM greater than the 0.22 mm detection limit. Conclusion. The implant subsides directly into the bone in the line of primary loading during standing or walking. For most of the patients the two year LM for the Mobility(TM) demonstrates a typical subsidence-stabilization behaviour seen in many RSA studies of orthopaedic implants. Based on the results of this study the Mobility(TM) components show no measurable ID. This is the first study of its kind internationally for total ankle arthroplasty and offers novel insight into the need for prosthetic design change

The use of percutaneous Kirschner wires [K-wires] and plaster is a popular method of treatment for displaced distal radius fracture. However, multi-database electronic literature review reveals unsurprisingly different views regarding their use. From August 2002 till June 2004, 280 distal radial fractures were admitted to our orthopaedic department. They were recorded prospectively in the departmental trauma admissions database. We studied the 87 cases treated with the K-wires and plaster technique. They were classified according to the AO classification system. The mean patient age was 53 [5-88] years. The mean delay before surgery was 7 [0-24] days. We studied the complications reported by the attending orthopaedic surgical team. 48 out of 87 patients [55.1%] were reported to have complications. We analysed the displacement and the pin tract infection, as they were the main reported complications. 28 out of 87 patients [32%] had displacement [9 had further surgery to correct the displacement, 19 did not have any further surgery as the displacement was accepted]. 11 out of 87 patients [12.6%] had pin tract infection [7 needed early removals of the K-wires and systematic treatment]. Further analysis showed no statistically significant relation between the complications rate and the age of the patients, the delay before surgery or the type of the fractures. We demonstrate a considerable high displacement and infection rate with the use of K-wires and plaster technique for fixation of distal fracture irrespective of the age of the patients, the delay before surgery or the fracture classification. There are other methods for fixation of the distal radial fracture with proven less morbidity which should be considered

Distal radius and ulna fractures are a common paediatric injury. Displaced or angulated fractures require manipulation under anaesthetic (MUA) with or without Kirchner (K) wire fixation to improve alignment and avoid malunion. After treatment a proportion redisplace requiring further surgical management. This study aimed to investigate whether the risk of redisplacement could be reduced by introducing surgical treatment guidelines to ascertain whether MUA alone or the addition of K wire fixation was required. A cohort of 51 paediatric forearm fractures managed either with an MUA alone or MUA and K wire fixation was analysed to determine fracture redisplacement rates and factors which predisposed to displacement. Guidelines for optimal management were developed based on these findings and published literature and implemented for the management of 36 further children. A 16% post-operative redisplacement rate was observed within the first cohort. Redisplacement was predicted if an ‘optimal reduction’ of less than 5° of angulation and/or 10% of translation was not achieved and no K wire fixation utilised. Adoption of the new guidelines resulted in a significantly reduced redisplacement rate of 6%. Implementation of departmental guidelines have reduced redisplacement rates of children's forearm fractures at Great Western Hospital

Introduction. The pathogenesis of primary knee osteoarthritis is due to excess mechanical loading of the articular cartilage. Previous studies have assessed the impact of muscle forces on tibiofemoral kinematics and force distribution. A cadaveric study was performed to evaluate the effect of altering the moment arm of the iliotibial band (ITB) on knee biomechanics. Method. A robotic system consisting of a 6-DOF manipulator capable of measuring forces on the medial and lateral condyle of a cadaveric knee at various flexion angles and muscle forces was utilized [1]. The system measured the compartment forces at flexion angles between 0° and 30° under 3 simulated loading conditions (300N quadriceps, 100N hamstrings and: i. 0N ITB; ii. 50N ITB; iii. 100N ITB). Eight fresh frozen human cadaver knee specimens (4 males, 4 females); age range 36 – 50 years; weight range 49 – 90 kg; height range 154 – 190 cm were used in the study. The ITB and associated lateral soft tissue structures were laterally displaced from the lateral femoral condyle by fixing a metal implant (like in Figure 1) to the distal lateral femur. Mechanical loads on the medial and lateral compartments (with and without the implant) were measured using piezoelectric pressure sensors. Results. For each specimen, lateral displacement of the ITB due to the implant was measured (15 – 20 mm). The % average unloading of the medial compartment for all the specimens ranged from 34% – 65% (Figure 2). Also observed was a concomitant increase in lateral compartment load. Medial unloading was even observed with no ITB force (0N) which indicates a role for other lateral structures attached to the ITB in unloading the medial compartment [2]. In addition, under these non-weight bearing conditions, on average, there was an increase in valgus tibial angulation through the flexion range. Discussion. Increasing mechanical leverage of muscles across a joint is accomplished in nature through sesamoid bones (e.g., patella) which increase the muscle moment arm. By increasing the moment arm of the ITB and lateral soft tissue structures by lateralizing these structures, our model demonstrates a 34–65% unloading of the medial compartment. Studies of knee braces and weight loss have shown that reducing mechanical load on the medial condyle by even 10% provides clinical benefits in terms of reduced pain and improved function. Based on the results of this study, unloading the medial compartment by displacing the ITB laterally may be a means of treating medial osteoarthritis (Figure 3). A prospective, multi-center, non-randomized, open label, single-arm study is currently underway to establish the safety and efficacy of providing medial osteoarthritis pain relief by displacing the ITB using Cotera, Inc.'s Latella™ Knee Implant

Operative approaches to the acetabulum are generally classified into anterior, posterior, extensile or combined approaches. The choice of approach depends upon the fracture pattern and the amount of relative displacement affecting the anterior and posterior bony structures. Occasionally, extensile or combined surgical approaches are indicated for the treatment of complex fracture patterns with extensive involvement of both the anterior and posterior acetabular anatomy. However, it is believed that these approaches may be associated with higher complication rates than more limited surgical approaches. The ilioinguinal approach described by Letournel is routinely employed in the treatment of anterior column, anterior wall, anterior column/posterior hemi- transverse and certain associated both-columns, transverse and T-type fractures. The utility of this approach is sometimes limited by difficulty in visualising, reducing and applying instrumentation to the quadrilateral plate and posterior column components of these fractures. A surgical approach described by Stoppa in 1989—and later extended to acetabular indications by Cole and Bolhofner—can be used, often in combination with the lateral window of the standard ilioinguinal approach, to effectively treat the same range of fractures as an ilioinguinal approach. Access to the quadrilateral plate and certain displaced posterior column fracture lines is enhanced by this approach—possibly eliminating the need for combined or extensile approaches in certain cases. A retrospective study undertaken at our institution demonstrated that anatomic articular reduction was achieved in 14 of 17 complex acetabular fractures treated via a Stoppa approach. All fractures in the study had at least 5 mm of posterior column displacement preoperatively

The posterior drawer is a commonly used test to diagnose an isolated PCL injury and combined PCL and PLC injury. Our aim was to analyse the effect of tibial internal and external rotation during the posterior drawer in isolated PCL and combined PCL and PLC deficient cadaver knee. Ten fresh frozen and overnight-thawed cadaver knees with an average age of 76 years and without any signs of previous knee injury were used. A custom made wooden rig with electromagnetic tracking system was used to measure the knee kinematics. Each knee was tested with posterior and anterior drawer forces of 80N and posterior drawer with simultaneous external or internal rotational torque of 5Nm. Each knee was tested in intact condition, after PCL resection and after PLC (lateral collateral ligament and popliteus tendon) resection. Intact condition of each knees served as its own control. One-tailed paired student's t test with Bonferroni correction was used. The posterior tibial displacement in a PCL deficient knee when a simultaneous external rotation torque was applied during posterior drawer at 90° flexion was not significantly different from the posterior tibial displacement with 80N posterior drawer in intact knee (p=0.22). In a PCL deficient knee posterior tibial displacement with simultaneous internal rotation torque and posterior drawer at 90° flexion was not significantly different from tibial displacement with isolated posterior drawer. In PCL and PLC deficient knee at extension with simultaneous internal rotational torque and posterior drawer force the posterior tibial displacement was not significantly different from an isolated PCL deficient condition (p=0.54). We conclude that posterior drawer in an isolated PCL deficient knee could result in negative test if tibia is held in external rotation. During a recurvatum test for PCL and PLC deficient knee, tibial internal rotation in extension results in reduced posterior laxity

Purpose. To describe a 10-year long history of recurrent displacement and infection in a 37 yo female patient, HIV+/HCV+, with an history of drug addiction. Clinical History. Starting from avascular necrosis of the hip (caused by prolonged HAART therapy), the patient underwent first uncemented THA in 2003. One month after implant a septic mobilization due to local abscess was treated with first two stage revision surgery (modular stem with use of retention liner for intraoperatory instability and dislocation of the implant) that lasted for almost 6 years. After 6 years of apparent good clinical condition and stability of the implants, the patient came back with a septic state of the hip, and recurrent instability, caused by complete abruption of the cup from acetabulum (Figure 1) Another two stage revision was planned; patient suffered dislocation of the spacer in first hours after intervention and 3 months later was performed second stage revision (stem with modular neck and head, cup with augmentation metal liner). Three days later patient suffered from another dislocation, so implant was further revised (change of modular neck + dual mobility head/cup), and a pelvipodalic cast was even made, considering the poor compliance of the patient,. One month later, due to another local septic state of the hip and in consideration of clinical history, a DAIR procedure was performed with revision of limited modular components until intraoperative stability was assessed (metal spacer + metal liner + dual mobility head and cup). For further assurance, an external fixator was placed around the hip (Figure 2). Results. After last intervention no dislocation occurred and external fixation was removed with success after 2 months. Clinical outcome at 2 years showed a good functional outcome, and painless walking with only one crutch and limited limping. Discussion. This is a challenging case in which the comorbidity of immunosuppression, poor compliance of the patient and multiple hip revision surgery, started a very long sequence of complications and led to poor clinical results for years. Although the use of modularity aids reaching good stability and function in this kind of revision surgery, only a good control of general conditions of the patient and a multidisciplinary approach to correct patient's lifestyle has brought to stability and “up to now” endurance for this THA implant

Introduction. Both cross and lateral pinning are common techniques used for displaced supracondylar elbow fractures in children. Our study aims to determine whether there are any radiological differences in outcome between the two techniques. Most recent studies involving radiological evaluation of supracondylar fractures had concentrated on use of Bauman's angle or humerocapitellar angles. Rotational displacement, which has been shown to be critical for stability, is often not adequately addressed. Our evaluation measures both linear displacement using Bauman's angle and rotational displacement through the measurement of the lateral rotational percentage (LRP). Method. We retrospectively reviewed the radiographs of all type III supracondylar fractures reduced with either crossed pins (one medial and one lateral, one medial and two lateral) or lateral pins (two or three lateral) between 2002 and 2006 at the Royal Children's Hospital. A good quality AP and lateral radiograph taken preoperatively, immediately postoperatively, and at the first follow up session was required for patients to be included in the study. Those that had LRP change of greater than 10% were further investigated. Results. 66 of the 184 patients identified with type III supracondylar fracture with k wire fixation had adequate radiographs for the study. Thirty-three in the lateral pinning group and 33 in the cross pinning group. Results using Mann-Whitely test show nil significant differenced between the crossed and lateral pinned groups in terms of both Bauman's (p value 0.5767) angle and Lateral Rotational Profile (p value 0.063). Those that had LRP change were further investigated. The results showed that there was no difference between the cross pinning and lateral pinning in carrying angle or range of motion by the time of their last follow up. Conclusion. There is no significant difference in terms of the rate of loss of reduction radiologically using either the lateral pinning or crossed pinning method for treatment of type III supracondylar fractures in children

Purpose

This studyevaluated the results of the acetabular medial wall osteotomy to reconstruct the acetabulum in dysplastic hip during total hip athroplasty.

Purpose:

Paediatric forearm fractures are commonly seen and treated by closed reduction and plaster cast application in theatre. Historically, cast application has been subjectively evaluated for its adequacy in maintaining fracture reduction. More recently emphasis has been placed on objectively evaluating the adequacy of cast application using indicators such as the Canterbury index (CI). The CI has been used in predicting post-reduction, re-displacement risk of patients by expressing the casting and padding indices as a ratio.

The CI has been criticized for not including cast 3 point pressure, fracture personality and lack of standardization of X-ray views as well as practical requirement of physical measurement using rulers.

The aim of this study was to determine whether subjective evaluation of these indices, on intra-operative fluoroscopy and the day 1 to 7 postoperative X-ray, was accurate in predicting a patient's ultimate risk of re-displacement, following reduction and casting.

A fracture of the tuberosity is associated with 16% of anterior glenohumeral dislocations. Manipulation of these injuries in the emergency department is safe with less than 1% risk of fracture propagation. However, there is a risk of associated neurological injury, recurrent instability and displacement of the greater tuberosity fragment. The risks and outcomes of these complications have not previously been reported. The purpose of this study was to establish the incidence and outcome of complications associated with this pattern of injury. We reviewed 339 consecutive glenohumeral dislocations with associated greater tuberosity fractures from a prospective trauma database. Documentation and radiographs were studied and the incidence of neurovascular compromise, greater tuberosity fragment migration and intervention and recurrent instability recorded. The mean age was 61 years (range, 18–96) with a female preponderance (140:199 male:female). At presentation 24% (n=78) patients had a nerve injury, with axillary nerve being most common (n=43, 55%). Of those patients with nerve injuries 15 (19%) did not resolve. Greater tuberosity displacement >5mm was observed in 36% (n=123) of patients with 40 undergoing acute surgery, the remainder did not due to comorbidities or patient choice. Persistent displacement after reduction accounted for 60 cases, later displacement within 6 weeks occurred in 63 patients. Recurrent instability occurred in 4 (1%) patients. Patient reported outcomes were poor with average EQ5D being 0.73, QDASH score of 16 and Oxford Shoulder Score of 41. Anterior glenohumeral dislocation with associated greater tuberosity fracture is common with poor long term patient reported outcomes. Our results demonstrate there is a high rate of neurological deficits at presentation with the majority resolving spontaneously. Recurrent instability is rare. Late tuberosity fragment displacement occurs in 18% of patients and regular follow-up for 6 weeks is recommended to detect this

Introduction. Knee dislocations, vascular injuries and floating knee injuries can be initially managed by a external fixator. Fixator design constructs include the AO pattern and the Diamond pattern. However, these traditional constructs do not adhere to basic principles of external fixation. The Manchester pattern knee-spanning external fixator is a new construct pattern, which uses beam loading and multiplanar fixation. There is no data on any construct pattern. This study compares the stability of these designs. Materials & Methods. Hoffman III (Stryker, USA) external fixation constructs were applied to articulated models of the lower limb, spanning the knee with a diamond pattern and a Manchester pattern. The stiffness was loaded both statically and cyclically with a Bose 3510 Electroforce mechanical testing jig (TA Instruments). A ramp to load test was performed initially and cyclical loading for measurement of stiffness over the test period. The results were analysed with a paired t-test and ANOVA. Results. The mean stiffness with the diamond pattern fixator was significantly less stiff than the Manchester pattern fixator – by a factor of 3 (40N/mm vs 115N/mm). Displacement increased in all patterns over simulated loading equating to six weeks. The diamond pattern demonstrated a 50%% increase in displacement over time. The Manchester pattern demonstrated only 20% increase in displacement over time. These are all statistically significant (p<0.01). Conclusions. The aim of an external fixator in knee dislocations and vascular injuries is to provide stability, prevent displacement and protect repairs. Vascular injuries often require fixation for several weeks to protect a repair. The Manchester pattern, applying the principles of external fixation, provides a stiffer construct and also confers greater stability over the time a fixator may be required. We commend this more informed design for the management of knee dislocations and vascular injuries

Minimally displaced paediatric proximal humerus fractures (PHFs) can be reliably managed non-operatively, however there is considerable debate regarding the appropriate management of severely displaced PHFs, particularly in older children and adolescents with limited remodelling potential. The purpose of this study was to perform a systematic review to answer the questions: “What are the functional and quality-of-life outcomes of paediatric PHFs?” and “What factors have been associated with a poorer outcome?”. A review of Medline and EMBASE was performed on 4. th. July 2021 using search terms relevant to PHFs, surgery, non-operative management, paediatrics and outcomes. Studies including ≥10 paediatric patients with PHFs, which assessed clinical outcomes by use of an established outcome measure, were selected. The following clinical information was collected: participant characteristics, treatment, complications, and outcomes. Twelve articles were selected, including four prospective cohort studies and eight retrospective cohort studies. Favourable outcome scores were found for patients with minimally displaced fractures, and for children aged less than ten years, irrespective of treatment methodology or grade of fracture displacement. Older age at injury and higher grade of fracture displacement were reported as risk factors for a poorer patient-reported outcome score. An excellent functional outcome can be expected following non-operative management for minimally displaced paediatric PHFs. Prospective trials are required to establish a guideline for the management of severely displaced PHFs in children and adolescents according to fracture displacement and the degree of skeletal maturity

Aims. During the COVID-19 pandemic, drilling has been classified as an aerosol-generating procedure. However, there is limited evidence on the effects of bone drilling on splatter generation. Our aim was to quantify the effect of drilling on splatter generation within the orthopaedic operative setting. Methods. This study was performed using a Stryker System 7 dual rotating drill at full speed. Two fluid mediums (Videne (Solution 1) and Fluorescein (Solution 2)) were used to simulate drill splatter conditions. Drilling occurred at saw bone level (0 cm) and at different heights (20 cm, 50 cm, and 100 cm) above the target to simulate the surgeon ‘working arm length’, with and without using a drill guide. The furthest droplets were marked and the droplet displacement was measured in cm. A surgical microscope was used to detect microscopic droplets. Results. Bone drilling produced 5 cm and 7 cm droplet displacement using Solutions 1 and 2, respectively. Drilling at 100 cm above the target produced the greatest splatter generation with a 95 cm macroscopic droplet displacement using Solution 2. Microscopic droplet generation was noticed at further distances than what can be macroscopically seen using Solution 1 (98 cm). Using the drill guide, there was negligible drill splatter generation. Conclusion. Our study has shown lower than anticipated drill splatter generation. The use of a drill guide acted as a protective measure and significantly reduced drill splatter. We therefore recommend using a drill guide at all times to reduce the risk of viral transmission in the operative setting. Cite this article: Bone Jt Open 2021;2(9):752–756