Aims. Postoperative malalignment of the femur is one of the main complications in distal femur fractures. Few papers have investigated the impact of intraoperative malalignment on postoperative function and bone healing outcomes. The aim of this study was to investigate how intraoperative fracture malalignment affects postoperative bone healing and functional outcomes. Methods. In total, 140 patients were retrospectively identified from data obtained from a database of hospitals participating in a trauma research group. We divided them into two groups according to coronal plane malalignment of more than 5°: 108 had satisfactory fracture alignment (< 5°, group S), and 32 had unsatisfactory alignment (> 5°, group U). Patient characteristics and injury-related factors were recorded. We compared the rates of nonunion, implant failure, and reoperation as healing outcomes and Knee Society Score (KSS) at three, six, and 12 months as functional outcomes. We also performed a sub-analysis to assess the effect of fracture malalignment by plates and nails on postoperative outcomes. Results. The rates of nonunion and reoperation in group U were worse than those in group S (25.0% vs 14.3%; 15.6% vs 5.6%), but the differences were not significant (p = 0.180 and p = 0.126, respectively). Mean KSS in group U at all follow-up periods was significantly worse that in group S (75.7 (SD 18.8) vs 86.0 (SD 8.7); p < 0.001; 78.9 (SD 17.2) vs 89.1 (SD 9.8); p < 0.001; 85.0 (SD 11.9) vs 91.1 (SD 7.2); p = 0.002, respectively). In the sub-analysis of plates, mean KSS was significantly worse in group U at three and six months. In the sub-analysis of nails, the rate of reoperation was significantly higher in group U (28.6% vs 5.8%; p = 0.025), and mean KSS at six and 12 months was significantly worse in Group U. Conclusion. To obtain good postoperative functional results, intraoperative alignment of the coronal plane should be accurately restored to less than 5°. Cite this article: Bone Jt Open 2022;3(2):165–172

Aims. Femoral bone preparation using compaction technique has been shown to preserve bone and improve implant fixation in animal models. No long-term clinical outcomes are available. There are no significant long-term differences between compaction and broaching techniques for primary total hip arthroplasty (THA) in terms of migration, clinical, and radiological outcomes. Methods. A total of 28 patients received one-stage bilateral primary THA with cementless femoral stems (56 hips). They were randomized to compaction on one femur and broaching on the contralateral femur. Overall, 13 patients were lost to the ten-year follow-up leaving 30 hips to be evaluated in terms of stem migration (using radiostereometry), radiological changes, Harris Hip Score, Oxford Hip Score, and complications. Results. Over a mean follow-up period of 10.6 years, the mean stem subsidence was similar between groups, with a mean of -1.20 mm (95% confidence interval (CI) -2.28 to -0.12) in the broaching group and a mean of -0.73 mm (95% CI -1.65 to 0.20) in the compaction group (p = 0.07). The long-term migration patterns of all stems were similar. The clinical and radiological outcomes were similar between groups. There were two intraoperative fractures in the compaction group that were fixed with cable wire and healed without complications. No stems were revised. Conclusion. Similar stem subsidence and radiological and clinical outcomes were identified after the use of compaction and broaching techniques of the femur at long-term follow-up. Only the compaction group had intraoperative periprosthetic femur fractures, but there were no long-term consequences of these. Cite this article: Bone Jt Open 2021;2(12):1035–1042

Introduction: Intraoperative femoral fractures occurring in cementless total hip replacement are not frequent. In a series of in 350 consecutive hip replacements 15 cases of fractures were recognized and included for this study. Materials and Methods: The fractures mainly occured during the femoral preparation rather than during the definitive stem impaction. Accurate reduction and stable internal fixation were considered necessary intraoperatively. Nevertheless in 4 cases the fixation of the stem was converted into a conventional cemented one. Postoperatively the patients were allowed to have an immediat full weight bearing on the operated side in 5 cases. The remainders (10 patients) had a delayed reloading on the lower limb. In this study the clinical and radiological results of the fracture group were compared to those of a control group of 15 patients. Results: One year after surgery the Harris Hip score was no significantly different between the groups. Postoperative complication rate (deep venous thrombosis, infection, dislocation) were not different between the groups. There was a significant increase of duration of the stay of the patient in the rehabilitation center (p=0.007) in the fracture group and the patient spend more time with the physiotherapist (p=0.001)as they left the center. The fracture rate was lower when the patients were operated by a senior surgeon (p=0.021). Discussion: These results are comparable to those of the literature. Nevertheless intraoperative fractures of the proximal femur occurring in cementless total hip replacement do not jeopardize the clinical final outcome. This study emphasizes the importance of the learning–curve in cementless THR. Additional studies could assess the real costs for the medical care of such fractures

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

The most common classification of periprosthetic femoral fractures is the Vancouver classification. The classification has been validated by multiple centers. Fractures are distinguished by location, stability of the femoral component, and bone quality. Although postoperative and intraoperative fractures are classified using the same three regions, the treatment algorithm is slightly different. Type A fractures involve the greater and lesser trochanter. Fractures around the stem or just distal to the stem are Type B and subcategorised depending on stem stability and bone quality. Type C fractures are well distal to the stem and are treated independent of the stem with standard fixation techniques. The majority of fractures are either B1 (stable stem) or B2 (unstable stem). The stem is retained and ORIF of the fracture performed for B1 fractures. B2 and B3 fractures require stem revision with primary stem fixation distal to the fracture. Intraoperative fractures use the same A, B, C regions but are subtyped 1–3 as cortical perforations, nondisplaced, and displaced unstable fractures, respectively. With the exception of A1 intraoperative fractures all other intraoperative fractures require surgical treatment. A recent publication utilizing a New York state registry highlighted the patient risk of mortality associated with periprosthetic hip fractures. One month, 6 month and 1 year mortality was 3.2%, 3.8% and 9.7%, respectively. The mortality risk was lower for periprosthetic fractures treated with ORIF at 1 and 6 months compared to fractures requiring revision total hip

Background. Core decompression (CD) is effective to relieve pain and delay the advent of total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH). However, the influence of CD on the subsequent THA has not been determined yet. Methods. Literatures published up to and including November 2018 were searched in PubMed, Embase and the Cochrane library databases with predetermined terms. Comparative studies of the clinical outcomes between conversion to THA with prior CD (the Prior CD group) and primary THA (the Control group) for ONFH were included. Data was extracted systematically and a meta- analysis was performed. Results. Overall, five retrospective cohort studies with 110 hips in the Prior CD group and 237 hips in the Control group were included and all the studies were of high quality in terms of Newcastle-Ottawa Scale. No difference in the rate of revision between the two groups showed (RR=1.92, P=0.46) after a minimal two-year follow-up. Postoperative Harris Hip Score were similar between the two groups in all the five studies. Two groups went through similar blood loss (P=0.38). But the operative time in the Prior CD group with tantalum rob was longer than that in the Control group (P=0.006, P<0,001, respectively in two papers). Moreover, intraoperative fracture and osteolysis or radiolucent lines were more likely to occur in the Prior CD group, though there is not statistical difference (RR=7.05, P=0.08; RR=3.14, P=0.05, respectively). Conclusion. The present evidence indicated that prior CD has no inferior effect on the survivorship nor hip scores to the subsequent THA. The operative time in the Prior CD group with tantalum rob was longer than that in the Control group. Attention should also be paid on possible more intraoperative fracture and postoperative osteolysis or radiolucent lines. For any figures or tables, please contact authors directly

Background. Uncemented dual-tapered stems are a popular choice for primary total hip arthroplasty (THA). The purpose of this study was to examine long-term outcomes after primary THA utilizing a single dual-tapered stem. Patients and Methods. Utilizing our total joint registry, we retrospectively identified 1215 THAs (1055 patients) performed with an uncemented dual-tapered stem from 1998 to 2009. Mean age was 55 years, 70% were male, and mean BMI was 30 kg/m. 2. Mean follow-up was 10 years. Analysis included implant survivorship, clinical outcomes, and radiographic results. Results. Survivorship from stem revision for any reason was 99.0% at 5 years postoperatively and 98.4% at both 10 and 15 years. Survivorship from stem revision for aseptic loosening was 99.9% at 5-, 10-, and 15-years postoperatively. Survivorship from stem revision for periprosthetic fracture was 99.7%, 99.1%, and 98.9% at 5, 10, and 15 years postoperatively, respectively. In total, 18 (1.5%) stems underwent revision. Revisions were performed for periprosthetic fracture (10, 0.82%), infection (7, 0.58%), and aseptic loosening (1, 0.08%). Intraoperative fracture occurred in 58 (4.77%) THAs treated with cerclage wiring (52, 89.66%) or no treatment (6, 10.34%) and insertion of a standard prosthesis. At mean radiographic follow-up of 10 years, only 4 of 1084 (0.37%) stems with 1-year radiographic follow-up had any radiolucency around the proximal ongrowth coating, and only 1 (0.10%) of these had a circumferential radiolucent line (Gruen zones 1–14). Conclusions. This uncemented dual-tapered femoral stem is associated with excellent survivorship, reasonably low intraoperative fracture rate, and extremely low rates of revision for aseptic loosening, periprosthetic fracture, and infection when used for primary THA at long-term follow up. For any tables or figures, please contact the authors directly

Periprosthetic fractures after total hip arthroplasty lead to considerable morbidity in terms of loss of component fixation, bone loss and subsequent functional compromise. The prevention, early recognition and appropriate management of such fractures are therefore critical. The pathogenesis of periprosthetic factors is multi-factorial. There are a number of intrinsic patient influences such as poor bone stock, biomechanics and compliance. There are also a host of extrinsic factors over which the surgeon has more control. The key tenets for fracture avoidance include careful planning, identifying the risk, choosing the correct implant, understanding the anatomy, and using appropriate surgical technique. There are a number of recognised risk factors for periprosthetic hip fractures The prevalence of intraoperative fractures during total hip arthroplasty is higher in the patient with osteopenia / osteoporosis. Other conditions causing increased bone fragility, such as osteomalacia, Paget's disease, osteopetrosis, and osteogenesis imperfecta are also at a higher risk of intraoperative fracture. The use of more and more press fit cementless components has also increased the number of periprosthetic femoral fractures because of the force required to obtain such a fit. Complex deformities of the proximal femur, particularly when associated with a narrow medullary canal, may also increase the risk of intraoperative fractures. Revision surgery is associated with a higher risk of intraoperative fracture than primary hip replacement surgery. These fractures typically occur during hip dislocation, cement extraction, or reaming through old cement. Other risk factors for postoperative femoral fractures following total hip replacement include loosening of the prosthesis with cortical bone loss, local osteolysis, stress risers within the cortex, such as old screw holes, the ends of plates, or impingement of a loose stem against the lateral femoral cortex. The management of periprosthetic fractures requires appropriate preoperative imaging, planning and templating, the availability of the necessary expertise and equipment, and knowledge of the potential pitfalls so that these can be avoided both intraoperatively and in follow-up. There is a danger that these cases fall between the expertise of the trauma surgeon and that of the revision arthroplasty surgeon. The past two decades have afforded us clear treatment algorithms based on fracture location, component fixation and the available bone stock. We still nevertheless face the enduring challenge of an elderly population with a high level of comorbidity who struggle to rehabilitate after such injuries. Perioperative optimization is critical as we have seen prolonged hospital stays, high rates of systemic complications and a significant short term mortality in this cohort. We have also been presented with new difficult fracture patterns around anatomic cementless stems and in relation to tapered cemented and cementless stems, as well as biologically challenging transverse or oblique fractures at the tip of a stem. In many cases, fixation techniques are biomechanically and biologically doomed to fail and intramedullary stability, achieved through complex revision is required. The sequelae of periprosthetic fractures include the financial cost of fixation or revision surgery, the associated morbidity and mortality in an elderly frail population, the difficulty with mobilization if the patient cannot fully weight bear, and a poor functional outcome in a proportion of cases. The battle over which patients or fractures require fixation and which require revision surgery continues

Background. In recent years, ‘Get It Right First Time (GIRFT)’ have advocated cemented replacements in femoral part of Total hip arthroplasty (THA) especially in older patients. However, many studies were unable to show any difference in outcomes and although cemented prostheses may be associated with better short-term pain outcomes there is no clear advantage in the longer term. It is not clear when and why to do cemented instead of cementless. Aim. To assess differences in patient reported outcomes in uncemented THAs based on patient demographics in order to decide when cementless THA can be done safely. Method. Prospective data collection of consecutive 1079 uncemented THAs performed for 954 patients in single trust between 2010 and 2020. Oxford Hip Score (OHS) and complications were analysed against demographic variables (age, sex, BMI, ASA) and prosthesis features (femoral and acetabular size, offset and acetabular screws). Results. The mean pre-operative OHS was 14.6 which improved to 39.0 at 1 year follow up (P Value=0.000). There was no statistically significant difference between OHS outcome in patients aged over 70 versus younger groups. With a small number of revisable complications increase with age from 50s upwards. Male patients’ OHS score was on average 2.4 points higher than women. Men, however were 2.9 times more likely to experience fractures and high offset hips were 2.5 times more likely to experience dislocations. DAIR, intraoperative calcar fractures, post-operative fractures and dislocations were not associated with worse OHS. Patients with increased BMI had worse pre and post-operative hip functions yet, there was a significant multivariate association between increased BMI and increased improvement in OHS from pre-op to 1 year in women aged 55–80 and men under the age of 60. Femoral stem size increases with age but decreases in male patients over 80. There was no difference found in OHS between bilateral hip replacements and unilateral, nor was there any change found with laterality side of the replacement. Conclusions. This study suggests that ageing >70 is not associated with poorer outcomes despite small number of revisable complication rates that increase with age from 50 upwards. Men had marginally higher average OHS than women At 1 year. Higher BMI or ASA scores are associated with worse pre-operative hips and worse final outcome score. Despite this, the Delta OHS increases with increased BMI shown in the 55–80 year old female patients and male patients under 60. Key Words: THR, Uncemented, Oxford hip score, outcome

Aims. The aim of this meta-analysis was to compare the outcome of total elbow arthroplasty (TEA) undertaken for rheumatoid arthritis (RA) with TEA performed for post-traumatic conditions with regard to implant failure, functional outcome, and perioperative complications. Materials and Methods. We completed a comprehensive literature search on PubMed, Web of Science, Embase, and the Cochrane Library and conducted a systematic review and meta-analysis. Nine cohort studies investigated the outcome of TEA between RA and post-traumatic conditions. The preferred reporting items for systematic reviews and meta-analysis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)) guidelines and Newcastle-Ottawa scale were applied to assess the quality of the included studies. We assessed three major outcome domains: implant failures (including aseptic loosening, septic loosening, bushing wear, axle failure, component disassembly, or component fracture); functional outcomes (including arc of range of movement, Mayo Elbow Performance Score (MEPS), and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire), and perioperative complications (including deep infection, intraoperative fracture, postoperative fracture, and ulnar neuropathy). Results. This study included a total of 679 TEAs for RA (n = 482) or post-traumatic conditions (n = 197). After exclusion, all of the TEAs included in this meta-analysis were cemented with linked components. Our analysis demonstrated that the RA group was associated with a higher risk of septic loosening after TEA (odds ratio (OR) 3.96, 95% confidence interval (CI) 1.11 to 14.12), while there was an increased risk of bushing wear, axle failure, component disassembly, or component fracture in the post-traumatic group (OR 4.72, 95% CI 2.37 to 9.35). A higher MEPS (standardized mean difference 0.634, 95% CI 0.379 to 0.890) was found in the RA group. There were no significant differences in arc of range of movement, DASH questionnaire, and risk of aseptic loosening, deep infection, perioperative fracture, or ulnar neuropathy. Conclusion. The aetiology of TEA surgery appears to have an impact on the outcome in terms of specific modes of implant failures. RA patients might have a better functional outcome after TEA surgery. Cite this article: Bone Joint J 2019;101-B:1489–1497

Incidence of intraoperative fracture during cementless Total Hip Arthroplasty (THA) is increasing. This is attributed to factors such as an increase in revision procedures and the favour of cementless fixation. Intraoperative fractures often occur during the seating of cementless components. A surgical mallet and introducer are used to generate the large impaction forces necessary to seat the component, sometimes leading to excessive hoop strain in the bone. The mechanisms of bone strain during impaction are complex and occur over very short timeframes. For this reason experimental and simulation models often focus on strain shortly after the implant is introduced, or seat it quasi-statically. This may not produce a realistic representation of the magnitude of strain in the bone and dangerously under-represent fracture risk. This in-vitro study seeks to determine whether strain induced during impaction is similar both during the strike (dynamic strain) and shortly after the strike has occurred (post-strike strain). It is also asked whether post-strike strain is a reliable predictor of dynamic strain. A custom drop tower was used to seat acetabular components in 45 Sawbones models (SKU: 1522–02, Malmo, Sweden), CNC milled to represent the acetabular cavity. Ten strikes were used to seat each cup. 3 strike velocities (1.5 m/s, 2.75 m/s, 4 m/s) and 3 impact masses (600 g, 1.2 kg, 1.8 kg) were chosen to represent 9 different surgical scenarios. Two strain gages per Sawbone were mounted on the surface of the block, 2 mm from the rim of the cavity. Strain data was acquired at 50 khz. Each strain trace was then analysed to determine the peak dynamic strain during mallet strike and the static strain post-strike. A typical strain pattern was observed during seating. An initial pre-strike strain is followed by a larger dynamic peak as the implant is progressed into the bone cavity. Strain subsequently settles at a lower (tensile) value than peak dynamic post-strike, but higher than pre-strike strain. Over the 450 strikes conducted dynamic strain was on average 3.39 times larger than post-strike strain. A statistically significant linear relationship was observed between the magnitude of post-strike and dynamic strain (adjusted R. 2. =0.391, p<0.005). This indicates that, for a known scenario, post-strike strain can be used as an indicator for dynamic peak strain. However when only the maximum dynamic and post-strike strains were taken from across the 10 strikes used to seat the implant, the relationship between the two strains was not significant (R. 2. =0.300, p=0.73). This may be due to the fact that the two maximums did not often occur on the same strike. On average, max dynamic strain occurred 1.7 strikes after max post-strike strain. We conclude that peak dynamic strain is much larger than the strain immediately post-strike in a synthetic bone model. It is shown that post-strike strain is not a good predictor of dynamic strain when the max strain during any strike to seat the component is considered, or variables (such as mallet mass or velocity) are changed. It is important to consider dynamic strain in bone as well as post-strike strain in experimental or simulated bone models to ensure the most reliable prediction of fracture

Introduction and Objectives: One of the complications of hip arthroplasty is intraoperative fractures of the femur. In this study, we reviewed the incidence of intraoperative fractures in 118 hip arthroplasty surgeries using a stem from Meridian Howmedica, Rutherford, New Jersey, in an attempt to analyse the risk factors for intra-operative fractures and their relationship to short-term radiographic characteristics of the prosthesis. Our aim is to determine if there are risk factors associated with a higher incidence of intraoperative fractures in the following categories: patient, shape and dimensions of the femur, and relative size of the implant with respect to the medullary cavity. We will also determine if short-term follow up of patients with fractures yields radiographic information to indicate early loosening of the prosthesis. Materials and Methods: We studied 118 implants from consecutive operations performed from January 1997 to December 2000. The following variables were evaluated: general patient factors; local factors (characteristics of the femur); previous treatments, degree of femoral osteoporosis, type of femur, cervicodiaphyseal angle, femoral flring, “canal flare index”, cortical index, canal width 20mm proximal to the lesser trochanter, at the lesser trochanter, and 20mm distal to the lesser trochanter, pre-operative proximal and distal measurement of the stem, and if this coincides with the actual size of the stem; intraoperative factors: type of anaesthesia, patient positioning, surgical approach, experience of the surgeon, surgical time, the need for transfusion and number of units, the use of prophylactic cerclage, detection and localization of the intraoperative femoral fracture, and treatment of the same when they occurred; postoperative radiographic factors: level of cutting femoral neck, orientation of the stem (varus or valgus), proximal and distal stem size, proximal and distal packing of the canal, and length of the neck of the head of the prosthesis; radiographic factors 12 months postoperatively: stem orientation (varus or valgus), rounding of the calcar, cortical thickening, osteolysis, osteopenia, the presence of a ledge, the presence of lines of sclerosis, sinking of the stem, loosening of the ball, and the type of integration of the stem into the bone. Results: Of the 118 cases that were studied, intraoperative fractures occurred in 13 cases, representing an incidence of 11.01%, a somewhat higher rate than others have reported. We analyzed the occurrence of fractures in relation to the different variables in our study. We found a higher incidence of fractures in type A femurs (p< 0.05) and in cases of greater proximal filling by the implant (p< 0.05). Discussion and Conclusions: Though our study is limited in number of patients and length of follow-up time, it has demonstrated that the incidence of intraoperative fractures is associated with a narrow metaphyseal medullary cavity and predominately with a type A femur, which is a femur with low “canal flare index” values. Furthermore, since the risk of fracture is greater when we attempt to significantly adjust the size of the pros-thesis to the metaphysis, the incidence of fractures was higher when proximal filling was higher. However, cases of prosthesis with fractures did not present with radiographic appearance after 12 months that was worse than those femurs that were not fractured

Fracture during total hip arthroplasty occurs partly because the acquisition of fixation at the time of stem implantation depends on the operator's experience and sensation due to the absence of definite criteria. Therefore, an objective evaluation method to determine whether the stem has been appropriately implanted is necessary. We clarified the relationship between the hammering sound frequency during stem implantation and internal stress in a femoral model, and evaluated the possible usefulness of hammering sound frequency analysis for preventing intraoperative fracture. Three types of cementless stem were used. Orthopedists performed stem insertion using a procedure similar to that employed in routine operation. Stress was estimated by finite element analysis using the hammering force calculated from the loading sensor as a loading condition, and frequency analysis of hammering sound data obtained using a microphone was performed (Fig. 1). Finite element analysis showed a decrease in the hammering sound frequency with an increase in the estimated maximum stress (Fig. 2, 3). When a decrease in frequency was observed, adequate hammering had already been performed to achieve press-fit stability. Therefore, there is a possibility that the continuation of hammering induces intraoperative fractures that become a problem. Based on the relationship between stress and frequency, the evaluation of changes in frequency may be useful for preventing the development of intraoperative fractures. When a decrease in frequency is observed, the hammering force should be reduced thereafter. Hammering sound frequency analysis may allow the prediction of bone fractures that can be visually confirmed, and may be a useful objective evaluation method for the prevention of intraoperative bone fracture

Introduction: Impaction bone grafting (IBG) for revision hip surgery can be a difficult surgical skill with a fine line between construct failure from insufficient compaction and intraoperative fracture from high impaction forces. Following on from our experience in the femur, in this study we used an acetabular model to test the hypothesis that the use of vibration for IBG could reduce the peak stresses thus reducing the intraoperative fracture risk and also improve the reliability and reproducibility of the impaction technique. Methods: Revision hemi pelvis models were made (Pra-prosky Type 2a). A standard impaction technique was used for the control group, and the impactor tamps were coupled with a pneumatic hammer for the vibration group. The cavity was filled in 6 set steps with strain gauge readings taken throughout. The pelvis construct was then mechanically loaded. Graft compaction and micro motion post mechanical testing was assessed with micro CT. Results: Vibration impaction led to a significant reduction (p=0.03) in the peak stresses during the impaction process. There was also significantly less variability in peak stresses for the vibration group compared to standard, both in sequential impactions by the same surgeon and between different surgeons. One medial wall fracture occurred in the control group only, similar to fractures encountered in the clinical situation. There was no significant difference in the degree of graft compaction or in the subsidence of the cup. Discussion: We believe that this new technique of applying vibration to the IBG process can reduce the risk of intraoperative fracture whilst achieving good graft compaction and implant stability. This technique therefore has the potential to widen the ‘safety margins’ of IBG and reduce the learning curve allowing more widespread adoption of the technique for replacing lost bone stock

Intraoperative fractures during primary total hip arthroplasty (THA) can occur on either the acetabular or the femoral side. A range of risk factors including smaller incision surgery, uncemented components, prior surgery, female sex, osteoporosis, and inflammatory arthritis have been identified. Acetabular fractures are rare but when they do occur often are underrecognised. It is not uncommon for intraoperative acetabular fractures to be discovered only postoperatively. Intraoperative acetabular fractures are associated with cementless implants and a number of identified anatomic risk factors. Factors related to surgical technique, including excessive under-reaming, excessive medialization with aggressive reaming, and implant designs such as an elliptical cup design are associated with higher risk. Treatment of acetabular fractures is dependent on whether they are diagnosed intraoperatively or postoperatively. When discovered intraoperatively, supplemental fixation should be added in the form of additional screw fixation, placing a pelvic plate, or using an acetabular reconstruction cage and morselised allografts. Acetabular reamings, obtained during preparation of the acetabulum, can be used for local bone graft. The goal should be stability of both the fracture and acetabular cup. Postoperatively, weight bearing and mobilization protocols may require modification, with many surgeons choosing a period of toe-touch weight-bearing in such cases. Acetabular fractures found postoperatively require the surgeon to make a judgement on the relative stability of the implant and the fracture to determine if immediate revision surgery or protected weight-bearing alone is appropriate. On the femoral side intraoperative fractures can occur around the greater trochanter, the calcar, or in the diaphysis. Fractures of the greater trochanter are problematic because of their tendency to displace due to the attachment of the abductors and the strong force they apply. Tension band wiring techniques will work for many greater trochanteric fractures while a trochanteric plate may be occasionally called for. With either form of fixation strong consideration should be given to 6–8 weeks of protected weight bearing postoperatively. Short longitudinal cracks in the medial calcar region are not rare with uncemented implants. Calcar fractures that do not extend below the lesser trochanter can often be managed with a single cerclage cable. Calcar fractures extending below the lesser trochanter should be scrutinised with additional intraoperative xrays; longer longitudinal cracks can be managed with 2 cables while more complex fractures that exit the diaphysis demand a change to a distally fixed implant and formal fracture reduction. Distal diaphyseal fractures are relatively uncommon in the primary setting, but not rare in the revision setting. When recognised intraoperatively, distal diaphyseal fractures can be treated effectively with cerclage cables. Distal diaphyseal longitudinal cracks noted postoperatively do not typically mandate a return to the OR and instead can be managed with 8 weeks of protected weight bearing

Introduction. Patients undergoing primary total hip arthroplasty (THA) with prior lumbar spine fusion (LSF) are at high risk for instability with reported incidence of dislocation as high as 8.3%. The use of dual mobility cups in patients undergoing revision THA, another high risk group, has demonstrated decreased incidence of instability. Purpose of this study was to evaluate the risk of instability in patients undergoing primary THA with a history of prior LSF using dual mobility cups. Methods. This was a multi-center retrospective study with 93 patients undergoing primary THA using a dual mobility cup with prior history of instrumented LSF. The primary outcome investigated was instability. Secondary variables investigated included number of levels fused, approach, length of stay, and other complications. The minimum follow-up time was 1 year since the majority of dislocations occur during first year following the primary THA. Results. There were 56 females and 47 males with average age of 66 years (46–87) and average BMI of 30. Mean follow up was 31 months (range 12 – 124.2). Surgical approach included: posterior (63), direct lateral (15), anterior (11), direct superior (4). 44% had one level fusion, 29% with 2 levels, and 15% with 3 or more levels fused. There were no dislocations or infections in this study group. There was one intraoperative fracture and one DVT. Conclusions. Patients undergoing primary THA with prior LSF are a high risk group with an increased risk for instability due to the loss of normal spino-pelvic relationship. The use of dual mobility cups in a high risk group of patients in this study demonstrated excellent results with no incidence of dislocation. Despite the limitations in this study with varying approaches and multiple sites, the use of dual mobility cups to decrease the incidence of instability in patients with prior LSF appears promising. For any tables or figures, please contact the authors directly

Background: Intraoperative femoral fracture is a well-known complication to primary total hip arthroplasty (THA). Experimental studies have suggested that intraoperative fractures may affect implant survival. How-ever, available clinical data are sparse. Methods: We used data from the Danish Hip Arthroplasty Registry to identify patients treated with a primary THA due to primary osteoarthritis in Denmark between 1995 and 2005 (n=39478). Data was linked to two national Danish databases to conduct time dependent implant survival analyses. Implant survival and relative risk estimates were calculated for patients treated conservatively and patients treated with osteosynthesis after sustaining intraoperative femoral fractures during THA surgery. The reference group was THA’s performed without sustaining intraoperative femoral fracture. Furthermore we assessed the relative risk for reoperations and readmission to an orthopaedic department 3 months postoperatively. Results: 282 patients (0.7%) were treated conservatively due to intraoperative femoral fracture and 237 patients (0.6%) were treated with osteosynthesis. The Kaplan– Meier survival plots revealed a significant poorer THA survival after osteosynthesis of intraoperative femoral fractures. In the 0–6 months postoperative period the adjusted relative risk (RR) for revision was 1.5 (95% CI: 1.1–1.7) for patients treated conservatively. In the same period the adjusted RR for revision was 5.7 (3.3–10.0) for patients treated with osteosynthesis. In the period 6 months to 11 years postoperatively we did not find any significant differences in the RR for revision among the groups. Interpretation: Intraoperative fractures increase the relative risk for revision the first 6 postoperative months. Therefore, patients should be informed about the risk for revision when sustaining an intraoperative femoral fracture. Further, initiatives aimed at reducing the risk of revision in the first 6 months following THA should be considered in patients with intraoperative fractures including immediate revision of the stem to a larger stem with distal fixation and restricted weight bearing

Background. Trochanteric fractures account for up to 20% of all periprosthetic fractures occurring during or after total hip arthroplasties (THAs). They are frequently managed conservatively except in cases with significant displacement. There is a paucity of literature describing the indications and results of operative or non-operative management of these fractures. Methods. 173 trochanteric fractures occurred in 171 patients, after all primary THAs performed from 1989–2017. Mean age at fracture was 64-years, with 65% being female. Mean follow-up was 7.6-years. Patient's radiographs and Harris Hip Scores (HHS) were recorded. There were 85 (49%) intraoperative and 88 postoperative fractures. Mean time from THA to fracture was 66 months for the postoperative group. 79 (46%) cases were fixed (68 intraoperative, 11 postoperative). Fixation was considered at the discretion of the surgeon. Within the 88 postoperative fractures, 30 were associated with polyethylene wear and osteolysis. 77 were initially treated conservatively and 11 were immediately fixed (8 revisions due to osteolysis, and 3 fracture fixations due to disability associated to displacement >1cm). 19 of the 30 postoperative fractures associated with polyethylene wear and osteolysis, eventually underwent revision. Results. Trochanteric union rate was 45% in the non-operative group, and 86% in the operative group (p<0.01). No patient undergoing trochanteric fracture fixation required fixation revision; however the reoperation rate for painful hardware was 6.3%. The non-operative group required unplanned fracture fixation in 3 cases: 2 associated to instability; and 1 due to pain, and displacement >1cm. The median HHS at last follow-up significantly improved when comparing the fixation and non-fixation groups (90 vs 81.5, respectively. p=0.02). Conclusions. Trochanteric fracture operative management was associated with high union rates and improved functional outcomes. When possible, intraoperative fractures should be treated with fixation; postoperative fractures were commonly treated non-operatively except in cases with osteolysis, instability or displacement greater >1cm. Summary. Operative management of periprosthetic trochanteric fractures resulted in increased fracture union rates and it improved functional outcomes. For any tables or figures, please contact the authors directly

Introduction. Metaphyseal fixation during revision total knee arthroplasties (TKAs) is important, but potentially challenging with historical cone designs. Material and manufacturing innovations have improved the size and shape of cones available, and simplified requisite bone preparation. In a very large series, we assessed implant survivorship, radiographic results, and clinical outcomes of new porous 3-D printed titanium metaphyseal cones featuring a reamer-based system. Methods. We reviewed 142 revision TKAs using 202 cones (134 tibial and 68 femoral) from 2015 to 2016. Sixty cases involved tibial and femoral cones. Most cones (149 of 202; 74%) were used for Type 2B or 3 bone loss. Mean age was 66 years, with 54 % females. Mean BMI was 34 kg/m. 2. Patients had a mean of 2.4 prior surgeries and 48% had a history of periprosthetic infection. Mean follow-up was 2 years. Results. At 2 years, survivorship free of cone revision for aseptic loosening was 100% and free of cone revision for any reason was 98%. Survivorships free of any component revision and any reoperation were 90% and 83%. Five cones had been revised at latest follow-up: 3 for infection, 1 for periprosthetic fracture, and 1 for aseptic tibial loosening. Radiographically, three unrevised femoral cones appeared loose in the presence of hinged implants, while the remainder of cones appeared stable. All cases of cone loosening occurred in Type 2B or 3 defects. Mean Knee Society scores improved from 50 preoperatively to 87 at latest follow-up (p<0.001). Three intraoperative fractures with cone impaction (two femoral, one tibial) all healed uneventfully. Conclusion. Novel 3-D printed titanium cones, with an efficient mill system, yielded excellent early survivorship and few complications in difficult revision TKAs with severe bone loss. The diversity of cone options, relative ease of preparation, and outcomes rivaling prior cone designs support the continued use of these modern cones. For figures, tables, or references, please contact authors directly

Aims

Safety concerns surrounding osseointegration are a significant barrier to replacing socket prosthesis as the standard of care following limb amputation. While implanted osseointegrated prostheses traditionally occur in two stages, a one-stage approach has emerged. Currently, there is no existing comparison of the outcomes of these different approaches. To address safety concerns, this study sought to determine whether a one-stage osseointegration procedure is associated with fewer adverse events than the two-staged approach.