Introduction. Hip and knee arthroplasty present surgeons with difficult bone loss. In these cases the use of morselized allograft is a well established way of optimizing early implant fixation. In revisions, the surgical field is potentially infected. The use of allograft bone creates a “dead space” in which the immune system has impaired access, and even a small amount of bacteria may therefore theoretically increase the risk of infection. In vivo studies have shown that allograft bone is suitable as a vehicle of local antibiotic delivery. We hypothesized that the allograft bone could be used as a local antibiotic delivery vehicle without impairing the implant fixation, tested by mechanical push-out. Material and Methods. Following approval of the Institutional Animal Care and use Committee we implanted a cylindrical (10×6 mm) porous-coated Ti implant in each distal femur of 12 dogs observed for 4 weeks. The implants were surrounded by a circumferential gap of 2.5 mm impacted with a standardized volume of morselized allograft. In the two intervention groups, 0.2ml tobramycin solution of high (800mg/ml) and low (200mg/ml) concentration was added to the allograft, respectively. In the control group 0.2ml saline was added to the allograft. ANOVA-test was applied followed by paired t-test where appropriate. A p-value < 0,05 was considered statistically significant. Results. The impregnation of allograft bone revealed a relative decrease in biomechanical fixation. The decrease was higher in the high dose group than in the low dose group. The most extreme difference was a decrease in strength by 18% (P = 0,511), stiffness 15% (P = 0,135) and energy absorption 27% (P = 0,784). Conclusion. The result shows a trend towards a decrease in implant fixation correlating with the antibiotic concentration. Although the results are not statistically significant the use of antibiotic impregnation should be used with caution until further reaserch has been conducted

Introduction. The combined incubation of a composite scaffold with bone marrow stromal cells in a perfusion bioreactor could make up a novel hybrid graft material with optimal properties for early fixation of implant to bone. The aim of this study was to create a bioreactor activated graft (BAG) material, which could induce early implant fixation similar to that of allograft. Two porous scaffold materials incubated with cells in a perfusion bioreactor were tested in this study. Methods and Materials. Two groups of 8 skeletally mature female sheep were anaesthetized before aspiration of bone marrow from the iliac crest. For both groups, mononuclear cells were isolated, and injected into a perfusion bioreactor (Millenium Biologix AG, Switzerland). Scaffold granules Ø∼900–1500 μm, ∼88% porosity) in group 1, consisted of hydroxyapatite (HA, 70%) with -tricalcium-phosphate (−TCP, 30%) (Danish Technological Institute, Denmark). The granules were coated with poly-lactic acid (PLA) 12%, in order to increase the mechanical strength of the material (Phusis, France). Scaffold granules Ø∼900–1400 μm, 80% porosity) in group 2 consisted of pure HA/-TCP (Fin Ceramica, Italy). For both groups, cells were incubated in the bioreactor for 2 weeks. Fresh culture medium supplemented with dexamethasone and ascorbic-acid was added every third or fourth day. Porous titanium alloy implants with diameter=length=10mm (Biomet, USA) were inserted bilaterally in each of the distal femurs of the sheep; thus 4 implants in each sheep. The concentric gap (2 mm) surrounding the implant was filled with 1) BAG (autogenous), 2) granules, 3) granules+bone marrow aspirate (BMA, autologous) or 4) allograft. The sheep were euthanized after 6 weeks. Distal femurs were removed and implant-bone samples were divided in two parts. The superficial part was used for mechanical testing and micro-CT scanning, and the profound part for histomorphometry. Push-out tests were performed on an 858 Bionix MTS hydraulic materials testing machine. Shear mechanical properties between implant and newly generated bone were calculated to assess implant fixation. Results were assessed by One-way ANOVA. P-values less than 0.05 were considered significant. Results. One sheep in group 1 had to be euthanized after 4 weeks (excluded). One implant in each group was loosened and could not undergo push-out test (excluded). Group 1: No significant differences regarding failure energy (kJ/m2, p=0.44) or ultimate shear strength (MPa, p=0.17) could be seen. Shear stiffness (MPa) was significantly higher for the allograft group (p=0.04). Group 2: No significant differences regarding failure energy (p=0.11) or shear stiffness (p=0.52) could be seen. Ultimate shear strength was significantly higher for allograft (p=0.04). Results from μ-CT scanning and histomorphometry are pending. Discussion and Conclusion. The present study shows a possible effect of bioreactor activated bone substitute on early implant fixation. We are currently working on bone microarchitecture surrounding implant and histomorphometry. These results will aid in determining if BAG could make up a promising alternative for allograft as bone graft material

Aims. The aim of this study was to describe the demographic details of patients who sustain a femoral periprosthetic fracture (PPF), the epidemiology of PPFs, PPF characteristics, and the predictors of PPF types in the UK population. Methods. This is a multicentre retrospective cohort study including adult patients presenting to hospital with a new PPF between 1 January 2018 and 31 December 2018. Data collected included: patient characteristics, comorbidities, anticoagulant use, social circumstances, level of mobility, fracture characteristics, Unified Classification System (UCS) type, and details of the original implant. Descriptive analysis by fracture location was performed, and predictors of PPF type were assessed using mixed-effects logistic regression models. Results. In total, 720 femoral PPFs from 27 NHS sites were included. PPF patients were typically elderly (mean 79.9 years (SD 10.6)), female (n = 455; 63.2%), had at least one comorbidity (n = 670; 93.1%), and were reliant on walking aids or bed-/chair-bound prior to admission (n = 419; 61.7%). The study population included 539 (74.9%) hip PPFs, 151 (21.0%) knee PPFs, and 30 (4.2%) dividing type PPFs. For hip (n = 407; 75.5%) and knee (n = 88; 58.3%) arthroplasty UCS B type fractures were most common. Overall, 556 (86.2%) were treated in the presenting hospital and 89 (13.8%) required transfer for treatment. Female sex was the only significant predictor of fracture type (A/B1/C type versus B2/B3) for femoral hip PPFs (odds ratio 0.61 (95% confidence interval 0.41 to 0.91); p = 0.014). Sex, residence type, primary versus revision implant PPF, implant fixation, and time between arthroplasty and PPF were not found to predict fracture type for hip PPFs. Conclusion. This multicentre analysis describes patient and injury factors for patients presenting with femoral PPFs to centres across the UK. These patients are generally elderly and frail, comparable to those sustaining a hip fracture. These data can be useful in planning future services and clinical trials. Cite this article: Bone Joint J 2022;104-B(8):987–996

Aims

The aim of this study was to describe services available to patients with periprosthetic femoral fracture (PPFF) in England and Wales, with focus on variation between centres and areas for care improvement.

Aims

Patients with A1 and A2 trochanteric hip fractures represent a substantial proportion of trauma caseload, and national guidelines recommend that sliding hip screws (SHS) should be used for these injuries. Despite this, intramedullary nails (IMNs) are routinely implanted in many hospitals, at extra cost and with unproven patient outcome benefit. We have used data from the National Hip Fracture Database (NHFD) to examine the use of SHS and IMN for A1 and A2 hip fractures at a national level, and to define the cost implications of management decisions that run counter to national guidelines.

Aims

The aim of this study was to describe the management and associated outcomes of patients sustaining a femoral hip periprosthetic fracture (PPF) in the UK population.

Aims

The aim of this study was to investigate the rate of revision for distal femoral arthroplasty (DFA) performed as a primary procedure for native knee fractures using data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR).

Aims

The incidence of atypical femoral fractures (AFFs) continues to increase. However, there are currently few long-term studies on the complications of AFFs and factors affecting them. Therefore, we attempted to investigate the outcomes, complications, and risk factors for complication through mid-term follow-up of more than three years.

Aims

To compare the functionality of adults with displaced mid-shaft clavicular fractures treated either operatively or nonoperatively and to compare the relative risk of nonunion and reoperation between the two groups.

Improving periprosthetic bone is essential for implant fixation and reducing peri-implant fracture risk. This studied examined the individual and combined effects of iPTH and mechanical loading at the cellular, molecular, and tissue level for periprosthetic cancellous bone. Adult rabbits had a porous titanium implant inserted bilaterally on the cancellous bone beneath a mechanical loading device on the distal lateral femur. The right femur was loaded daily, the left femur received a sham loading device, and half of the rabbits received daily PTH. Periprosthetic bone was processed up to 28 days for qPCR, histology, and uCT analysis. We observed an increase in cellular and molecular markers of osteoblast activity and decrease in adipocytic markers for both treatments, with small additional effects in the combined group. Loading and iPTH led to a decrease and increase, respectively, in osteoclast number, acting through changes in RANKL/OPG expression. Changes in SOST and beta-catenin mRNA levels suggested an integral role for the Wnt pathway. We observed strong singular effects on BV/TV of both loading (1.53 fold) and iPTH (1.54 fold). Combined treatment showed a small additive effect on bone volume. In conclusion, loading and iPTH act through a pro-osteoblastic/anti-adipocytic response and through control of bone turnover via changes in the RANKL/OPG pathway. These changes led to a small additional, but not synergistic, increase in bone volume with the combined therapy

The use of a total hip arthroplasty with alumina on alumina bearing couple should limit the risk of wear and secondary osteolysis. From June 1999 to December 2002, we have realised a continuous series of 265 ABGII cementless THA with Alumina bearing. The average age was 58 years (22–78 years). The main causes were osteoarthritis (81%) and osteonecrosis (13%). The operation was performed through a posterior standard approach. In all cases, an anatomic cementless ABG II stem and an acetabular cementless ABG II cup were implanted. The bearing couple was always Alumina Biolox Forte with a 28 mm femoral head in 99% of cases. To date, 12 patients died and 17 patients were lost to follow up (6.4%). 224 patients (232 hips) had a regular clinical and radiological follow-up. The mean follow up was 8.5 years (5–11 years). 9 patients were revised for septic loosening (4cases), femoral fracture (4 cases) and inveterate dislocation (1 case). There was no aseptic loosening. The overall survival rate at more than 10 years is 96.6%. We deplore 2 cases of postoperative dislocation. In this series, we did not observe any breakage of ceramic implant. The clinical and functional outcome is good and stable over time with an average PMA score at 17.6 and an average Harris score at 97.3. 16 patients reported at least one or more episode of abnormal noise “Squeaking” type (6%). It is most often a mild noise and it occurs in a static bending position. This noise disappeared with time in 10 cases. It never necessitated a prosthetic revision. The radiological control does not show any wear. There is no evidence of acetabular or femoral osteolysis. The radiological implant fixation according to the Engh and ARA criteria was good and stable in all cases. This series demonstrate that the implantation of an anatomic cementless HA arthroplasty with an alumina bearing in a young and active patient prevents the risk of wear and osteolysis and improves durability over time. The use of a 28 mm head does not increase the risk of instability and we did not observe failure of the ceramic implants

Background. Second-generation high-carbon CoCrMo-alloy metal-on-metal total hip arthroplasty (THA) was introduced in the late 1980s following reports of early loosening, impingement, pronounced wear, and hypersensitivity in the first-generation metal-on-metal articulations. There has been inconsistent data that specifically addresses the clinical performance and longevity of second-generation metal-on-metal THA. The purpose of this study was to evaluate the survival of second-generation metal-on-metal primary THA and to assess the influence of demographic factors on implant survival in a large patient cohort. Methods. One thousand two hundred and seventy second-generation 28 mm metal-on-metal primary THA in 1121 patients were performed at one institution from 1994 to 2004. According to the International Documentation and Evaluation System patients were followed routinely at one year, two years and every five years thereafter. Clinical and radiographic outcome data was prospectively recorded using a hospital joint registry. At a mean follow-up of 6.8 years postoperatively, the probability of survival of THA was estimated using the method of Kaplan and Meier. Relative risk factors for implant failure that included age, gender, BMI, type of implant fixation and size of implant components were calculated using the Cox proportional-hazards model. Results. Sixty three (5%) hips were revised because of aseptic loosening (28 hips), infection (8 hips), periprosthetic fracture (8 hips), recurrent dislocation (8 hips), pain without implant loosening (7 hips) and breakage of the cup (4 hips). The probability of survival at ten years, with revision for any reason as the endpoint, for the THA as a whole was 0.90 (95% confidence interval, 0.87 to 0.94). The probability of survival for the cup was 0.90 (95% confidence interval, 0.86 to 0.93) and for the stem 0.94 (95% confidence interval, 0.91 to 0.97). No demographic factors or covariates were found to significantly affect survivorship. Conclusion. Second-generation metal-on-metal primary THA did not demonstrate a superior probability of survival at ten years compared with previous reports on other weight-bearing surfaces. Based on these findings and with consideration of concerns that relate to putative local and systemic toxicity of metal debris, the use of second-generation metal-on-metal articulations for primary THA remains moot

Distal radius fractures are typical and frequent fracture of elderly woman with reduced bone density. Thus implant fixation is more difficult. Dorsal and radial comminution are frequent in these patients and so reduction and angle stable osteosynthesis needed. The angle stable plate, often also multidirectional is today the most common stabilisation device. Because of the introduction of bulky and bended implants as the Micronail or Targon DR wich require difficult opening of the bone with awles we decided to test the XS radius nail witch is a 4,5mm or 3,5mm straight nail and witch is introduced after guide wire placement and over drilling with a canulated drill of the same diameter. It is locked parallel to the joint in 3 different directions with angular stability with threaded wires. Methods 16 radius sawbones were osteotomised corresponding to a A3 Fracture and stabilised with a angle stable plate (8) and XS nail (8). 1000 alternating load cycles from 20–200N were performed and the deformation was registered. Also a FE analysis with the MSC Patran/Marc softwere were performed. Also the calculated deformation in the FE study was 20% lower. Also deformation amplitude was lower with 0.31mm compared to 0.42mm in the plate group. The differences however were not significant. Both devices show good biomechanical results. The XS nail has the advantage of mainly intraosseus position, simple operation technique with introduction over a guide wire from the proc. Styloideus radii and over drilling with a canulated drill of the same size. The exposure of the N rad. superf. must be performed. First clinical evaluation is presented. Due to the results we developed a anatomically adapted XS radius nail. The results of the first 100 patients are presented. Conclusions. Both angular stable plate and XSR nail can be used in unstable distal radius fracture fixation. The mainly intraosseus position of the nail and saving of the pronator quadratus as well as lower deformation are in favour of the XSR nail. However frontal plane fractures and very comminuted fractures are better treated with a multidirectional locking plate due to technical reasones so that we use the XSR nail mainly in A3 and C1 fractures

Background. In Sweden approximately 6000 patients yearly sustain displaced femoral neck fractures. During the last decade there has been a shift towards more arthroplasties at the expense of internal fixation. In 2008 approximately 75% of the dislocated femoral neck fractures in Sweden were treated with arthroplasties. Those patients are typically elderly and frail and the vast majority of them receive hemiarthroplasties. In 2005 a national hemiarthroplasty registration was established as part of the Swedish Hip Arthroplasty Register (SHAR). Material & Method. The SHAR aims to register all hemiarthroplasties performed in Sweden, including primary and salvage procedures. Surgical and patient details are recorded and re-operations are registered. Results. 21.346 hemiarthroplasties were recorded from 2005 through 2009. The most common diagnosis, acute fracture of the femoral neck, increased from 91.3 to 94.3 percent during this period. The most commonly used stems (i.e. the Lubinus SP II and the Exeter stems) accounted for 68.3 percent of the implants. In total 743 patients (3,6%) underwent additional surgery and the most common reason for this was dislocation. The strongest risk factors for re-operation and revision (Cox regression analysis) were hemiarthroplasty due to failed internal fixation (rr 2.1, 95%CI 1.7–2.7) and uncemented stem (2.0, CI 1.5–2.6). Even when only modern uncemented implants are analyzed (i.e. exclusion of Austin-Moore) we can still see an increased risk of any re-operation(1.8, CI 1.3–2.5) and re-operation due to periprosthetic fracture (3.8, CI 2.0–7.1). Bipolar hemiarthroplasty heads also increased the risk of re-operation, especially due to dislocation (1.4, CI 1.1–1.8). The most used bipolar head (Variocup) has no increased risk of re-operation compared to all other bipolar heads generally, but an increased risk of re-operation due to dislocation (1.7, CI 1.2–2.4). Anterolateral surgical approach (Gammer and Hardinge) decreased the risk of re-operation due to dislocation (0.63, CI 0,53-0.83). Other risk factors are male gender and age above 75 years. During the period the use of monoblock type implants decreased from 17.8 to 0.9 percent. Use of uncemented implants decreased from 10.4 percent in 2005 to 3.0 percent in 2009 and the number of procedures performed with anterolateral approach increased from 46.7 to 55.9 percent. Conclusion. The SHAR have identified risk factors for re-operation and subsequently some important changes have been seen in choice of implant and fixation. We conclude that the results from the hemiarthroplasty registration have a large impact on the methods and implants chosen by the Swedish orthopaedic surgeons and therefore is an important tool in the continuing effort for improving the patient care

Objectives

The PROximal Fracture of the Humerus: Evaluation by Randomisation (PROFHER) trial has recently demonstrated that surgery is non-superior to non-operative treatment in the management of displaced proximal humeral fractures. The objective of this study was to assess current surgical practice in the context of the PROFHER trial in terms of patient demographics, injury characteristics and the nature of the surgical treatment.

Filling the empty holes in peri-articular locking plates may improve the fatigue strength of the fixation. The purpose of this in vitro study was to investigate the effect of plugging the unused holes on the fatigue life of peri-articular distal femoral plates used to fix a comminuted supracondylar fracture model.

A locking/compression plate was applied to 33 synthetic femurs and then a 6 cm metaphyseal defect was created (AO Type 33-A3). The specimens were then divided into three groups: unplugged, plugged with locking screw only and fully plugged holes. They were then tested using a stepwise or run-out fatigue protocol, each applying cyclic physiological multiaxial loads.

All specimens in the stepwise group failed at the 770 N load level. The mean number of cycles to failure for the stepwise specimen was 25 500 cycles (sd 1500), 28 800 cycles (sd 6300), and 26 400 cycles (sd 2300) cycles for the unplugged, screw only and fully plugged configurations, respectively (p = 0.16). The mean number of cycles to failure for the run-out specimens was 42 800 cycles (sd 10 700), 36 000 cycles (sd 7200), and 36 600 cycles (sd 10 000) for the unplugged, screw only and fully plugged configurations, respectively (p = 0.50). There were also no differences in axial or torsional stiffness between the constructs. The failures were through the screw holes at the level of comminution.

In conclusion, filling the empty combination locking/compression holes in peri-articular distal femur locking plates at the level of supracondylar comminution does not increase the fatigue life of the fixation in a comminuted supracondylar femoral fracture model (AO 33-A3) with a 6 cm gap.