Aims

Ankle fracture is one of the most common musculoskeletal injuries sustained in the UK. Many patients experience pain and physical impairment, with the consequences of the fracture and its management lasting for several months or even years. The broad aim of ankle fracture treatment is to maintain the alignment of the joint while the fracture heals, and to reduce the risks of problems, such as stiffness. More severe injuries to the ankle are routinely treated surgically. However, even with advances in surgery, there remains a risk of complications; for patients experiencing these, the associated loss of function and quality of life (Qol) is considerable. Non-surgical treatment is an alternative to surgery and involves applying a cast carefully shaped to the patient’s ankle to correct and maintain alignment of the joint with the key benefit being a reduction in the frequency of common complications of surgery. The main potential risk of non-surgical treatment is a loss of alignment with a consequent reduction in ankle function. This study aims to determine whether ankle function, four months after treatment, in patients with unstable ankle fractures treated with close contact casting is not worse than in those treated with surgical intervention, which is the current standard of care.

Aims. Brace treatment is the cornerstone of managing developmental dysplasia of the hip (DDH), yet there is a lack of evidence-based treatment protocols, which results in wide variations in practice. To resolve this, we have developed a comprehensive nonoperative treatment protocol conforming to published consensus principles, with well-defined a priori criteria for inclusion and successful treatment. Methods. This was a single-centre, prospective, longitudinal cohort study of a consecutive series of infants with ultrasound-confirmed DDH who underwent a comprehensive nonoperative brace management protocol in a unified multidisciplinary clinic between January 2012 and December 2016 with five-year follow-up radiographs. The radiological outcomes were acetabular index-lateral edge (AI-L), acetabular index-sourcil (AI-S), centre-edge angle (CEA), acetabular depth ratio (ADR), International Hip Dysplasia Institute (IHDI) grade, and evidence of avascular necrosis (AVN). At five years, each hip was classified as normal (< 1 SD), borderline dysplastic (1 to 2 SDs), or dysplastic (> 2 SDs) based on validated radiological norm-referenced values. Results. Of 993 infants assessed clinically and sonographically, 21% (212 infants, 354 abnormal hips) had DDH and were included. Of these, 95% (202 infants, 335 hips) successfully completed bracing, and 5% (ten infants, 19 hips) failed bracing due to irreducible hip(s). The success rate of bracing for unilateral dislocations was 88% (45/51 infants) and for bilateral dislocations 83% (20/24 infants). The femoral nerve palsy rate was 1% (2/212 infants). At five-year follow-up (mean 63 months (SD 5.9; 49 to 83)) the prevalence of residual dysplasia after successful brace treatment was 1.6% (5/312 hips). All hips were IHDI grade I and none had AVN. Four children (4/186; 2%) subsequently underwent surgery for residual dysplasia. Conclusion. Our comprehensive protocol for nonoperative treatment of infant DDH has shown high rates of success and extremely low rates of residual dysplasia at a mean age of five years. Cite this article: Bone Joint J 2023;105-B(8):935–942

Aims. The timing of when to remove a circular frame is crucial; early removal results in refracture or deformity, while late removal increases the patient morbidity and delay in return to work. This study was designed to assess the effectiveness of a staged reloading protocol. We report the incidence of mechanical failure following both single-stage and two stage reloading protocols and analyze the associated risk factors. Methods. We identified consecutive patients from our departmental database. Both trauma and elective cases were included, of all ages, frame types, and pathologies who underwent circular frame treatment. Our protocol is either a single-stage or two-stage process implemented by defunctioning the frame, in order to progressively increase the weightbearing load through the bone, and promote full loading prior to frame removal. Before progression, through the process we monitor patients for any increase in pain and assess radiographs for deformity or refracture. Results. There were 244 frames (230 patients) included in the analyses, of which 90 were Ilizarov type frames and 154 were hexapods. There were 149 frames which underwent single-stage reloading and 95 frames which underwent a two-stage reloading protocol. Mechanical failure occurred after frame removal in 13 frames (5%), which suffered refracture. There were no cases of change in alignment. There was no difference between refracture patients who underwent single-stage or two-stage reloading protocols (p = 0.772). In all, 14 patients had failure prevented through identification with the reloading protocol. Conclusion. Our reloading protocol is a simple and effective way to confirm the timing of frame removal and minimize the rate of mechanical failure. Similar failure rates occurred between patients undergoing single-stage and two-stage reloading protocols. If the surgeon is confident with clinical and radiological assessment, it may be possible to progress directly to stage two and decrease frame time and patient morbidity. Cite this article: Bone Jt Open 2022;3(5):359–366

Platelet-rich plasma (PRP) has been demonstrated to benefit a variety of disciplines. But there exists heterogeneity in results obtained due to lack of standardization of the preparation protocols employed in them. We aim to identify and standardize a preparation protocol for PRP with maximum recovery of platelets to obtain reproducible results across studies. Blood samples were collected from 20 healthy volunteers. The double spin protocol of PRP preparation was analyzed for variables such as centrifugal acceleration, time, and volume of blood processed and final product utilized. The final PRP prepared was investigated for platelet recovery, concentration, integrity, and viability. We noted maximum platelet recovery (86-99%) with a mean concentration factor of 6-times baseline, with double centrifugation protocol at 100xg and 1600xg for 20 minutes each. We also noted that 10 ml of blood in a 15 ml tube was the ideal volume of blood to be processed to maximize platelet recovery. We demonstrated that the lower 1/3rd is the ideal volume to be utilized for clinical application. We did not note a loss of integrity or viability of the platelets in the final product from the above-said protocol. Preparation of PRP by the double spin protocol of 10 ml of blood at 100xg and 1600xg for 20 minutes each in a 15ml tube and using the lower 1/3rd of the final product demonstrated consistent high platelet recovery (86-99%) and concentration (6x) without disturbing the platelet integrity or viability

Decellularization techniques have advanced to reduce the risk of immune rejection in transplantation. Validation of these protocols typically relies on Crapo's criteria. 1. , which include the absence of visible nuclei and low DNA content. In our study, five decellularization protocols were compared to determine the optimal approach for human fascia lata (HFL) samples. However, our findings raised questions as to why recipients can still develop immunity despite meeting validation criteria. HFL samples were decellularized using four protocols with SDS-Triton X100-DNase (D1 to D4-HFL) and one protocol using solvent-detergent-based baths (D5-HFL). The decellularized samples (D-HFL) were compared to native samples (N-HFL) using histology, and DNA content was measured. The human leukocyte antigen (HLA) content within the matrix was assessed using western blot analysis. Both D-HFL and N-HFL samples, along with negative control patches, were implanted in the backs of 28 Wistar rats. Anti-human IgG serum levels were evaluated after one month. H&E and Hoechst staining revealed the absence of residual cells in all decellularization protocols. DNA content was consistently below the critical threshold (p<0.05). All implanted D-HFL samples resulted in significantly lower anti-human IgG levels compared to N-HFL (p<0.01). However, 2.5 out of 4 rats developed immunity after being implanted with D1 to D4-HFL, with varying levels of anti-human IgG. Only rats implanted with D5-HFL showed undetectable levels of IgG and were considered non-immunized. Western blot analysis indicated that only D5-HFL had a residual HLA content below 1%. The literature on decellularization has primarily relied on Crapo's criteria, which do not consider the role of HLA mismatch in acute immune rejection. Our results suggest that a residual HLA content below 1% should also be considered to prevent immunization, even if other validation criteria are met. Further research is needed to evaluate the impact of residual HLA levels on human allotransplantation outcomes

There is no consensus regarding the optimum frequency of ultrasound for monitoring the response to Pavlik harness (PH) treatment in developmental dysplasia of hip (DDH). The purpose of our study was to determine if a limited-frequency hip ultrasound (USS) assessment in children undergoing PH treatment for DDH had an adverse effect on treatment outcomes when compared to traditional comprehensive ultrasound monitoring. This study was a single-center non-inferiority randomized controlled trial. Children aged less than six months of age with dislocated, dislocatable and stable dysplastic hips undergoing a standardized treatment program with a PH were randomized, once stability had been achieved, to our current standard USS monitoring protocol (every clinic visit) or to a limited-frequency ultrasound protocol (USS only until hip stability and then end of treatment). Groups were compared based on alpha angle at the end of treatment, acetabular indices (AI) and IHDI grade on follow up radiographs at one-year post harness and complication rates. The premise was that if there were no differences in these outcomes, either protocol could be deemed safe and effective. One hundred patients were recruited to the study; after exclusions, 42 patients completed the standard protocol (SP) and 36 completed the limited protocol (LP). There was no significant difference between the mean age between both groups at follow up x-ray (SP: 17.8 months; LP: 16.6 months; p=0.26). There was no difference between the groups in mean alpha angle at the end of treatment (SP: 69°; LP: 68.1°: p=0.25). There was no significant difference in the mean right AI at follow up (SP: 23.1°; LP: 22.0°; p=0.26), nor on the left (SP:23.3°; LP 22.8°; p=0.59). All hips in both groups were IHDI grade 1 at follow up. The only complication was one femoral nerve palsy in the SP group. In addition, the LP group underwent a 60% reduction in USS use once stable. We found that once dysplastic or dislocated hips were reduced and stable on USS, a limited- frequency ultrasound protocol was not associated with an inferior complication or radiographic outcome profile compared to a standardized PH treatment pathway. Our study supports reducing the frequency of ultrasound assessment during PH treatment of hip dysplasia. Minimizing the need for expensive, time-consuming and in-person health care interventions is critical to reducing health care costs, improving patient experience and assists the move to remote care. Removing the need for USS assessment at every PH check will expand care to centers where USS is not routinely available and will facilitate the establishment of virtual care clinics where clinical examination may be performed remotely

Aims. There is no consensus regarding optimum timing and frequency of ultrasound (US) for monitoring response to Pavlik harness (PH) treatment in developmental dysplasia of the hip (DDH). The purpose of our study was to determine if a limited-frequency hip US assessment had an adverse effect on treatment outcomes compared to traditional comprehensive US monitoring. Methods. This study was a single-centre noninferiority randomized controlled trial. Infants aged under six months whose hips were reduced and centred in the harness at initiation of treatment (stable dysplastic or subluxable), or initially decentred (subluxated or dislocated) but reduced and centred within four weeks of PH treatment, were randomized to our current standard US monitoring protocol (every clinic visit) or to a limited-frequency US protocol (US only at end of treatment). Groups were compared based on α angle and femoral head coverage at the end of PH treatment, acetabular indices, and International Hip Dysplasia Institute (IHDI) grade on one-year follow-up radiographs. Results. Overall, 100 patients were included; 42 patients completed the standard protocol (SP) and 40 completed the limited protocol (LP). There was no significant difference in mean right α angle at the end of treatment (SP 70.0° (SD 3.2°) ; LP 68.7° (SD 2.9°); p = 0.033), nor on the left (SP 69.0° (SD 3.5°); LP 68.1° (SD 3.3°); p = 0.128). There was no significant difference in mean right acetabular index at follow-up (SP 23.1° (SD 4.3°); LP 22.0° (SD 4.1°); p = 0.129), nor on the left (SP 23.3° (SD 4.2°); LP 22.8° (SD 3.9°); p = 0.284). All hips had femoral head coverage of > 50% at end of treatment, and all were IHDI grade 1 at follow-up. In addition, the LP group underwent a 60% reduction in US use once stable. Conclusion. Our study supports reducing the frequency of US assessment during PH treatment of DDH once a hip is reduced and centred. Cite this article: Bone Joint J 2022;104-B(9):1081–1088

Augmented reality simulators offer opportunities for practice of orthopaedic procedures outside of theatre environments. We developed an augmented reality simulator that allows trainees to practice pinning of paediatric supracondylar humeral fractures (SCHF) in a radiation-free environment at no extra risk to patients. The simulator is composed of a tangible child's elbow model, and simulated fluoroscopy on a tablet device. The treatment of these fractures is likely one of the first procedures involving X-ray guided wire insertion that trainee orthopaedic surgeons will encounter. This study aims to examine the extent of improvement simulator training provides to real-world operating theatre performance. This multi-centre study will involve four cohorts of New Zealand orthopaedic trainees in their SET1 year. Trainees with no simulator exposure in 2019 - 2021 will form the comparator cohort. Trainees in 2022 will receive additional, regular simulator training as the intervention cohort. The comparator cohort's performance in paediatric SCHF surgery will be retrospectively audited using routinely collected operative outcomes and parameters over a six-month period. The performance of the intervention cohorts will be collected in the same way over a comparable period. The data collected for both groups will be used to examine whether additional training with an augmented reality simulator shows improved real-world surgical outcomes compared to traditional surgical training. This protocol has been approved by the University of Otago Health Ethics committee, and the study is due for completion in 2024. This study is the first nation-wide transfer validity study of a surgical simulator in New Zealand. As of September 2022, all trainees in the intervention cohort have been recruited along with eight retrospective trainees via email. We present this protocol to maintain transparency of the prespecified research plans and ensure robust scientific methods. This protocol may also assist other researchers conducting similar studies within small populations

This prospective study explores the outcomes of the Forth Valley Protocol (FVP) for the management of acute Achilles tendon ruptures. The protocol uses ultrasound as the primary mechanism to guide treatment. All patients presenting with acute tendoachilles rupture over a three-year period were included. Patients under 18 years of age, chronic ruptures, or prior surgery to the Achilles tendon were excluded. Patients with a gap ≤2cm had conservative management following an Early Rehabilitation Protocol (ERP) and >2cm underwent surgery (if an appropriate surgical candidate). Achilles Tendon Rupture Scores (ATRS) were obtained retrospectively. Fischer's exact test was used to determine statistical significance. 158 patients were included with a mean age of 53 (range 20–89). Ultrasound scans were obtained for 121 patients (76.5%), demonstrating a mean tendon gap of 1.61cm. 143 patients managed conservatively and 15 surgically. The overall re-rupture rate was 3.8% (n=6). All the re-ruptures occurred in patients treated conservatively, but this was not found to be statistically significant (n=6, P=1.0). The overall complication rate (excluding re-ruptures) was 1.9%. ATRS was comparable between both treatment modalities (P=0.382, 0.422), with a mean score of 86.6 in the conservative group and 81.4 in the surgical group. The FVP demonstrates low re-rupture and complication rates in line with other published studies. Patients with gaps ≤2.0cm on the ultrasound can be successfully treated conservatively with an ERP. This has potential benefits in terms improved patient outcomes, satisfaction, and preservation of resources

Aims. The management of fractures of the medial epicondyle is one of the greatest controversies in paediatric fracture care, with uncertainty concerning the need for surgery. The British Society of Children’s Orthopaedic Surgery prioritized this as their most important research question in paediatric trauma. This is the protocol for a randomized controlled, multicentre, prospective superiority trial of operative fixation versus nonoperative treatment for displaced medial epicondyle fractures: the Surgery or Cast of the EpicoNdyle in Children’s Elbows (SCIENCE) trial. Methods. Children aged seven to 15 years old inclusive, who have sustained a displaced fracture of the medial epicondyle, are eligible to take part. Baseline function using the Patient-Reported Outcomes Measurement Information System (PROMIS) upper limb score, pain measured using the Wong Baker FACES pain scale, and quality of life (QoL) assessed with the EuroQol five-dimension questionnaire for younger patients (EQ-5D-Y) will be collected. Each patient will be randomly allocated (1:1, stratified using a minimization algorithm by centre and initial elbow dislocation status (i.e. dislocated or not-dislocated at presentation to the emergency department)) to either a regimen of the operative fixation or non-surgical treatment. Outcomes. At six weeks, and three, six, and 12 months, data on function, pain, sports/music participation, QoL, immobilization, and analgesia will be collected. These will also be repeated annually until the child reaches the age of 16 years. Four weeks after injury, the main outcomes plus data on complications, resource use, and school absence will be collected. The primary outcome is the PROMIS upper limb score at 12 months post-randomization. All data will be obtained through electronic questionnaires completed by the participants and/or parents/guardians. The NHS number of participants will be stored to enable future data linkage to sources of routinely collected data (i.e. Hospital Episode Statistics). Cite this article: Bone Jt Open 2024;5(1):69–77

To be able to assess the biomechanical and functional effects of ankle injury and disease it is necessary to characterise healthy ankle kinematics. Due to the anatomical complexity of the ankle, it is difficult to accurately measure the Tibiotalar and Subtalar joint angles using traditional marker-based motion capture techniques. Biplane Video X-ray (BVX) is an imaging technique that allows direct measurement of individual bones using high-speed, dynamic X-rays. The objective is to develop an in-vivo protocol for the hindfoot looking at the tibiotalar and subtalar joint during different activities of living. A bespoke raised walkway was manufactured to position the foot and ankle inside the field of view of the BVX system. Three healthy volunteers performed three gait and step-down trials while capturing Biplane Video X-Ray (125Hz, 1.25ms, 80kVp and 160 mA) and underwent MR imaging (Magnetom 3T Prisma, Siemens) which were manually segmented into 3D bone models (Simpleware Scan IP, Synopsis). Bone position and orientation for the Talus, Calcaneus and Tibia were calculated by manual matching of 3D Bone models to X-Rays (DSX Suite, C-Motion, Inc.). Kinematics were calculated using MATLAB (MathWorks, Inc. USA). Pilot results showed that for the subtalar joint there was greater range of motion (ROM) for Inversion and Dorsiflexion angles during stance phase of gait and reduced ROM for Internal Rotation compared with step down. For the tibiotalar joint, Gait had greater inversion and internal rotation ROM and reduced dorsiflexion ROM when compared with step down. The developed protocol successfully calculated the in-vivo kinematics of the tibiotalar and subtalar joints for different dynamic activities of daily living. These pilot results show the different kinematic profiles between two different activities of daily living. Future work will investigate translation kinematics of the two joints to fully characterise healthy kinematics

Aims. We introduced a self-care pathway for minimally displaced distal radius fractures, which involved the patient being discharged from a Virtual Fracture Clinic (VFC) without a physical review and being provided with written instructions on how to remove their own cast or splint at home, plus advice on exercises and return to function. Methods. All patients managed via this protocol between March and October 2020 were contacted by a medical secretary at a minimum of six months post-injury. The patients were asked to complete the Patient-Rated Wrist Evaluation (PRWE), a satisfaction questionnaire, advise if they had required surgery and/or contacted any health professional, and were also asked for any recommendations on how to improve the service. A review with a hand surgeon was organized if required, and a cost analysis was also conducted. Results. Overall 71/101 patients completed the telephone consultation; no patients required surgery, and the mean and median PRWE scores were 23.9/100 (SD 24.9) and 17.0/100 (interquartile range (IQR) 0 to 40), respectively. Mean patient satisfaction with treatment was 34.3/40 (SD 9.2), and 65 patients (92%) were satisfied or highly satisfied. In total there were 16 contact calls, 12 requests for a consultant review, no formal complaints, and 15 minor adjustment suggestions to improve patient experience. A relationship was found between intra-articular injuries and lower patient satisfaction scores (p = 0.025), however no relationship was found between PRWE scores and the nature of the fracture. Also, no relationship was found between the type of immobilization and the functional outcome or patient satisfaction. Cost analysis of the self-care pathway V traditional pathway showed a cost savings of over £13,500 per year with the new self-care model compared to the traditional model. Conclusion. Our study supports a VFC self-care pathway for patients with minimally displaced distal radius fractures. The pathway provides a good level of patient satisfaction and function. To improve the service, we will make minor amendments to our patient information sheet. Cite this article: Bone Jt Open 2022;3(9):726–732

We undertook this study to investigate the outcomes of surgical treatment for acute carpal tunnel syndrome following our protocol for concurrent nerve decompression and skeletal stabilization for bony wrist trauma to be undertaken within 48-hours. We identified all patients treated at our trauma centre following this protocol between 1 January 2014 and 31 December 2019. All patients were clinically reviewed at least 12 months following surgery and assessed using the Brief Michigan Hand Outcomes Questionnaire (bMHQ), the Boston Carpal Tunnel Questionnaire (BCTQ) and sensory assessment with Semmes-Weinstein monofilament testing. The study group was made up of 35 patients. Thirty-three patients were treated within 36-hours. Patients treated with our unit protocol for early surgery comprising nerve decompression and bony stabilization within 36-hours, report excellent outcomes at medium term follow up. We propose that nerve decompression and bony surgical stabilization should be undertaken as soon as practically possible once the diagnosis is made. This is emergent treatment to protect and preserve nerve function. In our experience, the vast majority of patients were treated within 24-hours

Aim. Local antibiotics released through a carrier is a commonly used technique to prevent infection in orthopaedic procedures. An interesting carrier in aseptic bone reconstructive surgery are bone chips impregnated with AB solution. Systemically administered Cefazolin (CFZ) is used for surgical site infection prophylaxis however in vitro study showed that fresh frozen and processed bone chips impregnated with CFZ solution completely release the CFZ within a few hours. On the other hand irradiated freeze-dried bone chips, treated with supercritical CO2 (scCO2) have been shown to be an efficient carrier for the antibiotics vancomycine or tobramycine. With this pilot study we wanted to investigate if CFZ solution impregnation of bone chips treated with scCO2 shows a more favorable release pattern of CFZ. Method. The bone chips were prepared using the standard scCO2 protocol and were impregnated with 100 mg/ml cefazolin at different timepoints during the process: before freeze drying (BC type A), after freeze drying (BC type B) and after gamma-irradiation. 0.5g of the impregnated bone grafts were incubated with 5ml of fetal calf serum (FCS) at 37°C. At 2, 4, 6, 8 and 24h of incubation 200µl of eluate was taken for analysis. After 24h the remaining FCS was removed, bone grafts were washed and new FCS (5ml) was added. Consecutive eluate samples were taken at 48, 72 and 96h of incubation. The concentration of CFZ in the eluates was measured with the validated UPLC-DAD method. Analysis was performed in triplicate. Results. The mean concentration of CFZ in the eluate obtained from BC type A incubated for 2h was higher compared to BC type B, respectively 581 mg/l and 297 mg/l. However, the elution profile is the same for both types: the CFZ concentration in the eluates drops within the first 24h from 581 mg/l to 365 mg/l (37%) for BC type A and from 297 mg/l to 132 mg/l (56%) for BC type B. After 24h no further significant CFZ release is seen. Impregnation of the bone chips before or after gamma irradiation did not affect this elution profile. Conclusions. Bone chips treated with scCO2 show a comparable elution pattern compared to non-scCO2 treated bone chips. AB release depends on the properties of the AB, making it impossible to copy the same impregnation protocol for different antibiotics. The stability of CFZ in solution at 37°C and its release are a major concern when establishing an impregnation protocol with CFZ

Objectives. The optimal protocol for antibiotic loading in the articulating cement spacers for the treatment of prosthetic joint infection (PJI) remains controversial. The objective of the present study was to investigate the effectiveness of articulating cement spacers loaded with a new combination of antibiotics. Methods. A retrospective cohort study involving 114 PJI cases treated with implantation of an articulating cement spacer between 2005 and 2016 was performed. The treatment outcomes of the conventional protocol (i.e. gentamicin and vancomycin (GV protocol)) were compared with those reported using the sophisticated antibiotic-loading protocol (i.e. vancomycin, meropenem, and amphotericin (VMA protocol)). Results. There were 62 and 52 PJI cases treated with the GV and VMA protocols, respectively. Antimicrobial susceptibility testing revealed that 22/78 of all isolates (28.2%) in this series were resistant to gentamicin, whereas there were no vancomycin-, meropenem-, or amphotericin-resistant strains. The overall infection recurrence rates were 17.7% (11/62) and 1.9% (1/52), respectively (p = 0.006). In patients with a negative preoperative culture, there was no infection recurrence reported in the VMA cohort (0/45 (0%) vs 10/54 (18.5%) in the GV cohort; p = 0.002). Multivariate analysis indicated that the VMA protocol correlated with a decreased risk of infection recurrence compared with the GV protocol (p = 0.025). Conclusion. The sophisticated VMA protocol for the loading of antibiotics in articulating cement spacers, as part of a two-stage exchange, was associated with a reduced rate of infection recurrence. This proposed protocol appears to be safe and effective, especially in patients with negative culture results prior to the first-stage operation. Cite this article: Bone Joint Res 2019;8:526–534

Objectives. The optimal protocol for antibiotic loading in the articulating cement spacers for the treatment of prosthetic joint infection (PJI) remains controversial. The objective of the present study was to investigate the effectiveness of articulating cement spacers loaded with a new combination of antibiotics. Methods. A retrospective cohort study involving 114 PJI cases treated with implantation of an articulating cement spacer between 2005 and 2016 was performed. The treatment outcomes of the conventional protocol (i.e. gentamicin and vancomycin (GV protocol)) were compared with those reported using the sophisticated antibiotic-loading protocol (i.e. vancomycin, meropenem, and amphotericin (VMA protocol)). Results. There were 62 and 52 PJI cases treated with the GV and VMA protocols, respectively. Antimicrobial susceptibility testing revealed that 22/78 of all isolates (28.2%) in this series were resistant to gentamicin, whereas there were no vancomycin-, meropenem-, or amphotericin-resistant strains. The overall infection recurrence rates were 17.7% (11/62) and 1.9% (1/52), respectively (p = 0.006). In patients with a negative preoperative culture, there was no infection recurrence reported in the VMA cohort (0/45 (0%) vs 10/54 (18.5%) in the GV cohort; p = 0.002). Multivariate analysis indicated that the VMA protocol correlated with a decreased risk of infection recurrence compared with the GV protocol (p = 0.025). Conclusion. The sophisticated VMA protocol for the loading of antibiotics in articulating cement spacers, as part of a two-stage exchange, was associated with a reduced rate of infection recurrence. This proposed protocol appears to be safe and effective, especially in patients with negative culture results prior to the first-stage operation. Cite this article: Bone Joint Res 2019;8:526–534

Implant manufacturers develop new products to improve existing fracture fixation methods or to approach new fracture challenges. New implants are commonly tested and approved with respect to their corresponding predecessor products, because the knowledge about the internal forces and moments acting on implants in the human body is unclear. The aim of this study was to evaluate and validate implant internal forces and moments of a complex physiological loading case and translate this to a standard medical device approval test. A finite elements model for a transverse femur shaft fracture (AO/OTA type 32-B2) treated with a locked plate system (AxSOS 3 Ti Waisted Compression Plate Broad, Stryker, Kalamazoo, USA) was developed and experimentally validated. The fractured construct was physiologically loaded by resulting forces on the hip joint from previously measured in-vivo loading experiments (Bergmann et. al). The forces were reduced to a level where the material response in the construct remained linear elastic. Resulting forces, moments and stresses in the implant of the fractured model were analysed and compared to the manufacturers’ approval data. The FE-model accurately predicted the behaviour of the whole construct and the micro motion of the working length of the osteosynthesis. The resulting moment reaction in the working length was 24 Nm at a load of 400 N on the hip. The maximum principle strains on the locking plate were predicted well and did not exceed 1 %. In this study we presented a protocol by the example of locked plated femur shaft fracture to calculate and validate implant internal loading using finite element analysis of a complex loading. This might be a first step to move the basis of development of new implants from experience from previous products to calculation of mechanical behaviour of the implants and therefore, promote further optimization of the implants’ design

Stable Weber B fractures are typically treated non-operatively without complications but require close monitoring due to concerns over potential medial deltoid ligament injuries and the risk of delayed talar shift. Following recent evidence suggesting this is unlikely, a functional protocol with early weight bearing was introduced at Glasgow Royal Infirmary (GRI) following a pilot audit. This study aims to evaluate the risk of delayed talar shift in isolated Weber B fractures managed with functional bracing and early weight-bearing, particularly if signs of medial ligament injury are present. We conducted a retrospective review of 148 patients with isolated Weber B fractures without talar shift at presentation that were reviewed at the virtual fracture clinic at our institution between July 2019 and June 2020. The primary outcome was the incidence of delayed talar shift. Secondary outcomes were other complications and adherence to protocol. 48 patients had medial signs present and of these 1 (2%) showed possible talar shift on X-rays at 4 weeks, and was kept under review. This patient had a normal medial clear space at 3 months. No patients with medial signs not documented (n=19) or not present (n=81) had delayed talar shift. 10% of patients (n=15) had at least 1 complication: delayed union (n=2); non-union (n=3); ongoing pain (n=14). Functional bracing with early weight-bearing is a safe, effective protocol for managing isolated Weber B fractures without initial talar shift. This study concludes that the risk of delayed talar shift is low in all patients, with or without medial signs

Abstract. Introduction. The Wells score is commonly used to assess the risk of proximal Deep Vein Thrombosis (DVT) following Knee Arthroplasty (KA). The National Institute for Health and Care Excellence (NICE) guidelines recommend an Ultrasound scan in patients with a Wells score of 2 points or more. We wanted to assess how often this protocol resulted in a scan being done and how many were negative. Methodology. Details of all postoperative Ultrasound scans performed up to 90 days were audited in a high-volume unit between 1st January 2016 and 31st December 2020. This included all Lower Limb Arthroplasty patients. Results. Out of a total of 4955 KA (4506 Total Knee Arthroplasty, 449 Unilateral Knee Arthroplasty), 449 (9.1%) had a total of 561 scans, with 17 (3.0%) scans demonstrating a proximal DVT. Thus 97.0% of Ultrasound scans were negative. Conclusion. The present NICE guidelines with the two-Level DVT Wells score are inappropriate for the management of suspected proximal DVT following KA. We propose that swelling that fails to reduce after 4 hours of elevation, or new swelling after a period of recumbent rest, would be more appropriate indications for a scan and negative scans should not be repeated without a change in symptoms. Unless there are pressing clinical indications, therapeutic anticoagulation should not commence in the absence of a diagnosis

The purpose of this study is to enhance massive bone allografts osseointegration used to reconstruct large bone defects. These allografts show >50% complication rate requiring surgical revision in 20% cases. A new protocol for total bone decellularisation exploiting the vasculature can offer a reduction of postoperative complication by annihilating immune response and improving cellular colonization/ osseointegration. The nutrient artery of 18 porcine bones - humerus/femur/radius/ulna - was cannulated. The decellularization process involved immersion and sequential perfusion with specific solvents over a course of one week. Perfusion was realized by a peristaltic pump (mean flow rate: 6ml/min). The benefit of arterial perfusion was compared to a control group kept in immersion baths without perfusion. Bone samples were processed for histology (HE, Masson's trichrome and DAPI for cell detection), immunohistochemistry (IHC : Collagen IV/elastin for intraosseous vascular system evaluation, Swine Leukocyte Antigen – SLA for immunogenicity in addition to cellular clearance) and DNA quantification. Sterility and solvent residues in the graft were also evaluated with thioglycolate test and pH test respectively. Compared to native bones, no cells could be detected and residual DNA was <50ng/mg dry weight. Intramedullary spaces were completely cleaned. IHC showed the preservation of intracortical vasculature with channels bounded by Collagen IV and elastin within Haversian systems. IHC also showed a significant decrease in SLA signaling. All grafts were sterile at the last decellularization step and showed no solvent residue. The control group kept in immersion baths, paired with 6 perfused radii/ulnae, showed that the perfusion is mandatory to ensure complete decellularisation. Our results prove the effectiveness of a new concept of total bone decellularisation by perfusion. These promising results could lead to a new technique of Vascularized Composite Allograft transposable to pre-clinical and clinical models