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. Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation. Methods. A total of 122 patients who underwent reconstruction following resection of periacetabular tumour between January 2011 and January 2020 were studied. The risk factors for dislocation were investigated with univariate and multivariate logistic regression analysis on patient-specific, resection-specific, and reconstruction-specific variables. Results. The dislocation rate was 13.9% (n = 17). The hip COR was found to be significantly shifted anteriorly and inferiorly in most patients in the dislocation group compared with the non-dislocation group. Three independent risk factors were found to be related to dislocation: resection of gluteus medius (odds ratio (OR) 3.68 (95% confidence interval (CI) 1.24 to 19.70); p = 0.039), vertical shift of COR > 18 mm (OR 24.8 (95% CI 6.23 to 128.00); p = 0.001), and sagittal shift of COR > 20 mm (OR 6.22 (95% CI 1.33 to 32.2); p = 0.026). Conclusion. Among the 17 patients who dislocated, 70.3% (n = 12) were anterior dislocations. Three independent risk factors were identified, suggesting the importance of proper restoration of the COR and the role of the gluteus medius in maintaining hip joint stability. Cite this article: Bone Joint J 2022;104-B(10):1180–1188

Abstract

Abstract. Objectives. Impingement of total hip replacements (THRs) can cause rim damage of polyethylene liners, and lead to dislocation and/or mechanical failure of liner locking mechanisms[1]. A geometric model of a THR in situ was previously developed to predict impingement for different component orientations and joint motions of activities[2]. However, the consequence of any predicted impingement is unknown. This study aimed to develop an in-vitromethod to investigate the effects of different impingement scenarios. Method. A ProSim electro-mechanical single-station hip simulator (Simulation Solutions) was used, and the 32mm diameter metal-on-polyethylene THRs (DePuy Synthes) were assessed. The THR was mounted in an inverted orientation, and the input (motion and loading) applied simulated a patient stooping over to pick an object from the floor[3]. The impingement severity was varied by continuing motion past the point of impingement by 2.5° or 5°, and compressive load applied in the medial-lateral direction was varied from 100N to 200N. Each test condition was applied for 40,000 cycles (n=3). Rim penetration was assessed using a CMM and component separation was measured during the tests. Results. Varying the impingement severity from 2.5° to 5° increased rim penetration two-fold (by >0.05mm) and increased medial-lateral component separation three-fold (by >0.3mm) (both p<0.001). Increasing the medial-lateral load had less effect on the rim penetration and component separation, with exception of rim penetration with the higher impingement severity condition. Conclusion. The impingement severity influenced the medial-lateral component separation, suggesting that increasing the impingement severity could increase the risk of dislocation. The impingement severity, which could be predicted from geometric modelling, was also found to significantly affect rim penetration, meaning this method could be used alongside geometric modelling to predict impingement severity in a range of scenarios. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Introduction

Diabetic foot disease is a major public health problem with an annual NHS expenditure in excess of £1 billion. Infection increases risk of major amputation fivefold. Due to the polymicrobial nature of diabetic foot infections, it is often difficult to isolate the correct organism with conventional culture techniques, to deliver appropriate narrow spectrum antibiotics. Rapid DNA-based technology using multi-channel arrays presents a quicker alternative and has previously been used effectively in intensive care and respiratory medicine.

Aims. In recent conflicts, most injuries to the limbs are due to blasts resulting in a large number of lower limb amputations. These lead to heterotopic ossification (HO), phantom limb pain (PLP), and functional deficit. The mechanism of blast loading produces a combined fracture and amputation. Therefore, to study these conditions, in vivo models that replicate this combined effect are required. The aim of this study is to develop a preclinical model of blast-induced lower limb amputation. Methods. Cadaveric Sprague-Dawley rats’ left hindlimbs were exposed to blast waves of 7 to 13 bar burst pressures and 7.76 ms to 12.68 ms positive duration using a shock tube. Radiographs and dissection were used to identify the injuries. Results. Higher burst pressures of 13 and 12 bar caused multiple fractures at the hip, and the right and left limbs. Lowering the pressure to 10 bar eliminated hip fractures; however, the remaining fractures were not isolated to the left limb. Further reducing the pressure to 9 bar resulted in the desired isolated fracture of the left tibia with a dramatic reduction in the fractures to other sites. Conclusion. In this paper, a rodent blast injury model has been developed in the hindlimb of cadaveric rats that combines the blast and fracture in one insult, necessitating amputation. Experimental setup with 9 bar burst pressure and 9.13 ms positive duration created a fracture at the tibia with total reduction in non-targeted fractures, rendering 9 bar burst pressure suitable for translation to a survivable model to investigate blast injury-associated diseases. Cite this article: Bone Joint Res 2021;10(3):166–173

We have developed a novel technique to analyse bone, using imaging mass cytometry (IMC) without the constraints of using immunofluorescent histochemistry. IMC can measure the expression of over 40 proteins simultaneously, without autofluorescence. We analysed mitochondrial respiratory chain (RC) protein deficiencies in human bone which are thought to contribute to osteoporosis with increasing age.

Osteoporosis is characterised by reduced bone mineral density (BMD) and fragility fractures. Humans accumulate mitochondrial mutations and RC deficiency with age and this has been linked to the changing phenotype in advancing age and age-related disease. Mitochondrial mutations are detectable from the age of 30 onwards, coincidently the age BMD begins to decline. Mitochondria contain their own genome which accumulates somatic variants at around 10 times the rate of nuclear DNA. Once these mutations exceed a threshold, RC deficiency and cellular dysfunction occur. The PolgD257A/D257A mouse model expresses a proof-reading deficient version of PolgA, a mtDNA polymerase. These mice accumulate mutations 3-5 times higher than wild-type mice showing enhanced levels of age-related osteoporosis and RC deficiency in osteoblasts.

Bone samples were analysed from young and old patients, developing a protocol and analysis framework for IMC in bone tissue sections to analyse osteoblasts in-situ for RC deficiency.

Samples from the femoral neck of 10 older healthy volunteers aged 40 – 85 were compared with samples from young patients aged 1-19. We have identified RC complex I defect in osteoblasts from 6 of the older volunteers, complex II defects in 2 of the older volunteers, complex IV defect in just 1 older volunteer, and complex V defect in 4 of the older volunteers.

These observations are consistent with the PolgD257A/D257A mouse-model and suggest that RC deficiency, due to age-related pathogenic mitochondrial DNA mutations, may play a significant role in the pathogenesis of human age-related osteoporosis.

Aims. Periprosthetic joint infections (PJIs) are rare, but represent a great burden for the patient. In addition, the incidence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing. The aim of this rat experiment was therefore to compare the antibiotics commonly used in the treatment of PJIs caused by MRSA. Methods. For this purpose, sterilized steel implants were implanted into the femur of 77 rats. The metal devices were inoculated with suspensions of two different MRSA strains. The animals were divided into groups and treated with vancomycin, linezolid, cotrimoxazole, or rifampin as monotherapy, or with combination of antibiotics over a period of 14 days. After a two-day antibiotic-free interval, the implant was explanted, and bone, muscle, and periarticular tissue were microbiologically analyzed. Results. Vancomycin and linezolid were able to significantly (p < 0.05) reduce the MRSA bacterial count at implants. No significant effect was found at the bone. Rifampin was the only monotherapy that significantly reduced the bacterial count on implant and bone. The combination with vancomycin or linezolid showed significant efficacy. Treatment with cotrimoxazole alone did not achieve a significant bacterial count reduction. The combination of linezolid plus rifampin was significantly more effective on implant and bone than the control group in both trials. Conclusion. Although rifampicin is effective as a monotherapy, it should not be used because of the high rate of resistance development. Our animal experiments showed the great importance of combination antibiotic therapies. In the future, investigations with higher case numbers, varied bacterial concentrations, and changes in individual drug dosages will be necessary to be able to draw an exact comparison, possibly within a clinical trial. Cite this article: Bone Joint Res 2022;11(3):143–151

Introduction. Total hip arthroplasty (THA) is an effective surgery for the treatment of advanced osteoarthritis but increasing numbers of these procedures are having a significant impact on healthcare budgets. One route to mitigate the increasing costs is outpatient THA, discharging patients on the same day as their surgery. The purpose of this study was to determine the cost of outpatient THA compared to standard overnight stay in hospital. Methods. This was a prospective-randomized controlled trial for patients undergoing primary THA through a direct anterior approach. Participants were randomized to be discharged on the same day as surgery, as outpatients, or on day one post-surgery, as inpatients, using a Zelen consent model. Adverse events were assessed, and participants completed self-reported cost questionnaires at two-, six- and 12-weeks post-surgery, and the WOMAC preoperatively and at 12-weeks post-surgery. We performed a cost analysis from health care payer (HCP) and societal perspectives. Results. 106 patients were enrolled in this study, with 50 randomized to outpatient and 56 randomized to inpatient THA. Seven patients from the outpatient group and five patients from the inpatient group crossed-over. Adverse event rate was similar between the groups with seven events in four participants in the inpatient group and three events in two participants in the outpatient group. WOMAC scores were not significantly different between the groups (p=0.12). From both a HCP and societal perspective, inpatient THA was more costly than outpatient THA. The cost difference was $3,353.15 for HCP (p<0.0001) and $3,703.30 for societal (p=0.003) in favour of outpatient THA. Conclusion. Our results suggest that outpatient THA is a cost-saving procedure when compared to inpatient THA from both HCP and societal perspectives. We will continue recruitment to investigate whether these results hold true in a larger sample as well as assess for cost-effectiveness, patient safety and satisfaction. Acknowledgements. This study was supported by the Opportunities Fund of the Academic Health Sciences Centre Alternative Funding Plan of the Academic Medical Organization of Southwestern Ontario (AMOSO). We also received funding from the PSI Foundation. For any tables or figures, please contact the authors directly

Aims. Surgery is often indicated in patients with metastatic bone disease (MBD) to improve pain and maximize function. Few studies are available which report on clinically meaningful outcomes such as quality of life, function, and pain relief after surgery for MBD. This is the published protocol for the Bone Metastasis Audit — Patient Reported Outcomes (BoMA-PRO) multicentre MBD study. The primary objective is to ascertain patient-reported quality of life at three to 24 months post-surgery for MBD. Methods. This will be a prospective, longitudinal study across six UK orthopaedic centres powered to identify the influence of ten patient variables on quality of life at three months after surgery for MBD. Adult patients managed for bone metastases will be screened by their treating consultant and posted out participant materials. If they opt in to participate, they will receive questionnaire packs at regular intervals from three to 24 months post-surgery and their electronic records will be screened until death or five years from recruitment. The primary outcome is quality of life as measured by the European Organisation for Research and the Treatment of Cancer Quality of Life questionnaire (EORTC-QLQ) C30 questionnaire. The protocol has been approved by the Newcastle & North Tyneside 2 Research Ethics Committee (REC ref 19/NE/0303) and the study is funded by the Royal College of Physicians and Surgeons of Glasgow (RCPSG) and the Association for Cancer Surgery (BASO-ACS). Discussion. This will be the first powered study internationally to investigate patient-reported outcomes after orthopaedic treatment for bone metastases. We will assess quality of life, function, and pain relief at three to 24 months post-surgery and identify which patient variables are significantly associated with a good outcome after MBD treatment. Cite this article: Bone Jt Open 2021;2(2):79–85

Aims. To investigate metallosis in patients with magnetically controlled growing rods (MCGRs) and characterize the metal particle profile of the tissues surrounding the rod. Methods. This was a prospective observational study of patients with early onset scoliosis (EOS) treated with MCGRs and undergoing rod exchange who were consecutively recruited between February 2019 and January 2020. Ten patients were recruited (mean age 12 years (SD 1.3); 2 M:8 F). The configurations of the MCGR were studied to reveal the distraction mechanisms, with crucial rod parts being the distractable piston rod and the magnetically driven rotor inside the barrel of the MCGR. Metal-on-metal contact in the form of ring-like wear marks on the piston was found on the distracted portion of the piston immediately outside the barrel opening (BO) through which the piston rod distracts. Biopsies of paraspinal muscles and control tissue samples were taken over and away from the wear marks, respectively. Spectral analyses of the rod alloy and biopsies were performed to reveal the metal constituents and concentrations. Histological analyses of the biopsies were performed with haematoxylin and eosin staining. Results. Titanium (Ti), vanadium (V), and neodymium (Nd) concentrations in the biopsies taken near the wear marks were found to be significantly higher than those in the control tissue samples. Significantly increased Nd concentrations were also found in the tissues near the barrel of the MCGR. Chronic inflammation was revealed by the histological studies with fibrosis and macrophage infiltration. Black particles were present within the macrophages in the fibrotic tissues. Conclusion. Ti and V were generated mainly at the BO due to metal-on-metal contact, whereas the Nd from the rotor of the MCGR is likely released from the BO during distraction sessions. Phagocytotic immune cells with black particles inside raise concern regarding the long-term implications of metallosis. Cite this article: Bone Joint J 2020;102-B(10):1375–1383

In the course of uneventful secondary bone healing, a fracture gap is progressively overgrown by callus which subsequently calcifies and remodels into new bone. It is widely accepted that callus formation is promoted by mechanical stimulation of the tissue in the fracture gap. However, the optimal levels of the interfragmentary motion's amplitude, frequency and timing remain unknown. The aim of this study was to develop an active fixation system capable of installing a well-controlled mechanical environment in the fracture gap with continuous monitoring of the bone healing progression. The experimental model was adapted from Tufekci et al. 2018 and required creation of a critical size defect and an osteotomy in a sheep tibia. They were separated by a mobile bone fragment. The distal and proximal parts of the tibia were fixed with an external fixator, whereas the mobile fragment was connected to the proximal part with an active fixator equipped with a linear actuator to move it axially for mechanical stimulation of the tissue in the fracture gap. This configuration installed well-controlled mechanical conditions in the osteotomy, dependent only on the motion of the active fixator and shielded from the influence of the sheep's functional weightbearing. A load sensor was integrated to measure the force acting in the fracture gap during mechanical stimulation. The motion of the bone fragment was controlled by means of a custom-made controller allowing to program stimulation protocols of various profiles, amplitudes and frequencies of loading events. Following in vitro testing, the system was tested in two Swiss White Alpine Sheep. It was configured to simulate immediate weightbearing for one of the animals and delayed weightbearing for the other. The applied loading protocol consisted of 1000 loading events evenly distributed over 12 hours resulting in in a single loading event every 44 seconds. Bench testing confirmed the ability of the system to operate effectively with frequencies up to 1Hz over a range of stimulation amplitudes from 0.1 to 1.5 mm. Continuous measurements of in vivo callus stiffness revealed progressive fracture consolidation in the course of each experiment. A delayed onset of fracture healing was observed in the sheep with simulated delayed weightbearing. The conducted preclinical experiments demonstrated its robustness and reliability. The system can be applied for further preclinical research and comprehensive in-depth investigation of fracture healing

Purpose. Great expense is accumulated in investigation and management, often with poor outcome, of a patient with a painful TKR. We aim to produce guidelines for their investigation and careful, successful management. Method. We studied 42 cases of patients with a painful TKR. Costs were calculated of appointments, serological and radiological investigations for these patients and an average cost of investigating a patient was obtained. We also calculated costs of various forms of management, both surgical and non-surgical and correlated these with patient outcomes. Results. 41 patients with an average investigation time of 20 months had on average 4 Orthopaedic appointments for the investigation of a painful TKR. On average, 8 blood tests were performed along with 8 radiographs. The average cost of investigating a patient with a painful TKR was £2337. 22 patients underwent operative intervention compared to 19 having solely pharmaceutical intervention. There was a significant difference between the amounts spent in each group with £5051 spent per patient in the operative group compared to £190 per patient on the non-operative group. There was a higher percentage of patient improvement in the non-operative group. Conclusion: Costs for investigation of a patient with a painful TKR were high because of exceedingly high numbers of repeated investigations. There is no guidance currently on how to manage painful TKR which is becoming an increasing clinical problem because of the increasing number of TKR's being performed per year. A lot of money is wasted on over investigating patients and performing operations that do not improve symptoms or prognosis. Careful thought needs to be given to careful investigation and management of patients in order to achieve optimal patient improvement. We have proposed a protocol for the investigation and management that allows prompt diagnosis and intervention and helps improve symptoms while keeping costs down

Aims. There is increasing evidence that flexible flatfoot (FF) can lead to symptoms and impairment in health-related quality of life. As such we undertook an observational study investigating the aetiology of this condition, to help inform management. The hypothesis was that as well as increased body mass index (BMI) and increased flexibility of the lower limb, an absent anterior subtalar articulation would be associated with a flatter foot posture. . Patients and Methods. A total of 84 children aged between eight and 15 years old were prospectively recruited. The BMI for each child was calculated, flexibility was assessed using the lower limb assessment scale (LLAS) and foot posture was quantified using the arch height index (AHI). Each child underwent a sagittal T1-weighted MRI scan of at least one foot. . Results. An absent anterior subtalar articulation (p < 0.001) and increased LLAS (p = 0.001) predicted a low AHI. BMI was not a significant predictive factor (p = 0.566). . Conclusion. This is the first study to demonstrate the importance of the morphology of the subtalar joint on the underlying foot posture in vivo. . Take home message: Flexibility of the lower limb and absence of the anterior facet of the subtalar joint are associated with flexible FF and may influence management of this common condition. Cite this article: Bone Joint J 2016;98-B:564–8

Aims. Carpal malalignment after a distal radial fracture occurs due to loss of volar tilt. Several studies have shown that this has an adverse influence on function. We aimed to investigate the magnitude of dorsal tilt that leads to carpal malalignment, whether reduction of dorsal tilt will correct carpal malalignment, and which measure of carpal malalignment is the most useful. Methods. Radiographs of patients with a distal radial fracture were prospectively collected and reviewed. Measurements of carpal malalignment were recorded on the initial radiograph, the radiograph following reduction of the fracture, and after a further interval. Linear regression modelling was used to assess the relationship between dorsal tilt and carpal malalignment. Receiver operating characteristic (ROC) analysis was used to identify which values of dorsal tilt led to carpal malalignment. Results. A total of 250 consecutive patients with 252 distal radial fractures were identified. All measures of carpal alignment were significantly associated with dorsal tilt at each timepoint. This relationship persisted after adjustment for age, sex, and the position of the wrist. Capitate shift consistently had the strongest relationship with dorsal tilt and was the only parameter that was not influenced by age or the position of the wrist. ROC curve analysis identified that abnormal capitate shift was seen with > 9° of dorsal tilt. Conclusion. Carpal malalignment is related to dorsal tilt following a distal radial fracture. Reducing the fracture and improving dorsal tilt will reduce carpal malalignment. Capitate shift is easy to assess visually, unrelated to age and sex, and appears to be the most useful measure of carpal malalignment. The aim during reduction of a distal radial fracture should be to realign the capitate with the axis of the radius and prevent carpal malalignment. Cite this article: Bone Joint J 2020;102-B(1):137–143

Objectives. The medially spherical GMK Sphere (Medacta International AG, Castel San Pietro, Switzerland) total knee arthroplasty (TKA) was previously shown to accommodate lateral rollback while pivoting around a stable medial compartment, aiming to replicate native knee kinematics in which some coronal laxity, especially laterally, is also present. We assess coronal plane kinematics of the GMK Sphere and explore the occurrence and pattern of articular separation during static and dynamic activities. Methods. Using pulsed fluoroscopy and image matching, the coronal kinematics and articular surface separation of 16 well-functioning TKAs were studied during weight-bearing and non-weight-bearing, static, and dynamic activities. The closest distances between the modelled articular surfaces were examined with respect to knee position, and proportions of joint poses exhibiting separation were computed. Results. Overall, 1717 joint poses were analyzed. At a 1.0 mm detection threshold, 37 instances of surface separation were observed in the lateral compartment and four medially (p < 0.001). Separation was activity-dependent, both laterally and medially (p < 0.001), occurring more commonly during static deep flexion in the lateral compartment, and during static rotation in the medial compartment. Lateral separation occurred more frequently than medial during kneeling (7/14 lateral vs 1/14 medial; p = 0.031) and stepping (20/1022 lateral vs 0/1022 medial; p < 0.001). Separation varied significantly between individuals during dynamic activities. Conclusion. No consistent association between closest distances of the articular surfaces and knee position was found during any activity. Lift-off was infrequent and depended on the activity performed and the individual knee. Lateral separation was consistent with the design rationale. Medial lift-off was rare and mostly in non-weight-bearing activities. Cite this article: S. Key, G. Scott, J. G. Stammers, M. A. R. Freeman†, V. Pinskerova, R. E. Field, J. Skinner, S. A. Banks. Does lateral lift-off occur in static and dynamic activity in a medially spherical total knee arthroplasty? A pulsed-fluoroscopic investigation. Bone Joint Res 2019;8:207–215. DOI: 10.1302/2046-3758.85.BJR-2018-0237.R1

Introduction. Current strategies to treat back pain address the symptoms but not the underlying cause. Here we are investigating a novel hydrogel material (NPgel) which can promote MSC differentiation to Nucleus pulposus cells. Current in vitro studies have only explored conditions that mimic the native disc microenvironment. Here, we aim to determine the stem cells regenerative capacity under conditions that mimic the degenerate environment seen during disc degeneration. Methods. hMSCs were encapsulated in NPgel and cultured for 4 weeks under hypoxia (5%) with ± calcium (2.5mM and 5.0mM CaCl. 2. ), IL-1β and TNFα either individually or in combination to mimic the degenerate microenvironment. Cell viability was assessed by Alamar blue assay. Histological and immunohistochemical analysis investigated altered matrix and matrix degrading enzyme expression. Results. Viability of hMSCs was maintained under all culture conditions. Matrix deposition of glycosaminoglycans were observed under all conditions, MMP13 expression was upregulated by calcium but not by pro-inflammatory cytokines IL-1β and TNFα. Conclusions. We are developing an in vitro modelling system which can be used to test novel therapies within a degenerate microenvironment. Interestingly, our preliminary findings suggest calcium is a major contributor to regulating MMP13 in this model system. Investigating the degenerate niche will identify targets for inhibition to provide the correct niche to promote regeneration of the IVD. No conflict of interest. Funding: BMRC, MERI Sheffield Hallam University, for joint funding the Daphne Jackson Trust fellowship

It is well documented that implant loosening rate in sickle cell disease patients is higher than that seen in patients with hip arthroplasty from other indications. The Hypoxic inducible factor(HIF) - is activated in the microcellular hypoxic environment and this through a cascade of other enzymatic reactions promotes the activity of other factors and further help enhance angiogenesis and osteogenesis. The aim of this study was to investigate and propose a potential model for investigating osseointegration in a hypoxic microcellular environment using osteoblasts(MG63). Human MG63 osteoblastic cells were cultured under normoxia and hypoxic conditions (20%; and 1% oxygen saturation) for 72 hours under two different condition- with and without cobalt chloride. The samples cultured under normoxic condtions without cobalt chloride acted as control. Using qualitative polymerase chain reaction-(qPCR) - HIF expression was assessed under the above conditions in relation to the control. The results showed there was significant expression of the HIF 1 alpha protein under hypoxic condition with cobalt chloride in comparison with the control samples- all at 72hours incubation. Mann-Whitney U test was used to deduce level of significance of fold change.(p=0.002; <0.05). This was deemed as being a significant difference in the level of expression of HIF compared to the control. The results show that the hypoxic inducible factor can be expressed using the above tested. experimental invitro-model with significant results which can be a foundation for further research into improving hip implant prosthesis design to help enhance osseo-integration in sickle cell disease patient with AVN

The ankle radiograph is a commonly requested investigation as the ankle joint is commonly injured. Each radiograph exposes 0.01 mSv of radiation to the patient that is equivalent to 1.5 days of natural background radiation [1]. The aim of the clinical audit was to use the Ottawa Ankle Rule to attempt to reduce the number of ankle radiographs taken in patients with acute ankle injuries and hence reduce the dose of ionising radiation the patient receives. A retrospective audit was undertaken. 123 ankle radiograph requests and radiographs taken between May and July 2018 were evaluated. Each ankle radiograph request including patient history and clinical examination was graded against the Ottawa Ankle Rule. The rule states that 1 point(s) indicates radiograph series; (1) malleolar and/or midfoot pain; (1) tenderness over the posterior 6cm or tip of the lateral or medial malleolus (ankle); (1) tenderness over the navicular or the base of the fifth metatarsal (foot); (1) unable to take four steps both immediately and in the emergency department [2]. Patients who score 0 do not need radiograph series. Each radiograph was reviewed if a fracture was present or not. The clinical audit identified 14 true positives where the Ottawa Ankle Rule scored 1 and the patient had an ankle fracture, and 2 false negatives (sensitivity 88%). There were 81 false positives, and 23 true negatives (specificity 22%). Therefore, a total of 23/123 ankle radiographs were unnecessary which is equivalent to 34.5 days of background radiation. The negative predictive value of the Ottawa Ankle Rule in this audit was 92%. The low rate of Ottawa rule utilisation may unnecessarily cause patient harm that should be addressed. An educational intervention with physicians combined with integration of the Ottawa rule scoring in ankle radiograph requests is planned with re-audit in 6 months

To determine the usefulness of isotope bone scintigraphy in investigating skeletal pain in children, we reviewed the bone scans, plain radiographs and clinical notes of consecutive children under 16 years of age presenting to children’s orthopaedic surgeons at two teaching hospitals in one city. There were 229 patients, of which 87 were boys and 142 girls. They had an average age of 11 years. 139 were investigated for back pain and 90 for skeletal pain in the appendicular skeleton. They were investigated for a variety of conditions including idiopathic back and skeletal pain, scoliosis, Scheuermann’s disease, spondylolysis, osteomyelitis and postoperative pain. There were positive scans in 4 out of 78 patients with idiopathic back pain, and 13 out of 64 with idiopathic skeletal pain. Overall the positive scan rate for all conditions was 10% for back conditions and 22% for pain in the appendicular skeleton. Of all patients with back pain the management was altered in only 3 children. Of all those investigated for appendicular skeletal pain, the management was altered in 6 children. Isotope bone scanning is a low yield and non-specific investigation that imparts a significant dose of radiation to the patient. It should not be used as a first line investigation for idiopathic back or skeletal pain in children. Other tools such as MRI should be considered initially. It still has a role in the investigation of children with obvious abnormality on radiographs, with spondylolysis and probably where there are worrying clinical features to the pain such as night pain and recent onset. The role of bone scanning in the investigation of skeletal pain should be re-evaluated in the investigation of skeletal pain

Objectives. Secondary fracture healing is strongly influenced by the stiffness of the bone-fixator system. Biomechanical tests are extensively used to investigate stiffness and strength of fixation devices. The stiffness values reported in the literature for locked plating, however, vary by three orders of magnitude. The aim of this study was to examine the influence that the method of restraint and load application has on the stiffness produced, the strain distribution within the bone, and the stresses in the implant for locking plate constructs. Methods. Synthetic composite bones were used to evaluate experimentally the influence of four different methods of loading and restraining specimens, all used in recent previous studies. Two plate types and three screw arrangements were also evaluated for each loading scenario. Computational models were also developed and validated using the experimental tests. Results. The method of loading was found to affect the gap stiffness strongly (by up to six times) but also the magnitude of the plate stress and the location and magnitude of strains at the bone-screw interface. Conclusions. This study demonstrates that the method of loading is responsible for much of the difference in reported stiffness values in the literature. It also shows that previous contradictory findings, such as the influence of working length and very large differences in failure loads, can be readily explained by the choice of loading condition. Cite this article: A. MacLeod, A. H. R. W. Simpson, P. Pankaj. Experimental and numerical investigation into the influence of loading conditions in biomechanical testing of locking plate fracture fixation devices. Bone Joint Res 2018;7:111–120. DOI: 10.1302/2046-3758.71.BJR-2017-0074.R2

We undertook a review of bone scans requested for children to determine the usefulness of isotope bone scintigraphy in investigating skeletal pain in this population. We reviewed the bone scans, plain radiographs and clinical notes of consecutive children under 16 years of age presenting to children’s orthopaedic surgeons at two teaching hospitals in one city. There were 229 patients, of which 40% were boys and 60% girls. They had and average age of 11 years. 139 were investigated for back pain and 90 for skeletal pain in the appendicular skeleton. They were investigated for a variety of conditions including idiopathic back and skeletal pain, scoliosis, Scheuermann’s disease, spondylolysis and stress fractures, osteomyelitis and post-operative pain. There were positive scans in 4 out of 78 patients with idiopathic back pain, 1 of 25 patients with scoliosis and 1 out of 5 with spondylolysis and 11 out of 70 with idiopathic skeletal pain. Of all patients with back pain the management was altered in only 3 children. Of all those investigated for appendicular skeletal pain the management was altered in 6 children. Conclusion: Isotope bone scanning is a low yield, and non-specific investigation that imparts a significant dose of radiation to the patient. It should not be used as a first line investigation for idiopathic back or skeletal pain in children. Other tools such as MRI should be considered initially. The role of isotope bone scanning in the investigation of skeletal and joint pain in children should be reevaluated

An electromyographic investigation of patients with subluxation of the patella has been carried out on the parts of the extensor apparatus which actively contribute to the alignment of the patella, both before and after the operation to correct this disorder. The electromyographic pictures have revealed a sharp fall in the activity of the vastus medialis, with full recovery to normal values after a corrective operation. Even if the aligning function of the patella is altered by a variety of factors, the present study confirms the importance of the vastus medialis in the pathogenesis of malalignment of the extensor mechanism

Crown copyright 2009. Published with the (permission of the Defence Science and Technology Laboratory on behalf of the Controller of HMSO. Introduction. The optimum strategy for the care of war wounds is yet to be established. A need exists to model complex extremity injury, allowing investigation of wound management options. Aim. To develop a model of militarily relevant extremity wounding. Study Design. Laboratory study with New Zealand White Rabbits. Methods. Phase 1. Development of injury. Following induction of general anaesthesia, a muscle belly on the flexor aspect of the forelimb of the rabbit was exposed. This was achieved by creating a fascial tunnel under the belly of flexor carpi ulnaris (FCU). Utilising a custom built drop test rig a high energy, short duration impact was delivered. To replicate casualty evacuation timelines, the animal was maintained under anaesthesia for three hours and recovered. The wound was dressed with saline soaked gauze and supportive bandaging. 48 hrs later, the animal was culled and the muscle harvested for histological analysis. Analgesia was administered once a day. Animals were checked by experienced staff at least twice a day and body temperature recorded by a subcutaneous transponder. Phase 2. Contamination of muscle injury. Sequential animals had inoculums of 1×102/100μl, 1×106/100μl and 1×108/100μl of Staphylococcus aureus administered to the muscle immediately after injury. Animals were recovered from anaesthetic and monitored as per phase 1. Delivery was evaluated by droplet spread and via injection by fine bore needle into the muscle belly. At the 48 hour point, the animals were culled, dressings removed, the muscle harvested and auxiliary lymph nodes sampled. Quantitative microbiological analysis was performed to determine colony forming unit counts (CFU) at 24 hours post-collection. Results. Phase 1. Six animals were exposed to a loading of 0.5kg. Histological analysis demonstrated a consistent injury pattern with 20% of the muscle belly becoming necrotic. Following discussion with subject matter experts this was found to be representative of the nature of injury from ballistic limb trauma and was adopted as standard. Phase 2. Twenty-two animals were exposed to the standardised injury and then inoculated at the prescribed challenge doses and delivery methods. A challenge dose of 1×106/100μl S. aureus delivered by droplet provided the greatest consistency. A group of six animals with an average challenge dose of 3.3×106/100μl yielded growth at 48hrs on average of 9.2×106 CFU. There were no adverse effects on animal welfare throughout, with body temperatures within normal limits at all times. Discussion. The use of rabbits in the investigation of musculoskeletal injury and infection is well established. No study to date however has addressed high energy complex soft tissue wounding, contamination and its optimum management. Considering the current burden of such wounds the need for this question to be answered in a research setting is transparent. This model enables a significant, reproducible, contaminated soft tissue injury to be delivered in vivo. It will allow the investigation of complex wound management options including wound coverage and fracture fixation

There are eight reported cases in the literature of osteosarcomas secreting β-hCG. Our primary aim was to investigate the rate of β-hCG expression in osteosarcoma and attempt to understand the characteristics of osteosarcomas that secrete β-hCG. We reviewed 37 histopathology slides (14 biopsies and 23 surgical specimens) from 32 patients with osteosarcoma. The slides were retrospectively stained for β-hCG expression. Patient and tumour characteristics, including age, gender, tumour location, subtype, proportion of necrosis, presence of metastases and recurrence were recorded. A total of five of the 32 tumours were found to be positive for β-hCG expression (one strongly and four weakly). This incidence of this expression was found in tumours with poor histological response to neoadjuvant chemotherapy. The use of β-hCG expression as a diagnostic, prognostic or follow-up marker is questionable and needs further investigation with a larger sample size

Aim. This study reviewed the efficacy of a CT arthrogram in clinical decision making for wrist disorders. Methods. Sixty four consecutive CT arthrograms done in a three year period at Glenfield Hospital were selected. All patients were referred by hand consultants at the Glenfield Hospital and all investigations were performed by a single senior musculoskeletal radiologist. CT arthrograms focussed on the following areas: scapholunate interosseous ligament (SLIL), lunotriquetral interosseous ligament (LTIL), peripheral and central triangular fibrocartilage complex (TFCC) tears, and articular surface disorders. Referral and clinic letters for all patients were obtained. We collected patient demographic detail, prescan diagnosis and clinical plan, CT arthrogram findings, postscan diagnosis and clinical plan and the final outcome. A decision was made whether the scan helped in the clinician's management plan and if so how it helped. Results. There were 35 male and 29 female patients with a mean age of 44.1 years. The right wrist was involved in 42 and the left in 22 patients. Sixty three of the 64 patients had their management based on the CT scan. In 54 of these the CT arthrogram either confirmed and calibrated the diagnosis or identified a new diagnosis. In 10 patients the scan was normal and allowed patient reassurance. Thirty six patients had ulnar sided problems, 20 had radial sided disorders and eight had midcarpal abnormality. The most common abnormality noted was a TFCC tear (24). The next most common was chondral damage/arthritis (14) followed by scapholunate interosseous ligament tear (12). The diagnosis was either confirmed and its extent established (31) or identified in addition to the primary diagnosis (19). Conclusions. The CT arthrogram is a helpful tool in the management of intra-articular wrist pathology. We found it to be useful in both confirming and calibrating the diagnosis and also diagnosing occult patho

Aims: To determine the usefulness of isotope bone scintography in investigating skeletal pain in children. Methods: We reviewed bone scans, notes and radiographs requested for children under 16 years presenting to two teaching hospitals in the city. Results: There were 229 patients with and average age of 11 years. 139 were investigated for back pain and 90 for skeletal pain in the appendicular skeleton. There were positive scans in 13 patients with back pain and 22 with pain elsewhere. The management was altered in only 3 children with back pain and 6 with other skeletal pain. Conclusions: Isotope bone scintigraphy is a low yield, and non-speciþc investigation that imparts a signiþcant dose of radiation. Its role in the investigation of skeletal pain should be re-evaluated

Introduction

A search of the literature indicates several constrained total knee arthroplasty (TKA) systems are at risk for articular surface lockdown bolts backing out. The backing out of a lockdown bolt may lead to an unstable and/or painful knee and may necessitate revision. Upon backing out, the bolt may damage implant components and surrounding tissues. To date, studies in the literature have not simulated or replicated loosening of bolts in TKA. Therefore, the objectives of this study were to 1) develop a set of physiological loading parameters that challenge bolted articular surfaces; 2) evaluate whether significant bolt torque is lost during application of this loading to a CCK device with a bolt as a secondary locking mechanism.

There are many reasons why a total knee replacement (TKR) may fail and qualify for revision. Successful revision surgery depends as much on accurate assessment of the problem TKR as it does on revision implant design and surgical technique. Specific modes of failure require specific surgical solutions. Causes of failure are often presented as a list or catalogue, without a system or process for making a decision. In addition, strict definitions and consensus on modes of failure are lacking in published series and registry data. How we approach the problem TKR is an essential but neglected aspect of understanding knee replacement surgery. It must be carried out systematically, comprehensively and efficiently. Eight modes of failure are described: 1) sepsis; 2) extensor discontinuity; 3) stiffness; 4) tibial- femoral instability; 5) patellar tracking; 6) aseptic loosening and osteolysis; 7) periprosthetic fracture and 8) component breakage. A ninth ‘category’, unexplained pain is an indication for further investigation but not surgery. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):105–11

Aim To develop a militarily relevant complex extremity wounding model. Study Design Controlled laboratory study with New Zealand White Rabbits. Method Phase One: Injury Development. Under general anaesthesia, the flexor carpi ulnaris of the right forelimb was exposed and high energy, short duration impact delivered via drop test rig. Anaesthesia was maintained for three hours, the animal was recovered and saline soaked gauze and supportive bandaging applied. 48 hrs later, the animal was culled and muscle harvested for histological analysis. Analgesia was administered daily, animals checked by experienced staff at least twice daily and temperatures recorded by subcutaneous transponder. Phase Two: Contamination. Sequential groups of animals had inoculums of 1×102, 1×106 and 1×108/100μl of Staphylococcus aureus administered to the muscle immediately after injury. Animals were recovered as phase one. At 48 hours, animals were culled, muscle harvested and axillary lymph nodes sampled. Quantitative microbiological analysis was performed on the muscle. Results: Six animals given a loading of 0.5kg yielded consistent injury with 20% of the muscle becoming necrotic. Representative of injury from ballistic trauma, this was adopted as standard. Twenty-two subsequent animals were exposed to the injury and inoculated with the challenge doses. 1×106/100μl S.aureus provided the greatest consistency in recovered yield. There were no adverse effects on animal welfare and body temperatures were always within normal limits. Discussion. This model enables a consistent, contaminated soft tissue injury to be delivered in vivo. It will allow the investigation of complex wound management including wound coverage and fracture fixation

We reviewed 188 patients at one to 20 years (mean 9.5) after surgery for anterior shoulder instability. Twenty-one had shown bilateral instability at the time of surgery, and 26 of the remaining 167 subsequently developed instability of the contralateral shoulder, giving an overall incidence of 24% bilateral involvement. Fourteen of these patients ultimately required bilateral surgery. The onset of contralateral instability was at one month to 15 years (mean 5.7 years) after anterior repair of the operated shoulder, the cumulative incidence increasing with time (p less than 0.01). The incidence was significantly higher in those under 15 years at the time of initial dislocation or under 18 at the time of surgery. One-half of the patients with contralateral instability had signs of posterior instability at follow-up. Other predisposing factors included having sustained the initial injury to the operated shoulder as a result of minimal trauma, and persistence of a sensation of instability in the operated shoulder. Factors which were not statistically significant included sex, dominant side, athletic activity, work history, and whether the initial surgery was for recurrent subluxations or dislocations. The high prevalence of bilateral shoulder instability suggests an intrinsic abnormality such as capsular and ligamentous laxity or muscle imbalance and warrants further investigations

Aims

The purpose of the present study was to compare patient-specific instrumentation (PSI) and conventional surgical instrumentation (CSI) for total knee arthroplasty (TKA) in terms of early implant migration, alignment, surgical resources, patient outcomes, and costs.

We used gadolinium-enhanced fat-suppressed MRI to investigate 67 patients with persistent pain after lumbar discectomy. Twenty-five patients had reoperations for lesions diagnosed in this way. Eleven were for recurrent disc prolapse at the same level and sciatica was relieved by all but one. Five operations were for prolapse at an adjacent level and all were successful. The diagnosis of sepsis was less precise, but extension of tissue enhancement into the operated disc space was found to be significant. Only three patients had evidence of arachnoiditis which suggests that this condition has been too often diagnosed as a cause of persisting low back pain

Introduction and Aims: Regeneration of bone is an important goal in orthopaedic surgery. The repair of a critical skull defect is a model for investigating the efficacy of cell signalling factors and biomaterials in inducing new bone formation. We aim to investigate a 5mm critical skull defect in the mouse, as an in vivo tool for analysis of potential bone active factors that have been bio-prospected from dairy milk protein. Method: Adult Swiss CD1 mice were divided into two groups. Each group contained animals treated with vehicle (n=11), milk protein (4mg, n=10) and TGF-β. 1. (2μg, n=6). Under anaesthetic, a high-speed burr was used to create a five-mm craniotomy in the left parietal bone and a pre-cut collagen sponge with 20μl of the test factor inserted. Fluorochrome labels were administered to facilitate quantitative histological analysis of the defect. The animals were sacrificed on days 14 and 28 and the calvariae excised and fixed. The defects were assessed for percent closure using radiography, transillumination and histology. Results: The formal analysis of this study is underway at present. TGF-β1 has been shown in the literature to augment the healing of critical skull defects and is included in this study as a positive control. Our radiography results show significantly complete closure of the skull defect in TGF-β. 1. group. Preliminary work in our laboratory with this milk protein has shown it to be a novel bone active factor. In vivo, local injection above the calvariae in adult mice resulted in significant increase in bone area and dynamic histomorphometric indices of bone formation. In vitro, the protein is anabolic, an effect that is consequent upon its potent proliferative and anti-apoptotic actions in osteoblasts, and its ability to inhibit osteoclastogenesis. Conclusions: We believe the critical skull defect in the mouse may be a useful means to assess the role of potential bone active factors in wound healing of osseous defects. The purified milk protein tested may have a physiological role in bone growth and a potential therapeutic application in bone regeneration. We await formal analysis of the specimens to further elucidate this statement

Regeneration of bone is an important goal in orthopaedic surgery, such as in augmentation of fracture healing, spinal fusion and filling of osseous defects. The repair of a critical skull defect is a well-established model for investigating the efficacy of cell signalling factors and biomaterials in inducing new bone formation. We aimed to investigate a 5-mm critical skull defect in the mouse, as an in vivo tool for analysis of potential bone active factors that have been bioprospected from dairy milk protein. Adult Swiss CD1 mice were divided into 2 groups. Each group contained animals treated with vehicle (n=11), milk protein (4mg, n=10) and TGF-b1 (2μg, n=6). Under anaesthetic a high-speed burr was used to create a 5-mm craniotomy in the left parietal bone and a precut collagen sponge with 20ml of the test factor inserted. Fluorochrome labels were administered to facilitate quantitative histological analysis of the defect. The animals were sacrificed on days 14 and 28 and the calvariae excised and fixed. The defects were assessed for percent closure using radiography, transillumination and histology. The formal analysis of this study is underway at present. Preliminary work in our laboratory with this milk protein has shown it to be a novel bone active factor. In vivo, local injection above the calvariae in adult mice resulted in significant increase in bone area and dynamic histomorphometric indices of bone formation. In vitro, the protein is anabolic, an effect that is consequent upon its potent proliferative and anti-apoptotic actions in osteoblasts, and its ability to inhibit osteoclastogenesis. TGF-b1 has been shown in the literature to augment the healing of critical skull defects and is included in this study as a positive control. We believe the critical skull defect in the mouse may be a useful means to assess the role of potential bone active factors in wound healing. The purified milk protein used in this study may have a physiological role in bone growth and a potential therapeutic application in bone regeneration. We await formal analysis of the specimens to further elucidate this statement. Further experiments will be required to determine whether it provides results that are reproducible and/or comparable to other models of fracture repair

Cerebral palsy (CP) results from an injury to the immature brain; and it leads to progressive musculoskeletal (MS) impairment in most affected patients. Orthopaedic surgery involving muscle-tendon lengthening is a method for managing short muscles in CP patients. Knowledge of muscle length prior to surgery is beneficial to surgical success. However, using common assessment methods like 3D gait analysis or physical examination, accurate pre-surgery estimation of muscle lengths during walking is difficult. Computer models of the lower limbs, which provide more insight into muscle functioning during walking, have become increasingly important within the research field of CP. MS models are commonly driven by joint kinematics from clinical gait analysis. The most often used MS model in CP related research is based on the geometry of an adult human man with muscles modelled as line segments. This approach might be reasonable for small muscles with well-defined paths; however, for long muscles with multiple attachment points and curved paths, a more realistic 3D muscle model is required. The aim of this study is the development of a clinical assessment tool for CP patients by incorporating kinematic data from gait analysis into a 3D finite-element MS model of the lower limbs. Ethical approval has been obtained to develop subject-specific MS models of 12 children with CP and 12 control children (age 8 – 12 years) based on magnetic resonance images. Kinematic data from 3D gait analysis is used as input data to transform the bony structures. Soft-tissue muscle deformation is modelled according to a variant of free-form deformation called the Host-Mesh Fitting Technique. So far, MS models of the lower limbs of three control children and of one child with CP were developed. The resulting muscle length changes during walking agree reasonably well with published data. The proposed modelling approach together with the library of 24 MS models will enable us to develop a powerful tool to investigate gait of children with CP

Summary. Cognitive testing scores do not correlate with physical braking performance. Psychological questioning shows patients are more dependent on driving than a control group. Introduction. Returning to driving after surgery is a multifaceted issue. There are the medical aspects to consider- whether the patient is medically fit to drive. The term ‘medically fit to drive’ can encompass a range of issues which fall to doctors to solve, including the psychological and mental wellbeing. Groups whose governance involves patients or driving do not issue sound advice for patients or doctors to follow. Investigation of aspects affecting a driver's ability to control their vehicle in a safe manner could go towards providing an evidence base for guidance to be issued in the future. Methods. A custom force assessment rig was used to gather peak force and reaction time measurements from a group of patients waiting for, or having undergone lower limb surgery. A bespoke questionnaire that investigated patient's attitudes towards returning to driving; their behaviours and concerns was issued. Other mobility questions were also issued to these patients, including the lower extremity functional scale (LEFS). The final tests (Stroop task, tower of Hanoi, and the opposite worlds test [OWT]) were aimed at assessing a patient's neurological function, in an attempt to investigate the effect of post-operative cognitive dysfunction (POCD) on driving ability. These data were compared against a control cohort. Results. No significant differences were observed in the physical results between cohorts. However, significant differences between the control cohort and patient cohort were observed in a number of tests. The tower of Hanoi was the only significantly different neurological test (p=0.027). The Stroop task and OWT were not significantly different (p=0.103, p=0.131 respectively). There were significant differences in many of the psychological and mobility questions posed (reliance on driving [p<0.001], keenness to return [p=0.014], anxiety about being unable to drive [p=0.019], depression at being unable to drive [p=0.011], worries that driving would cause them pain [p<0.001], and confidence in using public transport [p=0.002]). Activity rankings also had a significant difference, with driving becoming a higher priority in the patient group (p=0.002). There were no significant differences between cohorts in physical testing, but LEFS was significantly different (p<0.001). There was no significant correlation between physical testing and neurological function, so we cannot prove nor disprove that neurological deficits affect physical function. Psychological variables and physical function did not correlate, but LEFS was correlated to a number of psychological variables. Conclusions. Due to the insignificance of correlations between neurological function tests and physical function, further work is recommended to conclusively determine whether there is a link or not. Different and/or additional neurological test batteries should be also considered, for example the CANTAB. Future studies should stratify cohorts based on surgical indication. Extension of the psychological research could identify the most popular goals or activities for those returning from surgery, potentially creating targets for the rehabilitation process

The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (. sd. 0.08) vs augmented 0.13 mm (. sd. 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (. sd. 0.02) vs augmented 0.15 mm (. sd. 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017). Cite this article: Bone Joint J 2013;95-B:1406–9

Aim of this experimental study was to develop an in vitro model that simplifies the study of various factors regulating neuronal regeneration. An in vitro-system that allows co-culture of slices from rat motorcortex and spinal cord (p4) was established. Two groups of cultures were investigated: In the first group, intact spinal cord slices were cultured adjacent to motorcortex slices, while in the second group the spinal cord slices were sagitally cut into halves, with the sectioned interface placed directly adjacent to the motorcortex, in order to prevent the spinal white matter from interference. Each group was further divided into two subgroups: The NT-3 group, where the culture medium contained 50 ng/ml NT-3 and the control group treated with normal culture medium. Motorcortex pyramidal neurons were anterogradely labelled with MiniRuby, a 10 kD biotinylated dextran amine. After 4 days the co-cultures were propagated, and axonal sprouting occurred. The group of co-cultures treated with NT-3 showed an improved cortical cytoarchitecture, and sprouting axons were more frequently observed. In NT-3-treated co-cultures where spinal cord gray matter was directly opposed to cortical slices sprouting axons entered the adjacent spinal cord tissue. This phenomenon was not observed if spinal white matter was opposed to the cortical slices, or if NT-3 was absent. Our data suggest that the absence of repellent factors such as white matter and the presence of neuro-trophic factors promote axonal sprouting. Co-cultures of motorcortex and spinal cord slices combined with anterograde axonal labelling could provide a valuable in vitro model for the simplified screening of factors influencing corticospinal tract regeneration

Aim. The knee radiograph is a commonly requested investigation as the knee joint is commonly injured. Each radiograph exposes 0.01mSv of radiation to the patient that is equivalent to 1.5 days of natural background radiation. Also, each knee radiograph costs approximately £37.16 to produce. The aim of the clinical audit was to use the Pittsburgh knee rules to attempt to reduce the number of knee radiographs taken in patients with acute knee injuries and hence reduce the dose of ionising radiation the patient receives. Method. A retrospective audit was undertaken. 149 knee requests and radiographs taken during October 2016 were evaluated. Each knee radiograph request including patient history and clinical examination was graded against the Pittsburgh knee rules to give a qualifying score. The Pittsburgh knee rules assigns 1 point for each of the following; blunt trauma or a fall, age less than 12 years or over 50 years, and unable to take 4 limping weight bearing steps in the emergency department. A Pittsburgh knee rule qualifying score warranting a knee radiograph is 2 or more points, where the patient must have had blunt trauma or a fall. A Pittsburgh knee rule score less than 2 points predicts a non-fractured knee and hence no radiograph warranted. Each radiograph was reviewed if a fracture was present or not. Results. The clinical audit identified 85 true negative patients where their Pittsburgh knee rule score was less than 2 points and they did not have a fracture of the knee joint. The Pittsburgh knee rule score of less than 2 points did not warrant obtaining knee radiographs. Therefore, a total of 85 knee radiographs were unnecessary which is equivalent to 127.5 days of background radiation. The financial burden of these unnecessary radiographs is £2648.60. The negative predictive value of the Pittsburgh knee rules in this audit was 93.4%. Discussion. The clinical audit shows that the use of the Pittsburgh knee rules scoring system can reduce the number of knee radiographs obtained by 57.4% and hence the doses of ionising radiation patients are exposed to. The audit also showed this clinical scoring system has a high negative predictive value that when utilised can discern patients with a normal knee joint who do not require a knee radiograph. In conclusion employing the Pittsburgh knee rule scoring system can improve patient safety by reducing ionising radiation exposure and can reduce financial costs of patient encounters

The term mid-flexion instability has entered the orthopaedic literature as a concept, but has not been confirmed as a distinct clinical entity. The term is used freely, sometimes as a synonym for flexion instability. However, the terms need to be clearly separated. A cadaver study published in 1990 associated joint line elevation with decreased stability at many angles of flexion, but that model was not typical of clinical scenarios. The literature is considered and it is proposed that the more common entity of an uncorrected flexion contracture after a measured resection arthroplasty technique is more likely to produce clinical findings that suggest instability mid-flexion.

It is proposed that the clinical scenario encountered is generalised instability, with the appearance of stability in full extension from tight posterior structures.

This paper seeks to clarify whether mid-flexion instability exists as an entity distinct from other commonly recognised forms of instability.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):84–8.

A study of the contamination of suckers used during total hip replacement has been undertaken. Thirty suckers used throughout the operation had their tips cultured: from 11 of these bacteria were grown. The organisms found were those which have previously been implicated in deep infection of total hip replacements. In subsequent operations a further 31 suckers were used for cleaning only the femoral shaft; of these only one was contaminated. This suggests that sucker contamination is related to how long the sucker is in use; consequently it is recommended that a new sucker be used for the preparation of the femoral shaft.

This paper reports a prospective study of the value of ultrasonography in detecting lesions of the lumbar spine in patients with compressive sciatica. The measurements of the diameter of the spinal canal obtained by using ultrasound were compared with the findings at operation in 17 patients in whom a total of 50 sites were examined. The ultrasound beam failed to penetrate the spinal canal at 15 sites and at only 10 of the remaining 35 sites did the ultrasound correctly detect narrowing. It is concluded that ultrasonography is unreliable in identifying the site of compression of the spinal cord and nerve roots. The technical limitations and the probable causes of failure of the technique are discussed.

The osteoinductive properties of demineralised bone matrix have been demonstrated in animal studies. However, its therapeutic efficacy has yet to be proven in humans. The clinical properties of AlloMatrix, an injectable calcium-based demineralised bone matrix allograft, were studied in a prospective randomised study of 50 patients with an isolated unstable distal radial fracture treated by reduction and Kirschner (K-) wire fixation. A total of 24 patients were randomised to the graft group (13 men and 11 women, mean age 42.3 years (20 to 62)) and 26 to the no graft group (8 men and 18 women, mean age 45.0 years (17 to 69)).

At one, three, six and nine weeks, and six and 12 months post-operatively, patients underwent radiological evaluation, assessments for range of movement, grip and pinch strength, and also completed the Disabilities of Arm, Shoulder and Hand questionnaire. At one and six weeks and one year post-operatively, bone mineral density evaluations of both wrists were performed.

No significant difference in wrist function and speed of recovery, rate of union, complications or bone mineral density was found between the two groups. The operating time was significantly higher in the graft group (p = 0.004). Radiologically, the reduction parameters remained similar in the two groups and all AlloMatrix extraosseous leakages disappeared after nine weeks.

This prospective randomised controlled trial did not demonstrate a beneficial effect of AlloMatrix demineralised bone matrix in the treatment of this category of distal radial fractures treated by K-wire fixation.

Cite this article: Bone Joint J 2013;95-B:1514–20.

Aims

To our knowledge, there is currently no information available about the rate of venous thromboembolism (VTE) or recommendations regarding chemoprophylaxis for patients whose lower limb is immobilized in a plaster cast. We report a retrospective case series assessing the rate of symptomatic VTE in patients treated with a lower limb cast. Given the complex, heterogeneous nature of this group of patients, with many risk factors for VTE, we hypothesized that the rate of VTE would be higher than in the general population.

In rabbits, repair of incisions in the central part of the meniscus has been demonstrated after surgical excision of the peripheral rim. Healing took place via a highly cellular but relatively avascular fibrous tissue stroma which proliferated from the synovial margin and invaded along the cut edge of the meniscus. Suturing facilitated this healing process by providing stability and possibly by supplying bridges for synovial cells to migrate onto the meniscus. Transformation of fibrous tissue into fibrocartilage has also been observed.

Objective

To assess the usefulness of radiographs alone to evaluate acute midfoot/forefoot injuries. We believe that foot injuries are often under-estimated and that CT scans should be routinely obtained to aid in their management and avoid additional morbidity for patients.

Background

Spondylolysis (SL) of the lower lumbar spine is frequently associated with spina bifida occulta (SBO). There has not been any study that has demonstrated biomechanical or genetic predispositions to explain the coexistence of these two pathologies.

The lumbar spines of 485 skeletons of adult South African "Whites" and "Blacks" of both sexes were examined to determine the incidence and morphology of defects in the pars interarticularis. The overall incidence was 3.5%, without significant variation between races and sexes. The incidence of lumbar spina bifida in the whole sample was 1.9%, but was 11.8% in those skeletons with spondylolysis. Some instances of unilateral spondylolysis demonstrated obvious callus formation, suggesting a capability for normal repair. It is possible that the defects in bilateral cases represent established non-union of fractures of the pars interarticularis resulting from excessive mobility, and are not due to dysplasia of bone. It is noted, for the first time, that the superior facets of affected vertebrae are abnormally enlarged, and that the inferior facets of the separate neural arch are characteristically elliptical.

We have studied the ability of a range of antibiotics to penetrate intervertebral disc tissue in vitro, using a mouse disc model. Equilibrium concentrations of antibiotics incorporated into the entire disc were determined by bioassay using a microbial growth-inhibition method. Uptake was significantly higher with positively-charged aminoglycosides compared with negatively-charged penicillins and cephalosporins. Uncharged ciprofloxacin showed an intermediate degree of uptake. Our results support the hypothesis that electrostatic interaction between charged antibiotics and negatively-charged glycosaminoglycans in the disc is an important factor in antibiotic penetration, and may explain their differential uptake.

A prospective nation-wide study of knee arthroplasty has been under way in Sweden since October 1975. By the end of 1983, 4505 arthroplasties for osteoarthritis and 3495 for rheumatoid arthritis had been recorded and reviewed one, three and six years after the operation. Using actuarial methods, the probability of the prosthesis remaining in situ after six years was calculated. In osteoarthritis this probability ranged from 65% for hinged prostheses to 90% for medial compartment prostheses. Two-and three-compartment prostheses produced intermediate results with 87% survival. In rheumatoid arthritis the probability varied from 72% for medial compartment prostheses to 90% for two- and three-compartment prostheses. The main reason for failure was loosening of the components, the second most common was infection. The probability of revision for infection by six years was 2% in osteoarthritis and 3% in rheumatoid arthritis. Most revisions were to a three-compartment prosthesis. Knee fusion at primary revision was required in 2% of the cases at six years.

Lumbosacral nerve root anomalies have been documented in the literature for over 30 years; however, no significant quantitative studies have been undertaken so far. We describe parallel studies of 100 cadaveric specimens and an equal number of metrizamide myelograms. The anatomical specimens were prepared by wide deroofing of the lumbar canal to permit precise examination of individual nerve roots and their intradural and extradural connections. The incidence of nerve root anomalies was 14%, the L5-S1 level being most commonly involved. In sharp contrast the incidence of nerve root anomalies determined by myelography was only 4%. The anomalies were classified into four groups and the diagnostic and practical implications of our findings are discussed.

A method for direct measurement of the local pressures in the acetabular cartilage is described. Pressure transducers were introduced into the subchondral bone and positioned there in contrast with the cartilage: the transducers were calibrated in situ. Twelve cadaveric hips were prepared in this way and the pressures were measured with the joint loaded in flexion, extension, abduction, adduction, and in lateral and medial rotation. The highest pressures were recorded in the anterior and posterior segments of the acetabulum; the lowest pressures were constantly found at the zenith of the joint. The relationship of these findings to the pathogenesis of osteoarthritis is considered.

Study design: Prospective cohort study. Objective: To investigate association between recovery from low back pain (LBP) and body mass index (BMI) in patients with LBP undergoing physiotherapy. Introduction: The relationship between obesity and LBP has long been debated. There are no published studies examining the influence of BMI on recovery from LBP. Methods: One hundred and forty patients with chronic LBP and no neurological deficit underwent a back-specific physiotherapy programme. BMI and recovery parameters such as pain intensity (visual analogue scale scores), and self-experienced impairment and disability scores were measured. The range of motion of the lumber spine was also recorded. These variables were compared pre and post treatment. Statistical analysis was performed using paired t tests, Spearman’s rank correlation coefficients and ANCOVA. Results: Mean age was 38 years (range 18–67) with 62% males and 38% females. The treatment resulted in significant improvements in all the recovery parameters (P < 0.005, paired t test). No significant association was detected between the BMI of subjects and % changes in pain intensity, self-experienced impairment and disability, and range of motion of the lumbar spine. A comparative analysis of the after treatment recovery parameter scores in normal (BMI ≤24.9), overweight (BMI 25–29.9) and obese (BMI ≥ 30) revealed no significant differences in the mean pain intensity and mean self-experienced impairment and disability scores. Conclusion: Although a BMI within normal range is desirable for prevention of many health conditions including LBP, it does not influence the overall recovery from low back pain in patients undergoing physiotherapy treatment

Our purpose was to determine whether continuous passive motion enhanced the quality of knee ligament reconstruction using carbon fibre. In 46 rabbits the medial collateral ligaments were excised and replaced with carbon fibre prostheses. The animals were treated postoperatively by either continuous passive motion, cast immobilisation or cage activity, termed intermittent active motion. At six weeks, the ligaments were compared histologically and biomechanically with normal (control) medial collateral ligaments and with sham-operated controls. The ligaments treated with continuous passive motion were superior to those in the other two treatment groups. There were no ligament failures in any of the groups. This study suggests that continuous passive motion, initiated immediately postoperatively, enhances the biomechanical properties of carbon fibre ligament replacement of the medial collateral ligament while preventing the harmful effects of joint immobilisation.

The release of gentamicin sulphate, sodium fusidate and diethanolamine fusidate from Palacos and CMW cements was studied using elution and serial plate transfer tests. Further tests were made to assay the drug remaining in the cement after antibacterial activity could no longer be detected by the above methods, to detect the sustained slow release of the residual drug, and to ascertain the mechanism of release. The results confirmed that the release of gentamicin sulphate could be detected for longer from Palacos cement than from CMW cement, but the opposite was true for sodium fusidate. Little difference was found in the case of diethanolamine fusidate. Comparison of elution and serial plate transfer tests, and of results of elution in buffers of different pH, demonstrated that the test method employed had a significant effect on the results, and the omission of details of methodology from some publications made comparison and evaluation of results difficult. Varying quantities of residual drug were found in cement from which antibacterial activity could no longer be demonstrated; further tests for sustained, slow release showed that the antibiotic did not remain fixed in the cement but was released at a rate too slow to be detected in the elution and serial plate transfer tests. It is concluded that antibiotics are released from the cement by a process of diffusion, but tests to determine the mechanism of diffusion were unhelpful. The theory of diffusion of drugs through solid matrices, and the clinical implications of the experimental findings, are discussed.

The beneficial effects of insulin in the maintenance of normoglycaemia in non-diabetic myocardial infarct and intensive care patients have recently been reported. Hyperglycaemia and neutrophilia have been shown to be independent prognostic indicators of poor outcome in the traumatised patient. The role of insulin and the maintenance of normoglycaemia in the trauma patient have as yet not been explored. We hypothesised that through the already described anti-inflammatory effects of insulin and the maintenance of normoglycaemia, that neutrophil activation and endothelial dysfunction would be attenuated, in the injured patient. This might result in less adult respiratory distress syndrome (ARDS) and multi-organ dysfunction and therefore less morbidity and mortality for the trauma patient.

Materials and Methods: To study this we used a previously validated rodent trauma model. There were 2 groups, both groups underwent bilateral femur fracture and 15% blood loss via cannulation and aspiration of the external jugular vein. The treatment group immediately receive subcutaneous insulin according to a recently identified sliding scale, and thereafter subcutaneous boluses, dependent on half hourly blood sugar estimations. The control group received the same volume of normal saline half hourly, subcutaneously. The animals were maintained under anaesthetic for 4 hours from injury via inhaled halothane and oxygen. Core temperature and 0₂ saturations were recorded throughout. At 4 hours, each animal underwent midline laparotomy and cannulation of the IVC for blood sampling for full blood counts, lactate levels and for flow cytometry to estimate neutrophil activation via respiratory burst and CD11b upregulation. Bronchoalveolar lavage (BAL) was performed for neutrophil content and total protein estimation. The left lower lobe was harvested for wet-dry lung weight ratios.

Results: While 0₂ saturations were equal throughout in both groups, respiratory rates were persistently elevated in the controls. Wet:Dry lung ratios and lactate levels were reduced in the insulin treated animals compared to controls. There were similarly fewer neutrophils in the BAL specimens of the insulin treated animals (p< 0.05).

Conclusions: Insulin reduces leukocyte lung sequestration in the injured animal model. This work confirms that insulin may have a role in reducing ARDS in the trauma patient, be that as an anti-inflammatory agent or anti-hyperglycaemic agent, or both, indicating that outcomes might be improved by treating hyperglycaemic trauma patients with insulin. Further work needs to be done to elucidate its exact mechanism of action and role in the injured patient.

Purpose: The aim was to determine whether intra-articular bupivacaine provides effective analgesia following ankle arthroscopy and whether it reduces the need for supplemental analgesia.

Methods: A power calculation revealed that 40 patients were required to provide a 5% significant level using a visual analogue scale. 40 patients were therefore randomised to receiving 20 mls of either bupivacaine or saline (control) after routine anterior ankle arthroscopic surgery. The tourniquet was released 10 minutes later. In recovery, supplementary analgesia of 2 tablets of co-codomol 30/500 orally or 50–100mg tramadol IV was available on request. A 10 day supply of 50mg diclofenac (8 hourly) and co-codomol 30/500 2 tablets (6 hourly) was provided.

A visual analogue scale (VAS) was employed as a direct indicator of pain and indirectly, supplemental analgesic requirement. Measurements were made pre-operatively and postoperatively.

Age, weight and tourniquet times were compared with Mann Whitney U test and Chi-square. Pain scores and analgesic requirements were compared using ANOVA at a 5% significance level.

Results: Pain scores were lower in the bupivacaine group compared to the control as was the need for supplemental analgesia.

Significance: We conclude that postoperative intraarticular bupivacaine provides effective analgesia following ankle arthroscopy.

Introduction Musculoskeletal injuries, especially fractures, cause reduced limb mobilization. The diminished limb activity promotes muscular atrophy, leading to a slower return to function. Attempts to prevent this atrophy using electrical stimulation have been described after knee reconstruction.

The Myospare percutaneous electrical stimulator has been developed to prevent immobilization related atrophy. We undertook this pilot study to assess feasibility, safety, and efficacy of applying electrical stimulation under a cast after ankle fractures.

Patients and Methods Between May and December 2004, patients who sustained closed ankle fractures requiring surgery, were recruited to participate in this study. 24 patients took part in the study, sixteen male and eight female. Age range was 18 to 62 years (average 40). All patients underwent open reduction and internal fixation using standard AO technique. A short walking cast was applied after surgery. Patients were randomized into a treatment and a control group. The experimental device was applied in the treatment group for 6 weeks. Patients were examined at 2, 6 and 12 weeks.

Evaluation included measurement of calf and ankle circumference, dorsiflexion and plantiflexion, and calculation of the ratio between the injured and uninjured side. At each visit pain intensity was assessed using a visual analog score, and patients filled out a function assessment questionnaire. Analysis was performed using chi square, t-test and repeated measures analysis.

Results All patients tolerated the stimulator well. No adverse effects were encountered. There is a trend toward improvement in calf diameter, dorsiflexion and plantarflexion. However, with the small number of patients in this study, no significant difference was apparent. Functional recovery and VAS scores were borderline higher in the treatment group at 12 weeks (p=0.043 and p=.049) when compared to baseline.

Discussion The use of the Myospare device under a cast in patients after surgical fixation of ankle fractures has been demonstrated as feasible and safe. In this pilot study a trend toward enhanced recovery was apparent in the treatment group.

Aims. The aim of this study was to investigate the agreement in interpretation of the quality of the paediatric hip ultrasound examination, the reliability of geometric and morphological assessment, and the relationship between these measurements. Methods. Four investigators evaluated 60 hip ultrasounds and assessed their quality based the standard plane of Graf et al. They measured geometric parameters, described the morphology of the hip, and assigned the Graf grade of dysplasia. They analyzed one self-selected image and one randomly selected image from the ultrasound series, and repeated the process four weeks later. The intra- and interobserver agreement, and correlations between various parameters were analyzed. Results. In the assessment of quality, there a was moderate to substantial intraobserver agreement for each element investigated, but interobserver agreement was poor. Morphological features showed weak to moderate agreement across all parameters but improved to significant when responses were reduced. The geometric measurements showed nearly perfect agreement, and the relationship between them and the morphological features showed a dose response across all parameters with moderate to substantial correlations. There were strong correlations between geometric measurements. The Graf classification showed a fair to moderate interobserver agreement, and moderate to substantial intraobserver agreement. Conclusion. This investigation into the reliability of the interpretation of hip ultrasound scans identified the difficulties in defining what is a high-quality ultrasound. We confirmed that geometric measurements are reliably interpreted and may be useful as a further measurement of quality. Morphological features are generally poorly interpreted, but a simpler binary classification considerably improves agreement. As there is a clear dose response relationship between geometric and morphological measurements, the importance of morphology in the diagnosis of hip dysplasia should be questioned. Cite this article: Bone Joint J 2023;105-B(10):1123–1130

Aims. The aims of this study were to identify and evaluate the current literature examining the prognostic factors which are associated with failure of total elbow arthroplasty (TEA). Methods. Electronic literature searches were conducted using MEDLINE, Embase, PubMed, and Cochrane. All studies reporting prognostic estimates for factors associated with the revision of a primary TEA were included. The risk of bias was assessed using the Quality In Prognosis Studies (QUIPS) tool, and the quality of evidence was assessed using the modified Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework. Due to low quality of the evidence and the heterogeneous nature of the studies, a narrative synthesis was used. Results. A total of 19 studies met the inclusion criteria, investigating 28 possible prognostic factors. Most QUIPS domains (84%) were rated as moderate to high risk of bias. The quality of the evidence was low or very low for all prognostic factors. In low-quality evidence, prognostic factors with consistent associations with failure of TEA in more than one study were: the sequelae of trauma leading to TEA, either independently or combined with acute trauma, and male sex. Several other studies investigating sex reported no association. The evidence for other factors was of very low quality and mostly involved exploratory studies. Conclusion. The current evidence investigating the prognostic factors associated with failure of TEA is of low or very low quality, and studies generally have a moderate to high risk of bias. Prognostic factors are subject to uncertainty, should be interpreted with caution, and are of little clinical value. Higher-quality evidence is required to determine robust prognostic factors for failure of TEA. Cite this article: Bone Joint Res 2024;13(5):201–213

Aims. Most patients with advanced malignancy suffer bone metastases, which pose a significant challenge to orthopaedic services and burden to the health economy. This study aimed to assess adherence to the British Orthopaedic Oncology Society (BOOS)/British Orthopaedic Association (BOA) guidelines on patients with metastatic bone disease (MBD) in the UK. Methods. A prospective, multicentre, national collaborative audit was designed and delivered by a trainee-led collaborative group. Data were collected over three months (1 April 2021 to 30 June 2021) for all patients presenting with MBD. A data collection tool allowed investigators at each hospital to compare practice against guidelines. Data were collated and analyzed centrally to quantify compliance from 84 hospitals in the UK for a total of 1,137 patients who were eligible for inclusion. Results. A total of 846 patients with pelvic and appendicular MBD were analyzed, after excluding those with only spinal metastatic disease. A designated MBD lead was not present in 39% of centres (33/84). Adequate radiographs were not performed in 19% of patients (160/846), and 29% (247/846) did not have an up-to-date CT of thorax, abdomen, and pelvis to stage their disease. Compliance was low obtaining an oncological opinion (69%; 584/846) and prognosis estimations (38%; 223/846). Surgery was performed in 38% of patients (319/846), with the rates of up-to-date radiological investigations and oncology input with prognosis below the expected standard. Of the 25% (215/846) presenting with a solitary metastasis, a tertiary opinion from a MBD centre and biopsy was sought in 60% (130/215). Conclusion. Current practice in the UK does not comply with national guidelines, especially regarding investigations prior to surgery and for patients with solitary metastases. This study highlights the need for investment and improvement in care. The recent publication of British Orthopaedic Association Standards for Trauma (BOAST) defines auditable standards to drive these improvements for this vulnerable patient group. Cite this article: Bone Joint J 2023;105-B(10):1115–1122

Aims. Metal particles detached from metal-on-metal hip prostheses (MoM-THA) have been shown to cause inflammation and destruction of tissues. To further explore this, we investigated the histopathology (aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL) score) and metal concentrations of the periprosthetic tissues obtained from patients who underwent revision knee arthroplasty. We also aimed to investigate whether accumulated metal debris was associated with ALVAL-type reactions in the synovium. Methods. Periprosthetic metal concentrations in the synovia and histopathological samples were analyzed from 230 patients from our institution from October 2016 to December 2019. An ordinal regression model was calculated to investigate the effect of the accumulated metals on the histopathological reaction of the synovia. Results. Median metal concentrations were as follows: cobalt: 0.69 μg/g (interquartile range (IQR) 0.10 to 6.10); chromium: 1.1 μg/g (IQR 0.27 to 4.10); and titanium: 1.6 μg/g (IQR 0.90 to 4.07). Moderate ALVAL scores were found in 30% (n = 39) of the revised knees. There were ten patients with an ALVAL score of 6 or more who were revised for suspected periprosthetic joint infection (PJI), aseptic loosening, or osteolysis. R2 varied between 0.269 and 0.369 for the ordinal regression models. The most important variables were model type, indication for revision, and cobalt and chromium in the ordinal regression models. Conclusion. We found that metal particles released from the knee prosthesis can accumulate in the periprosthetic tissues. Several patients revised for suspected culture-negative PJI had features of an ALVAL reaction, which is a novel finding. Therefore, ALVAL-type reactions can also be found around knee prostheses, but they are mostly mild and less common than those found around metal-on-metal prostheses. Cite this article: Bone Joint Res 2024;13(4):149–156

While high-performance ceramics like alumina and zirconia exhibit excellent wear resistance, they provide poor osseointegration capacity. As osseointegration is crucial for non-cemented joint prostheses, new techniques have been successfully developed for biofunctionalizing high-performance ceramic surfaces. Stable cell adhesion can be achieved by covalently bound specific peptides. In this study we investigate the effect of sterilization processes on organo-chemically functionalized surfaces. To enhance the performance of alumina-toughened zirconia ceramics (ATZ), a 3-aminopropyldiisopropylethoxysilane (APDS) monolayer was applied and coupled with cyclo-RGD peptides (cRGD) by using bifunctional crosslinker bis(sulfosuccinimidyl)suberat (BS³). The samples were sterilized using e-beam or gamma-sterilization at 25 kGy, either before or after biofunctionalization with cRGD. Functionalization stability was investigated by contact angle measurements. The functionality of cRGD after sterilization was demonstrated using proliferation tests and cytotoxicity assays. Immunofluorescence staining (pFAK, Actin, DAPI) was conducted to evaluate the adhesion potential between the samples and human mesenchymal stem cells (hMSCs). Functionalized samples before and after sterilization showed no significant difference regarding their contact angles. A proliferation test demonstrated that the cells on functionalized samples proliferate significantly more than on untreated samples before and after sterilization. hMSCs showed a significant higher proliferation on gamma sterilized samples compared to all other groups after 14 days. It was confirmed that the samples did not exhibit cytotoxic behavior before or after sterilization. Fluorescence microscopy demonstrated that both, cells on sterilized and on non-sterilized samples, expressed high levels of pFAK-Y397. The investigated functionalization enables improved adhesion and proliferation of hMSCs and is stable against the investigated sterilization processes. This is of importance as the option of having a sterile product enables the start of the translation of this biofunctional coating towards preclinical and subsequently first-in-man applications. Acknowledgments: We acknowledge the financial support of the Federal Ministry of Education and Research, BMBF (13GW0452A-C)

Total joint arthroplasty (TJA) is one of the commonest and most successful orthopaedic procedures used for the management of end-stage arthritis. With the recent introduction of robotic-assisted joint replacement, Computed tomography (CT) has become part of required pre-operative planning. The aim of this study is to quantify and characterise incidental CT findings, their clinical significance, and their effect on the planned joint arthroplasty. All consecutive patients undergoing an elective TJA (total joint arthroplasty; hip or knee) were retrospectively identified, over a 4-year period (December 2019 and November 2023). Data documented and analysed included patient demographics, type of joint arthroplasty, CT findings, their clinical significance, as well as potential delays to the planned arthroplasty because of these findings and subsequent further investigation. A total of 987 patients (female: 514 patients (52.1%)) undergoing TJA were identified (THA: 444 patients (45.0%); TKA: 400 patients (40.5%); UKA: 143 patients (14.5%)). Incidental findings within imaged areas were identified in 227 patients (23.0%). Of these findings, 74 (7.5%) were significant, requiring further investigation or management, 40 (4.1%) of which represented potential malignancy and 4 (0.4%) resulting in a new cancer diagnosis. A single patient was found to have an aneurysm requiring urgent vascular intervention. Surgery was delayed for further investigation in 4 patients (0.4%). Significant findings were more frequent in THA patients (THA: 43 (9.7%) TKA/UKA: 31 (5.7%). Within our cohort, 74 (7.5%) patients had significant incidental findings that required further investigations or management, with 4 (0.4%) having a previously undiagnosed malignancy. We strongly advocate that all robotic arthroplasty planning CTs are reviewed and reported by a specialist, to avoid missing undiagnosed malignancies and other significant diagnoses

The in vitro mimicking of bone microenvironment for the study of pathologies is a challenging field that requires the design of scaffolds with suitable morphological, structural and cytocompatible properties. During last years, 3D in vitro tumour models have been developed to reproduce mechanical, biochemical and structural bone microenvironment elements, allowing cells to behave as in vivo. In this work, gas foamed polyether urethane foams (PUF) and 3D printed thermoplastic polyether urethane (3DP-PU) designed with different patterns are proposed as scaffolds for in vitro model of bone tissue. Surface coatings for a biomimetic behaviour of the 3D scaffold models were also investigated. Morphological, chemico-physical, mechanical properties, and biological in vitro behaviour were investigated. PUFs for metastases investigation. The suitability of PUF as 3D in vitro model to study the interactions between bone tumour initiating cells and the bone microenvironment was investigated. PUF open porosity (>70%) appeared suitable to mimic trabecular bone structure. Human adipose derived stem cells (ADSC) were cultured and differentiated into osteoblast lineage on the PU foam, as confirmed by Alizarin Red staining and RT-PCR, thus offering a bone biomimetic microenvironment to the further co-culture with bone derived tumour-initiating cells (MCFS). Tumour aggregates were observed after three weeks of co-culture by e-cadherin staining and SEM; modification in CaP distribution was identified by SEM-EDX and associated to the presence of tumour cells. 3DP-PU as tumour bone model. 3D printed scaffolds have pores with a precise and regular geometry (0°-90°, 0°-45°-90°-135°, 0°-60°-120°). PU scaffold porosity evidenced values from 55 to 67%, values that belong to the porosity range of the trabecular bone tissue (30-90%). The compressive modulus varied between 2 and 4 MPa, depending on the printed pattern. Biomimetic nanostructured coating was performed on 0-90° 3DP-PU by Ionized Jet Deposition. Coatings had a submicrometric thickness, variable tuning deposition time, nanostructured surface morphology and biomimetic composition. Coating on 3DP-PU promoted cells colonization of the whole porous scaffolds, compared to the controls, where cells concentrated mostly on the outer layers. In conclusion, based on the obtained results, scaffolds with different geometries have been successfully produced. Morphological and structural properties of the scaffolds here presented are suitable for mimicking the bone tissue, in order to produce a 3D in vitro model useful for bone pathologies research

Several synthetic polymers have been widely investigated for their use in bone tissue engineering applications, but the ideal material is yet to be engineered. Triazine-trione (TATO) based materials and their derivatives are novel in the field of biomedical engineering but have started to draw interest. Different designs of the TATO monomers and introduction of different chemical linkages and end-groups widens the scope of the materials due to a range of mechanical properties. The aim of our work is to investigate novel TATO based materials, with or without hydroxyapatite filler, for their potential in bone tissue engineering constructs. Initially the biocompatibility of the materials was tested, indirectly and directly, according to ISO standards. Following this the osteoconductive properties were investigated with primary osteoblasts and an osteoblastic cell line. Bone marrow derived mesenchymal stem cells were used to evaluate the osteogenic differentiation and consequently the materials potential in bone tissue engineering applications

Aims. Our objective was describing an algorithm to identify and prevent vascular injury in patients with intrapelvic components. Methods. Patients were defined as at risk to vascular injuries when components or cement migrated 5 mm or more beyond the ilioischial line in any of the pelvic incidences (anteroposterior and Judet view). In those patients, a serial investigation was initiated by a CT angiography, followed by a vascular surgeon evaluation. The investigation proceeded if necessary. The main goal was to assure a safe tissue plane between the hardware and the vessels. Results. In ten at-risk patients undergoing revision hip arthroplasty and submitted to our algorithm, six were recognized as being high risk to vascular injury during surgery. In those six high-risk patients, a preventive preoperative stent was implanted before the orthopaedic procedure. Four patients needed a second reinforcing stent to protect and to maintain the vessel anatomy deformed by the intrapelvic implants. Conclusion. The evaluation algorithm was useful to avoid blood vessels injury during revision total hip arthroplasty in high-risk patients. Cite this article: Bone Jt Open 2022;3(11):859–866

Aims. The present study investigated receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), and Runt-related transcription factor 2 (RUNX2) gene expressions in giant cell tumour of bone (GCTB) patients in relationship with tumour recurrence. We also aimed to investigate the influence of CpG methylation on the transcriptional levels of RANKL and OPG. Methods. A total of 32 GCTB tissue samples were analyzed, and the expression of RANKL, OPG, and RUNX2 was evaluated by quantitative polymerase chain reaction (qPCR). The methylation status of RANKL and OPG was also evaluated by quantitative methylation-specific polymerase chain reaction (qMSP). Results. We found that RANKL and RUNX2 gene expression was upregulated more in recurrent than in non-recurrent GCTB tissues, while OPG gene expression was downregulated more in recurrent than in non-recurrent GCTB tissues. Additionally, we proved that changes in DNA methylation contribute to upregulating the expression of RANKL and downregulating the expression of OPG, which are critical for bone homeostasis and GCTB development. Conclusion. Our results suggest that the overexpression of RANKL/RUNX2 and the lower expression of OPG are associated with recurrence in GCTB patients. Cite this article: Bone Joint Res 2024;13(2):84–91

Abstract. Introduction. National BOAST guidelines have been developed to coordinate and improve the standard of care for all patients with problems after knee replacement surgery. Since the inception of these guidelines we wanted to assess the impact of these guidelines on patients and their pathways following their discussions at our weekly revision MDT meetings. Methodology. Trust casenotes programs, PACS software and MDT notes were evaluated over the past 12 months (January 2022 to December 2022) to collect data for all patients with problematic knee replacements. Current in-patients discussed at MDT were excluded. Results. In total 52 patients with problematic knees were discussed. In terms of the SPECIFIC criteria described in BOAST guidelines, 39% met one or more of these criteria (component loosening, infection, instability, component wear) of which 90% are have had or planned for revision surgery. Of those (61%) not meeting this criteria, 77% have been deemed not to have a surgical cause after further investigations with the rest still pending further investigation. Conclusion. The publication of guidelines has aided in the ongoing management of patients with problematic knee replacements. From our MDT discussions over the last year, its clear that when appropriately investigated and a cause found from the SPECIFIC criteria, patients are offered appropriate revision surgery. Further work with longer-term outcomes from MDT discussions would help to evaluate the impact of these discussions on which problematic knees benefit most from revision surgery and the effect on knee revision networks

The use of mesenchymal stromal cells (MSCs) in regenerative medicine and tissue engineering is well established, given their properties of self-renewal and differentiation. However, several studies have shown that these properties diminish with age, and understanding the pathways involved are important to provide regenerative therapies in an ageing population. In this PRISMA systematic review, we investigated the effects of chronological donor ageing on the senescence of MSCs. We identified 3023 studies after searching four databases including PubMed, Web of Science, Cochrane, and Medline. Nine studies met the inclusion and exclusion criteria and were included in the final analyses. These studies showed an increase in the expression of p21, p53, p16, ROS, and NF- B with chronological age. This implies an activated DNA damage response (DDR), as well as increased levels of stress and inflammation in the MSCs of older donors. Additionally, highlighting the effects of an activated DDR in cells from older donors, a decrease in the expression of proliferative markers including Ki67, MAPK pathway elements, and Wnt/ -catenin pathway elements was observed. Furthermore, we found an increase in the levels of SA- -galactosidase, a specific marker of cellular senescence. Together, these findings support an association between chronological age and MSC senescence. The precise threshold for chronological age where the reported changes become significant is yet to be defined and should form the basis for further scientific investigations. The outcomes of this review should direct further investigations into reversing the biological effects of chronological age on the MSC senescence phenotype

Revision Total Knee Arthroplasty (rTKA) is predicted to increase by more than 600% between 2005 and 2030. The survivorship of primary TKA has been extensively investigated, however more granular information on the risks of rTKA is needed. The aim of the study was to investigate the incidence of re-revision TKA, with explanatory variables of time from primary to revision, and indication (aseptic vs septic). Secondary aim was to investigate mortality. This is an analysis of the Scottish Arthroplasty Project data set, a national audit prospectively recording data on all joint replacements performed in Scotland. The period from 2000 to 2019 was studied. 4723 patients underwent revision TKA. The relationship between time from primary to revision TKA and 2nd revision was significant (p<0.001), with increasing time lowering probability of re-revision (OR 0.99 95% CI 0.987 to 0.993). There was no significant association in time to first revision on time from 1st revision to re-revision (p>0.05). Overall mortality for all patients was 32% at 10 years (95% CI 31-34), Time from primary TKA to revision TKA had a significant effect on mortality: p=0.004 OR 1.03 (1.01-1.05). Septic revisions had a reduced mortality compared to aseptic, OR 0.95 (0.71-1.25) however this was not significant (p=0.69). This is the first study to demonstrate time from primary TKA to revision TKA having a significant effect on probability of re-revision TKA. Furthermore the study suggests mortality is increased with increasing time from primary procedure to revision, however decreased if the indication is septic rather than aseptic

Ten to twenty percent of patients are dissatisfied with the clinical result after total knee arthroplasty (TKA). Aim of this study was to investigate the impact of personality traits on patient satisfaction and subjective outcome of TKA. We investigated 80 patients with 86 computer navigated TKAs (Emotion®, B Braun Aesculap) and asked for patient satisfaction. We divided patients into two groups (satisfied or dissatisfied). 12 personality traits were tested by an independent psychologist, using the Freiburg Personality Inventory (FPI-R). Postoperative examination included Knee Society Score (KSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the Visual Analogue Scale (VAS). Radiologic investigation was done in all patients. 84% of our patients were satisfied, while 16% were not satisfied with clinical outcome. The FPI-R showed statistically significant influence of four personality traits on patient satisfaction: life satisfaction (ρ = 0.006), performance orientation (ρ =0.015), somatic distress (ρ = 0.001), and emotional stability (ρ = 0.002). All clinical scores (VAS, WOMAC, and KSS) showed significant better results in the satisfied patient group. Radiological examination showed optimal alignment of all TKAs. There were no complications requiring revision surgery in both groups. The results of our study show that personality traits may influence patient satisfaction and clinical outcome after TKA. Thus, patients personality traits may be a useful predictive factor for postoperative satisfaction after TKA

Aims. Iliopsoas impingement occurs in 4% to 30% of patients after undergoing total hip arthroplasty (THA). Despite a relatively high incidence, there are few attempts at modelling impingement between the iliopsoas and acetabular component, and no attempts at modelling this in a representative cohort of subjects. The purpose of this study was to develop a novel computational model for quantifying the impingement between the iliopsoas and acetabular component and validate its utility in a case-controlled investigation. Methods. This was a retrospective cohort study of patients who underwent THA surgery that included 23 symptomatic patients diagnosed with iliopsoas tendonitis, and 23 patients not diagnosed with iliopsoas tendonitis. All patients received postoperative CT imaging, postoperative standing radiography, and had minimum six months’ follow-up. 3D models of each patient’s prosthetic and bony anatomy were generated, landmarked, and simulated in a novel iliopsoas impingement detection model in supine and standing pelvic positions. Logistic regression models were implemented to determine if the probability of pain could be significantly predicted. Receiver operating characteristic curves were generated to determine the model’s sensitivity, specificity, and area under the curve (AUC). Results. Highly significant differences between the symptomatic and asymptomatic cohorts were observed for iliopsoas impingement. Logistic regression models determined that the impingement values significantly predicted the probability of groin pain. The simulation had a sensitivity of 74%, specificity of 100%, and an AUC of 0.86. Conclusion. We developed a computational model that can quantify iliopsoas impingement and verified its accuracy in a case-controlled investigation. This tool has the potential to be used preoperatively, to guide decisions about optimal cup placement, and postoperatively, to assist in the diagnosis of iliopsoas tendonitis. Cite this article: Bone Jt Open 2023;4(1):3–12

Periprosthetic joint infections (PJI) are one of the most common reasons for orthopedic revision surgeries. In previous studies, it has been shown that silver modification of titanium (Ti-6Al-4V) surfaces by PMEDM (powder mixed electrical discharge machining) has an antibacterial effect on Staphylococcus aureus adhesion. Whether this method also influences the proliferation of bacteria has not been investigated so far. Furthermore, the effect is only limitedly investigated on the ossification processes. Therefore, the aim of this work is to investigate the antibacterial effect as well as the in vitro ossification process of PMEDM machined surfaces modified by integration of silver. In this study, we analyzed adhesion and proliferation of S. aureus in comparison to of surface roughness, silver content and layer thickness of the silver-integrated-PMEDM surfaces (N = 5). To test the in vitro ossification, human osteoblasts (SaOs-2) and osteoclasts (differentiated from murine-bone-marrow-macrophages) were cultured on the silver surfaces (N = 3). We showed that the attachment of S. aureus on the surfaces was significantly lower than on the comparative control surfaces of pure Ti-6Al-4V without incorporated silver, independently of the measured surface properties. Bacterial proliferation, however, was not affected by the silver content. No influence on the in vitro ossification was observed, whereas osteoclast formation was drastically reduced on the silver-modified surfaces. We showed that 1 to 3% of silver in the surface layer significantly reduced the adhesion of S. aureus, but not the proliferation of already attached bacteria. At the same time, no influence on the in vitro ossification was observed, while no osteoclasts were formed on the surface. Therefore, we state that PMEDM with simultaneous silver modification of the machined surfaces represents a promising technology for endoprostheses manufacturing to reduce infections while at the same time optimizing bone ingrowth

Radiological investigations are essential in the work-up of patients presenting with non-arthritic hip pain, to allow close review of the complex anatomy around the hip and proximal femur. The aim of this study is to quantify the radiation exposure associated with common radiological investigations performed in assessing young adult patients presenting with non-arthritic hip pain. A retrospective review of our UK tertiary hip preservation centre institutional imaging database was performed. Data was obtained for antero-posterior, cross-table lateral and frog-lateral radiographs, along with data for the low dose CT hip protocol and the Mako CT Hip protocol. The radiation dose of each imaging technique was measured in terms of dose-area product (DAP) with units of mGycm2, and the effective doses (ED, mSv) calculated. The mean effective radiation dose for hip radiographs was in the range 0.03 to 0.83mSv (mean DLP 126.7–156.2 mGycm2). The mean effective dose associated with the low-dose CT hip protocol was 3.04mSv (416.8 mGycm2) and for the Stryker Mako CT Hip protocol was 8.4mSv (1061 mGycm2). The radiation dose associated with use of CT imaging was significantly greater than plain radiographs (p<0.005). Investigation of non-arthritic hip pain can lead to significant ionising radiation exposure for patients. In our institution, the routine protocol is to obtain an anteroposterior radiograph and then a specific hip sequence 3 Tesla MRI including anteversion views. This provides the necessary information in the majority of cases, with CT scanning reserved for more complex cases where we feel there is a specific indication. We would encourage the hip preservation community to carefully consider and review the use of ionising radiation investigations

Purpose. Intra-articular corticosteroid injection is widely used for symptomatic relief of knee osteoarthritis. However, if pain is not improved which consequences a total knee arthroplasty (TKA), there is a potential risk of post-operative periprosthetic joint infection (PJI). The aim of this study is to investigate whether the use of preoperative intra-articular corticosteroid injection increases the risk of PJI and to investigate a time frame in which the risk of subsequent infection is significantly increased. Methods. A systematic search was performed in PubMed (Medline), Scopus, and the Cochrane Library. Inclusion criteria were original studies investigating the rate of PJI in patients receiving pre-operative intra-articular corticosteroid injection compared to controls. Results. A total of 380 unique articles were screened. Six studies met the inclusion criteria with 255,627 patients in total. Overall, no statistical significance was observed in the intra-articular infection rate in corticosteroid compared to controls groups. However, intra-articular corticosteroid injections within 3 months prior to TKA were associated with a significantly increased risk of infection (OR: 1.52, 95% CI 1.37–1.67, p < 0.01); this was not observed in the 6-month period (OR: 1.05, 95% CI 0.80–1.39, p = 0.72). Conclusions. Performing an intra-articular corticosteroid injection within 3 months prior to TKA is associated with a significantly increased risk of PJI. The current evidence supports the safe use of intra-articular corticosteroid injection more than 6 months before TKA. However, additional studies are needed to clarify the risk of PJI after TKA implantation between 3 and 6 months after the last corticoid injection

Aims. Transcription factor nuclear factor kappa B (NF-κB) plays a major role in the pathogenesis of chronic inflammatory diseases in all organ systems. Despite its importance, NF-κB targeted drug therapy to mitigate chronic inflammation has had limited success in preclinical studies. We hypothesized that sex differences affect the response to NF-κB treatment during chronic inflammation in bone. This study investigated the therapeutic effects of NF-κB decoy oligodeoxynucleotides (ODN) during chronic inflammation in male and female mice. Methods. We used a murine model of chronic inflammation induced by continuous intramedullary delivery of lipopolysaccharide-contaminated polyethylene particles (cPE) using an osmotic pump. Specimens were evaluated using micro-CT and histomorphometric analyses. Sex-specific osteogenic and osteoclastic differentiation potentials were also investigated in vitro, including alkaline phosphatase, Alizarin Red, tartrate-resistant acid phosphatase staining, and gene expression using reverse transcription polymerase chain reaction (RT-PCR). Results. Local delivery of NF-κB decoy ODN in vivo increased osteogenesis in males, but not females, in the presence of chronic inflammation induced by cPE. Bone resorption activity was decreased in both sexes. In vitro osteogenic and osteoclastic differentiation assays during inflammatory conditions did not reveal differences among the groups. Receptor activator of nuclear factor kappa Β ligand (Rankl) gene expression by osteoblasts was significantly decreased only in males when treated with ODN. Conclusion. We demonstrated that NF-κB decoy ODN increased osteogenesis in male mice and decreased bone resorption activity in both sexes in preclinical models of chronic inflammation. NF-κB signalling could be a therapeutic target for chronic inflammatory diseases involving bone, especially in males. Cite this article: Bone Joint Res 2024;13(1):28–39

Low back pain (LBP) is the main cause of disability worldwide and is primarily triggered by intervertebral disc degeneration (IDD). Although several treatment options exist, no therapeutic tool has demonstrated to halt the progressive course of IDD. Therefore, several clinical trials are being conducted to investigate different strategies to regenerate the intervertebral disc, with numerous studies not reaching completion nor being published. The aim of this study was to analyze the publication status of clinical trials on novel regenerative treatments for IDD by funding source and identify critical obstacles preventing their conclusion. Prospective clinical trials investigating regenerative treatments for IDD and registered on . ClinicalTrials.gov. were included. Primary outcomes were publication status and investigational treatment funding. Fisher's exact test was utilized to test the association for categorical variables between groups. 25 clinical trials were identified. Among these, only 6 (24%) have been published. The most common source of funding was university (52%), followed by industry (36%) and private companies (12%). Investigational treatments included autologous (56%) or allogeneic (12%) products alone or in combination with a carrier or delivery system (32%). The latter were more likely utilized in industry or privately funded studies (Fig. 1, p=0.0112). No significant difference was found in terms of funding regarding the publication status of included trials (Table 1, p=0.9104). Most clinical trials investigating regenerative approaches for the treatment of IDD were never completed nor published. This is likely due to multiple factors, including difficult enrollment, high dropout rate, and publication bias. 3. More accurate design and technical support from stakeholders and clinical research organization (CROs) may likely increase the quality of future clinical trials in the field. For any figures or tables, please contact the authors directly

Objectives. This study aims to investigate whether bacteria are present in intervertebral discs (IVDs) and their influence. Causality between chronic infection of the IVD and its degenerative process gained great interest recently. Granville Smith et al. (2021) identified 36 articles from 34 research studies investigating bacteria in IVDs, from these 27 studies found, Cutibacterium acnes being the most abundant. However, whether bacteria identified were present in vivo or if they represent contamination remains unclear. Methods. Human IVD tissue was fixed in paraffin and Immunohistochemical stained for Gram-positive bacteria. NP cells in monolayer have been stimulated with LPS (0.1–50 µg/ml) and Peptidoglycan (0.1–50 µg/ml) for 24, 48 and 72 hrs to investigate their influence. The concentration of proinflammatory and catabolic cytokines in the media is being measured using ELISA. RNA extracted and RT-qPCR utilised for factors associated with disc degeneration matrix genes, matrix degrading enzymes, cytokines, neurotrophic factors and angiogenic factors. Results. Bacteria were detected within IVD tissue. Bacteria was internalized by the NP cells and influenced the nuclei morphology. Preliminary results of the exposure of NP cells to bacterial components demonstrate that ADAMTS4 as well as IL-8 were showed an increase in gene expression after LPS and peptidoglycan treatment compared to the non-treated control. Underlining these results, IL-8 protein was increased in treated groups, whereas peptidoglycan treated groups showed a dose dependence. Conclusion. This study demonstrates that Gram positive bacteria are present within the IVD. The exposure of NP cells to peptidoglycans indicates that bacterial components trigger a stress response. Conflicts of Interest: No conflict of interest. Sources of Funding: This project is part of the Disc4All Training network to advance integrated computational simulations in translational medicine, applies to intervertebral disc degeneration and funded by Horizon 2020 (H2020-MSCA-ITN-ETN-2020 GA: 955735)

Metabolic bone diseases, such as osteoporosis and osteopetrosis, result from an imbalanced bone remodeling process. In vitro bone models are often used to investigate either bone formation or resorption independently, while in vivo, these processes are coupled. Combining these processes in a co-culture is challenging as it requires finding the right medium components to stimulate each cell type involved without interfering with the other cell type's differentiation. Furthermore, differentiation stimulating factors often comprise growth factors in supraphysiological concentrations, which can overshadow the cell-mediated crosstalk and coupling. To address these challenges, we aimed to recreate the physiological bone remodeling process, which follows a specific sequence of events starting with cell activation and bone resorption by osteoclasts, reversal, followed by bone formation by osteoblasts. We used a mineralized silk fibroin scaffold as a bone-mimetic template, inspired by bone's extracellular matrix composition and organization. Our model supported osteoclastic resorption and osteoblastic mineralization in the specific sequence that represents physiological bone remodeling. We also demonstrated how culture variables, such as different cell ratios, base media, and the use of osteogenic/osteoclast supplements, and the application of mechanical load, can be adjusted to represent either a high bone turnover system or a self-regulating system. The latter system did not require the addition of osteoclastic and osteogenic differentiation factors for remodeling, therefore avoiding growth factor use. Our in vitro model for bone remodeling has the potential to reduce animal experiments and advance in vitro drug development for bone remodeling pathologies like osteoporosis. By recreating the physiological bone remodeling cycle, we can investigate cell-cell and cell-matrix interactions, which are essential for understanding bone physiology and pathology. Furthermore, by tuning the culture variables, we can investigate bone remodeling under various conditions, potentially providing insights into the mechanisms underlying different bone disorders

Unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) are well-established operative interventions in the treatment of knee osteoarthritis (KOA). However, which of these interventions is more beneficial, to patients with KOA, is not known and remains a topic of much debate. Aims: (i) To determine whether UKA or HTO is more beneficial in the treatment of isolated medial compartment KOA, via an assessment of patient-reported outcome measures (PROMs). (ii) To investigate the relationship between PROMs and radiographic parameters of knee joint orientation/alignment. This longitudinal observational study assessed a total of 42 patients that had undergone UKA (n=23) or HTO (n=19) to treat isolated medial compartment KOA. The PROMs assessed, pre-operatively and 1-year post-operatively, consisted of the: self-administered comorbidity questionnaire; short form-12; oxford knee score; knee injury and osteoarthritis outcome score; and the EQ-5D-5L. The radiographic parameters of knee joint alignment/orientation assessed, pre-operatively and 8-weeks post-operatively, included the: hip-knee-ankle angle; mechanical axis deviation; and the angle of the Mikulicz line. Statistical analysis demonstrated an overall significant (p<0.001), pre-operative to post-operative, improvement in the PROM scores of both groups. There were no significant differences in the post-operative PROM scores of the UKA and HTO group. Correlation analyses revealed that pre-operatively, a more distolaterally angled Mikulicz line was associated with worse knee function (p<0.05) and overall health (p<0.05); a relationship that, until now, has not been investigated nor commented upon within the literature. UKAs and HTOs are both efficacious operations that provide a comparable degree of clinical benefit to patients with isolated medial compartment KOA. To further the scientific/medical community's understanding of the factors that impact upon health-outcomes in KOA, future research should seek to investigate the mechanism underlying the relationship, between Mikulicz line and PROMs, observed within the current study

Aims. The aim of this study was to determine the consensus best practice approach for the investigation and management of children (aged 0 to 15 years) in the UK with musculoskeletal infection (including septic arthritis, osteomyelitis, pyomyositis, tenosynovitis, fasciitis, and discitis). This consensus can then be used to ensure consistent, safe care for children in UK hospitals and those elsewhere with similar healthcare systems. Methods. A Delphi approach was used to determine consensus in three core aspects of care: 1) assessment, investigation, and diagnosis; 2) treatment; and 3) service, pathways, and networks. A steering group of paediatric orthopaedic surgeons created statements which were then evaluated through a two-round Delphi survey sent to all members of the British Society for Children’s Orthopaedic Surgery (BSCOS). Statements were only included (‘consensus in’) in the final agreed consensus if at least 75% of respondents scored the statement as critical for inclusion. Statements were discarded (‘consensus out’) if at least 75% of respondents scored them as not important for inclusion. Reporting these results followed the Appraisal Guidelines for Research and Evaluation. Results. A total of 133 children’s orthopaedic surgeons completed the first survey, and 109 the second. Out of 43 proposed statements included in the initial Delphi, 32 reached ‘consensus in’, 0 ‘consensus out’, and 11 ‘no consensus’. These 11 statements were then reworded, amalgamated, or deleted before the second Delphi round of eight statements. All eight were accepted as ‘consensus in’, resulting in a total of 40 approved statements. Conclusion. In the many aspects of medicine where relevant evidence is not available for clinicians to base their practice, a Delphi consensus can provide a strong body of opinion that acts as a benchmark for good quality clinical care. We would recommend clinicians managing children with musculoskeletal infection follow the guidance in the consensus statements in this article, to ensure care in all medical settings is consistent and safe. Cite this article: Bone Joint J 2023;105-B(7):815–820

Aims. The localization of necrotic areas has been reported to impact the prognosis and treatment strategy for osteonecrosis of the femoral head (ONFH). Anteroposterior localization of the necrotic area after a femoral neck fracture (FNF) has not been properly investigated. We hypothesize that the change of the weight loading direction on the femoral head due to residual posterior tilt caused by malunited FNF may affect the location of ONFH. We investigate the relationship between the posterior tilt angle (PTA) and anteroposterior localization of osteonecrosis using lateral hip radiographs. Methods. Patients aged younger than 55 years diagnosed with ONFH after FNF were retrospectively reviewed. Overall, 65 hips (38 males and 27 females; mean age 32.6 years (SD 12.2)) met the inclusion criteria. Patients with stage 1 or 4 ONFH, as per the Association Research Circulation Osseous classification, were excluded. The ratios of anterior and posterior viable areas and necrotic areas of the femoral head to the articular surface were calculated by setting the femoral head centre as the reference point. The PTA was measured using Palm’s method. The association between the PTA and viable or necrotic areas of the femoral head was assessed using Spearman’s rank correlation analysis (median PTA 6.0° (interquartile range 3 to 11.5)). Results. We identified a negative correlation between PTA and anterior viable areas (rho −0.477; p = 0.001), and no correlation between PTA and necrotic (rho 0.229; p = 0.067) or posterior viable areas (rho 0.204; p = 0.132). Conclusion. Our results suggest that residual posterior tilt after FNF could affect the anteroposterior localization of necrosis. Cite this article: Bone Jt Open 2024;5(5):394–400

Purpose and background. Work-related musculoskeletal disorders, particularly back pain, are a significant issue for healthcare workers, with patient handling being the most frequently reported risk factor. Patient handling is often performed without assistive devices or equipment, which can cause healthcare staff to maintain awkward postures or experience high loads. This review aimed to comprehensively map the literature surrounding manual patient handling (without assistive devices) by healthcare practitioners to identify the current evidence-base on moving and handling of patients and explore what primary research had been conducted. Methods and results. JBI methodology for scoping reviews and an a priori registered protocol (DOI 10.17605/OSF.IO/8PR7A) was followed and AMED, CINAHL, MEDLINE, SPORTDiscus and EMBASE databases were searched. Literature published in English between 2002 and 2021 was included. Forty-nine records were included: 36 primary research studies, 1 systematic review and 12 ‘other’ including narrative and government reports. Primary research predominantly used observational cross-sectional designs (n = 21 studies). Most studies took place in hospitals (n = 13) and laboratories (n = 12). Nurses formed the largest population group (n = 13), with very little research on physiotherapists and other allied health professionals. Conclusion. This scoping review comprehensively reviewed the available literature in the area. Most of the included primary research was observational. Nurses were often investigated in hospitals and laboratories. Qualitative research investigating moving and handling and further biomechanical investigation into therapeutic handling by healthcare staff were identified as areas for further research. Conflicts of interest. None. Sources of funding. None. This work has been published in Physiotherapy: Johnson, K., Swinton, P., Pavlova, A. and Cooper, K., 2023. Manual patient handling in the healthcare setting: a scoping review. Physiotherapy. (120) 60–77 . https://doi.org/10.1016/j.physio.2023.06.003

A key cause of low back pain is the degeneration of the intervertebral disc (IVD). Causality between infection of the IVD and its degenerative process gained great interest over the last decade. Granville Smith et al. (2021) identified 36 articles from 34 research studies investigating bacteria in human IVDs. Bacteria was identified in 27 studies, whereas 9 attributed bacterial presence to contamination. Cutibacterium acnes was the most abundant, followed by coagulase-negative staphylococcus. However, whether bacteria identified were present in vivo or represent perioperative contamination remains unclear. This study investigated whether bacteria are present in IVDs and what potential effects they may have on native disc cells. Immunohistochemical staining for Gram positive bacteria was performed on human IVD tissue to identify presence and characterise bacterial species. Nucleus pulposus (NP) cells in monolayer and 3D alginate were stimulated with LPS and Peptidoglycan (0.1-50 µg/ml) for 48hrs. Following stimulation qPCR for factors associated with disc degeneration including matrix genes, matrix degrading enzymes, cytokines, neurotrophic factors and angiogenic factors and conditioned media collected for ELISA and luminex analysis. Gram positive bacteria was detected within human IVD tissue. Internalisation of bacteria by NP cells influenced the cell and nuclei morphology. Preliminary results of exposure of NP cells to bacterial components indicate that LPS as well as Peptidoglycan increase IL-8 and ADAMTS-4 gene expression following 48 hours of stimulation with a dose response seen for IL-8 induction by peptidoglycan compared to the control group. Underlining these results, IL-8 protein release was increased for treated groups compared to non-treated control. Further analysis is underway investigating other output measures and additional biological repeats. This study has demonstrated bacteria are present within IVD cells within IVD tissue removed from degenerate IVD and is determining the potential influence of these on disc degeneration

Aims. This systematic review aims to identify 3D predictors derived from biplanar reconstruction, and to describe current methods for improving curve prediction in patients with mild adolescent idiopathic scoliosis. Methods. A comprehensive search was conducted by three independent investigators on MEDLINE, PubMed, Web of Science, and Cochrane Library. Search terms included “adolescent idiopathic scoliosis”,“3D”, and “progression”. The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool (QUIPS) and Appraisal tool for Cross-Sectional Studies (AXIS), and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. In all, 915 publications were identified, with 377 articles subjected to full-text screening; overall, 31 articles were included. Results. Torsion index (TI) and apical vertebral rotation (AVR) were identified as accurate predictors of curve progression in early visits. Initial TI > 3.7° and AVR > 5.8° were predictive of curve progression. Thoracic hypokyphosis was inconsistently observed in progressive curves with weak evidence. While sagittal wedging was observed in mild curves, there is insufficient evidence for its correlation with curve progression. In curves with initial Cobb angle < 25°, Cobb angle was a poor predictor for future curve progression. Prediction accuracy was improved by incorporating serial reconstructions in stepwise layers. However, a lack of post-hoc analysis was identified in studies involving geometrical models. Conclusion. For patients with mild curves, TI and AVR were identified as predictors of curve progression, with TI > 3.7° and AVR > 5.8° found to be important thresholds. Cobb angle acts as a poor predictor in mild curves, and more investigations are required to assess thoracic kyphosis and wedging as predictors. Cumulative reconstruction of radiographs improves prediction accuracy. Comprehensive analysis between progressive and non-progressive curves is recommended to extract meaningful thresholds for clinical prognostication. Cite this article: Bone Jt Open 2024;5(3):243–251

The anterior cruciate ligament (ACL) is frequently injured in elite athletes, with females up to eight times more likely to suffer an ACL tear than males. Biomechanical and hormonal factors have been thoroughly investigated; however, there remain unknown factors that need investigation. The mechanism of injury differs between males and females, and anatomical differences contribute significantly to the increased risk in females. Hormonal factors, both endogenous and exogenous, play a role in ACL laxity and may modify the risk of injury. However, data are still limited, and research involving oral contraceptives is potentially associated with methodological and ethical problems. Such characteristics can also influence the outcome after ACL reconstruction, with higher failure rates in females linked to a smaller diameter of the graft, especially in athletes aged < 21 years. The addition of a lateral extra-articular tenodesis can improve the outcomes after ACL reconstruction and reduce the risk of failure, and it should be routinely considered in young elite athletes. Sex-specific environmental differences can also contribute to the increased risk of injury, with more limited access to and availablility of advanced training facilities for female athletes. In addition, football kits are designed for male players, and increased attention should be focused on improving the quality of pitches, as female leagues usually play the day after male leagues. The kit, including boots, the length of studs, and the footballs themselves, should be tailored to the needs and body shapes of female athletes. Specific physiotherapy programmes and training protocols have yielded remarkable results in reducing the risk of injury, and these should be extended to school-age athletes. Finally, psychological factors should not be overlooked, with females’ greater fear of re-injury and lack of confidence in their knee compromising their return to sport after ACL injury. Both intrinsic and extrinsic factors should be recognized and addressed to optimize the training programmes which are designed to prevent injury, and improve our understanding of these injuries. Cite this article: Bone Joint J 2023;105-B(10):1033–1037

Lumbar fusion surgery is an established procedure for the treatment of several spinal pathologies. Despite numerous techniques and existing devices, common surgical trends in lumbar fusion surgery are scarcely investigated. The purpose of this Canada-based study was to provide a descriptive portrait of current surgeons’ practice and implant preferences in lumbar fusion surgery while comparing findings to similar investigations performed in the United Kingdom. Canadian Spine Society (CSS) members were sampled using an online questionnaire which was based on previous investigations performed in the United Kingdom. Fifteen questions addressed the various aspects of surgeons’ practice: fusion techniques, implant preferences, and bone grafting procedures. Responses were analyzed by means of descriptive statistics. Of 139 eligible CSS members, 41 spinal surgeons completed the survey (29.5%). The most common fusion approach was via transforaminal lumber interbody fusion (TLIF) with 87.8% performing at least one procedure in the previous year. In keeping with this, 24 surgeons (58.5%) had performed 11 to 50 cases in that time frame. Eighty-six percent had performed no lumbar artificial disc replacements over their last year of practice. There was clear consistency on the relevance of a patient specific management (73.2%) on the preferred fusion approach. The most preferred method was pedicle screw fixation (78%). The use of stand-alone cages was not supported by any respondents. With regards to the cage material, titanium cages were the most used (41.5%). Published clinical outcome data was the most important variable in dictating implant choice (87.8%). Cage thickness was considered the most important aspect of cage geometry and hyperlordotic cages were preferred at the lower lumbar levels. Autograft bone graft was most commonly preferred (61.0%). Amongst the synthetic options, DBX/DBM graft (64.1%) in injectable paste form (47.5%) was preferred. In conclusion, findings from this study are in partial agreement with previous work from the United Kingdom, but highlight the variance of practice within Canada and the need for large-scale clinical studies aimed to set specific guidelines for certain pathologies or patient categories

Restoration a joint's articular surface following degenerative or traumatic pathology to the osteochondral unit pose a significant challenge. Recent advances have shown the utility of collagen-based scaffolds in the regeneration of osteochondral tissue. To provide these collagen scaffolds with the appropriate superstructure novel techniques in 3D printing have been investigated. This study investigates the use of polyɛ-caprolactone (PCL) collagen scaffolds in a porcine cadaveric model to establish the stability of the biomaterial once implanted. This study was performed in a porcine cadaveric knee model. 8mm defects were created in the medial femoral trochlea and repaired with a PCL collagen scaffold. Scaffolds were secured by one of three designs; Press Fit (PF), Press Fit with Rings (PFR), Press Fit with Fibrin Glue (PFFG). Mobilisation was simulated by mounting the pig legs on a continuous passive motion (CPM) machine for either 50 or 500 cycles. Biomechanical tensile testing was performed to examine the force required to displace the scaffold. 18 legs were used (6 PF, 6 PFR, 6 PFFG). Fixation remained intact in 17 of the cohort (94%). None of the PF or PFFG scaffolds displaced after CPM cycling. Mean peak forces required to displace the scaffold were highest in the PFFG group (3.173 Newtons, Standard deviation = 1.392N). The lowest peak forces were observed in the PFR group (0.871N, SD = 0.412N), while mean peak force observed in the PF group was 2.436N (SD = 0.768). There was a significant difference between PFFG and PFR (p = 0.005). There was no statistical significance in the relationship between the other groups. PCL reinforcement of collagen scaffolds provide an innovative solution for improving stiffness of the construct, allowing easier handling for the surgeon. Increasing the stiffness of the scaffold also allows press fit solutions for reliable fixation. Press fit PCL collagen scaffolds with and without fibrin glue provide dependable stability. Tensile testing provides an objective analysis of scaffold fixation. Further investigation of PCL collagen scaffolds in a live animal model to establish quality of osteochondral tissue regeneration are required

Aims. Computer-assisted 3D preoperative planning software has the potential to improve postoperative stability in total hip arthroplasty (THA). Commonly, preoperative protocols simulate two functional positions (standing and relaxed sitting) but do not consider other common positions that may increase postoperative impingement and possible dislocation. This study investigates the feasibility of simulating commonly encountered positions, and positions with an increased risk of impingement, to lower postoperative impingement risk in a CT-based 3D model. Methods. A robotic arm-assisted arthroplasty planning platform was used to investigate 11 patient positions. Data from 43 primary THAs were used for simulation. Sacral slope was retrieved from patient preoperative imaging, while angles of hip flexion/extension, hip external/internal rotation, and hip abduction/adduction for tested positions were derived from literature or estimated with a biomechanical model. The hip was placed in the described positions, and if impingement was detected by the software, inspection of the impingement type was performed. Results. In flexion, an overall impingement rate of 2.3% was detected for flexed-seated, squatting, forward-bending, and criss-cross-sitting positions, and 4.7% for the ankle-over-knee position. In extension, most hips (60.5%) were found to impinge at or prior to 50° of external rotation (pivoting). Many of these impingement events were due to a prominent ischium. The mean maximum external rotation prior to impingement was 45.9° (15° to 80°) and 57.9° (20° to 90°) prior to prosthetic impingement. No impingement was found in standing, sitting, crossing ankles, seiza, and downward dog. Conclusion. This study demonstrated that positions of daily living tested in a CT-based 3D model show high rates of impingement. Simulating additional positions through 3D modelling is a low-cost method of potentially improving outcomes without compromising patient safety. By incorporating CT-based 3D modelling of positions of daily living into routine preoperative protocols for THA, there is the potential to lower the risk of postoperative impingement events. Cite this article: Bone Jt Open 2023;4(6):416–423

Aims. To evaluate mid-to long-term patient-reported outcome measures (PROMs) of endoprosthetic reconstruction after resection of malignant tumours arising around the knee, and to investigate the risk factors for unfavourable PROMs. Methods. The medical records of 75 patients who underwent surgery between 2000 and 2020 were retrospectively reviewed, and 44 patients who were alive and available for follow-up (at a mean of 9.7 years postoperatively) were included in the study. Leg length discrepancy was measured on whole-leg radiographs, and functional assessment was performed with PROMs (Toronto Extremity Salvage Score (TESS) and Comprehensive Outcome Measure for Musculoskeletal Oncology Lower Extremity (COMMON-LE)) with two different aspects. The thresholds for unfavourable PROMs were determined using anchor questions regarding satisfaction, and the risk factors for unfavourable PROMs were investigated. Results. The thresholds for favourable TESS and COMMON were 64.8 and 70.4 points, respectively. Multivariate analysis showed that age at surgery (p = 0.004) and postoperative leg length discrepancy (p = 0.043) were significant risk factors for unfavourable TESS results, while age at surgery (p < 0.001) was a significant risk factor for unfavourable COMMON-LE results. Following receiver operating characteristic analysis, the threshold for both TESS and COMMON-LE was 29 years of age at surgery. Additionally, a leg length discrepancy of 8.2 mm was the threshold for unfavourable TESS. Conclusion. Patients aged > 29 years at the time of surgery require appropriate preoperative counselling and adequate postoperative physical and socioemotional support. Reconstruction equivalent to the length of the resected bone can reduce the risk of functional disabilities in daily living. Cite this article: Bone Jt Open 2023;4(12):906–913

To investigate if the countermovement jump height differs between ACL injured and uninjured female adolescents and to explore kinematic differences between limbs. Additionally, the association between isometric knee extension strength and jump height was investigated. Thirty-one ACL injured female adolescents (ACLi, 15.3 ± 1.4yrs, 163.9 ± 6.6cm, 63.0 ± 9.3kg) and thirty-eight uninjured (CON, 13.2±1.7yrs, 161.7 ± 8.1cm, 50.6 ± 11.1kg) participated in this study. All participants performed a countermovement jump task, with 3D kinematics collected using a motion analysis system (Vicon, Nexus, Oxford, UK) at 200Hz, and a maximum isometric knee extension task on an isokinetic dynamometer (Biodex Medical Systems, New York, USA) for three trials. The peak torque was extracted from the isometric trials. Independent samples t-test compared the maximum jump height normalised by the dominant leg length between groups, paired samples t-test compared the maximum hip and knee extension and ankle plantar flexion velocities before take-off between limbs in both groups, and a Pearson's correlation test investigated the association between the isometric knee extension strength and jump height. The ACLi jumped 13% lower compared to the CON (p=0.022). In the ACLi, the maximum hip and knee extension and ankle plantar flexion velocities were greater in the non-injured limb, compared to the injured limb; however, no differences between limbs were found in the CON. The isometric knee extension strength of both limbs was positively correlated with jump height (limb 1: r=0.329; p=0.006, and limb 2: r=0.386; p=0.001; whereas limb 1 corresponds to the ACLi injured limb and CON non-dominant limb, and limb 2 to the ACLi non-injured limb and CON dominant limb). ACL injured female adolescents present lower jump height than controls and greater contribution of their non-injured limb, compared to their injured limb, during a countermovement jump task. Also, current results indicate that jump height is positively related to isometric knee extension strength measure

Aims. In the UK, the NHS generates an estimated 25 megatonnes of carbon dioxide equivalents (4% to 5% of the nation’s total carbon emissions) and produces over 500,000 tonnes of waste annually. There is limited evidence demonstrating the principles of sustainability and its benefits within orthopaedic surgery. The primary aim of this study was to analyze the environmental impact of orthopaedic surgery and the environmentally sustainable initiatives undertaken to address this. The secondary aim of this study was to describe the barriers to making sustainable changes within orthopaedic surgery. Methods. A literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines through EMBASE, Medline, and PubMed libraries using two domains of terms: “orthopaedic surgery” and “environmental sustainability”. Results. A total of 13 studies were included in the final analysis. All papers studied the environmental impact of orthopaedic surgery in one of three areas: waste management, resource consumption, and carbon emissions. Waste segregation was a prevalent issue and described by nine studies, with up to 74.4% of hazardous waste being generated. Of this, six studies reported recycling waste and up to 43.9% of waste per procedure was recyclable. Large joint arthroplasties generated the highest amount of recyclable waste per procedure. Three studies investigated carbon emissions from intraoperative consumables, sterilization methods, and through the use of telemedicine. One study investigated water wastage and demonstrated that simple changes to practice can reduce water consumption by up to 63%. The two most common barriers to implementing environmentally sustainable changes identified across the studies was a lack of appropriate infrastructure and lack of education and training. Conclusion. Environmental sustainability in orthopaedic surgery is a growing area with a wide potential for meaningful change. Further research to cumulatively study the carbon footprint of orthopaedic surgery and the wider impact of environmentally sustainable changes is necessary. Cite this article: Bone Jt Open 2022;3(8):628–640

Aims. The rationale for exacting restoration of skeletal anatomy after unstable ankle fracture is to improve outcomes by reducing complications from malunion; however, current definitions of malunion lack confirmatory clinical evidence. Methods. Radiological (absolute radiological measurements aided by computer software) and clinical (clinical interpretation of radiographs) definitions of malunion were compared within the Ankle Injury Management (AIM) trial cohort, including people aged ≥ 60 years with an unstable ankle fracture. Linear regressions were used to explore the relationship between radiological malunion (RM) at six months and changes in function at three years. Function was assessed with the Olerud-Molander Ankle Score (OMAS), with a minimal clinically important difference set as six points, as per the AIM trial. Piecewise linear models were used to investigate new radiological thresholds which better explain symptom impact on ankle function. Results. Previously described measures of RM and surgeon opinion of clinically significant malunion (CSM) were shown to be related but with important differences. CSM was more strongly related to outcome (-13.9 points on the OMAS; 95% confidence interval (CI) -21.9 to -5.4) than RM (-5.5 points; 95% CI -9.8 to -1.2). Existing malunion thresholds for talar tilt and tibiofibular clear space were shown to be slightly conservative; new thresholds which better explain function were identified (talar tilt > 2.4°; tibiofibular clear space > 6 mm). Based on this new definition the presence of RM had an impact on function, which was statistically significant, but the clinical significance was uncertain (-9.1 points; 95% CI -13.8 to -4.4). In subsequent analysis, RM of a posterior malleolar fracture was shown to have a statistically significant impact on OMAS change scores, but the clinical significance was uncertain (-11.6 points; 95% CI -21.9 to -0.6). Conclusion. These results provide clinical evidence which supports the previously accepted definitions. Further research to investigate more conservative clinical thresholds for malunion is indicated. Cite this article: Bone Jt Open 2022;3(10):841–849

Aims. The aim of this study was to investigate the incidence and characteristics of instrumentation failure (IF) after total en bloc spondylectomy (TES), and to analyze risk factors for IF. Methods. The medical records from 136 patients (65 male, 71 female) with a mean age of 52.7 years (14 to 80) who underwent TES were retrospectively reviewed. The mean follow-up period was 101 months (36 to 232). Analyzed factors included incidence of IF, age, sex, BMI, history of chemotherapy or radiotherapy, tumour histology (primary or metastasis; benign or malignant), surgical approach (posterior or combined), tumour location (thoracic or lumbar; junctional or non-junctional), number of resected vertebrae (single or multilevel), anterior resection line (disc-to-disc or intravertebra), type of bone graft (autograft or frozen autograft), cage subsidence (CS), and local alignment (LA). A survival analysis of the instrumentation was performed, and relationships between IF and other factors were investigated using the Cox regression model. Results. A total of 44 patients (32.4%) developed IF at a median of 31 months (interquartile range 23 to 74) following TES. Most IFs were rod fractures preceded by a mean CS of 6.1 mm (2 to 18) and LA kyphotic enhancement of 10.8° (-1 to 36). IF-free survival rates were 75.8% at five years and 56.9% at ten years. The interval from TES to IF peaked at two to three years postoperatively and continued to occur over a period of time thereafter; the early IF-developing group had greater CS at one month postoperatively (CS1M) and more lumbar TES. CS1M ≥ 3 mm and sole use of frozen autografts were identified as independent risk factors for IF. Conclusion. IF is a common complication following TES. We have demonstrated that robust spinal reconstruction preventing CS, and high-quality bone grafting are necessary for successful reconstruction. Cite this article: Bone Joint J 2023;105-B(2):172–179

Aims. The aim of this study was to analyze how proximal radial neck resorption (PRNR) starts and progresses radiologically in two types of press-fit radial head arthroplasties (RHAs), and to investigate its clinical relevance. Methods. A total of 97 patients with RHA were analyzed: 56 received a bipolar RHA (Group 1) while 41 received an anatomical implant (Group 2). Radiographs were performed postoperatively and after three, six, nine, and 12 weeks, six, nine, 12, 18, and 24 months, and annually thereafter. PRNR was measured in all radiographs in the four radial neck quadrants. The Mayo Elbow Performance Score (MEPS), the abbreviated version of the Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), and the patient-assessed American Shoulder and Elbow Surgeons score - Elbow (pASES-E) were used for the clinical assessment. Radiological signs of implant loosening were investigated. Results. The mean follow-up was six years (2 to 14). PRNR started after a mean of 7.5 weeks (SD 2.1) and progressed significantly during the first two years, by the end of which the bone resorption stabilized. PRNR was detected in 81% (n = 45) of patients in Group 1 and 88% (n = 36) in Group 2. The final mean PRNR was 3.0 mm (SD 2.3) in Group 1 and 3.7 mm (SD 2.5) in Group 2. The mean MEPS, QuickDASH, and pASES-E were 95.9 (SD 11.5), 4.4 (SD 9.2), and 94.8 (SD 10.9) in Group 1 and 92.2 (SD 16.2), 9.9 (SD 21.5), and 90.8 (SD 15) in Group 2, respectively. No significant differences were observed between groups in the clinical and radiological outcomes. No correlations were found between PRNR and the clinical results. Conclusion. PRNR after press-fit RHA is a common radiological finding that develops in the first 24 months before stabilizing definitively. PRNR does not affect the clinical results or implant survival in the mid term. Cite this article: Bone Joint J 2023;105-B(8):905–911