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

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

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.

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

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.

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

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.