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

The aim is to investigate if there is a relation between patellar height and knee flexion angle. For this purpose we retrospectively evaluated the radiographs of 500 knees presented for a variety of reasons.

We measure knee flexion angle using a computer-generated goniometer. Patellar height was determined using computer generated measurement for the selected ratios, namely, the Insall–Salvati (I/S), Caton–Deschamps (C/D) and Blackburne–Peel (B/P) indices and Modified I/S Ratio.

A search of an NHS hospital database was made to identify the knee x rays for patients who were below the age of forty. A senior knee surgeon (DC) supervised three trainee trauma and orthopaedics doctors (HA, JM, ES) working on this research. Measurements were made on the Insall–Salvati (I/S), Caton–Deschamps (C/D) and Blackburne–Peel (B/P) indices and Modified I/S Ratio. The team leader then categorised the experimental measurement of patients’ knee flexion angle into three groups. This categorisation was according to the extent of knee flexion. The angles were specifically, 10.1 to 20, 20.1 to 30, and 30.1 to 40 degrees of knee flexion.

Out of the five-hundred at the start of the investigation, four hundred and eighteen patients were excluded because they had had either an operation on the knee or traumatic fracture that was treated conservatively.

Odontoid fracture of the second cervical vertebra (C2) is the most common spinal fracture type in elderly patients. However, very little is known about the biomechanical fracture mechanisms, but could play a role in fracture prevention and treatment. This study aimed to investigate the biomechanical competence and fracture characteristics of the odontoid process.

A total of 42 human C2 specimens (14 female and 28 male, 71.5 ± 6.5 years) were scanned via quantitative computed tomography, divided in 6 groups (n = 7) and subjected to combined quasi-static loading at a rate of 0.1 mm/s until fracturing at inclinations of −15°, 0° and 15° in sagittal plane, and −50° and 0° in transverse plane. Bone mineral density (BMD), specimen height, fusion state of the ossification centers, stiffness, yield load, ultimate load, and fracture type according to Anderson and d'Alonzo were assessed.

While the lowest values for stiffness, yield, and ultimate load were observed at load inclination of 15° in sagittal plane, no statistically significant differences could be observed among the six groups (p = 0.235, p = 0.646, and p = 0.505, respectively). Evaluating specimens with only clearly distinguishable fusion of the ossification centers (n = 26) reveled even less differences among the groups for all mechanical parameters. BMD was positively correlated with yield load (R² = 0.350, p < 0.001), and ultimate load (R² = 0.955, p < 0.001), but not with stiffness (p = 0.070). Type III was the most common fracture type (23.5%).

These biomechanical outcomes indicate that load direction plays a subordinate role in traumatic fractures of the odontoid process in contrast to BMD which is a strong determinant of stiffness and strength. Thus, odontoid fractures appear to result from an interaction between load magnitude and bone quality.

The periclavicular space is a conduit for the brachial plexus and subclavian-axillary vascular system. Changes in its shape/form generated by alteration in the anatomy of its bounding structures, e.g. clavicle malunion, cause distortion of the containing structures, particularly during arm motion, leading to syndromes of thoracic outlet stenosis etc., or alterations of scapular posture with potential reduction in shoulder function.

Aim of this study was developing an in vitro methodology for systematic and repeatable measurements of the clinically poorly characterized periclavicular space during arm motion using CT-imaging and computer-aided 3D-methodologies.

A radiolucent frame, mountable to the CT-table, was constructed to fix an upper torso in an upright position with the shoulder joint lying in the isocentre. The centrally osteotomized humerus is fixed to a semi-circular bracket mounted centrally at the end of the frame. All arm movements (ante-/retroversion, abduction/elevation, in-/external rotation) can be set and scanned in a defined and reproducible manner. Clavicle fractures healed in malposition can be simulated by osteotomy and fixation using a titanium/carbon external fixator.

During image processing the first rib served as fixed reference in space. Clavicle, scapula and humerus were registered, segmented, and triangulated. The different positions were displayed as superimposed surface meshes and measurements performed automatically. Initial results of an intact shoulder girdle demonstrated that different arm positions including ante-/retroversion and abduction/elevation resulted solely in a transverse movement of the clavicle along/parallel to the first rib maintaining the periclavicular space.

A radiolucent frame enabling systematic and reproducible CT scanning of upper torsos in various arm movements was developed and utilized to characterize the effect on the 3D volume of the periclavicular space. Initial results demonstrated exclusively transverse movement of the clavicle along/parallel to the first rib maintaining the periclavicular space during arm positions within a physiological range of motion.

We test the clinical validity and financial implications of the proposed Choosing Wisely statement: “Using ultrasound as a screening test for shoulder instability is inappropriate in people under 30 years of age, unless there is clinical suspicion of a rotator cuff tear.”

A retrospective chart review from a specialist shoulder surgeon's practice over a two-year period recorded 124 patients under the age of 30 referred with shoulder instability. Of these, forty-one had already had ultrasound scans performed prior to specialist review. The scan results and patient files were reviewed to determine the reported findings on the scans and whether these findings were clinically relevant to diagnosis and decision-making. Comparison was made with subsequent MRI scan results. The data, obtained from the Accident Compensation Corporation (ACC), recorded the number of cases and costs incurred for ultrasound scans of the shoulder in patients under 30 years old over a 10-year period.

There were no cases where the ultrasound scan was considered useful in decision-making. No patient had a full thickness rotator cuff tear. Thirty-nine of the 41 patients subsequently had MRI scans. The cost to the ACC for funding ultrasound scans in patients under 30 has increased over the last decade and exceeded one million dollars in the 2020/2021 financial year. In addition, patients pay a surcharge for this test.

The proposed Choosing Wisely statement is valid. This evidence supports that ultrasound is an unnecessary investigation for patients with shoulder instability unless there is clinical suspicion of a rotator cuff tear. Ultrasound also incurs costs to the insurer (ACC) and the patient. We recommend x-rays and, if further imaging is indicated, High Tech Imaging with MRI and sometimes CT scans in these patients

Abstract

We present the results of a retrospective study of 561 consecutive Total Knee replacements performed by one consultant between January 1990 and June 2000 on 456 patients. The groups included 500 PFC, 40 PROM and 21 Kinematic TKRs. These were assessed using two postal questionnaires, a clinical evaluation and radiographic investigation. 464 patients survived to follow-up of which 421 returned the questionnaires and 292 were seen in clinic. 89% had good to excellent Oxford and clinical scores. There were no radiographically loose implants at the time of evaluation. The three types of prosthesis were then compared and a review of those that had undergone revision surgery.

The detailed anatomy of interconnectivity of intervertebral disc annular fibre layers remains unclear and a structural survey of interlammellar connectivity is required to understand this anatomy and mechanical behavior. The subsequent failure modes of the annulus under hydrostatic loading require definition to understand genesis of annular tears and disc herniation. Interlamellar Connectivity. We imaged anterior annular sections from ovine lumbar discs. Using differential interference contrast microscopy we were able to reconstruct a three-dimensional image of the interconnecting bridging network between layers. Annular Disruption. The nuclei of ovine lumbar discs were gradually pressurised to failure by injecting a viscous radio-opaque gel via their inferior vertebrae. Investigation of the resulting annular disruption was carried out using micro-computed tomography and DIC microscopy. This allowed analysis of annular failure patterns and herniation, with analysis of the pathway of nuclear movement during prolapse in relation to annular fibre separation within and between fibre layers. Interlamellar Connectivity. A high level of connectivity between apparently disparate bridging elements was revealed. The extended form of the bridging network is that of occasional substantial radial connections spanning many lamellae with a subsidiary fine branching network. The fibrous bridging network is highly integrated with the lamellar architecture via a collagen-based system of interconnectivity. In particular this bridging network appears to have a major role in anchoring leading edges of incomplete annular lamellae. Annular Disruption and Disc Herniation. Gel extrusion from the posterior annulus was the most common mode of disc failure. Unlike other regions of the annular wall, the posterior region was unable to distribute hydrostatic pressures circumferentially. In each extrusion case, severe disruption to the posterior annulus was observed. While intralamellar disruption occurred in the mid annulus, interlamellar disrupt ion occurred in the outer posterior annulus. Radial ruptures between lamellae always propagated in the mid-axial plane. The interlamellar architecture of the annulus is far more complex than has previously been recognised and this paper further defines the microanatomy of the disc wall. The hydrostatic pressure failure mode of the posterior annulus mirrors clinic al sites of annular tear and disc prolapsed in the neutral loading position

Mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) have great promise in the field of orthopaedic nanomedicine due to their regenerative, as well as immunomodulatory and anti-inflammatory properties. Researchers are interested in harnessing these biologically sourced nanovesicles as powerful therapeutic tools with intrinsic bioactivity to help treat various orthopaedic diseases and defects. Recently, a new class of EV mimetics has emerged known as nanoghosts (NGs). These vesicles are derived from the plasma membrane of ghost cells, thus inheriting the surface functionalities and characteristics of the parent cell while at the same time allowing for a more standardized and reproducible production and significantly greater yield when compared to EVs. This study aims to investigate and compare the osteoinductive potential of MSC-EVs and MSC-NGs in vitro as novel tools in the field of bone tissue engineering and nanomedicine. To carry out this investigation, MSC-EVs were isolated from serum-free MSC conditioned media through differential ultracentrifugation. The remaining cells were treated with hypotonic buffer to produce MSC-ghosts that were then homogenized and serially extruded through 400 and 200 nm polycarbonate membranes to form the MSC-NGs. The concentration, size distribution, zeta potential, and protein content of the isolated nanoparticles were assessed. Afterwards, MSCs were treated with either MSC-EVs or MSC-NGs under osteogenic conditions, and their differentiation was assessed through secreted ALP assay, qPCR, and Alizarin Red mineralization staining. Isolation of MSC-EVs and MSC-NGs was successful, with relatively similar mean diameter size and colloidal stability. No effect on MSC viability and metabolic activity was observed with either treatment. Both MSC-EV and MSC-NG groups had enhanced osteogenic outcomes compared to the control; however, a trend was observed that suggests MSC-NGs as better osteoinductive mediators compared to MSC-EVs.

Acknowledgements: The authors would like to acknowledge Canada Research Chair – Tier 1 in Regenerative Medicine and Nanomedicine, CHRP, and McGill's Faculty of Dental Medicine and Oral Health Sciences for their financial support.

Background

Lateral ankle instability is a common problem, but the precise role of the lateral ankle structures has not been accurately investigated. This study aimed to accurately investigate lateral ankle complex stability for the first time using a novel robotic testing platform.

Abstract

Introduction and Objective

Scaphoid waist fractures (SWF) are notable in upper limb trauma and predominantly occur in young men. Morbidities associated with SWF include fracture non-union, premature arthritis and humpback deformity. Delayed treatment and non-adherence to fracture immobilisation increases likelihood of these complications. There is evidence that men engage in negative health behaviours such as delayed help-seeking. The Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) conducted interviews in individuals who had sustained a SWF. Although SWIFFT showed multiple social determinants for the overall injury and healing experience, a key factor this novel study considers is age and sex. This study aimed to analyse interview data from young male participants in SWIFFT to help distinguish the experience of SWF in young men, through exploring the influence of masculinity.

Aim

While metagenomic (microbial DNA) sequencing technologies can detect the presence of microbes in a clinical sample, it is unknown whether this signal represents dead or live organisms. Metatranscriptomics (sequencing of RNA) offers the potential to detect transcriptionally “active” organisms within a microbial community, and map expressed genes to functional pathways of interest (e.g. antibiotic resistance). We used this approach to evaluate the utility of metatrancriptomics to diagnose PJI and predict antibiotic resistance.

Iliopsoas tendonitis occurs in up to 30% of patients after hip resurfacing arthroplasty (HRA) and is a common reason for revision. The primary purpose of this study was to validate our novel computational model for quantifying iliopsoas impingement in HRA patients using a case-controlled investigation. Secondary purpose was to compare these results with previously measured THA patients.

We conducted a retrospective search in an experienced surgeon's database for HRA patients with iliopsoas tendonitis, confirmed via the active hip flexion test in supine, and control patients without iliopsoas tendonitis, resulting in two cohorts of 12 patients. The CT scans were segmented, landmarked, and used to simulate the iliopsoas impingement in supine and standing pelvic positions. Three discrete impingement values were output for each pelvic position, and the mean and maximum of these values were reported. Cup prominence was measured using a novel, nearest-neighbour algorithm.

The mean cup prominence for the symptomatic cohort was 10.7mm and 5.1mm for the asymptomatic cohort (p << 0.01). The average standing mean impingement for the symptomatic cohort was 0.1mm and 0.0mm for the asymptomatic cohort (p << 0.01). The average standing maximum impingement for the symptomatic cohort was 0.2mm and 0.0mm for the asymptomatic cohort (p << 0.01). Impingement significantly predicted the probability of pain in logistic regression models and the simulation had a sensitivity of 92%, specificity of 91%, and an AUC ROC curve of 0.95.

Using a case-controlled investigation, we demonstrated that our novel simulation could detect iliopsoas impingement and differentiate between the symptomatic and asymptomatic cohorts. Interestingly, the HRA patients demonstrated less impingement than the THA patients, despite greater cup prominence. In conclusion, 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.

Elevated synovial leukocyte count is a minor criterion derived from the musculoskeletal infection society (MSIS) widely used in clinical practice for diagnosis of prosthetic joint infection. There is evidence to suggest analysis within 1 hour, preferentially within 30 minutes, of aspiration reduces the risk of ex vivo cell lysis occurring during prolonged transport. Multiple site working is more common practice and the availability of a lab on site to perform these tests is not always possible. We aimed to assess whether we could safely perform synovial leukocyte counts within our cold site in the diagnosis of prosthetic joint infection.

We reviewed all orthopaedic synovial fluid aspirates within the lower limb arthroplasty unit from April 2021 – April 2022 performed at South Tees NHS Foundation Trust. We assessed time from aspirate to the lab using electronic data resources. This information was compared with the labs ability to perform a synovial leukocyte count to determine the impact of delays on testing.

110 patients (34.5% hips and 63.6% knees) were identified between two sites. Time from aspirate to lab ranged from 0 mins to 26 hrs 34 mins. Mean time to processing was 3hrs 10 mins. 50% of all samples had a synovial leukocyte count performed. 67% of patients had a cell differential performed. There was no difference in the ability to perform a synovial leukocyte count between samples process in < 2hours vs > 6 hours.

We conclude that it is safe practice to perform joint aspirates for the work up of periprosthetic joint infections in sites where no laboratory is immediately available as the delay to processing synovial fluid does not alter the ability to perform a synovial leukocyte count. This study will provide evidence to enable the work up of periprosthetic joint infections in cold centres and therefore reduce the delay in diagnosis and proceeding management.

Our previous research has demonstrated that minor adjustments to in vitro cellular aggregation parameters, i.e. alterations to aggregate size, can influence temporal and spatial mineral depositions within maturing bone cell nodules. What remains unclear, however, is how aggregate size might affect mineralisation within said nodules over long-term in vivo culture.

In this study, we used an osteoblast cell line, MLO-A5, and a primary cell culture, mesenchymal stem cells (MSC), to compare small (approximately 80 µm) with large (approximately 220 µm) cellular aggregates for potential bone nodule development after 8 weeks of culturing in a mouse model (n = 4 each group). In total, 30 chambers were implanted into the intra-peritoneal cavity of 20 male, immunocompromised mice (MF1-Nu/Nu, 4 – 5 weeks old). Nine small or three large aggregates were used per chamber. Neoveil mesh was seeded directly with 2 × 10³ cells for monolayer control. At 8 weeks, the animals were euthanised and chambers fixed with formalin. Aggregate integrity and extracellular material growth were assessed via light microscopy and the potential mineralisation was assessed via micro-CT.

Many large aggregates appeared to disintegrate, whilst the small aggregates maintained their form and produced additional extracellular material with increased sizes. Both MLO-A5 cells and MSC cells saw similar results. Interestingly, however, the MSCs were also seen to produce a significantly higher volume of dense material compared to the MLO-A5 cells from micro-CT analysis.

Overall, a critical cell aggregate size appeared to exist balancing optimal tissue growth with oxygen diffusion, and cell source may influence differentiation pathway despite similar experimental parameters. The MSCs, for example, were likely producing bone via the endochondral ossification pathway, whilst the matured bone cells, MLO-A5 cells, were likely producing bone via the intramembranous ossification pathway.

Aim

The efficacy of various irrigation solutions in removing microbial contamination of a surgical wound and reducing the rate of subsequent surgical site infection (SSI), has been demonstrated extensively. However, it is not known if irrigation solutions have any activity against established biofilm. This issue is pertinent as successful management of patients with periprosthetic joint infection (PJI) includes the ability to remove biofilm established on the surface of implants and necrotic tissues. The purpose of this study was to evaluate the efficacy of various irrigation solutions in eradicating established biofilm, as opposed to planktonic bacteria, in a validated in vitro model.

This study aims to assess the fracture mechanics of type-2 diabetic (T2D) femoral bone using innovative site-specific tests, whilst also examining the cortical and trabecular bone microarchitecture from various regions using micro-computed tomography (CT) of the femur as the disease progresses.

Male [Zucker Diabetic Fatty (ZDF: fa/fa) (T2D) and Zucker Lean (ZL: fa/+) (Control)] rats were euthanized at 12-weeks of age, thereafter, right and left femora were dissected (Right femora: n = 6, per age, per condition; Left femora: n=8-9, per age, per condition). Right femurs were notched in the posterior of the midshaft. Micro-CT was used to scan the proximal femur, notched and unnotched femoral midshaft (cortical) of the right femur and the distal metaphysis (trabecular) of the left femur to investigate microarchitecture and composition. Right femurs were fracture toughness tested to measure the stress intensity factor (Kic) followed by a sideways fall test using a custom-made rig to investigate femoral neck mechanical properties.

There was no difference in trabecular and cortical tissue material density (TMD) between T2D and control rats. Cortical thickness was unchanged, but trabeculae were thinner (p<0.01) in T2D rats versus controls. However, T2D rats had a greater number of trabeculae (p<0.05) although trabecular spacing was not different to controls. T2D rats had a higher connectivity distribution (p<0.05) and degree of anisotropy (p<0.05) in comparison to controls. There was no difference in the mechanical properties between strains.

At 12-weeks of age, rats are experiencing early-stage T2Ds and the disease impact is currently not very clear. Structural and material properties are unchanged between strains, but the trabecular morphology shows that T2D rats have more trabecular struts present in order to account for the thinner trabeculae.

Abstract

The purpose of this study was to determine whether the reasons for delay to surgery are secondary to health system constraints or patient factors. This study explored factors that contribute to patients' delay to surgery as well as how patients perceive the delay in surgery to have affected their treatment and care.

Semi-structured qualitative interviews were conducted with 30 patients aged 18 to 50 years old who had undergone arthroscopic ACL reconstruction. Qualitative data analysis was performed in accordance with the Straus and Corbin theory to derive codes, categories and themes.

Patient interviews revealed three overarching themes regarding delay to ACL reconstruction surgery: access to care, finances and work, and personal advocacy. Elements of those factors were shown to influence the timing of ACL reconstruction surgery. Less common factors included choice of imaging study (i.e., ultrasound), geography, and family commitments.

Patients' perceptions of delay in access to care was overwhelming due to the wait time for MRI. Several patients also described significant self-advocacy required to navigate the healthcare system, suggesting that some level of medical literacy may be necessary to gain timely access to surgery. Once patients had seen the surgeon, few patients described untimely delay to surgery, suggesting that OR resources are adequate. Recommendations to decrease delays to ACL reconstruction surgery include better access to MRI and broader education of non-surgical healthcare providers to help navigate access to surgery.

Introduction and Objective

It is widely accepted that interfragmentary strain stimulus promotes callus formation during secondary bone healing. However, the impact of the temporal variation of mechanical stimulation on fracture healing is still not well understood. Moreover, the minimum strain value that initiates callus formation is unknown. The goal of this study was to develop an active fixation system that allows for in vivo testing of varying temporal distribution of mechanical stimulation and that enables detection of the strain limit that initiates callus formation.

No therapeutic strategy, administered in the early stage of osteoarthritis (OA), is fully able to block the degenerative and inflammatory progress of the pathology, whose only solution remains surgery. Aiming to identify minimally invasive therapies able to act on both degenerative and inflammatory processes, infiltrative treatments based on mesenchymal stem cells represent a promising solution due to their proliferative, immunomodulatory, anti-inflammatory, and paracrine ability. Accordingly, the aim of the present study was to investigate the performance of different cell therapies (stem cells from adipose tissue, ADSCs, stromal vascular fraction, SVF, and culture expanded, AECs vs negative control NaCl) in the treatment of OA. An in vivo model of early OA was developed in sheep knee (research protocol N.62/2018-PR date 29/01/2018 approved by the local Ethical Committee). Three and six months after the treatments injections, gross evaluation of articular surfaces (damage score, DS), histological (cartilage thickness, Th; fibrillation index, FI; collagen II content, C2) and mechanical assessment (elastic modulus, E; stress-relaxation time, τ) of cartilage were carried out. Due to the importance of the relationship between structure/composition (histology) and function (mechanics), this study investigated which of the revealed parameters were involved in such relation and how they were influenced by the level of degeneration and by the specific cell treatment, thus to better understand cell-tissue interaction.

A statistically significant multi-variable linear regression model was found between τ and Th, FI, C2 (R2 0.7, p-value 8.39E-5). The relation was particularly strong between τ and C2 (p-value 7E-4), with a positive coefficient of 0.92. This is in agreement with literature, where a higher cartilage viscosity was related to a major content of collagen. By dividing the samples in two groups depending on cartilage damage, the more degenerated group (DS > 5) showed statistically significant lower C2 (p-value 0.0124) and τ (p-value 0.05), confirming that collagen content and viscosity decrease with OA grade increasing. Averaging the entire group of samples, the OA degeneration progressed between 3 and 6 months after, and despite, the treatment. But focusing on specific treatments, SVF and AECs differed from the general trend, inducing a higher amount of collagen at 6 months respect to 3 months. Moreover, articular cartilage treated by AECs and, overall, SVF showed a higher content of collagen and a major viscosity respect to the other treatments.

We conclude that an injection of mesenchymal stem cells from stromal vascular fraction in early OA articulations could hinder the degenerative process, preserving or even restoring collagen content and viscosity of the articular cartilage.

Abstract

Shortening of patellar tendon after total knee arthroplasty (TKA) was previously reported by several studies. Its etiology still remains controversial. Patellar tendon shortening, a direct cause of patella baja, has a dramatic negative impact in terms of clinical outcomes after TKA. Main objective of this study is to assess the feasibility of utilizing a different technique with Ultrasound that is easy to use, cost-effective and able to eliminate the problem of differential magnification occurring in other techniques which count on standard x-rays and to establish the correlation between clinical outcomes and changes in patellar tendon length and thickness after TKA.

The study was designed as prospective cohort and, after a minimum of 4-year-follow up period, 47 knees of 24 patients who had undergone primary TKA without patellar resurfacing were included in the study. All patients were scored with Kujala and HSS scores and all patellar tendons were evaluated with USG regarding their length and thickness. We used conventional grey-scale ultrasound imaging (US) to determine any changes in patellar tendon morphology. All cases were evaluated by the same radiologist. The patellar tendon was examined with the knee in 30° flexion. The flexion angle helped to stretch the extensor mechanism and avoid anisotropy (concavity) of the patellar tendon. The transducer was placed along the long axis of the tendon. The patellar tendon was initially examined in the longitudinal plane in order to measure the total length. Then, total length was divided into three parts and sagittal thickness was calculated at the proximal, median, and distal thirds of the patellar tendon. Both the length and thickness of the tendon were measured before surgery and at the 4th year of follow-up.

Of the 47 knees that were included in our study, the mean pre-operative and postoperative length of the patellar tendon was 40.78±6.15 mm and 35.93±4.52 mm. Our results suggested significant shortening of the patellar tendon after primary TKA surgery (p<0.05). Intergroup analysis suggested that reduced sagittal thickness in the proximal third of the tendon was more strongly correlated with an increase in functional outcomes (p<0.05). Our results suggested no significant difference in clinical outcome scores between patients with increased or decreased length of the patellar tendon after TKA (p>0.05).

We suggest that determining morphologic changes in sagittal thickness as well as length is important in explaining some of the ambiguous causes of anterior knee pain and impaired clinical outcomes after TKA. More accurate documentation of morphologic changes in the patellar tendon after TKA will certainly help to develop new techniques by surgeons or avoid some existing routines that may harm the tendon. USG is a feasible method for evaluating patellar tendon morphology after TKA but more future studies are needed.

Frozen shoulder is commonly encountered in general orthopaedic practice. It may arise spontaneously without an obvious predisposing cause, or be associated with a variety of local or systemic disorders. Diagnosis is based upon the recognition of the characteristic features of the pain, and selective limitation of passive external rotation. The macroscopic and histological features of the capsular contracture are well-defined, but the underlying pathological processes remain poorly understood. It may cause protracted disability, and imposes a considerable burden on health service resources. Most patients are still managed by physiotherapy in primary care, and only the more refractory cases are referred for specialist intervention. Targeted therapy is not possible and treatment remains predominantly symptomatic. However, over the last ten years, more active interventions that may shorten the clinical course, such as capsular distension arthrography and arthroscopic capsular release, have become more popular.

This review describes the clinical and pathological features of frozen shoulder. We also outline the current treatment options, review the published results and present our own treatment algorithm.

Balloon kyphoplasty (BKP) is a minimally invasive surgical technique used to correct kyphosis and vertebral compression fractures. BKP uses cement to fill a void created by the inflation of a balloon in a vertebra, it can be used as an alternative to vertebroplasty to reduce cement extravasation. Issues such as poor inter digitisation of the cement and the trabecular bone can arise with the BKP method. This can be due to a compacted layer created during the procedure which can cause complications post-surgery. The primary aim of this study was to investigate alternative cement application methods which could improve the mechanical strength of the bone-cement interface. Three alternative methods were investigated, and cylindrical bone-cement specimens were created for all methods (BKP and three alternatives). An important part of this study was to replicate the compacted layer created by the inflation of the balloon tamp in BKP. Synthetic trabecular bone specimens (Sawbones®, Pacific Research Laboratories, Vashon Island, Washington, USA) were pre-loaded in compression and the resultant compacted layers were found to replicate the compacted layers found in surgery. Mechanical testing was carried out with an MTS Model 858 Bionix^® Servohydraulic load frame using static tensile and torsion loads. Static tests revealed that two of the three alternative methods were an improvement on BKP, with a high statistical significance in relation to the mechanical performance of the bone-cement interface (P < 0.001). This data illustrates the potential to improve the standard BKP technique, in terms of bone-cement interface performance.

Previous biomechanical studies of lateral collateral ligament (LCL) injuries and their surgical repair, reconstruction and rehabilitation have primarily relied on gravity effects with the arm in the varus position. The application of torsional moments to the forearm manually in the laboratory is not reproducible, hence studies to date likely do not represent forces encountered clinically.

The aim of this investigation was to develop a new biomechanical testing model to quantify posterolateral stability of the elbow using an in vitro elbow motion simulator.

Six cadaveric upper extremities were mounted in an elbow motion simulator in the varus position. A threaded screw was then inserted on the dorsal aspect of the proximal ulna and a weight hanger was used to suspend 400g, 600g, and 800g of weight from the screw head to allow torsional moments to be applied to the ulna. An LCL injured (LCLI) model was created by sectioning of the common extensor origin, and the LCL. Ulnohumeral rotation was recorded using an electromagnetic tracking system during simulated active and passive elbow flexion with the forearm pronated and supinated. A repeated measures analysis of variance was performed to compare elbow states (intact, LCLI, and LCLI with 400g, 600g, and 800g of weight).

During active motion, there was a significant difference between different elbow states (P=.001 pronation, P=.0001 supination). Post hoc analysis showed that the addition of weights did not significantly increase the external rotation (ER) of the ulnohumeral articulation (10°±7°, P=.268 400g, 10.5°±7.1°, P=.156 600g, 11°±7.2°, P=.111 800g) compared to the LCLI state (8.4°±6.4°) with the forearm pronated. However, with the forearm supinated, the addition of 800g of weight significantly increased the ER (9.2°±5.9°, P=.038) compared to the LCLI state (5.9°±5.5°) and the addition of 400g and 600g of weights approached significance (8.2°±5.7°, P=.083 400g, 8.7°±5.9°, P=.054 600g).

During passive motion, there was a significant difference between different elbow states (P=.0001 pronation, P=.0001 supination). Post hoc analysis showed that the addition of 600g and 800g but not 400g resulted in a significant increase in ER of the ulnohumeral articulation (9.3°±7.8°, P=.103 400g, 11.2°±6.2°, P=.004 600g, 12.7°±6.8°, P=.006 800g) compared to the LCLI state (3.7°±5.4°) with the forearm pronated. With the forearm supinated, the addition of 400g, 600g, and 800g significantly increased the ER (11.7°±6.7°, P=.031 400g, 13.5°±6.8°, P=.019 600g, 14.9°±6.9°, P=.024 800g) compared to the LCLI state (4.3°±6.6°).

This investigation confirms a novel biomechanical testing model for studying PLRI. Moreover, it demonstrates that the application of even small amounts of torsional moment on the forearm with the arm in the varus position exacerbates the rotational instability seen with the LCL deficient elbow. The effect of torsional loading was significantly worse with the forearm supinated and during passive elbow motion. This new model allows for a more provocative testing of elbow stability after LCL repair or reconstruction. Furthermore, this model will allow for smaller sample sizes to be used while still demonstrating clinically significant differences. Future biomechanical studies evaluating LCL injuries and their repair and rehabilitation should consider using this testing protocol.

Osteochondral (OC) grafting is one available method currently used to repair full thickness cartilage lesions with good results clinically when grafting occurs in patients with specific positive prognostic factors. However, there is poor understanding of the effect of individual patient and surgical factors. With limited tissue availability, development of Finite Element (FE) models taking into account these variations is essential. The aim of this study was to evaluate the effect of altering the material properties of OC grafts and their host environment through computer simulation.

A generic FE model (ABAQUS CAE 2017) of a push-out test was developed as a press-fit bone cylinder (graft) sliding inside a bone ring (host tissue). Press-fit fixation was simulated using an interference fit. Overlap between host and graft (0.01mm–0.05mm) and coefficient of friction (0.3–0.7) were varied sequentially. Bone Young's moduli (YM) were varied individually between graft and host within the range of otherwise derived tissue moduli (46MPa, 82MPa, 123MPa).

Increasing both overlap and frictional coefficient increased peak dislodging force independently (overlap: 490% & frictional coefficient: 176% across range tested). Increasing bone modulus also increased dislodging force, with host bone modulus (107%, 128%, and 140% increase across range, when Graft YM = 123MPa, 82 MPa, and 46MPa, respectively) having a greater influence than graft modulus (28%, 19% and 10% increase across range, when Host YM = 123 MPa, 82MPa and 46MPa, respectively).

As anticipated increasing overlap and friction caused an increase in force necessary to dislodge the graft. Importantly, differentially changing the graft and host material properties changed the dislodging force indicating that difference between graft and host may be an important factor in the success or failure clinically of osteochondral grafting.

Introduction

Cobalt-Chromium-Molybdenum (CoCr) and Titanium-Aluminium-Vanadium (Ti) alloys are the most commonly used alloys used for Total Hip Replacement due to their excellent biocompatibility and mechanical properties. However, both are susceptible to fretting corrosion In-vivo. The objective of this study was to understand the damage mechanism of both combinations through a sub-surface damage assessment of the alloys at various fretting amplitudes using the Transmission Electron Microscopy (TEM – CM200 FEGTEM). The TEM was used to attain a cross sectional view of the alloys in orderto see the effect of high shear stress on the grain structure.

Introduction

Dislocation is one of severe complications after total hip arthroplasty (THA). Direct anterior approach (DAA) is useful for muscle preservation. Therefore, it might be also effective to reduce dislocation. The purpose of this study is to investigate the ratio and factors of dislocations after THA with DAA.

Aims

The aims of this study were to evaluate the morphology of the ankle in patients with an osteochondral lesion of the talus using 3D CT, and to investigate factors that predispose to this condition.

[Background]

Bipolar hemiarthroplasty (following BHA) have historically had poor results in patients with idiopathic osteonecrosis of femoral head (OFNH). However, most recent report have shown excellent results with new generation BHA designs that incorporate advances in bearing technology. These optimal outcomes with bipolar hemiarthroplasty will be more attractive procedure for young patients who need bone stock for future total arthroplasty. The purpose of the current study was to evaluate the clinical and radiographic finding of this procedure for the treatment of OFNH at our institution after 7-to 21years follow-up.

Metallic contacts in hip replacements are susceptible to wear and corrosion processes which lead to the release of particles and metal ions. Adverse local tissue reactions (ALTRs) and systemic manifestations to solid and soluble debris can be debilitating for the patients. It is believed that particles originating from CoCrMo taper junctions trigger more severe body reactions compared to debris from MoM hip bearings. The body's reaction is highly dependent on particle characteristics, such as size, morphology, composition and aggregation state, which can reflect the specific wear and corrosion conditions at the site of release.

Here we proposed to investigate wear and corrosion flakes collected from around CoCrMo tapers at the time of revision. The particles were initially characterised with scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). This revealed the microstructure of the corrosion products, which appeared to be made of smaller metallic aggregates, entrapped in a biological matrix. The in depth characterisation of the particles released from the organo-metallic composite, was performed with transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM), both fitted with EDX. The investigation revealed clusters and individual nanoparticles, as small as 3 nm, which represent the building blocks of the large corrosion flakes, reported and characterised in the past mainly with low resolution microscopy techniques. The majority of the particles consisted of Cr and O, potentially in the form of chromium oxides, with little evidence of Co and Mo. Particles size distribution (PSD) provided by STEM and TEM characterisation showed statistically different results. The STEM technique was able to resolve tiny particles found in close proximity and provided a PSD shift towards the smaller end of the size range.

The study is the first to show microscopy evidence of Cr rich nanoparticles (3–60 nm) released in vivo from the modular taper interface, which can have important health implications caused by their increased potential to disseminate and corrode within the body.

Radiological assessment of total and unicompartmental knee replacement remains an essential part of routine care and follow-up. Appreciation of the various measurements that can be identified radiologically is important. It is likely that routine plain radiographs will continue to be used, although there has been a trend towards using newer technologies such as CT, especially in a failing knee, where it provides more detailed information, albeit with a higher radiation exposure.

The purpose of this paper is to outline the radiological parameters used to evaluate knee replacements, describe how these are measured or classified, and review the current literature to determine their efficacy where possible.

Creating cement keyholes (i.e. drilling simple holes in cancellous bone to allow cement filling) is a practice used in multiple scenarios in orthopaedic surgery to ensure improved fixation between the bone-cement interface and as such between bone and prosthesis. It is most commonly used in hip arthroplasty to secure fixation of the cup to the acetabulum by drilling keyholes in acetabulum. However very little research has been conducted into what the dimensions of such cement keyholes should be. The following laboratory based research was performed to provide insight into the optimum dimensions of cement keyholes.

The investigator designed a novel arrangement to enable testing of keyholes. Beechwood block models were then made to this design testing keyholes of varying diameters and depths. These were cemented with acrylic bone cement and then loaded to failure. A finite system analysis was also performed.

Results show that stresses are concentrated at the base of the keyhole. As such increasing diameter of keyhole infers greater strength, but there is no relationship between depth and strength. This has been further confirmed with finite element analysis. We suggest the width of cement keyholes bears more importance than the depth and propose drilling wide but shallow keyholes.

Introduction

The success of cementless total hip arthroplasty (THA) depends on the primary stability of the components. One of the biomechanical factors that comes into play is the mechanical quality of the bone. To our knowledge, there are no reported studies in the literature analyzing the impact of the preoperative bone mineral density on the outcomes of cementless THA. The goal of the study was to analyze the clinical results at 2 year follow-up according to the preoperative cancellous bone mineral density (BD). Our hypothesis was that the clinical outcomes were correlated to the BD.

Dislocation of the shoulder may occur during seizures in epileptics and other patients who have convulsions. Following the initial injury, recurrent instability is common owing to a tendency to develop large bony abnormalities of the humeral head and glenoid and a susceptibility to further seizures. Assessment is difficult and diagnosis may be missed, resulting in chronic locked dislocations with protracted morbidity. Many patients have medical comorbidities, and successful treatment requires a multidisciplinary approach addressing the underlying seizure disorder in addition to the shoulder pathology. The use of bony augmentation procedures may have improved the outcomes after surgical intervention, but currently there is no evidence-based consensus to guide treatment. This review outlines the epidemiology and pathoanatomy of seizure-related instability, summarising the currently-favoured options for treatment, and their results.

Introduction

The ability to manufacture implants at the point-of-care has become a desire for clinicians wanting to provide efficient patient-specific treatment. While some hospitals have adopted extrusion-based 3D printing (fused filament fabrication; FFF) for creating non-implantable instruments with low-temperature plastics, recent innovations have allowed for the printing of high-temperature polymers such as polyetheretherketone (PEEK). Due to its low modulus of elasticity, high yield strength, and radiolucency, PEEK is an attractive biomaterial for implantable devices. Though concerns exist regarding PEEK for orthopaedic implants due to its bioinertness, the creation of porous networks has shown promising results for bone ingrowth.

In this study, we endeavor to manufacture porous PEEK constructs via clinically-used FFF. We assess the effect of porous geometry on cell response and hypothesize that porous PEEK will exhibit greater preosteoblast viability and activity compared to solid PEEK. The work represents an innovative approach to advancing point-of-care 3D printing, cementless fixation for total joint arthroplasty, and additional applications typically reserved for porous metal.

Introduction

Migration of bone cells and precursor cells to the site of a bone defect can accelerate bone regeneration. Therefore, guidance of these cells by direct current (DC) is an interesting approach to improve implant ingrowth or fracture healing. To allow a better understanding of DC-induced directed migration, a specific stimulation chamber was established and the influence of DC on calcium channel expression in osteoblasts was investigated.

INTRODUCTION

Osteoarthritis (OA) can be artificially simulated ex vivo on healthy articular cartilage (AC) samples by use of proteolytic enzymes. In this article we will present preliminary analyses of the physical degradation of AC when subjected to alternating mechanical stresses. Since AC damage due to OA is believed to be mechanically induced, the first step towards the realisation of an improved understanding of degenerative behaviour of AC under physiological loading conditions is to perform ex vivo tests which mimic such conditions at best.

Purpose

To calculate the cost of investigation of a painful Total Knee Replacement (TKR) to the hospital trust and Primary Care Trust (PCT).

In addition to mechanical stresses, an inflammatory mediated association between obesity and knee osteoarthritis (OA) is increasingly being recognised. Adipokines, such as adiponectin and leptin, have been postulated as likely mediators. Clinical and epidemiological differences in OA by race have been reported. What contributes to these differences is not well understood. In this study, we examined the profile of adipokines in knee synovial fluid (SF) and the gene expression profile of the infra-patellar fat pad (IFP) by race among patients with end-stage knee OA scheduled for knee arthroplasty.

Age, sex, weight and height (used to derive body mass index (BMI)) and race (White, Asian and Black) were elicited through self-report questionnaire prior to surgery. SF and IFP samples were collected at the time of surgery. Adipokines (adiponectin and leptin) were examined in the SF using MAGPIX Multiplex platform. IFP was profiled using Human Adipogenesis PCRArray and genes of interest were further validated via quantitative relative RT-PCR using Student's t-test. Overall differences in adiponectin and leptin concentrations were tested across race. Linear regression modeling was used to investigate the association between adiponectin and leptin concentrations (outcomes) and race (predictor; referent group: White), adjusting for age, sex and BMI.

67 patients (18 White, 33 Asian, 16 Black) were included. Mean SF adiponectin concentration was greatest in Whites (1175.05 ng/mL), followed by Blacks (868.53 ng/mL) and Asians (702.23 ng/mL) (p=0.034). The mean SF leptin concentration was highest in Blacks (44.88 ng/mL), followed by Whites (29.86 ng/mL) and Asians (20.18 ng/mL) (p=0.021). Regression analysis showed Asians had significantly lower adiponectin concentrations compared to Whites (p<0.05). However, leptin concentrations did not differ significantly by race after adjusting for covariates. Testing of the IFP, using the Adipogenesis PCRArray, showed significant higher expression of LEP gene (leptin, p=0.03) in Asians (n=4) compared to Whites (n=4).

There appears to be important racial differences in the SF adiponectin profile among individuals with end-stage knee OA. Differential gene expression in the IFP across racial groups could be a potential contributory source for the noted SF variations. Further work to determine the source and function of adipokines in knee OA pathophysiology across racial groups is warranted.

A postal questionnaire was sent to 225 GPs and 225 Orthopaedic Surgeons (Consultant and Specialist Registrars) in 20 hospitals in North West England. They were asked to give their routine clinical practice with regard to investigation of underlying osteoporosis in 3 clinical scenarios :

55 year old lady with a low trauma Colles fracture

The participants were asked whether patients over 50 years old with low trauma fractures required investigation for osteoporosis, and whether an osteoporosis Nurse Specialist would provide a beneficial service.

The response rate was 52% (n=l17) from Orthopaedic Surgeons and 49% (n=l11) from GPs. Both groups agreed that patients over 50 years old with low trauma fractures required investigation for osteoporosis (81 % surgeons and 96% GPs), and that Osteoporosis Nurse Specialists may provide a beneficial Service (81% Surgeons and 94% of GPs).

A majority of surgeons (56%) replied that they would routinely discharge the Colles fracture patient without requesting or initiating investigation for underlying osteoporosis. However, a majority of GPs (67%) would not investigate a similar patient for osteoporosis, unless prompted by the surgeon or patient.

A greater proportion of both surgeons (71%) and GPs (64%) would routinely initiate investigations or treatment for osteoporosis in the Vertebral Wedge fracture patient.

65% of surgeons would simply discharge a patient with a femoral neck fracture after orthopaedic treatment and 40% of GPs will simply file the hospital discharge letter.

Most Orthopaedic Surgeons and GPs are aware that low trauma fractures in patients over 50 years old require investigation for Osteoporosis, however, a large population of patients with Colles and Femoral Neck fractures are not being given the advantages of secondary prevention of Osteoporosis. This may lead to greater workload for Orthopaedic Surgeons in the future.

Aims: To determine the usefulness of preoperative CRP, ESR, WCC and joint aspirate in the diagnosis of infective loosening before revision TKA.

Methods and Materials: Retrospective review of patients undergoing revision TKA for the period May 1998 to May 2008 was performed, examining the results of preoperative CRP, ESR, WCC, joint aspirate and intra-operative microbiological samples. Positive results were CRP ≥10 mg/dL, ESR ≥ 22mm/hr, WCC ≥11 g/dL and positive growth on culture unless stated as contaminant. The data was analysed to determine sensitivity, specificity, negative and positive predictive values of the tests for single stage and staged revisions.

Results: 51 patients underwent single stage revision with 10 positive cultures. CRP and WCC were highly specific for infection (84%, 98%) with low sensitivities (10%). ESR was 66% specific and 25% sensitive. All had high negative predictive values (76–86%).

23 patients underwent staged revision. 17 cases had positive cultures at 1st stage and 8 at 2nd stage. 1st stage CRP, ESR and WCC had low sensitivity (67%, 59%, 17%). WCC was 80% specific whereas CRP and ESR had low specificity (25%, 20%). All had high positive predictive value (71–80%). 2nd stage CRP and ESR were specific for infection (71%) but had low sensitivities (22 and 44%). WCC was 0% sensitive but 87% specific. Negative predictive values of CRP, ESR and WCC were 63, 71 and 62%.

For both single stage and 1st stage staged revisions, pre-operative joint aspirate was 100% specific with sensitivities of 0% for single stage and 50% in staged revisions.

Conclusion: All patients undergoing both staged and single stage revision arthroplasty should routinely have preoperative inflammatory markers and joint aspirate. However, positive intraoperative cultures may still be obtained despite negative preoperative investigations.

This work examines the Upper limb (UL) blast-mediated traumatic amputation (TA) significance from recent operations in Afghanistan. It is hypothesized that the presence of an UL amputation at any level is an independent predictor of torso injury.

A joint theatre trauma registry search was performed to determine the number of British casualties with TA and their associated injuries.

UL TA accounted for 15.7% of all amputations; distributed: shoulder disarticulation 2.5%, trans-humeral 30%, elbow disarticulation 10%, trans-radial 20% and hand 37.5%. The presence of an UL amputation was more likely in dismounted casualties (P=0.015) and is a predictor of an increased number of total body regions injured and thoracic injuries (P 0.001 and P 0.026 respectively). An increased Injury Severity Score (ISS) was seen in patients with multiple amputations involving the UL (UL TA present ISS=30, no UL TA ISS=21; P=0.000) and the ISS was not significantly different whether mounted or dismounted (P=0.806).

The presence of an upper limb amputation at any level should insight in the receiving clinician a high index of suspicion of concomitant internal injury; especially thoracic injury. Therefore with regards to blast mediated TA the injury patterns observed reflect a primary and tertiary blast mechanism of injury.

With an increasing ageing population and a rise in the number of primary hip arthroplasty, peri-prosthetic fracture (PPF) reconstructive surgery is becoming more commonplace. The Swedish National Hip Registry reported that, in 2002, 5.1% of primary total hip replacements required revision due to PPF. Laboratory studies have indicated that age, bone quality and BMI all contribute to an increased risk of PPF. Osteolysis and aseptic loosening contribute to the formation of loosening zones as described by Gruen, with subsequent increased risk of fracture. The aim of the study was to identify significant risk factors for PPF in patients who have undergone primary total hip replacement (THR).

Logbooks of three Consultant hip surgeons were filtered for patients who had THR-PPF fixation subsequent to trauma. Risk factors evaluated included sex, age, bone density (Singhs index), loosening zones, Vancouver classification, prosthesis stem angle relative to the axis of the femur, and length of time from THR to fracture. A control group of uncomplicated primary THR patients was also scrutinised.

Forty-six PPF were identified representing 2.59% of THR workload. The male: female ratios in both groups were not significantly different (1:1.27 and 1:1.14 respectively). Average age of PPF was 72.1, which was significantly older than the control group (54.7, p>0.05). The commonest type of PPF was Vancouver type B. Whilst stem position in the AP plane was similar in both groups, in lateral views the PPF stem angle demonstrated significant antero-grade leg position compared to the non-PPF group (p.0.05). The PPF group demonstrated a greater number of loosening zones in pre-fracture radiographs compared to the control group (2.59 and 1.39 respectively, p>0.05)

Our workload from PPF reflects that seen in Europe. Age, stem position and the degree of stem loosening appear to contribute to the risk of a peri-prosthetic fracture.

Purpose

Investigating the effects of femoral stem length on hip and knee muscle strength.

Introduction: The Donjoy OA Orthesis has been developed to treat unicompartimental osteoarthrosis of the knee joint. The idea is to reduce the load in the affected joint compartment. Sofar only clinical evaluations and gait analysis have been published. The aim of this study is to use intraarticular pressure sensors in an anatomical model to work out the existing intraarticular pressures.

Method: 5 fresh non fixated anatomical knee models were used. The models were prepared leaving the 2/3 of the femur as well as the tibia and fibula. We used a right and left-sided version of the Donjoy OA Orthesis. A defined pressure was applied via the pressure application screw.

The dorsal capsule of the knee joint was opened and the meniscus were mobilised in a way that the pressure foils (Fuji typ super low) could be placed between the undersurface of the meniscus and the tibia plateau in each joint compartment. The measurements were recorded in four different joint positions (0°, 30°, 60° flexion and 0° with removed meniscus).

Each anatomical model was well fixed in a universal testing machine” (Instron, System ID: 5565 H1703). The used axial pressure in all set ups used was 1500N.

We used 4 four different test series:

no pressure, no orthesis

After removing the pressure foils the actual pressure could be estimated by the diameter of the coloured foil. Using the programm Mortphomet it was possible to calculate these pressure areas and give procentual figures.

Results: The Antivarus Orthesis could reduce the intraarticular joint pressure between 55–70%

Without pressure:

Knee → 64,37 %

Mean value 55%.

With pressure:

Knee → 74,59 %

mean value 70%.

The Antivalgus Orthesis could reduce the intraarticular joint pressure between 46–74%

Without pressure:

Knee → 79,78 %

Mean value 74%.

With pressure:

Knee → 42,68 %

Mean value 46%.

Conclusion: This anatomical investigation has proved for the first time via intraarticular pressure measurements that it is possible to considerable reduce the intraarticular pressure using the Donjoy antivarus and antivalgus Orthesis.

Thermonecrosis either results in bone loss which may weaken the purchase of surgically-inserted screws leading to loosening or the dead bone may remain in situ and become infected resulting in a ring sequestrum. The aim of this project was to measure the heat generated during drilling of bone. By using a novel realtime thermal camera the thermal events could be visualised topographically.

An experimental setup comprising a force table, an infrared camera, a power drill and a new surgical 2.5mm drill bit was constructed. This enabled measurements of the force applied and temperature changes in sheep cortical bone during a drilling operation. The temperature was observed throughout the drilling period and for further 15s after the drill bit was withdrawn. Images were grabbed using a LAND FTI Mv thermal camera which was driven by LIPS Mini software. Calibration was made in the range 20-200 degrees C, the upper value being provided by a high wattage resistor. Data was processed using routines written in MATLAB.

It was found that 12s were required to drill through a single cortex. Within one second of drilling, the maximum recorded temperature in the vicinity of the drill increased from the baseline of 20 to 170 degrees C. It remained above this temperature for 25s. Immediately after the drill bit was withdrawn, a region of approximately 15mm of diameter of cortical surface had a sustained temperature above 50 degrees C. After 15s of cooling, this diameter had only reduced to 10mm. By modelling the cooling curve, the maximum temperature at the drill tip was extrapolated to be between 500-600 degrees C.

Thermography has proven to be useful in the study of the thermal characteristics of bone during drilling. The process of drilling generates significant increase in temperature in the vicinity of the drill. This temperature elevation has been found to be sustained for a significant period of time.

Purpose

Change of the pelvic tilt is an important factor affecting walking after total hip arthroplasty (THA). There are many reports of static evaluation of pelvic tilt by X-ray, however, there are few reports of dynamic evaluation during walking. In this study, we investigated change of pelvic tilt of THA subjects before and after operation during walking using an optical position sensor.

Malorientation of the acetabular cup in Total Hip replacement (THR) may contribute to premature failure of the joint through instability (impingement, subluxation or dislocation), runaway wear in metal-metal bearings when the edge of the contact patch encroaches on the edge of the bearing surface, squeaking of ceramic-ceramic bearings and excess wear of polyethylene bearing surfaces leading to osteolysis.

However as component malorientation often only occurs in functional positions it has been difficult to demonstrate and often is unremarkable on standard (usually supine) pelvic radiographs. The effects of spinal pathology as well as hip pathology can cause large rotations of the pelvis in the sagittal plane, again usually not recognized on standard pelvic views. While Posterior pelvic rotation with sitting increases the functional arc of the hip and is protective of a THR in regards to both edge loading and risk of dislocation, conversely Anterior rotation with sitting is potentially hazardous.

We developed a protocol using three functional positions – standing, supine and flexed seated (posture at “seat-off” from a standard chair). Lateral radiographs were used to define the pelvic tilt in the standing and flexed seated positions. Pelvic tilt was defined as the angle between a vertical reference line and the anterior pelvic plane. Supine pelvic tilt was measured from computed tomography.

Proprietary software (Optimized Ortho, Sydney) based on Rigid Body Dynamics then modelled the patients’ dynamics through their functional range producing a patient-specific simulation which also calculates the magnitude and direction of the dynamic force at the hip and traces the contact area between prosthetic head/liner onto a polar plot of the articulating surface. Given prosthesis specific information edge-loading can then be predicted based on the measured distance of the edge of the contact patch to the edge of the acetabular bearing.

Introduction Successful glenoid component fixation in shoulder arthroplasty is dependent on the quality of the underlying bone. The quantity of trabecular bone available for fixation is small and its properties are critical for both fixation and load bearing. Indentation testing has been used previously to determine regional changes in the mechanical properties of the glenoid surface [1]. However, there has been no attempt to relate these properties to the quality of the surrounding bone. The aim of this study was to investigate the relationship between the mechanical properties of the surface with both the trabecular bone volume fraction and the cortical thickness of the underlying bone. Materials and

Methods Nineteen embalmed glenoids were obtained from human cadavers (mean age 82 years). Previous work had shown that embalming had minimal impact on the mechanical properties of bone derived using indentation testing [2]. Indentation tests were performed using a 2.95 mm flat cylindrical indenter, with a speed of 2 mm/min, at 11 pre-selected grid points, up to a depth of 3 mm. Care was taken to ensure that the indenter surface was perpendicular to the local surface of the glenoid. The stiffness and maximum load following mechanical properties were measured from the resulting load-displacement curve. The Young’s modulus and strength were derived using the formula given in [3] and normalising with respect to the indenter cross section, respectively. Each of the glenoids was scanned using a large sample microCT (Scanco uCT 80) at a resolution of 78 microns. The cortical thickness and bone volume fraction (BV/TV) local to each of the grid points was determined from the 3-D reconstructions of these scans.

Results The mean strength and elastic modulus of each of the 11 indentation sites ranged from 26 to 67 MPa and 83 to 184 MPa, respectively. The largest value of BV/TV was found at the posterior edge (0.41%) and the lowest at the inferior edge (0.14%). The measured cortical thickness ranged from 0.68mm to 0.88mm with the thickest at the superior edge. Multiple regression analysis found, in the main, a significant correlation between strength and BV/TV for data derived from each of the indentation sites. The elastic modulus had only a weak correlation with BV/TV. Cortical thickness was found to have only a very marginal influence on both the elastic modulus and strength.

Discussion The indentation and uCT analysis have been used for the first time to relate the glenoid’s mechanical properties to bone morphology. The distribution of the BV/TV data is similar to that found by Frich et al [4] and for BMD measurements for BMD [5]. However, the cortical thickness measurements differ from those of Frich [4]. The local bone volume fraction strongly influenced the strength at the glenoid surface. Further investigations are ongoing to determine more fully the morphological factors important in the properties of the glenoid surface and whether such factors can be a predictor of clinical success.

Background

Office seating includes a variety of chair styles. There is limited research investigating their effects on spinal angles.

Introduction

Acetabular cup orientation has been shown to be a factor in edge-loading of a ceramic-on-ceramic THR bearing. Currently all recommended guidelines for cup orientation are defined from static measurements with the patient positioned supine. The objectives of this study are to investigate functional cup orientation and the incidence of edge-loading in ceramic hips using commercially available, dynamic musculoskeletal modelling software that simulates each patient performing activities associated with edge-loading.

Purpose

Full-thickness tendon tears of the supraspinatus (SP) are common and can have a significant impact on shoulder function. To optimally treat supraspinatus tendon tears an accurate understanding of its musculotendinous architecture is needed. We have previously shown that the architecture of supraspinatus is complex. It has architecturally distinct regions: anterior and posterior, each of which is further subdivided into superficial, middle and deep parts (Kim et al., 2007). Data of FBL and PA of the torn supraspinatus could enhance clinical decision making and guide rehabilitative treatments (Ward et al., 2006). Currently, however, in vivo US quantification of the fiber bundle architecture of the distinct regions of supraspinatus in subjects with full-thickness tendon tears has not been investigated.

PURPOSE: To quantify architectural parameters within the distinct regions of supraspinatus in subjects with a full-thickness tendon tear using the US protocol that we previously developed (Kim et al., 2010), and to compare findings with age and gender matched normal controls.

Aim

The primary aim of this pilot study was to assess and evaluate the SpineCor Pain Relief Brace as a method of reducing the pain experienced by patients diagnosed with degenerative scoliosis

Successful total knee arthroplasty design is related to the joint dynamics imposed by the design. This study examined the clinical and biomechanical performance of patients who received a PFC Sigma total knee implant (posterior cruciate substituting design). Radiographic, strength testing, gait pattern and clinical survey data were collected. Pre-operative and post-operative outcome measures were compared. Statistically significant differences were found on the pain, stiffness and physical function scales of the WOMAC as well as the knee and total score parameters of the Knee Society Score. Significant improvements were also seen on several gait pattern parameters.

Factors such as implant design and surgical technique have been found to influence knee kinematics and kinetics thereby effecting patient function and implant survival after total knee arthroplasty. Numerous gait studies have reported a lack of normal gait pattern for TKA patients (Wilson et al., 1996; Andriacchi, 1993; Jevsevar et al., 1993). There is debate in the literature as to which design best improves patient function and implant survival, the posterior cruciate (PC) substituting or PC-retaining. The purpose of this study is to determine the clinical outcome and biomechanical performance of patients who receive PFC Sigma total knee arthroplasty.

The PC substituting implant design provided significant improvements in clinical and gait outcomes at two years post-op in this patient sample.

Patients experience significant pain and stiffness relief, and better functional outcomes.

A cohort of eighteen total knee replacement patients were followed for two years post-operatively. Radiographic, strength testing, gait pattern and clinical survey data (SF36, WOMAC, Knee Society Score) were collected. Paired sample t-tests, repeated measures general linear modeling and principle component analyses comparing aged matched normals were conducted to evaluate pre-operative and post-operative outcomes. Statistically significant differences were found on the pain, stiffness and physical function scales of the WOMAC as well as the knee and total score parameters of the Knee Society survey. There were also significant improvements found on gait pattern parameters. Findings like these point to a need for larger population studies of patients with PC-substituting TKA.

Funding: Funding for this study was provided by Depuy Orthopaedics, Inc.

There are a number of periprosthetic femoral fracture (PFF) fixation failures. In several cases the effect of fracture configuration on the performance of the chosen fixation method has been underestimated. As a result, fracture movement within the window that seems to promote callus formation has not been achieved and fixations ultimately failed.

This study tested the hypothesis that: PFF configuration and the choice of plate fixation method can be detrimental to healing.

A series of computational models were developed, corroborated against measurements from a series of instrumented laboratory models and in vivo case studies. The models were used to investigate the fixation of different fracture configurations and plate fixation parameters. Surface strain and fracture movement were compared between the constructs.

A strong correlation between the computational and experimental models was found. Computational models showed that unstable fracture configurations increase the stress on the plate fixation. It was found that bridging length plays a pivotal role in the fracture movement. Rigid fixations, where there is clinical evidence of failure, showed low fracture movement in the models (<0.05mm); this could be increased with different screw and plate configurations to promote healing.

In summary our results highlighted the role of fracture configuration in PFF fixations and showed that rigid fixations that suppress fracture movement could be detrimental to healing.

Introduction

Fracture healing is governed by biological and mechanical factors. Circular frames are one method to fix fractures. Recently, the number of frame designs that are available has increased and these different designs may have different effects on the mechanical environment created. The senior author has been concerned by the stability of the construction when a short frame is used. This study examined the stability of different frames and the possible use of additional 7th struts to aid stability.

Introduction

Metal on metal (MoM) bearings have been dealt a severe blow in the past few years. The release of metal ions may have arisen from corrosion, wear, or a combination of the two. Edge loading due to implant malposition is thought to cause a failure of lubrication and to contribute to excessive wear and increased metal ion release [1]. Literature reports aseptic lymphocytic vasculitis-associated lesions (ALVAL) are associated with a variety of failures which occur to some degree in all implanted metal femoral components [2, 3]. Moreover, Willert et al [4] has described ALVAL in non-MoM bearing designs too. This paper has investigated the metal ion release due to total hip replacement (THR), Hip Resurfacing (HR) and total knee replacement (TKR).

Magnetic resonance imaging (MRI) validation of a novel method of assessing Distal Radial Fracture (DRF) reduction using the hypothesised constant relationship between the dorsal radial cortex (DC) and the superior pole of the lunate (SL).

MRI scans of 28 normal wrists were examined. Scans included the distal third of the radius to the proximal carpal row. Beginning 5cm proximal to the distal radius articular surface, a line was superimposed upon the DC extending distally through the metaphyseal flare.

Lunate height (LH) and distance from the DC line to the SL (DC-SL) were measured at 5-degree rotational increments around the radial shaft central axis to a total of 30 degrees of supination and pronation (S+P). The DC-SL/LH ratio was compared to 0 degrees (anatomical lateral) using the two-tailed paired student t-test.

There was no significant difference in DC-SL:LH between 0 degrees of rotation and any 5-degree increment up to 30 degrees of S+P (lowest p=0.075). The DC line lay consistently dorsal to the SL.

A constant DC-SL relationship exists with up to 30 degrees of S+P. This reference can be quickly and accurately used to assess DRF reduction in poorly-taken films with malrotation up to 30 degrees from anatomical lateral. Research comparing DC-SL distance with volar tilt to assess DRF reduction is needed.

Summary Statement

Burst fractures were simulated in vitro on human cadaveric spine segments. Displacement of the facet joints and pedicles were measured throughout the fracture process showing how these bony structures behave when an impact load is delivered.

Summary

When a TFCC tear is diagnosed, practitioners should maintain a high level of suspicion for the presence of a concomitant SL or LT ligament tear.

Introduction

To meet the demands of younger more active patients more robust pre-clinical wear testing methods are required, in order to simulate a wider range of activities. A new electromechanical simulator (Simulation Solutions, UK) with a greater range of motion, a driven abduction/adduction axis and improved input kinematic following has been developed to meet these requirements, as well as requirements of the relevant international standards. This study investigated the wear of a fixed bearing total knee replacement using this new electromechanical knee simulator, comparing with previous data from a pneumatic simulator.

Introduction: Immature individuals with known neuromotor disorders are subject to the development of scoliosis; therefore a subclinical dysfunction or anatomic abnormality of the neurologic system has been hypothesized as a causative factor of adolescent idiopathic scoliosis.

In previous clinical studies, authors have tested a wide range of functions, including proprioception, postural equilibrium, oculovestibular complex and vibratory sensation and multiple techniques, including electronystagmography, electroencephalography and electromyography in select scoliotic patient populations

Material and Methods: The present study was designed to investigate the motor system of scoliotic patients with magnetic stimulation. female patients 12 to 14 years old (mean age=13.36) with right idiopathic scoliosis (curves:20–40°) (study group) and 20 normal subjects in the same age group (mean age=12.6) (control group) entered the study. Magnetic stimulation of the brain was performed with a figure of eight coil angled 45° to the parasagittal plane and positioned so as to overly the hand area.

Transcranial stimulation was performed with a Magstim 200 stimulator (Magstim Co, Dyfed, Wales). Stimulation was performed with a figure of 8 coil for upper limbs and a double cone coil for lower limbs. Recordings were made with surface electrodes from 1st dorsal interosseous and abductor hallucis muscles. Threshold measurements included upper (UT) and lower threshold (LT), defined as the stimulus intensities producing MEPs with a propability of 100 and 0%, respectively. Mean threshold (MT) was the mean of UT and LT. Cortical latencies of MEP’s during muscle activation were also measured.

Results: In the patients’ right hemisphere UT,MT and LT were 46.5±8.2, 41.6±7.6 and 36.6±7.3% respectively and the activated cortical latency was 18.6±l.lms.

In the left hemisphere UT, MT and LT were 45.9±9.8, 41.4±9.1 and 36.9±8.7%, respectively and the activated cortical latency was 18.3±0.8ms. These differences were not statistically significant (p> 0.05, t-test). The side-to-side difference of UT,MT and LT were 4.5±2.4, 4.3±2.8 and 4.4±3.7.

None of all the above parameters differed significantly from those of the control group (p> 0.05, t-test).

The differences in the corticomotor excitability in the upper and lower extremities were not statistical significant.

Conclusion: In the study group revealed asymmetries between left and right hemisphere in cortical latencies of MEP’s facillitated.

Introduction: The cause of idiopathic scoliosis remains unknown, although research has possibly eliminated some hypothetical causes.

The fact that many patients with idiopathic scoliosis appear to be out of balance, has led many researchers to postulate that a brain stem abnormality involving the vestibular system in the cause of this condition.

Material and Methods: Forty – five female patients 12 to 14 years old (mean age 13.5) with right thoracic idiopathic scoliosis (scoliotic curves:20°–40°, study group) and 31 non-scoliotic healthy subjects in the same age group (mean age=13.1, control group) were included in this study.

An electronystagmographic study of labyrinthine function with caloric stimulation was performed in all patients. The nystagmus was recorded with the electronystagmographic technique (ENG) using Hartmann device. The recordings were performed in a dark, silent room with the tested subject in the supine position and with it’s eyes closed.

We evaluated: the frequency, the amplitude and the slow phase velocity of nystagmus.

The differences in labyrinthine sensitivity were evaluated with the use of unilateral weakness parameter, while differences in left – and right – beating nystagmus evaluated by estimating the directional preponderance parameter.

Results: No one children of the study presented spontaneous or positional nystagmus.

Nineteen patients from the study group (44.2%), revealed unilateral weakness (difference between left and right labyrinth > 20%) of the left labyrinth.

Seventeen patients from the study group (39.5%) revealed directional preponderance of the right-beating nystagmus. These differences were statistical significant (p< 0.05, Chi-Square test). Seventeen patients from the study group revealed both left unilateral weakness and directional preponderance of the right labyrinth, while two patients revealed only left unilateral weakness. A significant correlation was found between the degree of the curvature and the percentage of unilateral weakness.

Conclusion: It is very difficult to draw any conclusions as to whether a vestibular imbalance may be a contributory factor to adolescent idiopathic scoliosis or whether the vestibular findings are secondary to the spine deformity.

Low back pain has been described as a 20th century health care enigma. Increasingly, adolescents report back discomfort at an earlier age. In a cross-sectional study amongst a Danish population of 29,424 twins, Leboeuf-Yde reported a rapid increase in back pain prevalence after the age of 12. The link between childhood and adult back pain however, remains controversial.

In 1997 the NBPA School Bag Survey reported that 80% of school children carry ‘too much weight’ in ‘poorly designed’ school bags, resulting in postural stress. In response, BackCare (formerly NBPA) designed an ergonomic school bag. This study was undertaken to establish 16-year-olds’ views on the comfort and usability of the ergonomic bag in comparison to their usual school bag.

Thirty students, aged 16 years, were recruited from three local sixth form colleges. Each student used the ergonomic bag for one week. They evaluated the comfort and usability of both the ergonomic bag and their usual school bag using self-report questionnaires.

Seventy percent of the students reported back pain within the last 12 months. Ratings for the comfort of the ergonomic bag were compared with those for their usual school bag using the Wilcoxon test. There were statistically significant differences between the bags for comfort at the shoulders (p = 0.001) and all regions of the spine: neck (p = 0.000); upper back (p = 0.008); lower back (p = 0.001), with the ergonomic bag more comfortable than the students’ own. No significant differences were found between the bags for comfort in the arms, hands or legs.

Despite this improvement in spinal comfort, only 13% of students said they would use the ergonomic bag in preference to their usual bag. This was due to practical aspects such as its appearance and perceived lack of security for valuable items, such as ‘money and mobile phones’.

In this population of 16-year-olds, cosmetic and practical aspects of a school bag were more important than comfort. If such bags are to be accepted, manufacturers must create a fusion between ergonomics and fashion.

This study evaluates the relationship between radiographic knee osteoarthritis and the presence of a relevant meniscal tear detected with MRI in symptomatic patients over the age of 60.

Seventy-seven patients over 60 investigated with a knee MRI in a 1 year period were identified. 60 patients had a full set of data available for analysis. The plain radiographs were graded for osteoarthritis using the Kellgren – Lawrence (K-L) scale in a blinded manner. The indication for the MRI was subdivided into: meniscal symptoms, general knee pain and other. These indications were correlated with the K-L grade and result of the MRI.

Overall, 40% of patients with a K-L grade of 0 had a meniscal tear compared to 89% of patients with a K-L score of 3 and 88% with a K-L score of 4. The indication for a MRI was meniscal symptoms in 49, general pain in 6 and other in 5. In the group investigated for meniscal symptoms, the incidence of meniscal tears was 92% and 100% with a K-L grade of 3 and 4 respectively.

In patients with meniscal symptoms and significant radiographic osteoarthritis the outcome of the MRI is so predictable that the scan is unnecessary.

Objectives

To investigate the views and experiences of patients with sciatica who have undergone a bespoke physiotherapy programme whilst awaiting primary lumbar microdiscectomy.

Introduction

Lumbar spondylolysis is a fatigue fracture of the pars interarticularis and correlates with Spina Bifida Oculta (SBO) in 67%.

Given their role in reducing anterior tibial translation, the recruitment patterns and viscoelastic properties of the hamstring muscles have been implicated as neuromuscular factors contributing to the ACL gender bias. Nevertheless, it is uncertain whether patterns of aberration displayed by the female neuromuscular system significantly alters the antagonist moments generated by the hamstrings during maximal effort knee extension. The purpose of the current study was to examine the effect of gender on hamstring antagonist moments in order to explain the higher ACL injury rates in females.

Eleven females (age 30.6 ± 10.1 years, mass 62.1± 6.9 kg, height 165.9 ± 4.6) and 11 males (age 29.0 ± 8.2 years, mass 78.6± 14.4 kg, height 178.5± 6.2) were recruited as subjects. Surface electrodes were placed over the semitendinosus (ST) and biceps femoris (BF) muscles of the dominant and non-dominant limbs. Each subject performed two sets of five maximal extension and flexion repetitions at 180-1. EMG, isokinetic torque and knee displacement data were sampled at 1000Hz using an AMLAB data acquisition system.

Average hamstring antagonist torque data across the range of knee flexion for female subjects was significantly higher (%Diff=24%) than for the male control subject. Statistical analyses revealed a significant main effect of gender (F = 4.802; p = 0.036).

Given that females possess a more compliant ACL and hamstring musculature, compared with their male counterparts, an augmented hamstring antagonist may represent a compensatory neuromuscular strategy to increase knee stiffness to control tibial translation and ACL strain. The results of this project suggest that it is unlikely that gender-related differences in hamstring antagonist torque is one of the predisposing factors contributing to the higher ACL injury rates in females.

Restoration of normal anatomy following a distal radial fracture is an important factor in determining functional recovery. However, current methods of assessing dorsal tilt and displacement require ‘true’ lateral radiographs, and important reference points are often obscured by metalwork.

Aims: to investigate if an easily identifiable and predictable relationship exists in the normal wrist between the distal radius and lunate; and if so,to compare fractured wrists (pre and postoperatively)using conventional and new assessment methods.

22 patients with displaced distal radial fractures treated by ORIF, were included. Patients had pre and postoperative radiographs taken of the injured and uninjured wrists. From lateral radiographs, measurements were performed using the PACS system. A line was superimposed upon the dorsal radial cortex 2cm proximal to the wrist passing distally. The following measurements were performed: lunate height, distance from the ‘line’ to the superior and inferior poles of the lunate, and conventional measurements of dorsal tilt and angulation.

Uninjured wrist: Most noticeably the dorsal radial line always passed superior to the lunate, mean distance of 3.27mm (1.75-6.6mm). As a ratio, the distance from the line to the superior pole of the lunate divided by the distance to the inferior pole (‘lunate ratio’) had a mean of 0.16 (0.11-0.19).

Fractured wrist, PreORIF: Using conventional methods, the mean fracture displacement was 2.64mm (0-5.1mm) and the mean dorsal tilt was 23.3 degrees(4 degrees volar tilt to 43 degrees dorsal tilt). Using the dorsal reference ‘line’, in all cases the lunate was either above or transected by the line; mean lunate ratio of 1.61 (0.54-8.05). The mean height of the lunate projecting dorsal to the line was 9.5mm (6.1-16.1mm).

Fractured wrist, PostORIF: Apart from one radiograph, the ‘line’ passed superior to the lunate; mean distance of 2.64mm (0-3.9mm), with a mean lunate ratio of 1.13 (0.61-2.74). These measurements correlated well with measurements of dorsal tilt and displacement.

Our study suggests that there is a strong relationship between the distal radius and the lunate that could be used to assess fracture displacement and quality of reduction. Its main advantages are simplicity and ease of use despite the presence of metalwork.

The aim of the study to analyze the circulating white blood cells including the intensity expression of surface receptors and cytoplasmic molecules in patients underwent total hip replacement, with either aseptic or septic loosening of hip prostheses in order to identify cell-surface and cytoplasmic markers that could be indicative of early loosening. Flow cytometry was performed in whole peripheral blood samples of 20 patients with loosening (10 septic and 10 aseptic). Ten healthy individuals served a control group. The CD62L, CD18, CD11a, CD11b and CD11c expressions were evaluated. The mean fluorescence intensity (MFI) of CD 18 was decreased on all leukocytes subsets compared to control group. For patients with aseptic loosening we demonstrated an increase of MFI for CD11b in granulocytes and for CD11c in monocytes and granulocytes compared to control group. In patients with septic loosening an increase of MFI for CD 11c was observed in monocytes compared to control group. The comparison between aseptic and septic loosening showed a statistically significant lower CD18 MFI value in granulocytes for aseptic loosening. A trend towards lower MFI values of CD 62L in lymphocytes and granulocytes were observed in aseptic but not in septic loosening patients compared to control group. The present study is the first study in published literature to demonstrate cell surface and cytoplasmic markers in peripheral blood indicative of loosening of THAs by means of flow cytometry.

MRI arthography (MRA) is commonly used in the investigation of shoulder instability. However many surgeons are now using CT arthography (CTA) as their primary radiological investigative modality. They argue that CTA is cheaper, and give satisfactory soft tissue images in the “soft tissue window” mode. They believe that CTA give superior images when looking at bone loss and bony defects, and as such is more useful in deciding whether a patient requires an open procedure or not.

In this study we aimed to compare the results of MRA and CTA in the investigation of shoulder instability.

We reviewed the operative and arthographic findings in all patients who had surgery for shoulder instability in our unit over a 4 year period. We compared the results of the arthograms with the definitive findings found at the time of surgery. All arthograms were performed by standard techniques and were reported by musculoskeletal radiology consultants. All surgery was performed by experienced consultant shoulder surgeons.

In total 48 CTAs and 50 MRAs were performed. We found that there was no significant difference between the two wrt sensitivity (p=0.1) and specificity (p=0.4) when looking at labral pathology. However CTA was more sensitive at picking up bony lesions (p< 0.05).

This study supports the view that CT arthography is the superior radiological modality in identifying pathology when investigating patients with shoulder instability. It is cheaper and better tolerated by patients than MRA and gives useful information on whether a patient needs an open or arthroscopic stabilisation procedure.

Intro

Distal radial fractures are a commonly encountered fracture & anatomical reduction is the standard. Dorsal angulation is the traditional method of assessment but is inaccurate in rotated lateral xrays. Previously a relationship has been demonstrated between the dorsal cortex (DC) of the radius & the superior pole of the lunate (SL) & its sensitivity for assessing dorsal angulation & translation.

Introduction

The use modular total hip arthroplasty is associated with potentially serious local and systemic complications. Each modular interface introduces a source for wear particle generation. Research suggests the etiology of wear particle generation and subsequent corrosion begins with mechanical fretting and disruption of the protective oxide layer leading to release of metal ions at the taper interface. The purpose of this study was to conduct three dimensional (3D) surface scans of the mating surfaces of the neck-stem taper to identify features that may contribute to the fretting and surface corrosion.

We report the largest multicentre series analysing the use of bone scans investigating painful post-operative Total Knee Replacements (TKR). We questioned the usefulness of reported scintigraphic abnormalities, and how often this changed subsequent management. 127 three-phase bone-scans were performed during a two-year period. Early and late flow phases were objectively classified. Reported incidences of infection and loosening were determined. Reports were subjectively summarised and objectively analysed to establish the usefulness of this investigation. Eight cases were excluded.

Scans were classified as: 33% (39) normal, 53% (63) as possibly abnormal, 6% (7) probably abnormal, and 8% (10) as definitely abnormal. Thirteen patients (11%) underwent revision TKR surgery. Intra-operative analysis revealed loosening of one femoral component, and massive metallosis of the patella in another. Cultures were negative in all cases. The sensitivity and specificity of a definitely abnormal investigation in predicting need for revision surgery was 23% and 82% (respectively). High instances of ambiguously reported abnormalities were observed.

This investigation has no role to play in the routine investigation of a painful TKR. It is unnecessary in investigation of periprosthetic infection and should not be used in a routine assessment of a painful TKR. If used it should be limited until an experienced revision surgeon has made a full assessment.

Introduction

The posterior condylar axis of the distal femur is the common reference used to describe femoral anteversion. In the context of Total Hip Arthroplasty (THA), this reference can be used to define the native femoral anteversion, as well as the anteversion of the stem. However, these measurements are fixed to a femoral reference. The authors propose that the functional position of the proximal femur must be considered, as well as the functional relationship between stem and cup (combined anteversion) when considering the clinical implications of stem anteversion. This study investigates the post-operative differences between anatomically-referenced and functionally-referenced stem and combined anteversion in the supine and standing positions.

Aim

Diagnosing prosthetic joint infections(PJI) is sometimes difficult. Being able to identify the bacteria involved in intraoperative samples is an essential diagnostic criterion.

There are however some cases in which the traditional cultures are not capable of providing a definitive diagnosis. In this regard, implant sonication has emerged as a complementary test.

The aim of this study was to analyze the results of microbiological studies obtained with and without implants sonication, in order to understand its real contribution to diagnosis.

378 patients have been studied since 1988 when we started the investigation of scaphoid fractures and pseudarthrosis. 306 patients were scaphoid pseudarthrosis and 72 scaphoid fractures or control of fracture healing. This study consists of 3 groups:

Group l: 72 patients with acute injury of the carpus are examined radiographically and no scaphoid fracture was observed. A scaphoid cast is applied in these patients for 10 days. In follow up, the cast is removed and new comparative radiologic examination is performed. In 30 of these patients a scaphoid fracture was observed and the limb was inmmobilized in a scaphoid cast for 4 weeks. In the remaining 42 patients, in whom a fracture line could not be observed in a simple x-Ray, but continued to have clinical findings, a CT-scan was performed in 2 planes. In 26 patients with no fracture in the CT-scan were discharged, while in the remaining 16 patients with obvious fracture in the CT-scan a scaphoid cast was applied for 4 weeks.

Group 2: 30 patients with scaphoid fracture, from which the cast was removed and the fracture line was still visible in a simple X-Ray were examined with CT-scan in 2 different planes. In 18 we found intense healing of the fracture in all the width of the scaphoid and the patients were discharged . The remaining 12 displayed delayed non union with obvious fracture line in all the width of the scaphoid. These patients were treated operatively, by compressing the fracture line with a Herbert screw.

Group 3: This is the largest group of patients concerning the scaphoid pseudarthrosis and consists a topic of a different study. In conclusion the computer tomography scan in two different planes is the most reliable method for the investigation not only of scaphoid fractures but also of the efficiency of the callus. The contribution of the above method in the study of the scaphoid pdeudarhrosis is very important and valuable.

Early discharge from hospital has the potential to reduce direct costs, but may result in patients being discharged without adequate preparation for a return to the community. This qualitative study aimed to investigate patient expectations of and satisfaction with in-hospital discharge planning after hip arthroplasty in early and late discharge patient groups. A prospective study of 33 consecutive patients requiring hip arthroplasty were recruited from two tertiary hospitals in the lower North Island. Participants were interviewed using in-depth, semi-structured interviews on the day of discharge from hospital and again four-eight weeks later. Comparative analysis of the interviews from patients in early and late discharge groups was made.

Findings reveal good levels of satisfaction with discharge planning for patients in both early and late discharge groups, facilitated by the opportunity to attend a pre-assessment clinic. Discharge planning was viewed as a partnership between patients and key members of the multi-disciplinary team. While written information provided was timely, restricted opportunity for dialogue with health professionals limited patient knowledge and understanding of recovery. Different needs of participants indicate that discharge planning needs to be tailored and more responsive to individuals. The role of health professionals as a mentor-coach is pivotal. Further interaction from health professionals, as a follow-up to written information provided may be a way to improve the discharge process and lead to more consistent outcomes.

Several authors have used 3D motion analysis to measure upper limb kinematics, but none have focused solely on wrist movements, in six degrees of freedom, during activities of daily living (ADL). This study aimed to determine the role of the different planar wrist movements during three standardised tasks, which may be affected by surgical procedures.

Nine volunteers (age range 22-45) were recruited and each participant performed three simulated ADLs: using a door lever, a door knob and opening/closing a jam jar. The ADLs were simulated using a work-sim kit on an isokinetic dynamometer. Motion analysis was performed by a 10-camera Oqus system (Qualisys Medical AB, Gothenburg, Sweden). All raw kinematic data were exported to Visual3D (C-Motion Inc.), where the biomechanical model was defined and joint kinematics calculated.

Table 1 shows a similar range of radial-ulnar deviation and flexion-extension as previous studies. However a substantial amount of wrist rotation also occurred in all tasks. This was significantly greater when using the door lever compared with the door knob and jam jar tasks.

Previous studies have stated that a negligible degree of rotation occurs at the wrist. This study found a maximum mean of 31.7 degrees of wrist rotation. This indicates that considerable rotational movement occurs at the wrist during certain functional tasks. Surgical approaches and clinical pathology may disrupt structures responsible for rotational stability. Further investigation of this rotational component of carpal movement during additional ADLs is proposed in both normal and clinical subjects, to explore the potential relationship between carpal surgery and rotational laxity.

The forces under the foot while walking have been measured using a high sensitivity force-plate of the strip-suspended type combined with simultaneous filming of the sole of the foot. The recording of data and the calculation and plotting of results were much simplified by computer aid. Normal and abnormal feet, both barefoot and shod, were investigated in sixteen subjects. It was found that in normal barefoot walking the forefoot carried a total load of the order of three times that of the heel. When footwear was worn the function of the forefoot was progressively reduced as the rigidity of the sole of the shoe increased. Painful conditions of the forefoot also produced a large reduction in the proportion of the total load transferred.

Objective

Shoulder instability is a common cause of morbidity amongst Professional Rugby Union players. This study explores whether the risk of shoulder dislocation is associated with innate shoulder laxity.

Introduction: For years traditional intramedullary nails (IMNs) have been used with great success to treat long bone fractures, however, based upon our clinical observations, we hypothesise that design changes incorporated into newer femoral IMNs reduces fracture stability resulting is a higher incidence of non-union.

AIMS: To biomechanically test the factors that may reduce fracture stability.

Materials and methods: The fracture fixation model consisted of custom made stainless steel IMNs of different wall thicknesses and outer diameters, cylinders manufactured from stainless steel, aluminium or HDPE of differing inner diameters and wall thicknesses, and 5mm rods made from stainless steel or titanium. The dimensions of the cylinders were chosen to resemble those commonly observed in the distal femur. The test nails and cylinders were connected using a single rod. Axial loading was undertaken up to 2KN (constant rate of 0.5KN/sec) and repeated a minimum of three times. The effects of various factors such as IM nail wall thickness and outer diameter, the alloy from which the rods were manufactured, and, the diameter, wall thickness and material properties of the cylinders were studied.

Results: The factors that most affected stability were the diameter, wall thickness and the material properties of the cylinders, with the least stable configuration being a HDPE cylinder with a diameter of 75mm and a wall thickness of 3mm. By reducing the diameter of the cylinder to 50mm combined with increasing the wall thickness to 5mm, stability increased considerably even when HDPE was used. The stability of each fracture fixation system was further reduced by using titanium rods.

Discussion: In clinical practice, new femoral IMNs permit longer cross screws to be inserted in the distal femur where the diameter is greatest and the cortical bone is thinnest. Since cancellous bone offers little resistance, screws effectively span from one cortex to the other gaining limited purchase in the bone. As a result, the newer IMN systems are more likely to displace regardless of the direction and force applied. This effect is exaggerated by using titanium. Overall the combination of screw length, choice of alloy and cortical thickness could easily explain our unsatisfactory clinical observations.

The aim of this study is to evaluate the effectiveness of the application of vibration, during the femoral cementation, as a cementing technique.

It has been demonstrated that when vibration of a constant frequency was utilised, flow of low viscosity cement increased with vibration of increasing amplitude up to a particular acceleration. Above this acceleration there was little additional benefit. It has also been shown that when constant amplitude was used the flow increase was uniform over a wide frequency range, eventually falling off over a particular frequency. These results prove that the flow of orthopaedic bone cement is significantly affected by mechanical vibration of the receiving structure. It is our hypothesis that vibration promotes the ingress of bone cement into cancellous bone.

The effect of mechanical vibration in the frequency range 0–500 Hz on the cadaveric human femur has been assessed in the past. It was found that when the bone was fixed at both ends, its resonant frequency was markedly affected by end loading and damping. If the conditions of the experiment were designed to simulate the condition of the femur when prepared for a total hip replacement, it was found that the bone did not resonate but behaved in a mass-like mode. The significance of this observation is that in the event of vibration being applied to enhance the penetration of orthopaedic bone cement, the movement induced in the bone will be proportional to the force applied regardless of frequency.

Introduction: Wrist injuries are common presentations at Accidents and Emergencies. Distal radius fractures are by far the most common. Scaphoid injuries constitute about 60% of carpal injuries. 35% occult wrist fractures are undiagnosed on 2nd visit radiography (50% distal radius/ulna). Moreover 30% patients with significant soft tissue injuries not diagnosed.

Aim: To compare the MRI (magnetic resonance imaging) and bone scans in the diagnosis of X-Ray negative wrist injuries. To functionally score these wrist at the end of 1-year to assess the outcome.

Materials and methods: A prospective study was done in 33 wrists that did not have a fracture wrist detectable on plain X-ray. The MRI and bone scan were done on the same day within 5-7 days after the injury. PD Fat Saturation Axial and Coronal images were undertaken with MRI. Clinical scoring was done after 1 year after the injury to assess the outcome of these injuries.

Results: We detected fractures in 10 wrists on bone scans and 8 fractures on MRI scans. There was a correlation between MRI and bone scan in 5 Cases. We noted 9% (3/33) of false positive cases with bone scan. Bone scans correlated with the site of injury in 10% of cases. 1 fracture was missed in both MRI and bone scan. MRI identified 4 significant soft tissue injuries and capsular edema in 29/33 cases, which were not identified on bone scans. MRI findings showed superior correlation than bone scans with clinical findings on re-examination, which was done following the scans. PRWE (patient rated wrist evaluation) was used to score the outcome of the wrists at the end of 1 year. The patients who had soft tissue or bony damage detected on MRI had significantly higher scores at 1 year of follow-up.

Conclusion: Though bone scan has high sensitivity in diagnosis of fracture, significant soft tissue injuries will be missed. On the other hand, MRI had a high sensitivity and specificity in diagnosis of a fracture and soft tissue injuries. MRI can differentiate between a bone edema and a fracture. MRI has a disadvantage of limited exposure. Clinicians must be aware of the limitations of both investigations. Though majority of these injuries do not active intervention apart from plaster or splinting, detection of these injuries is essential to prognosticate the outcome.

Resurfacing hip implants differ in macro- and microstructure. Manufacturing related parameters like clearance or carbon content influence the wear behaviour of these metal-on-metal bearings. The aim of this study was to analyse the main macro- and micro-structural differences of commercially available resurfacing hip implants.

Ten different commercially available resurfacing hip implant designs were included in this investigation:

- BHR^® (Smith& Nephew/MMT)

The heads and cups were measured in a coordinate measuring machine and radial clearance as well as sphericity deviation were calculated. Surface roughness measurements were carried out. The microstructures of the heads and cups were inspected using SEM and element analysis was performed using EDX to identify carbides and the alloy composition.

The mean radial clearance was found to be 85.53 μm. The range was from 49.47 μm (DePuy, ASR^®) to 120.93 μm (Biomet, ReCap^®). All implants showed a sphericity deviation of less than 10 μm. The highest sphericity deviation was found to be 7.3 μm (Corin Cormet^® head), while the lowest was 0.8 μm (Smith& Nephew BHR^® head). On average, the heads tended to have a higher sphericity deviation (4.1 μm, SD: 2.3 μm) compared to the cups (2.7 μm, SD: 1.4 μm). SEM revealed that most manufacturers use a high carbon alloy casting manufacturing process combined with heat treatment after casting (Corin Cormet^® and Wright Conserve^®: head and cup; DePuy ASR^®: cup; Eska BS^®: head).

Commercially available resurfacing hip implants differ in design and manufacturing parameters, including macro- and microstructure, which are critical in achieving low wear and ion release. This study was designed to aid in the understanding of clinical observations. Also, specific information is now available for surgeons choosing an implant designs.

Introduction

Problematic bone defects are encountered regularly in orthopaedic practice particularly in fracture non-union, revision hip and knee arthroplasty, following bone tumour excision and in spinal fusion surgery. At present the optimal source of graft to ‘fill’ these defects is autologous bone but this has significant drawbacks including harvest site morbidity and limited quantities.

Bone marrow has been proposed as the main source of osteogenic stem cells for the tissue-engineered cell therapy approach to bone defect management. Such cells constitute a minute proportion of the total marrow cell population and their isolation and expansion is a time consuming and expensive strategy.

In this study we investigated human bone marrow stem cells as a potential treatment of bone defect by looking at variability in patient osteogenic cell populations as a function of patient differences. We produced a model to predict which patients would be more suited to cell based therapies and propose possible methods for improving the quality of grafts.

1. The detailed anatomy and calcification of the upper half of the tibia in rabbits varying in age from six weeks to twelve months has been studied.

2. The structure of the bone varies at different levels, but a section taken from the same level in the tibia from animals of the same age presents a reasonably constant picture.

3. It has been shown that this variation in structure at different levels is directly related to a difference between the axis of growth and the bone axis. This difference is a result of the unique shape of the tibia.

4. Autoradiographic studies confirm the localised concentration of radioactive strontium in areas of active bone formation where uptake is rapid.

5. The long retention of radioactive strontium in the skeleton (that is, the slow turnover) is a result of the slowness of resorption of bone (endosteal, periosteal or Haversian) in the cortex. Not only is the process slow but it is extremely localised.

6. The significance of these anatomical and physiological characteristics in relation to radiation injury is discussed.

Purpose: To investigate the natural history and clinical outcomes of patients suffering from various stages of Kienbock’s disease (KD) in the NL population.

Method: The present study was a retrospective analysis of 66 patients (42 male and 24 female) diagnosed with KD. Following chart reviews of these patients, a telephone interview was conducted to acquire responses to the DASH questionnaire. All analyses were performed using SPSS for Windows (version 15.0), and significance was set at P10 years). Pearson correlation was used to assess for a correlation between DASH scores and age of diagnosis as well as radiographic stage of disease. Multivariate linear regression analysis was used to account for confounding factors.

Results: The average age of diagnosis was 38.8 ±11.6 (18–70), right wrist affected in 61.5% of cases and left in 38.5%. History of trauma was present in 25 cases. With respect to radiographic stage of KD at time of diagnosis, 6 cases were in stage I, 26 in stage II, 9 in stage IIIa, 16 in stage IIIb, 5 in stage IV, and 4 with unknown stage. Forty-eight patients were treated conservatively, while 18 surgically (7 following failed conservative treatment). Thirty-nine patients provided a response to the DASH questionnaire. There was no statistically significant difference in DASH scores between any of the groups according to time since first diagnosed. There was also no significant difference in DASH scores between surgically treated and conservatively treated patients, regardless of stage of KD. Nor was there any difference in DASH scores among surgical and conservatively treated patients when individual stages of KD were considered. Furthermore, because of low numbers within each KD stage, stage III and stage IV were combined. However, once again no significant difference was found between the surgical and conservative treatment modalities. Interestingly, a positive correlation was found between age of diagnosis and DASH score (r=0.42, p=0.007). Multivariate linear regression analysis showed that the correlations remained significant after accounting for the radiographic stage of KD, gender, and time since diagnosed (p=0.02).

Conclusion: No statistically significant difference in DASH scores were found between surgically treated and conservatively treated patients in the NL population with KD regardless of stage of disease. A positive association was found between age of diagnosis of KD and DASH score, even after accounting for gender, stage of disease, and time since diagnosis. This finding suggests that those patients’ who are diagnosed and treated for KD later in life, tend not to do as well as their younger counterparts.

Introduction: Percutaneous vertebroplasty (PVP) is a treatment option for osteoporotic vertebral compression fractures (VCFs). Short-term results are promising but longer-term studies have demonstrated an accelerated failure rate in the adjacent vertebral body (VB). Limited research has been conducted into the effects of prophylactic PVP in osteoporotic vertebrae. The objective of this study was to investigate the biomechanical characteristics of prophylactic vertebral reinforcement and post-fracture augmentation.

Methods: Human vertebrae were assigned to two scenarios: Scenario 1 used an experimental model for simulating VCFs followed by cement augmentation; Scenario 2 involved prophylactic augmentation using vertebroplasty. μCT imaging was performed to assess the bone mineral density (BMD), vertebral dimensions, fracture pattern and cement volume. All augmented VBs were then axially compressed to failure.

Results: Product of BMD value and endplate surface area gave the best prediction of failure strength when compared to actual failure strength of specimens in scenario 1. Augmented VBs showed an average cement fill of 23.9%±8.07% S.D.. In scenario 1, there was a significant post-vertebroplasty factorial increase of 1.72 and in scenario 2 a 1.38 increase in failure strength. There was a significant reduction in stiffness following augmentation for scenario 1 (t=3.5, P=0.005). Stiffness of the VB in scenario 2 was significantly greater than observed in scenario 1 (t=4.4, P=0.0002).

Discussion: Results suggest that augmentation of the VB post-fracture significantly increases failure load, whilst stiffness is not restored. Prophylactic augmentation was seen to increase failure strength in comparison to the predicted failure load. Stiffness appears to be maintained suggesting that prophylactic PVP maintains stiffness better than PVP post-fracture.

To evaluate in-vivo the effectiveness of the double bundle technique for Anterior Cruciate ligament (ACL) reconstruction in restoring knee rotational stability under varying dynamic loading conditions.

The study group included 10 patients who underwent double-bundle ACL reconstruction with hamstrings tendon autograft, 12 patients with single-bundle reconstruction, 10 ACL deficient subjects and 12 healthy control individuals. Kinematic and kinetic data were collected using an 8-camera optoelectronic motion analysis system and one force plate. Knee rotational stability was examined during two maneuvers: a combined 60o pivoting turn and immediate stairs ascend and a combined stairs descend and immediate 60o pivoting maneuver. The two factors evaluated were the maximum

There were no significant differences in tibial rotation between the four groups in the examined maneuvers. Tibial rotation in the single- and the double-bundle groups were even lower than the control group. Rotational moments did not differ significantly between the four groups in any of the examined maneuvers. In general, rotational moments in the affected side of the ACL reconstructed and deficient groups were found reduced compared to the unaffected side.

Double-bundle reconstruction does not reduce knee rotation further compared to the single-bundle technique during dynamic stability testing under varying conditions. The injured side of ACL reconstructed or deficient individuals is exposed to substantially lower rotational moment compared to the intact side.

Background: Acute traumatic rupture of the Tendo-Achilles is a common problem. Review of the published literature shows a conflict between surgical and non-surgical management. Primarily, surgical treatment has repeatedly been shown to have a lower re-rupture rate compared with conservative treatment. However, it is associated with a higher rate of other complications, principally infective soft tissue complications. Debate concerning the method and duration of conservative treatment regimens also remains.

Methods: We aimed to assess the effect of knee position on the gap in acute tendo-Achilles ruptures. Our null hypothesis was there is no difference in tendon gap with variation of knee position. Patients with a history and examination consistent with an acute rupture were collected prospectively. They were imaged by the same consultant musculoskeletal consultant radiologist using ultrasound. Tendon gap was measured with the foot in neutral and full tolerable equinus with the knee both flexed to 90° and fully extended. A pilot study of 10 patients was used to provide data for a power calculation and consequently a total of 25 patients were recruited.

Results: All patients had their clinical diagnosis confirmed and tendon gap measured in each of the 4 positions. A paired t-test was used to compare mean differences between each position. This confirmed there was no significant difference in the tendon gap with the knee flexed or extended providing the foot is in full equinus. This may have considerable implications on the rationale behind conservative treatment and splinting of acute tendo-Achilles ruptures.

The giant cell tumor of bone (GCT) is a locally aggressive intraosseous neoplasm, with an uncertain biological behavior, constituted of giant multinuclear cells spread over tumoral tissue with a nucleus presenting the same features of the ovoid and fusiform cells forming its stroma. The local recurrence of GCT is often observed, mainly in the first three years after treatment, giving a rate of recurrence ranging in 20 to 50% of cases. Further aggravating the recurrence is the fact that after the relapse, the patient often also presents metastases in other organs.

The aim of this study was to identify and to characterize differentially expressed genes that can be used in the prognostic, treatment and understanding of this physiopathology. To identify novel genes differentially expressed in GCT, we have applied rapid subtractive hybridization (RaSH). Samples of GCT and normal tissues were obtained at Tumor Bank of Barretos Cancer Hospital. After RNA extraction and cDNA synthesis the samples were submitted to Rapid hybridization Subtraction (RaSH) methodology for subtractive libraries elaboration.

The RaSH subtractive libraries reveals the presence of 619 different clones including both normal and tumor tissues were identified. Of these, 450 in tumor sample and 169 in control tissue. Four biomarkers candidates were selected for validation: ZAK, KTN1, NEB, and ROCK1 genes, whose functions are, related to cell cycle checkpoint, transport of organelles, cytoskeletal matrix and cell adhesions. The validation of selected differentially expressed genes was performed using real time PCR. The putative molecular markers found in this work may help to find the basis for a molecular comprehension of GCT, thus improving diagnosis, treatment and outcome for patients with this tumor.

The first Ceramic knee implant in a human patient was used by Dr. G. Langer of the Orthopedic Clinic at the University of Jena, Germany in 1972 [1]. In 1980, Drs. Oonishi and Hasegave began using a Alumina femoral component on a polyethylene tibial component [2]. These early attempts all involve the search for solutions to the wear and degradation problems. The application of ceramics was limited by the demand of thin components. In the present feasibility study the in vitro wear behavior of a knee concept with a novel Alumina Matrix Composite (AMC) Ceramic was examined [3,4].

The wear behavior of the Ceramic components for the knee system were tested in accordance to ISO/WD 14243-3 for 5*106 cycles. Six samples were tested. The lubricant was calf serum diluted with deionized water. All tests have been performed with components made of the novel AMC Ceramic.

The wear test performed showed an average gravimetric wear rate below 1 mg/1*106 cycles on each of the six components. A change of geometry was not measurable after 5 million cycles. No significant change of the surface structure was detectable with a conventional surface tracer. SEM and AFM pictures show traces of ultra mild abrasive wear at the surface. The performed investigation on the novel knee concept shows the following potential benefits for a Ceramic knee bearing:

approx. 500 times lower volumetric wear

The novel AMC Ceramic offers a solution to minimize the allergic and wear related problems of knee implants. New concepts on the basis of hard on hard combination are to be realized. The use of knee endo-prosthesis with Ceramic on Ceramic combination is an option for îzeroî wear bearings in the knee. These first results motivate to start further R& D on Ceramic on Ceramic bearings for total knee implants.

The first Ceramic knee implant in a human patient was used by Dr. G. Langer of the Orthopedic Clinic at the University of Jena, Germany in 1972 [1]. In 1980, Drs. Oonishi and Hasegave began using an Alumina femoral component on a polyethylene tibial component [2]. These early attempts all involve the search for solutions to the wear and degradation problems. The application of ceramics was limited by the demand of thin components. In the present feasibility study the in vitro wear behavior of a knee concept with a novel Alumina Matrix Composite (AMC) Ceramic was examined [3,4].

The wear behaviour of the Ceramic components for the knee system were tested in accordance to ISO/WD 14243-3 for 5*106 cycles. Six samples were tested. The lubricant was calf serum diluted with deionized water. All tests have been performed with components made of the novel AMC Ceramic. The wear test performed showed an average gravimetric wear rate below 1 mg/1*106 cycles on each of the six components. A change of geometry was not measurable after 5 million cycles. No significant change of the surface structure was detectable with a conventional surface tracer. SEM and AFM pictures show traces of ultra mild abrasive wear at the surface.

The performed investigation on the novel knee concept shows the following potential benefits for a Ceramic knee bearing:

approx. 500 times lower volumetric wear

The novel AMC Ceramic offers a solution to minimize the allergic and wear related problems of knee implants. New concepts on the basis of hard on hard combination are to be realized. The use of knee endoprosthesis with Ceramic on Ceramic combination is an option for ”zero” wear bearings in the knee. These first results motivate to start further R& D on Ceramic on Ceramic bearings for total knee implants.

To assess the percentage of patients with an osteoporotic distal radial fracture who had any subsequent investigation or treatment for osteoporosis, and to compare this to the gold standard, all patients seen in a hospital fracture clinic with an osteoporotic fracture should be advised of the possibility of osteoporosis and their primary care team informed of the need for follow-up (Royal College of Physicians, National Osteoporosis Society and The Advisory Group on Osteoporosis).

All patients over 50 years old who sustained a distal radial fracture and a subsequent fractured neck of femur after simple falls, over a 7-year period, were included. Evidence of any treatment for, or investigation of, osteoporosis between the initial radial fracture and subsequent neck of femur fracture was recorded.

74 patients met the above criteria. 7 male and 67 female, median age 83 (54 to 99). Eight percent of cases were on treatment for osteoporosis at time of first fracture. A further 8% had evidence of treatment for, or investigation of, osteoporosis commenced by time of their 2nd fracture. 84% of patients received no advice, investigation or treatment.

As orthopaedic surgeons we have a duty to inform the primary care team of the need to follow-up patients with osteoporotic fractures. There is a significant cost benefit both to the patient and the health service. We aim to introduce a system whereby a letter is automatically sent to the GP informing them that their patient has been seen in fracture clinic with an osteoporotic distal radial fracture. The letter will also advise them of the current Royal College and Government guidelines on investigation and treatment of osteoporosis. We aim to repeat the audit cycle after a 5-year period with the new system in place.

Osteoarthritis of the hip exhibits progressive degeneration of articular cartilage frequently resulting in total hip arthroplasty (THA). Expression of cytokines such as tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL6) is increased in the synovium and articular cartilage of these patients. Furthermore, these cytokines have been shown to have a negative regulatory effect on chondrocyte proliferation and articular cartilage metabolism. We investigated the frequency of a G/C polymorphism at position −174 of the promoter region of the IL-6 gene and a G/A polymorphism at position −308 of the TNF alpha gene, both of which cause increased expression of these cytokines. We observed that the G variant of the IL6 gene was significantly higher in patients who had undergone revision THA compared to controls (P=0.05). It was also elevated in primary THA patients compared to controls. The G/A polymorphism in TNF alpha was not significantly associated with THA; however, this may reflect the lower incidence of this polymorphism in the population. These results suggest that an alteration in cytokine expression produced by the IL6 −174G/C mutation may have a role in the aetiology of osteoarthritis and the outcome of total hip arthroplasty.