The aim of this study was to compare outcomes after growth-friendly treatment for early-onset scoliosis (EOS) between patients with skeletal dysplasias versus those with other syndromes. We retrospectively identified 20 patients with skeletal dysplasias and 292 with other syndromes (control group) who had completed surgical growth-friendly EOS treatment between 1 January 2000 and 31 December 2018. We compared radiological parameters, complications, and health-related quality of life (HRQoL) at mean follow-up of 8.6 years (SD 3.3) in the dysplasia group and 6.6 years (SD 2.6) in the control group.Aims
Methods
Disability and slow return to sport and work after tendon rupture are major challenges. Platelet Rich Plasma (PRP) is an autologous supraphysiological concentration of platelets from whole blood that has demonstrated positive cellular and physiological effects on healing in laboratory conditions but evidence from adequately powered robust clinical trials is lacking. We aimed to determine the clinical efficacy of PRP for treatment of acute Achilles tendon rupture. In a placebo-controlled, participant- and assessor-blinded, trial at 19 NHS hospitals we randomly assigned 230 adults starting acute Achilles rupture non-surgical management to PRP injection or dry-needle insertion (placebo) to the rupture gap under local anaesthetic. Patients with confounding or contraindicated concurrent medical conditions were excluded. The primary outcome was muscle-tendon function, assessed by the limb symmetry index (LSI, uninjured limb/injured limb × 100, higher scores better) of the work (Joules) performed during the heel-rise endurance test at 24 weeks. Secondary outcomes were: Achilles Tendon Rupture Score (ATRS, 0–100, higher scores better), quality of life (SF-12), pain, and goal attainment. Trial registration: ISRCTN54992179Background
Methods
Management of deformity involving limb length discrepancy (LLD) using intramedullary devices offers significant benefits to both patients and clinicians over traditional external fixation. Following the withdrawal of the PRECICE nail, the Fitbone became the primary implant available for intramedullary lengthening and deformity correction within our service. This consecutive series illustrates the advantages and complications associated with the use of this device, and describes a novel technique modification for antegrade intramedullary lengthening nails. A retrospective cohort review was performed of patient outcomes after treatment with the Fitbone nail at two tertiary referral limb reconstruction services (one adult, one paediatric) between January 2021 to December 2023. Aetiology, indications, initial and final LLD, use of concomitant rail assisted deformity correction (ORDER), removal time and healing index were assessed. Complications of treatment were evaluated and described in detail, alongside technique modifications to reduce the rate of these complications.Introduction
Materials & Methods
In 2021 the bone grafting market was worth €2.72 billion globally. As allograft bone has a limited supply and risk of disease transmission, the demand for synthetic grafting substitutes (BGS) continues to grow while allograft bone grafts steadily decrease. Synthetic BGS are low in mechanical strength and bioactivity, inspiring the development of novel grafting materials, a traditionally laborious and expensive process. Here a novel BGS derived from sustainably grown coral was evaluated. Coral-derived scaffolds are a natural calcium carbonate bio-ceramic, which induces osteogenesis in bone marrow mesenchymal stem cells (MSCs), the cells responsible for maintaining bone homeostasis and orchestrating fracture repair. By 3D printing MSCs in coral-laden bioinks we utilise high throughput (HT) fabrication and evaluation of osteogenesis, overcoming the limitations of traditional screening methods. MSC and coral-laden GelXA (CELLINK) bioinks were 3D printed in square bottom 96 well plates using a CELLINK BIO X printer with pneumatic adapter Samples were non-destructively monitored during the culture period, evaluating both the sample and the culture media for metabolism (PrestoBlue), cytotoxicity (lactose dehydrogenase (LDH)) and osteogenic differentiation (alkaline phosphatase (ALP)). Endpoint, destructive assays used included qRT-PCR and SEM imaging. The inclusion of coral in the printed bioink was biocompatable with the MSCs, as reflected by maintained metabolism and low LDH release. The inclusion of coral induced osteogenic differentiation in the MSCs as seen by ALP secretion and increased RUNX2, collagen I and osteocalcin transcription. Sustainably grown coral was successfully incorporated into bioinks, reproducibly 3D printed, non-destructively monitored throughout culture and induced osteogenic differentiation in MSCs. This HT fabrication and monitoring workflow offers a faster, less labour-intensive system for the translation of bone substitute materials to clinic.
Children with osteogenesis imperfecta (OI) frequently present with coxa vara (CV). Skeletal fragility, severe deformity and limited fixation options make this a challenging condition to correct surgically. Our study aimed to determine the efficacy of the Fassier technique to correct CV and determine the complication rate. Retrospective, descriptive case series from a tertiary hospital. We retrospectively reviewed records of a cohort of eight children (four females, 12 hips) with OI (6/8 Sillence type III, 2/8 type IV) who had surgical treatment with Fassier technique for CV between 2014 and 2020. Inclusion Criteria: All patients with CV secondary to OI treated surgically with Fassier technique. Exclusion Criteria: Patients older than 18 years; Patients with CV treated non-operatively or by surgical technique different to Fassier technique. Data relating to the following parameters was collected and analyzed: demographic data, pre- and postoperative neck shaft angle (NSA), complications and NSA at final follow-up. The mean age at operation was 5.8 years (range 2–10). The mean NSA was corrected from 96.8° preoperatively to 137º postoperatively. At a mean follow-up of 38.6 months, the mean NSA was maintained at 133°, and 83% (10/12) of hips had an NSA that remained greater than 120°. There was a 42% (5/12) complication rate: three Fassier–Duval rods failed to expand after distal epiphyseal fixation was lost during growth; one Rush rod migrated through the lateral proximal femur cortex with recurrent coxa vara; and one Rush rod migrated proximally and required rod revision. The Fassier technique effectively corrected CV in children with moderate and progressively deforming OI. The deformity correction was maintained in the short term. The complication rate was high, but mainly related to the failed expansion of the Fassier–Duval rods.
Osteochondral allograft (OCA) transplantation is a clinically and cost-effective option for symptomatic cartilage defects. In 2017 we initiated a program for OCA transplantation for complex chondral and osteochondral defects as a UK tertiary referral centre. To characterise the complications, re-operation rate, graft survivorship and clinical outcomes of knee OCA transplantation.Abstract
Background
Aim
The Montgomery ruling advocates patients be informed of ‘material risks’ of a procedure. With no guidelines for patients wishing to return to high activity levels after knee arthroplasty, we explore patient and surgeon perceptions in climbers. Ethical approval was granted by the University of Central Lancashire. Anonymous questionnaires were sent via email and social media to consultant knee arthroplasty surgeons and to climbers/mountaineers across the UK. Consultants were asked about advice given for patients who participate in climbing. Climbers were asked about their experiences of knee arthroplasty and return to activity. Of 33 knee arthroplasty surgeons, 11(33%) were firmly against any return to climbing, 10(30%) counselled against it, and 12(36%) were open to return to previous activity. Of 11(33%) surgeons who do not gather information about levels of climbing, 8 would not provide specific advice regarding risks of returning to sport. Of 28 climbers, only 5(18%) were informed to cease completely, with 11(39%) cautioned against and 12(43%) permitted to return. There was no correlation between the advice received and climbing ability post-operatively, (kappa=0.143,p=0.058), with a substantial agreement between ability 1-year post-operatively and currently, (kappa=0.689,p<0.001). There is a discrepancy between the advice given and received by climbers/mountaineers prior to knee arthroplasty, with ability post-operatively having no relationship to advice given. Climbing is possible at high level with no reported complications following knee arthroplasty. The 1-year time point is predictive of longer-term outcome. This information should help surgeons better inform their patients preoperatively.Abstract
Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMD. 119 patients were randomized to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years comparing the unoperated contralateral femur as a control. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7) whilst the anatomic and triple taper stem declined in this region, however this was not statistically significant (p = 0.059). BMD decreased on average by 2.1% in the mid-diaphysis region, distal to the stem tip (zone 4) for all implants. All stems performed equivalently at final follow-up in all patient reported outcome measures. Implant design was shown to impact BMD changes. All stems preserved bone at the metaphyseal level in early follow-up, which theoretically indicates favorable implant fixation. There was no significant stress shielding observed, however longer follow-up is required to elucidate the impact of this finding on implant survivorship.
Climbers and mountaineers will present to arthroplasty surgeons in need of hip replacement surgeries. There is a lack of guidance for both parties with a paucity in the literature. Climbing is often considered a high-risk activity to perform with a total hip replacement, due to the positions the hip is weighted in, and the potential austere environment in which an injury may occur. The aim was to assess levels of climbing and mountaineering possible following hip arthroplasty, and any factors affecting these levels. Ethical approval was obtained from the University of Central Lancashire. An anonymous online questionnaire was disseminated via email, social media and word-of-mouth to include all climbers, hill-walkers or mountaineers across the UK. This was used to collect climbing and mountaineering ability at various timepoints, along with scores such as the Oxford Hip Score and UCLA Score. The Kappa statistic was used to assess for correlations. Of the responders, 28 had undergone right hip arthroplasty surgery, with 11 having left hips and 22 receiving bilateral hips. A total of 67 of the replaced hips were total hip replacements, with 16 having undergone hip resurfacing. There is a fair agreement in level of climbing ability 3 months pre- and 3 months post-operatively (kappa=0.287, p<0.001), and a substantial agreement between 1 year post-operatively and currently for both climbing (kappa=0.730, p<0.001) and mountaineering (kappa=0.684, p<0.001). Impressively, 17 participants are climbing at more than E1 trad or 6c sport at one or more time points post operatively, which is regarded as an advanced level within the climbing community. Out of those 17 participants, 8 were climbing at this level within 3 months post-operatively. The level of climbing possible following hip arthroplasty surgery is above what is expected and perhaps desired by the operating surgeon. It is essential to take the individual patient into account when planning an operative intervention such as arthroplasty. The one year post-operative time point is highly predictive of longer term outcomes for both climbing and mountaineering.
Circular external fixators are fundamental to lower limb reconstruction, primarily in situations with a high risk of infection such as open fractures. During the Covid-19 pandemic, use of circular frames in our unit decreased, following departmental approval, due to resource management and in keeping with BOA guidelines as we opted to “consider alternative techniques for patients who require soft tissue reconstruction to avoid multiple operations”. These alternatives included the use of internal fixation (plate osteosynthesis and intramedullary nailing) as a measure to reduce the number of hospital attendances for patients and to conserve resources. This change in practice has continued in part following the pandemic with the increased use of internal fixation in cases previously deemed unsuitable for such techniques. We present our experience of this treatment strategy in the management of complex lower limb injuries, focusing on outcomes and consider the lessons learnt. Data of patients with complex lower limb injuries treated before, during and after the pandemic were collected from our in-house trauma database, theatre records and follow up clinics. The rationale for choosing other techniques over a circular frame, the type of alternative technique used, the cost of such alternatives, the need for soft tissue reconstruction, time to recovery, complications and amputation rates were compared among groups.Introduction
Materials & Methods
Autologous cancellous bone graft is the gold standard in large bone defect repair. However, studies using autologous bone grafting in rats are rare and donor sites as well as harvesting techniques vary. The aim of this study was to determine the feasibility of autologous cancellous bone graft harvest from 5 different anatomical sites in rats and compare their suitability as donor sites for autologous bone graft. 13 freshly euthanised rats were used to describe the surgical approaches for autologous bone graft harvest from the humerus, iliac crest, femur, tibia and tail vertebrae (n=4), determine the cancellous bone volume and microstructure of those five donor sites using µCT (n=5), and compare their cancellous bone collected qualitatively by looking at cell outgrowth and osteogenic differentiation using an ALP assay and Alizarin Red S staining (n=4). It was feasible to harvest cancellous bone graft from all 5 anatomical sites with the humerus and tail being more surgically challenging. The microstructural analysis showed a significantly lower bone volume fraction, bone mineral density, and trabecular thickness of the humerus and iliac crest compared to the femur, tibia, and tail vertebrae. The harvested volume did not differ between the donor sites. All donor sites apart from the femur yielded primary osteogenic cells confirmed by the presence of ALP and Alizarin Red S stain. Bone samples from the iliac crest showed the most consistent outgrowth of osteoprogenitor cells. The tibia and iliac crest may be the most favourable donor sites considering the surgical approach. However, due to the differences in microstructure of the cancellous bone and the consistency of outgrowth of osteoprogenitor cells, the donor sites may have different healing properties, that need further investigation in an in vivo study.
Variations in component positioning of total hip replacements can lead to edge loading of the liner, and potentially affect device longevity. These effects are evaluated using ISO 14242:4 edge loading test results in a dynamic system. Mediolateral translation of one of the components during testing is caused by a compressed spring, and therefore the kinematics will depend on the spring stiffness and damping coefficient, and the mass of the translating component and fixture. This study aims to describe the sensitivity of the liner plastic strain to these variables, to better understand how tests using different simulator designs might produce different amounts of liner rim deformation. A dynamic explicit deformable finite element model with 36mm Pinnacle metal-on-polyethylene bearing geometry (DePuy Synthes, Leeds, UK) was used with material properties for conventional UHMWPE. Setup was 65° clinical inclination, 4mm mismatch, 70N swing phase load, and 100N/mm spring. Fixture mass was varied from 0.5-5kg, spring damping coefficient was varied from 0-2Ns/mm. They were changed independently, and in combination. Maximum separation values were relatively insensitive to changes in the mass, damping coefficient, or both. The sensitivity of peak plastic strain, to this range of inputs, was similar to changing the swing phase load from 70N to approximately 150N – 200N. Increasing the fixture mass and/or damping coefficient increased the peak plastic strain, with values from 0.15-0.19. Liner plastic deformation was sensitive to the spring damping and fixture mass, which may explain some of the differences in fatigue and deformation results in UHMWPE liners tested on different machines or with modified fixtures. These values should be described when reporting the results of ISO14242:4 testing. Acknowledgements Funded by EPSRC grant EP/N02480X/1; CAD supplied by DePuy Synthes.
Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMDMethods: 119 patients were randomised to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. All surgeries were performed via the posterior approach with mobilization on the day of surgery. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years and compared to the unoperated contralateral femur as a control. Patient reported outcome measures of pain, function and health were also included at these corresponding follow-ups. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7) whilst the anatomic and triple taper stem declined in this region, however this was not statistically significant (p = 0.059). BMD decreased on average by 2.1% inthe mid-diaphysis region, distal to the stem tip (zone 4) for all implants. All stems performed equivalently at final follow-up in all patient reported outcome measures. This study demonstrated maintenance of femoral BMD in three different cementless femoral stem designs, with all achieving excellent improvements in patient reported outcomes. There was no significant stress shielding observed, however longer follow-up is required to elucidate the impact of this finding on implant survivorship.
Thumb carpometacarpal joint (CMCJ) arthritis is a common and debilitating condition. The mainstay of surgical management is Trapeziectomy. Concerns about possible functional implications of collapse of the metacarpal into the arthroplasty space as well as the potential for scaphometacarpal led to the development of techniques to try and prevent this. The purpose of this study was to investigate if there were any significant differences in the long-term outcomes of patients who participated in a randomized trial of trapeziectomy alone compared with trapeziectomy with ligament reconstruction and tendon interposition (LRTI). Sixty-five patients participated in our original trial, the 1 year findings of which were published in 2007. These patients were invited for a follow-up visit at a mean of 17 years (range 15–20) postoperatively. Twenty-eight patients attended, who had 34 operations, 14 trapeziectomy alone and 20 with LRTI. Patients were asked to complete a visual analogue scale (VAS) for satisfaction with the outcome of their procedure, rated on a scale from 0 (most dissatisfied) to 100 (most satisfied). They also completed the short version of the Disabilities of the Arm, Shoulder and Hand Score (QuickDASH) at their appointment. They underwent a functional assessment with a hand therapist and had a radiograph of the thumb. There were no statistically significant differences between the two groups in terms of satisfaction with surgery or functional outcomes, with most measurements showing minimal or no differences in means between the two groups. There was no difference in the space between the metacarpal and scaphoid on radiograph. Radial abduction was the only parameter that was significantly greater in the patients with simple trapeziectomy (median 79°) compared with trapeziectomy with LRTI (median 71°) (p = 0.04). Even at 17 years there is no significant benefit of LRTI over trapeziectomy alone for thumb carpometacarpal joint osteoarthritis.
Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a severe complication in terms of disability, morbidity, and cost. We performed a study to investigate whether early PJI (within 90 days of primary TKA) is associated with increased mortality. Secondary aims were to compare mortality rates over time and between surgical treatment methods. Patients with suspected PJI were identified by linkage of the Swedish Knee Arthroplasty Register (SKAR) and the Swedish Prescribed Drug Register (SPDR) in 2007–2008 and 2012–2013. Medical records of patients receiving more than 4 weeks of continuous antibiotic therapy were subsequently reviewed to verify the PJI diagnosis. Information on mortality was obtained through the SKAR which is updated daily from the tax agency and patients with PJI were compared to patients without PJI.Background
Methods
To achieve expert clinical consensus in the delivery of hydrodilatation for the treatment of primary frozen shoulder to inform clinical practice and the design of an intervention for evaluation. We conducted a two-stage, electronic questionnaire-based, modified Delphi survey of shoulder experts in the UK NHS. Round one required positive, negative, or neutral ratings about hydrodilatation. In round two, each participant was reminded of their round one responses and the modal (or ‘group’) response from all participants. This allowed participants to modify their responses in round two. We proposed respectively mandating or encouraging elements of hydrodilatation with 100% and 90% positive consensus, and respectively disallowing or discouraging with 90% and 80% negative consensus. Other elements would be optional.Aims
Methods
The association between body mass index (BMI) and venous thromboembolism (VTE) is well studied, but remains unclear in the literature. We aimed to determine whether morbid obesity (BMI≥40) was associated with increased risk of VTE following total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA), compared to those of BMI<40. Between January 2016 and December 2020, our institution performed 4506 TKAs and 449 UKAs. 450 (9.1%) patients had a BMI≥40. CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE) and ultrasound scan for suspected proximal deep vein thrombosis (DVT) were recorded up to 90 days post-operatively.Abstract
Aims
Methods
Meniscal allograft transplantation (MAT) for patients with symptomatic meniscal loss has demonstrated good clinical results and survivorship. Factors that affect both functional outcome and survivorship have been reported in the literature. These are typically single-centre case series with relatively small numbers and conflicting results. Our aim was to describe an international, two-centre case series, and identify factors that affect both functional outcome and survival. We report factors that affect outcome on 526 patients undergoing MAT across two sites (one in the UK and one in Italy). Outcomes of interest were the Knee injury and Osteoarthritis Outcome Score four (KOOS4) at two years and failure rates. We performed multiple regression analysis to examine for factors affecting KOOS, and Cox proportional hazards models for survivorship.Aims
Methods
Traditionally, limb reconstruction physiotherapy consisted of face to face group rehabilitation. During the COVID-19 pandemic OP physiotherapy service provision was significantly reduced and delivery methods limited due to staff redeployment, service prioritisation and restriction of footfall within the hospital. A virtual exercise group for acute limb reconstruction patients was set up to maintain contact and clinical support. A small single centre study was performed over two 4 week periods capturing the experience of 35 patients. A patient reported questionnaire was used and revised post-pandemic to gather quantitative and qualitative data about the patients experience of the Limb Reconstruction Physiotherapy Service at each point in time. The qualitative data was analysed using an inductive thematic analysis.Introduction
Materials and Methods
The jackaling position within rugby has not been previously described as a mechanism for proximal hamstring injuries. This prospective single surgeon study included 54 professional rugby players (mean age 26 ± 4.8 years) undergoing acute primary surgical repair of complete, proximal hamstring avulsion injuries confirmed on preoperative magnetic resonance imaging. All study patients underwent a standardised postoperative rehabilitation programme. Predefined outcomes were recorded at regular intervals. Mean follow-up time was 17 months (range, 12 months to 24 months) from date of surgery. 51 patients (94.4%) returned to their pre-injury level of sporting activity. Mean time from surgical repair to full sporting activity was 7 months (range, 4 months to 12 months). Zero patients had recurrence of the primary injury. At 1 year after surgery compared to 3 months after surgery, patients had increased mean isometric hamstring muscle strength at 0° (98.4 ± 2.8% vs 88.1% ± 5.4%, p<0.001), 15° (95.9 ± 2.9 vs 88.2 ± 8.1%, p<0.001) and 45° (92.9% ± 4.1% vs 76.8% ± 9.7%, p<0.001), higher mean lower extremity functional scores (77.0 ± 2.3 vs 64.5 ± 4.5, p<0.001), and improved Marx activity rating scores (14.3 ± 1.5 vs 10.7 ± 2.6, p<0.001). Acute surgical repair of proximal hamstring avulsion injuries caused by the contact jackaling position produces high patient satisfaction, high return to preinjury level of sporting activity, with low risk of recurrence at short-term follow-up.
Strenuous efforts to minimize postoperative infection rates have been made, including the Swedish nation-wide initiative Prosthesis Related Infections Shall be Stopped (PRISS). The aim of this study was to calculate the incidence rate of periprosthetic joint infections (PJI) following primary total knee arthroplasty (TKA) before and after PRISS. All 45,438 primary TKAs registered in the Swedish knee arthroplasty register (SKAR) during 2007–2008 and 2012–2013 were included. Matched data on antibiotic prescriptions were obtained from the Swedish Prescribed Drug Register (SPDR). All patients with ≥28 days of continuous antibiotic treatment within 2 years of primary surgery had their medical charts reviewed to identify cases of PJI.Aim
Method
Pelvic tilt (PT) can significantly change the functional orientation of the acetabular component and may differ markedly between patients undergoing total hip arthroplasty (THA). Patients with stiff spines who have little change in PT are considered at high risk for instability following THA. Femoral component position also contributes to the limits of impingement-free range of motion (ROM), but has been less studied. Little is known about the impact of combined anteversion on risk of impingement with changing pelvic position. We used a virtual hip ROM (vROM) tool to investigate whether there is an ideal functional combined anteversion for reduced risk of hip impingement. We collected PT information from functional lateral radiographs (standing and sitting) and a supine CT scan, which was then input into the vROM tool. We developed a novel vROM scoring system, considering both seated flexion and standing extension manoeuvres, to quantify whether hips had limited ROM and then correlated the vROM score to component position.Aims
Methods
The Exeter™ V40 cemented polished tapered stem system has demonstrated excellent long-term outcomes. This paper presents a systematic review of the existing literature and reports on a large case series comparing implant fractures between the Exeter V40 series; 125 mm and conventional length stem systems. A systematic literature search was performed adhering to PRISMA criteria. In parallel we performed a retrospective single centre study of Exeter™ V40 femoral stem prosthetic fractures between April 2003– June 2020. There are 25 reported cases of such prosthetic fractures confined to small case series and case reports within the literature. We report an additional 19 cases to the literature (mean age 66.3 ± 11.7 years; 12 female [63%]; body mass index 32.9 ± 5.9 kg/m2). The mean time from index procedure to fracture was 7.8 years (2.5–16.3, ±3.6). Exeter V40 stem fracture incidence was 0.27%. Incidence was significantly higher in 125 mm length stems compared to ≥150 mm length stems (1.26% vs 0.13%, respectively, p <0.001) and revision arthroplasty (1.209% vs 0.149%, p <0.001). When comparing different stem length cohorts, 125-mm short-stem were associated with stem body fractures (92% vs 29%, p = 0.0095), earlier time to fracture (6.2 vs 11.0 years, p = 0.0018), younger patient age at time of fracture (62.7 vs 72.6 years old, p = 0.037) and female sex (75% vs 43%, p = 0.33). This case series in conjunction with the systematic review provides evidence stem morphology plays a role in femoral implant fracture. This complication remains rare, although we report a significantly higher incidence at up to 17 years follow-up than in the literature. As femoral geometries remain the same, increasing BMIs in THR patients should raise concern. Short 125 mm length Exeter V40 stems undoubtedly have a role in restoring anatomy and biomechanics in smaller femoral geometries, although the surgeon has to appreciate the higher risk of stem fracture and the associated predisposing factors which may necessitate meticulous surgical technique and planning.
The Exeter V40 cemented polished tapered stem system has demonstrated excellent long-term outcomes. This paper presents a systematic review of the existing literature and reports on a large case series comparing implant fractures between the Exeter V40 series; 125 mm and conventional length stem systems. A systematic literature search was performed adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. In parallel, we performed a retrospective single centre study of Exeter V40 femoral stem prosthetic fractures between April 2003 and June 2020.Aims
Methods
Although 80% of fractures typically heal without any problems, there is a small proportion (<20%) that suffer complications such as delayed healing and potential progression to non-union. In patients with healing complications, the coordinated regulation between pro- and anti-inflammatory cytokines, such as interleukin-1β (IL-1β) and interleukin-1 receptor antagonist (IL-1Ra) respectively, is often dysregulated. The aim of this study is to develop a therapeutic strategy based on the local delivery of genes to reparative mesenchymal stromal cells (MSCs) migrating into the local fracture microenvironment, thereby promoting a more favourable healing environment to enhance fracture repair. Our approach involves the local delivery of nanoparticles complexing the non-viral vector polyethyleneimine (PEI) with therapeutic plasmid DNA (pDNA) encoding for IL-1Ra. pDNA encoding green fluorescent protein and Gaussia luciferase were used as reporter genes to determine the transfection efficiency of both rat and human MSCs using flow cytometry and to assess the transgene expression profile using a luciferase expression assay. The effect of transfection with PEI on the viability of MSCs was assessed using the metabolic assay Cell Titer Blue and dsDNA quantification. Levels of IL-1Ra produced by cells following transfection with nanoparticles encoding IL-1Ra was assessed using enzyme-linked immunosorbent assays (ELISA). HEK-Blue IL-1β reporter cells, which secrete alkaline phosphatase in response to IL-1β stimulation, were used to confirm that the IL-1Ra produced by transfected cells is functionally active, i.e. the successful antagonism of IL-1β bioactivity. We have determined that using PEI-based nanoparticles we can achieve a transfection efficiency of 14.8 + 1.8% in rat MSCs. Transgene expression was found to be transient, with a peak in expression at 7 days post-transfection and a gradual decrease over time, which was maintained for up to 4 weeks. Using an optimized concentration of PEI, the impact of the nanoparticles on MSC viability was limited, with no significant difference in cellular metabolic activity compared to non-transfected cells at 10 days post-transfection. We have additionally demonstrated the capacity to successfully transfect both rat and human MSCs with pDNA encoding for IL-1Ra, resulting in enhanced levels of IL-1Ra, which is functionally active. The use of non-viral gene therapy to locally deliver immunomodulatory genes, such as IL-1Ra, to MSCs presents a promising strategy to enhance bone healing. Specifically, the transgene expression levels achieved with such an approach can remain therapeutically effective and are transient in nature, presenting an advantage over other methods such as recombinant protein delivery and viral-based gene delivery methodologies.
Scoliosis is estimated to occur between 21–64% of patients with cerebral palsy (CP), where a subset of patients develops early onset scoliosis (EOS) before the age of ten. Traditional growth friendly (TGF) surgeries in the context of traditional growing rods have been shown to be effective in treating scoliosis in this population, however significant complication rates are reported. Currently, no studies have been done to examine the effect of novel growth friendly surgeries such as magnetically controlled growing rods (MCGR) on EOS in CP patients. The objective of this study is to compare MCGR with TGF surgeries in this patient population, specifically by evaluating radiographic measurements and risk of unplanned reoperations (UPRORs). Patients with EOS secondary to CP were prospectively identified from an international database, with data retrospectively analyzed. Scoliosis (primary curve), maximum kyphosis, T1-S1 and T1-T12 height were measured pre-operation, immediate post-operation, and at two-years follow-up. The risk and etiology of UPRORs were compared between MCGR and TGF. P < 0.05 was considered statistically significant for all analyses. Of the 120 patients that met inclusion criteria, 86 received TGF (age 7.5 ± 1.8 years; follow-up 7.0 ± 2.9 years) and 34 received MCGR (age 7.1 ± 2.2 years, follow-up 2.8 ± 0.5 years). Compared to TGF, MCGR resulted in significant improvements in maintenance of scoliosis correction (p=0.04). At final follow-up, UPRORs were 24% for MCGR (8/34 patients) and 43% (37/86 patients) for TGF (p=0.05). To minimize the influence of follow-up period, UPRORs within the first two years post-operation were evaluated: MCGR (21%, 7/34 patients) vs. TGF (14%, 12/86 patients; p=0.37). Within the first two years, etiology of UPROR as a percentage of all patients per group were deep infection (5% TGF, 6% MCGR), implant failure/migration (5% TGF, 9% MCGR), dehiscence (2% TGF, 3% MCGR), and superficial infection (1% TGF, 3% MCGR). The most common etiology of UPROR for TGF was deep infection and implant failure/migration and for MCGR was implant failure/migration. For patients with CP, at final follow-up, MCGR had superior maintenance of scoliosis correction; however, there was no difference in risk of UPROR within the first two years post-operatively (21% MCGR, 14% TGF).
The importance of cup position on the performance of total hip replacements (THR) has been demonstrated in Pelvic movement data for walking for 39 unilateral THR patients was acquired (Leeds Biomedical Research Centre). Patient's elected walking speed was used to group patients into high- and low-functioning (mean speed, 1.36(SD 0.09)ms−1 and 0.85(SD 0.08)ms−1 respectively). A computational algorithm (Python3.7) was developed to calculate cup version during gait cycle. Inputs were pelvic angles and initial cup orientation (assumed to be 45° inclination and 7° version, anterior pelvic plane was parallel to radiological frontal plane). Outputs were cup version angles during a gait cycle (101 measurements/cycle). Minimum, maximum and average cup version during gait cycle were measured for each patient. Two-sample t-test (p=0.05) was used to compare groups.Abstract
Objectives
Methods
Impingement of total hip replacements (THRs) can cause rim damage of polyethylene liners, and lead to dislocation and/or mechanical failure of liner locking mechanisms[1]. A geometric model of a THR in situ was previously developed to predict impingement for different component orientations and joint motions of activities[2]. However, the consequence of any predicted impingement is unknown. This study aimed to develop an in-vitromethod to investigate the effects of different impingement scenarios. A ProSim electro-mechanical single-station hip simulator (Simulation Solutions) was used, and the 32mm diameter metal-on-polyethylene THRs (DePuy Synthes) were assessed. The THR was mounted in an inverted orientation, and the input (motion and loading) applied simulated a patient stooping over to pick an object from the floor[3]. The impingement severity was varied by continuing motion past the point of impingement by 2.5° or 5°, and compressive load applied in the medial-lateral direction was varied from 100N to 200N. Each test condition was applied for 40,000 cycles (n=3). Rim penetration was assessed using a CMM and component separation was measured during the tests.Abstract
Objectives
Method
Staphylococcus aureus is the main cause of osteomyelitis and forms biofilm and staphylococcal abscess communities (SACs) in humans. While S. aureus has several toxins with specificity for human targets and working with human host cells would be preferred, for SACs no in vitro models, two-dimensional (2D) or three-dimensional (3D), have been described in literature to date. Advanced 3D in vitro cell culture models enable the incorporation of human cells and resemble in vivo tissue more closely than conventional 2D cell culture. Therefore, the aim of this study was to develop an in vitro model of SACs by using a 3D system. The model should allow for studies into antibiotic tolerance and S. aureus - human host cells interactions. With a clinical isolate (S. aureus JAR) or a lab strain (S. aureus ATCC 49230-GFP), SACs were grown in a collagen gel (1.78 mg/ml, Gibco) supplemented with 200 µl human plasma at 37 °C. Transmission and scanning electron microscopy was used to obtain a detailed overview of SACs, whereas immunofluorescent stainings were done to determine whether the pseudocapsule around SACs consist of fibrin. Antibiotic tolerance of SACs was assessed with 100× the minimal inhibitory concentration (MIC) of gentamicin (Roth). Bacterial clearance of non-establised SACs and established SACs with or without pseudocapsule was determined by exposure to differentiated PLB neutrophil-like cells (differentiation with 1.25% DMSO and 5% FBS for 5 days; dPLB) or primary neutrophils isolated with lymphoprep from fresh heparin blood. Degradation of the pseudocapsule was done with 7.5 µl/ml plasmin (Sigma). Colony forming unit (CFU) counts were performed as quantification method. Statistical analysis was performed with the ANOVA multiple comparison test or, when data was not normally distributed, with a Mann-Whitney U test. We have developed a 3D in vitro model of SACs which after overnight growth were on average 200 micrometers in diameter, consisted of 8 log10 CFUs and were surrounded by an inner and outer fibrin pseudocapsule. The in vitro grown SACs tolerated 100× the MIC of gentamicin for 24h and did not significantly differ from control SACs (p=0.1000). dPLB neutrophil-like cells or primary neutrophils did not clear established in vitro SACs (p=0.1102 and p=0.8767, respectively). When the fibrin pseudocapsule was degraded by the enzyme plasmin, dPLB neutrophil-like cells or primary neutrophils caused for a significant decrease in total CFU compared the SACs that did had a pseudocapsule (p=0.0333 and p=0.0272, respectively). The in vitro SACs model offers a tool for host-pathogen interaction and drug efficacy assessments and is a valuable starting point for future research.
Total Hip Arthroplasty (THA) devices are now increasingly subjected to a progressively greater range of kinematic and loading regimes from substantially younger and more active patients. In the interest of ensuring adequate THA solutions for all patient groups, THA polyethylene acetabular liner (PE Liner) wear representative of younger, heavier, and more active patients (referred to as HA in this study) warrants further understanding. Previous studies have investigated HA joint related morbidity [1]. Current or past rugby players are more likely to report osteoarthritis, osteoporosis, and joint replacement than a general population. This investigation aimed to provide a preliminary understanding of HA patient specific PE liner tribological performance during Standard Walking (SW) gait in comparison to IS0:14242-1:2014 standardized testing. Nine healthy male subjects volunteered for a gait lab-based study to collect kinematics and loading profiles. Owing to limitations in subject selection, five subjects wore a weighted jacket to increase Body Mass Index ≥30 (BMI). An induced increase in Bodyweight was capped (<30%BW) to avoid significantly effecting gait [3] (mean=11%BW). Six subjects identified as HA per BMI≥30, but with anthropometric ratios indicative of lower body fat as previously detailed by the author [2] (Waist-to-hip circumference ratio and waist circumference-to-height ratio). Three subjects identified as Normal (BMI<25). Instrumented force plate loading profiles were scaled (≈270%BW) in agreement with instrumented hip force data [4]. A previously verified THA (Pinnacle® Marathon® 36×56mm, DePuy Synthes) Finite Element Analysis wear model based on Archard's law and modified time hardening model [5] was used to predict geometrical changes due to wear and deformation, respectively (Figure 1). Subject dependent kinematic and loading conditions were sampled to generate, for both legs, 19 SW simulation runs using a central composite design of response surface method.Introduction
Materials and Methods
We present the development of a day-case total hip arthroplasty (THA) pathway in a UK National Health Service institution in conjunction with an extensive evidence-based summary of the interventions used to achieve successful day-case THA to which the protocol is founded upon. We performed a prospective audit of day-case THA in our institution as we reinitiate our full capacity elective services. In parallel, we performed a review of the literature reporting complication or readmission rates at ≥ 30-day postoperative following day-case THA. Electronic searches were performed using four databases from the date of inception to November 2020. Relevant studies were identified, data extracted, and qualitative synthesis performed.Aims
Methods
To compare changes in gait kinematics and walking speed 24 months after conventional (C-MLS) and minimally invasive (MI-MLS) multilevel surgery for children with diplegic cerebral palsy (CP). A retrospective analysis of 19 children following C-MLS, with mean age at surgery of 12 years five months (seven years ten months to 15 years 11 months), and 36 children following MI-MLS, with mean age at surgery of ten years seven months (seven years one month to 14 years ten months), was performed. The Gait Profile Score (GPS) and walking speed were collected preoperatively and six, 12 and 24 months postoperatively. Type and frequency of procedures as part of MLS, surgical adverse events, and subsequent surgery were recorded.Aims
Methods
Intrathecal morphine (IM) is a common adjunct in paediatric spinal deformity surgery. We previously demonstrated with idiopathic scoliosis it provides safe and effective analgesia in the immediate postoperative period. This study represents our 25 year experience with IM in all diagnostic groups. Our prospective Pediatric Orthopaedic Spine Database (1993–2018) was reviewed to identify all patients undergoing spinal deformity surgery who received IM and who did not. Patients 21 years of age or less who had a posterior spinal fusion (PSF) with segmental spinal instrumentation (SSI), and received 9–19 mcg/kg (up to 1 mg) of IM were included. Early onset scoliosis surgical patients were excluded. We assessed demographics, pain scores, time to first dose of opioids, diagnoses, surgical time, paediatric intensive care unit (PICU) admission and IM complications (respiratory depression, pruritus, nausea/ vomiting). There were 986 patients who met inclusion criteria. This included 760 patients who received IM and 226 who did not. IM was not used for short procedures (< 3 hrs), respiratory concerns, unsuccessful access of intrathecal space, paraplegia, and anesthesiologist decision. Both groups followed the same strict perioperative care path. The patients were divided into 5 diagnostic groups (IM / non IM patients): idiopathic (578/28), neuromuscular (100/151), syndromic (36/17), and congenital scoliosis (32/21) and kyphosis (14/9). Females predominated over males (697/289). The first dose of opioids after surgery was delayed for a mean of 10.6 hrs in IM group compared to 2.3 hrs in the non-IM group (p=0.001). The postoperative pain scores were significantly lower in the IM groups in the Post Anesthesia Care Unite (p=0.001). Only 17 IM patients (2%) were admitted to the PICU for observation secondary to respiratory depression, none required re-intubation. None of the IM group were re-intubated. Forty-nine patients (6%) experienced pruritus in the IM group compared to 4 of 226 patients (2%) in the non IM group. There were 169 patients (22%) of the IM patients and 21 patients (9%) of the non IM had nausea and vomiting postoperatively. Three patients (0.39%) had a dural leak from the administration of IM but did not require surgical repair. There were no other perioperative complications related to the use of IM. There were no significant group differences. Pre-incision IM is a safe and effective adjunct for pain management in all diagnostic groups undergoing spinal surgery. The IM patients had lower pain scores and a longer time to first administration of post-operative opioids. Although there is an increased frequency of respiratory depression, pruritus, and nausea/vomiting in the IM group, there were no serious complications.
Non-steroidal anti-inflammatory drugs (NSAIDs) are a cornerstone of perioperative pain management in orthopedic trauma surgery, although concerns persist regarding the potential impact of these drugs on fracture healing. Furthermore, NSAIDs may also exert an influence on host immune defenses, which may also be important in the context of infection treatment. However, this has been very much under-investigated in the clinical and scientific literature. The aim of this study was to determine the impact of NSAIDs on the course of an orthopedic device-related infection (ODRI) and its response to antibiotic therapy in a rat model. A polyetheretherketone (PEEK) screw was inserted in the proximal tibia of 48 skeletally mature female Wistar rats: 12 control animals received a sterile screw, of which 6 also received NSAID therapy (carprofen, 5 mg/kg s.c. once daily); 36 rats received a Aim
Method
The aim of this study was to compare the surgical and quality-of-life outcomes of children with skeletal dysplasia to those in children with idiopathic early-onset scoliosis (EOS) undergoing growth-friendly management. A retrospective review of two prospective multicentre EOS databases identified 33 children with skeletal dysplasia and EOS (major curve ≥ 30°) who were treated with growth-friendly instrumentation at younger than ten years of age, had a minimum two years of postoperative follow-up, and had undergone three or more lengthening procedures. From the same registries, 33 matched controls with idiopathic EOS were identified. A total of 20 children in both groups were treated with growing rods and 13 children were treated with vertical expandable prosthetic titanium rib (VEPTR) instrumentation.Aims
Patients and Methods
Sensory profiles classified in Low Registration, Sensory Sensitive, Sensation Avoiding and Sensation Seeking may be used in patients with non-specific chronic low back pain (CLBP) to develop a more personalized treatment program. Although psychometric properties have not been studied up till now the Adult Adolescent Sensory Profile (AASP) can be used to measure sensory profiles in CLBP patients. The study aim was to asses internal consistency, test-retest reliability, agreement and construct validity of the AASP in a CLBP population with nociplastic pain.Introduction
Objectives
Impingement of total hip replacements (THRs) can cause rim damage of polyethylene liners, and lead to dislocation and/or mechanical failure of liner locking mechanisms[1]. Previous work has focussed on the influence of femoral neck profile on impingement without consideration of neck-shaft angle. This study assessed the occurrence of impingement with two different stem designs (Corail standard [135°] and coxa vara [125°]) under different activities with varying acetabular cup orientation (30° to 70° inclination; 0° to 50° anteversion) using a geometric modelling tool. The tool was created in a computer aided design software programme, and incorporated an individual's hemi-pelvis and femur geometry[3] with a THR (DePuy Synthes Pinnacle® shell and neutral liner; size 12 Corail® standard or coxa vara and 32mm head). Kinematic data of activities associated with dislocation[2], such as stooping to pick an object from the floor was applied and incidences of impingement were recorded. Predicted implant impingement was influenced by stem design. The coxa vara stem was predicted to cause implant impingement less frequently across the range of activities and cup orientations investigated, compared to the standard stem [Fig. 1]. The cup orientations predicted to cause impingement the least frequently were at lower inclination and anteversion angles, relative to the standard stem [Fig. 1]. The coxa vara stem included a collar, while the standard stem was collarless; additional analysis indicated that differences were due to neck angle and not the presence of a collar. This study demonstrated that stem neck-shaft angle is an important variable in prosthetic impingement in THR and surgeons should be aware of this when choosing implants. Future work will consider further implant design and bone geometry variables. This tool has the potential for use in optimising stem design and position and could assist with patient specific stem selection based on an individual's activity profile. For any figures or tables, please contact the authors directly.
Impingement of total hip arthroplasties (THAs) has been reported to cause rim damage of polyethylene liners, and in some instances has led to dislocation and/or mechanical failure of liner locking mechanisms in modular designs. Elevated rim liners are used to improve stability and reduce the risk of dislocation, however they restrict the possible range of motion of the joint, and retrieval studies have found impingement related damage on lipped liners. The aim of this study was to develop a tool for assessing the occurrence of impingement under different activities, and use it to evaluate the effects a lipped liner and position of the lip has on the impingement-free range of motion. A geometrical model incorporated a hemi-pelvis and femur geometries of one individual with a THA (DePuy Pinnacle® acetabular cup with neutral and lipped liners; size 12 Corail® stem with 32mm diameter head) was created in SOLIDWORKS (Dassault Systèmes). Joint motions were taken from kinematic data of activities of daily living that were associated with dislocation of THA, such as stooping to pick an object off the floor and rolling over. The femoral component was positioned to conform within the geometry of the femur, and the acetabular component was orientated in a clinically acceptable position (45° inclination and 20° anteversion). Variation in orientation of the apex of the lip was investigated by rotating about the acetabular axes from the superior (0°) in increments of 45° (0°−315°), and compared to a neutral liner.Introduction
MATERIALS & METHOD
There is great potential for the use of computational tools within the design and test cycle for joint replacement devices. The increasing need for stratified treatments that are more relevant to specific patients, and implant testing under more realistic, less idealised, conditions, will progressively increase the pre-clinical experimental testing work load. If the outcomes of experimental tests can be predicted using low cost computational tools, then these tools can be embedded early in the design cycle, e.g. benchmarking various design concepts, optimising component geometrical features and virtually predicting factors affecting the implant performance. Rapid, predictive tools could also allow population-stratified scenario testing at an early design stage, resulting in devices which are better suited to a patient-specific approach to treatment. The aim of the current study was to demonstrate the ability of a rapid computational analysis tool to predict the behaviour of a total hip replacement (THR) device, specifically the risk of edge loading due to separation under experimental conditions. A series of models of a 36mm BIOLOX® Delta THR bearing (DePuy Synthes, Leeds, UK) were generated to match an experimental simulator study which included a mediolateral spring to cause lateral head separation due to a simulated mediolateral component misalignment of 4mm. A static, rigid, frictionless model was implemented in Python (PyEL, runtime: ∼1m), and results were compared against 1) a critically damped dynamic, rigid, FE model (runtime: ∼10h), 2) a critically damped dynamic, rigid, FE model with friction (µ = 0.05) (runtime: ∼10h), and 3) kinematic experimental test data from a hip simulator (ProSim EM13) under matching settings (runtime: ∼6h). Outputs recorded were the variation of mediolateral separation and force with time.INTRODUCTION
METHODS
Component positioning of an artificial hip joint plays a key role in durability of implant. Despite the fact that a number of numerical, experimental and clinical studies have been carried out to investigate the effects of cup inclination on polyethylene wear, steep inclination has been reported to be associated with both high and low volumetric wear. Moreover, how cup anteversion affects wear and its interaction with inclination are still unclear. To address these knowledge gaps, in this study wear and contact mechanics of a hip joint under various cup positioning has been investigated by using FEA (Finite Element Analysis). A Pinnacle® Marathon neutral liner 36×56mm was chosen to model the wear and creep over 3 million cycles (mc) based on the Archard's law and modified time hardening model in ANSYS, respectively. Central composite design of response surface method was used to generate 9 FEA runs, where the operative inclination angles varied from 35º, 45º to 55º and operative anteversion angles differed amongst 0º, 15º and 30º. The range of cup angles were chosen to be similar to the Lewinnek “golden” safe zone for dislocation. The gait cycle as specified in ISO 14242-1 was applied to the femoral head.INTRODUCTION
METHOD
One of the known mechanisms which could contribute to the failure of total hip replacements (THR) is edge contact. Failures associated with edge contact include rim damage and lysis due to altered loading and torques. Recent study on four THR patients showed that the inclusion of pelvic motions in a contact model increased the risk of edge contact in some patients. The aim of current study was to determine whether pelvic motions have the same effect on contact location for a larger patient cohort and determine the contribution of each of the pelvic rotations to this effect. Gait data was acquired from five male and five female unilateral THR patients using a ten camera Vicon system (Oxford Metrics, UK) interfaced with twin force plates (AMTI) and using a CAST marker set. All patients had good surgical outcomes, confirmed by patient-reported outcomes and were considered well-functioning, based on elective walking speed. Joint contact forces and pelvic motions were obtained from the AnyBody modelling system (AnyBody Technologies, DK). Only gait cycle regions with available force plate data were considered. A finite element model of a 32mm head on a featureless hemispherical polyethylene cup, 0.5mm radial clearance, was used to obtain the contact area from the contact force. A bespoke computational tool was used to analyse patients' gait profiles with and without pelvic motions. The risk of edge contact was measured as a “centre proximity angle” between the cup pole and centre of the contact area, and “edge proximity angle” between the cup pole and the furthest contact area point away from the pole. Pelvic tilt, drop and internal-external rotation were considered one at a time and in combinations.Introduction
Methods
Mismatch of bearing component centres and tension of soft tissues surrounding the hip joint can lead to component separation during gait cycle and cause the femoral head to contact the rim of an acetabular liner, which could increase wear and shorten lifespan of an implant. This study aims to investigate the contact and wear mechanics of a metal-on-polyethylene hip joint under dynamic separation by using Finite Element Analysis (FEA). A Pinnacle® cup with a Marathon neutral liner 36×56mm with a 45° inclination was constrained by a spring element in the medial-lateral axis. The spring was pre-compressed by 4mm to represent the corresponding translational mismatch of a simulator testing. Archard's law was used to predict wear over one ISO 14242-1 gait cycle. Contact pressure is proportional to the load input during the stance phase, associated with concentric contact condition; it increases threefold just before the swing phase (time C), reaching 46.2MPa, where edge loading occurs. Consequently, separation climbs to 3.54mm, which is comparable to the mathematical prediction (3.34mm) and dynamic FEA (3.2mm). The predicted volumetric wear after this gait cycle is 1.22 × 10–5 mm3. Dynamic separation between femoral head and acetabular liner can result in edge loading, consequently high contact pressure on the edge of a liner. In combination with cyclic loading, fatigue damage could take place and may be worth investigating in the future.
The purpose of this study was to report on outcomes after stabilization of large skeletal defects following radical debridement of hip or knee infections and staged reimplantation using segmental antibiotic mega-spacers. From 1998–2018, 39 patients (18 male, 21 female) were treated for musculoskeletal infections at the hip (14) or knee (25). Patients were treated for infection after a procedure related to oncology (20), arthroplasty (16), or trauma (3). Following debridement, defects were stabilized with antibiotic impregnated PMMA and intramedullary nails. All patients underwent a standardized protocol: 6 weeks of intravenous antibiotics followed by 6 weeks of oral antibiotics guided by intraoperative cultures. After a 6-week holiday of antibiotics, repeat intraoperative cultures and inflammatory markers were analysed for infection resolution. Success was defined by reimplantation without additional infection-related complications or requirement of suppressive antibiotics at latest follow-up.Aim
Method
The significance of the ‘clicky hip’ in neonatal and infant examination
remains controversial with recent conflicting papers reigniting
the debate. We aimed to quantify rates of developmental dysplasia
of the hip (DDH) in babies referred with ‘clicky hips’ to our dedicated
DDH clinic. A three-year prospective cohort study was undertaken between
2014 and 2016 assessing the diagnosis and treatment outcomes of
all children referred specifically with ‘clicky hips’ as the primary
reason for referral to our dedicated DDH clinic. Depending on their
age, they were all imaged with either ultrasound scan or radiographs.Aims
Patients and Methods
The aim of this study was to compare the outcomes of surgery
using growing rods in patients with severe A review of a multicentre EOS database identified 107 children
with severe EOS (major curve ≥ 90°) treated with growing rods before
the age of ten years with a minimum follow-up of two years and three
or more lengthening procedures. From the same database, 107 matched
controls with moderate EOS were identified.Aims
Patients and Methods
Primary cilia are singular structures containing a microtubule-based axoneme which are believed to not only be mechanosensitive but also to co-ordinate many cell functions via signalling pathways including Hedgehog and Wnt. Primary cilia have previously been described on cells of mouse intervertebral discs (IVDs), but not in bovine or human IVDs. Our aim was to examine primary cilia in these species. Nucleus pulposus cells were obtained from cows with no overt disc degeneration and patients following spine surgery (for herniations and/or degenerative disc disease) and cultured until confluent before maintaining with or without serum for 24h. Primary cilia were visualised with antibodies to the axoneme (acetylated α-tubulin and Arl13b) and/or the basal body (pericentrin) using fluorescent secondary antibodies and ≥200 cells per sample were counted.Introduction
Methods
Meniscal allograft transplantation is undertaken to improve pain
and function in patients with a symptomatic meniscal deficient knee
compartment. While case series have shown improvements in patient
reported outcome measures (PROMs), its efficacy has not been rigorously
evaluated. This study aimed to compare PROMs in patients having
meniscal transplantation with those having personalized physiotherapy
at 12 months. A single-centre assessor-blinded, comprehensive cohort study,
incorporating a pilot randomized controlled trial (RCT) was performed
on patients with a symptomatic compartment of the knee in which
a (sub)total meniscectomy had previously been performed. They were
randomized to be treated either with a meniscal allograft transplantation
or personalized physiotherapy, and stratified for malalignment of
the limb. They entered the preference groups if they were not willing
to be randomized. The Knee injury and Osteoarthritis Outcome Score (KOOS),
International Knee Documentation Committee (IKDC) score and Lysholm
score and complications were collected at baseline and at four,
eight and 12 months following the interventions.Aims
Patients and Methods