Machine-learning (ML) prediction models in orthopaedic trauma hold great promise in assisting clinicians in various tasks, such as personalized risk stratification. However, an overview of current applications and critical appraisal to peer-reviewed guidelines is lacking. The objectives of this study are to 1) provide an overview of current ML prediction models in orthopaedic trauma; 2) evaluate the completeness of reporting following the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) statement; and 3) assess the risk of bias following the Prediction model Risk Of Bias Assessment Tool (PROBAST) tool. A systematic search screening 3,252 studies identified 45 ML-based prediction models in orthopaedic trauma up to January 2023. The TRIPOD statement assessed transparent reporting and the PROBAST tool the risk of bias.Aims
Methods
There is growing evidence that bacteria encountered in periprosthetic joint infections (PJI) form surface-attached biofilms on prostheses, as well as biofilm aggregates embedded in synovial fluid and tissues. However, models allowing the investigation of these biofilms and the assessment of their antimicrobial susceptibility in physiologically relevant conditions are currently lacking. To address this, we developed a synthetic synovial fluid (SSF) model and we validated this model in terms of growth, aggregate formation and antimicrobial susceptibility testing, using multiple PJI isolates. 17 PJI isolates were included, belonging to Aim
Methods
The computational modelling and 3D technology are finding more and more applications in the medical field. Orthopedic surgery is one of the specialties that can benefit the most from this solution. Three case reports drawn from the experience of the authors’ Orthopedic Clinic are illustraded to highlight the benefits of applying this technology. Drawing on the extensive experience gained within the authors’ Operating Unit, three cases regarding different body segments have been selected to prove the importance of 3D technology in preoperative planning and during the surgery. A sternal transplant by allograft from a cryopreserved cadaver, the realization of a custom made implant of the glenoid component in a two-stage revision of a reverse shoulder arthroplasty, and a case of revision on a hip prosthesis with acetabular bone loss (Paprosky 3B) treated with custom system. In all cases the surgery was planned using 3D processing software and models of the affected bone segments, printed by 3D printer, and based on CT scans of the patients. The surgical implant was managed with dedicated instruments. The use of 3D technology can improve the results of orthopedic surgery in many ways: by optimizing the outcomes of the operation as it allows a preliminary study of the bone loss and an evalutation of feasibility of the surgery, it improves the precision of the positioning of the implant, especially in the context of severe deformity and bone loss, and it reduces the operating time; by improving surgeon training; by increasing patient involvement in decision making and informed consent. 3D technology, by offering targeted and customized solutions, is a valid tool to obtain the tailored care that every patient needs and deserves, also providing the surgeon with an important help in cases of great complexity.
In a clinical setting, there is a need for simple gait kinematic measurements to facilitate objective unobtrusive patient monitoring. The objective of this study is to determine if a learned classification model's output can be used to monitor a person's recovery status post-TKA. The gait kinematics of 20 asymptomatic and 17 people with TKA were measured using a full-body Xsens model1. The experimental group was measured at 6 weeks, 3, 6, and 12 months post-surgery. Joint angles of the ankle, knee, hip, and spine per stride (10 strides) were extracted from the Xsens software (MVN Awinda studio 4.4)1. Statistical features for each subject at each evaluation moment were derived from the kinematic time-series data. We normalised the features using standard scaling2. We trained a logistic regression (LR) model using L1-regularisation on the 6 weeks post-surgery data2–4. After training, we applied the trained LR- model to the normalised features computed for the subsequent timepoints. The model returns a score between 0 (100% confident the person is an asymptomatic control) and 1 (100% confident this person is a patient). The decision boundary is set at 0.5. The classification accuracy of our LR-model was 94.58%. Our population's probability of belonging to the patient class decreases over time. At 12 months post-TKA, 38% of our patients were classified as asymptomatic.
To develop prediction models using machine-learning (ML) algorithms for 90-day and one-year mortality prediction in femoral neck fracture (FNF) patients aged 50 years or older based on the Hip fracture Evaluation with Alternatives of Total Hip arthroplasty versus Hemiarthroplasty (HEALTH) and Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trials. This study included 2,388 patients from the HEALTH and FAITH trials, with 90-day and one-year mortality proportions of 3.0% (71/2,388) and 6.4% (153/2,388), respectively. The mean age was 75.9 years (SD 10.8) and 65.9% of patients (1,574/2,388) were female. The algorithms included patient and injury characteristics. Six algorithms were developed, internally validated and evaluated across discrimination (c-statistic; discriminative ability between those with risk of mortality and those without), calibration (observed outcome compared to the predicted probability), and the Brier score (composite of discrimination and calibration).Aims
Methods
Several factors contribute to the duration of the hospital stay in patients that undergo to total hip arthroplasty (THA), either subjective or perioperative. However, no definite evidence has been provided on the role of any of these factors on the hospitalization length. The aim of this retrospective investigation is to evaluate the correlation between several preoperative and perioperative factors and the length of hospital stay (LOS) in patients that underwent elective total hip arthroplasty. Medical records of patients that underwent THA since the beginning of 2016 to the end of 2018 were retrospectively screened. Demographics, comorbidities, renal function, whole blood count. and length of post-operative ward stay were retrieved. The association between clinical, biochemical and surgical factors and the length of hospital stay was explored by means of linear regression models.Introduction and Objective
Materials and Methods
Patients with FNF may be treated by either total hip arthroplasty (THA) or hemiarthroplasty (HA). Utilizing American Joint Replacement Registry (AJRR) data, we aimed to evaluate outcomes in FNF treatment. Medicare patients with FNF treated with HA or THA reported to the AJRR database from 2012–2019 and CMS claims data from 2012–2017 were analyzed in this retrospective cohort study. “Early” was defined as less than 90 days from index procedure. A logistic regression model, including index arthroplasty, age, sex, stem fixation method, hospital size1, hospital teaching affiliation1, and Charlson comorbidity index (CCI), was utilized to determine associations between index procedure and revision rates.Introduction
Methods
Cellular therapies play an important role in tendon tissue engineering with tenocytes being described as the most prominent cell population if available in large numbers. However, in vitro expansion of tenocytes in standard culture leads to phenotypic drift and cellular senescence. Recent work suggests that maintenance of tenogenic phenotype in vitro can be achieved by recapitulating different aspects of the native tendon microenvironment. One approach used to modulate the in vitro microenvironment and enhance extracellular matrix (ECM) deposition is macromolecular crowding (MMC). MMC is based on the addition of inert macromolecules to the culture media mimicking the dense extracellular matrix. In addition, as tendon has been described to be a relatively avascular and hypoxic tissue and low oxygen tension can stimulate collagen synthesis and cross-linking, we venture to assess the synergistic effect of MMC and low oxygen tension on human tenocyte phenotype maintenance by enhancing synthesis and deposition of tissue-specific ECM. Human tendons were kindly provided from University Hospital Galway, after obtaining appropriate licenses, ethical approvals and patient consent. Afterwards, tenocytes were extracted using the migration method. Experiments were conducted at passage three. Optimization of MMC conditions was assessed using 50 to 500 μg/ml carrageenan (Sigma Aldrich, UK). For variable oxygen tension cultures, tenocytes were incubated in a Coy Lab (USA) hypoxia chamber. ECM synthesis and deposition were assessed using SDS-PAGE (BioRad, UK) and immunocytochemistry (ABCAM, UK) analysis. Protein analysis for Scleraxis (ABCAM, UK) was performed using western blot. Gene analysis was conducted using a gene array (Roche, Ireland). Cell morphology was assessed using bright-field microscopy. All experiments were performed at least in triplicate. MINITAB (version 16, Minitab, Inc.) was used for statistical analysis. Two-sample t-test for pairwise comparisons and ANOVA for multiple comparisons were conducted SDS-PAGE and immunocytochemistry analysis demonstrated that human tenocytes treated with the optimal MMC concentration at 2% oxygen tension showed increased synthesis and deposition of collagen type I, the major component of tendon ECM. Moreover, immunocytochemistry for the tendon-specific ECM proteins collagen type III, V, VI and fibronectin illustrated enhanced deposition when cells were treated with MMC at 2% oxygen tension. In addition, protein analysis revealed elevated dexpression of the tendon-specific protein Sclearaxis, while a detailed gene analysis revealed upregulation of tendon-related genes and downregulation of trans-differentiation markers again when cells cultured with MMC at 2% oxygen tension. Finally, low oxygen tension and MMC did not affect the metabolic activity, proliferation and viability of human tenocytes. Collectively, results suggest that the synergistic effect of MMC and low oxygen tension can accelerate the formation of ECM-rich substitutes, which stimulates tenogenic phenotype maintenance. Currently, the addition of substrate aligned topography together with MMC and hypoxia is being investigated in this multifactorial study for the development of an implantable device for tendon regeneration.
Tissue engineering by self-assembly is a technique that consists of growing cells on surfaces made of thermoresponsive polymers, that allow the production of contiguous cell sheets by simply lowering the temperature below the polymer's low critical solution temperature. In this approach cell-cell junctions and deposited extracellular matrix (ECM) remain intact, which provides a better cell localisation at the site of injury. However, these systems lack the possibility to fabricate multi-layered and three-dimensional cell sheets that would better recapitulate native tissues. Moreover, the fabrication of ECM-rich cell sheets would be highly desirable. This limitation could be overcome by inducing macromolecular crowding (MMC) conditions. Herein we venture to fabricate electrospun thermoresponsive nanofibres to sustain the growth and detachment of ECM-rich tissue substitutes in the presence of a MMC microenvironment. A copolymer of 85% poly-N-isopropylacrylamide and 15% N-tert-butylacrylamide (pNIPAAm/NTBA) were used for all experiments. To create aligned nanofibers, the polymer was electrospun and collected on a mandrel rotating at 2000 rpm. Human adipose derived stem cells (hADSC) were treated with media containing macromolecular crowders to enhance matrix deposition. Cell viability and morphology were assessed, and immunocytochemistry was conducted in order to estimate matrix deposition and composition. Adipogenic, osteogenic and chondrogenic assays were performed both with and without the presence of MMC. Non-invasive cell detachment was enabled by decreasing the temperature of culture to 10 °C for 20 minutes. The electrospinning process resulted in the production of pNIPAm/NTBA fibres in the diameter range from 1 to 2 µm and an overall alignment of 80%. Cell viability, proliferation and metabolic activity revealed that hADSCs were able to grow on the thermoresponsive scaffold. The cells were able to detach as an intact cell sheet in presence of MMC. Moreover, it was demonstated that MMC, by a volume extrusion effect, enhances Collagen type I deposition, which is one of the main components of the ECM. Histological analysis revealed that in the presence of MMC the cells were able to self-assembled into three dimensional multi-layers. The cells were able to differentiate towards the osteogenic and adipogenic lineage in the presence of MMC. Interestingly we were able to fabricate three-dimensional chondrogenic cell sheet both with and without MMC. Collectively the pNIPAm/NTBA thermoresponsive fibres were able to sustain the growth and the detachment of ECM-rich multi-layered cell sheets. The pNIPAm/NTBA fibres were able to successfully sustain growth and detachment of ECM-rich tissue equivalents. We believe that replacement, repair and restoration of tissue function can be accomplished best using cells that create their own tissue-specific extracellular matrix with a precision and stoichiometric efficiency still unmatched by man-made devices.
Deep venous thrombosis (DVT) is a potentially serious complication after total hip (THA) and knee (TKA) arthroplasty, traditionally justifying aggressive prophylaxis with low molecular weight heparin (LMWH) or direct oral anticoagulants (DOA) at the cost of an increased risk of bleeding. However, fast-track procedures might reduce the DVT risk and decrease the cost-benefit ratio of the current recommendations. The objective of this study was to compare thrombotic and bleeding risk in an unselected population of elective THA and TKA with a fast-track procedure. A series of 1,949 patients were analyzed prospectively. There were 1,136 women and 813 men, with a mean age of 70 years. In particular, 16% were previously treated by antiplatelet agents and 8% by anticoagulants. All patients followed a fast-track procedure including early walking within 24 hours of surgery, and 80% of patients returned home after surgery, with a mean length of stay of 3 days (THA) or 4 days (TKA). The occurrence of a thromboembolic event or hemorrhagic complication has been identified.Introduction
MATERIAL - METHODS
Prosthetic joint infection (PJI) remains the most severe complication of arthroplasty. Failure of intensive, long-term antibiotic treatment for PJI often requires removal of the implant. Antibiotic failure is thought to be caused by biofilm and persister formation. Novel anti-biofilm and anti-persister strategies are urgently needed. Here, we investigated the effects of several antimicrobial peptides on the bacteria within antibiotic-treated biofilms in an On polystyrene, a mature (7 day-old) methicillin-resistant Aims
Methods
A 2011 Cochrane review concluded that spinal manipulative therapy (SMT) is no better than other interventions for reducing pain and improving function in chronic low back pain (CLBP). Using individual participant data (IPD) from trials has advantages, among others: a more precise estimate of the effect and the potential to identify moderators. Our objective was to assess the effect of SMT in adults with CLBP and to identify relevant moderators. All trials from the 2011 Cochrane review were included in this IPD. We updated the search (April 2016) IPD from eligible studies was requested. Primary outcomes were pain intensity (VAS/NRS) and back-specific function (RMDQ). Risk of bias was assessed. For the treatment effect, an one-stage approach (mixed model technique, intention-to-treat principle) was used; a second-stage approach was conducted as confirmation. For the moderator analyses, one-stage approach was conducted for 19 variables.Purpose of the study and background
Methods
Rotational or axial alignment is an important concept in total knee surgery. Malrotation of the femoral component can lead to patellofemoral maltracking, pain and stiffness. In reconstruction surgery of the knee, achievement of correct rotation is even more difficult because of the lack of anatomical landmarks. The linea aspera is often the only remaining landmark, but its reliability is questionable. Can custom-made 3D-guides help with rotational alignment of the knee after a wide resection of the distal femur?Introduction
Goal of research
Orthopedic implant related surgical site infection (SSI) is a severe complication which represents an important challenge concerning to its treatment. Therefore, gram-negative orthopedic infections have recently become a global concern. Retrospective study through searching of the SCIH (infection control service) database, concerning to the year 2016 and 2017. Cases selected were those of implant placement clean surgeries (osteosynthesis or prosthetic placement) which evolved with SSI and Gram-negative bacterial growth in bone tissue or periprosthetic cultures.Aim
Method
Obese patients are not only more likely to receive total joint arthroplasty, but are also more prone to postoperative complications. The most severe complication is a prosthetic joint infection (PJI), occurring two to four times more often in severely obese patients (BMI ≥ 35kg/m2) compared to non-obese patients. This higher risk for PJI may be attributed to higher glucose levels in case of diabetes mellitus, diminished wound healing or inadequate antibiotic prophylaxis. To ultimately improve the prevention measures for this specific patient category, we aimed to describe the clinical and microbiological characteristics of early acute PJI in severely obese patients. We retrospectively evaluated patients with early acute PJI of the hip and knee treated with DAIR between 2006 and 2016 in three Dutch hospitals. According to protocol, cefazolin was administered as antibiotic prophylaxis during arthroplasty and adjusted to bodyweight. PJI was diagnosed using the criteria described by the Musculoskeletal Infection Society. Early acute PJI was defined as less than 21 days of symptoms and a DAIR performed within 90 days after index surgery. Several clinical and microbiological variables were collected and analyzed. Severe obesity was defined as a BMI ≥ 35kg/m2.Aim
Method
Debridement, antibiotics and implant retention (DAIR) is a widely used treatment modality for early acute prosthetic joint infection (PJI). A preoperative risk score was previously designed for predicting DAIR failure, consisting of chronic renal failure (K), liver cirrhosis (L), index surgery (I), cemented prosthesis (C) and C-reactive protein >115mg/L (KLIC). The aim of this study was to validate the KLIC score in an external cohort. We retrospectively evaluated patients with early acute PJI treated with DAIR between 2006 and 2016 in three Dutch hospitals. Early acute PJI was defined as less than 21 days of symptoms and DAIR performed within 90 days after index surgery. Failure was defined as the need for 1) second DAIR, 2) implant removal, 3) suppressive antimicrobial treatment or 4) infection-related death within 60 days after debridement.Aim
Method
Tissue engineering by self-assembly offers the possibility to fabricate contiguous cell sheets that are stabilised by intact cell-cell contacts and endogenously produced extracellular matrix (ECM) However, these systems lack the possibility to introduce topographical cues, that are fundamental for the organisation of many types of tissues. Herein we venture to fabricate aligned electrospun thermoresponsive nanofibres to sustain growth and detachment of ECM-rich living substitutes in the presence of a MMC microenvironment. A copolymer of 85% poly-N-isopropylacrylamide and 15% N-tert-butylacrylamide (pNIPAAm/NTBA) were used. To create aligned nanofibers, the polymer was electrospun and collected on a mandrel rotating at 2000 rpm. Human adipose derived stem cells (hADSC) were treated with media containing macromolecular crowders to enhance matrix deposition. Cell viability and morphology were assessed, and immunocytochemistry was conducted to estimate matrix deposition and composition. Non-invasive cell detachment was enabled by decreasing the temperature of culture to 10 °C for 20 minutes. The electrospinning process resulted in the production of pNIPAm/NTBA fibres in the diameter range from 1 to 2 µm and an overall alignment of 80%. Cell viability revealed that hADSCs were able to grow on the scaffold. The cells aligned on the fibres after 3 days and they were able to detach as intact cell sheets in presence of MMC. Moreover, it was demonstrated that MMC, by a volume extrusion effect, enhances collagen type I deposition, one of the main components of the ECM. Collectively the pNIPAm/NTBA fibres were able to successfully sustain growth and detachment of ECM-rich cell sheets.
Conventional marker based optical motion capture (mocap) methods for estimating the position and orientation (pose) of anatomical segments use assumptions that anatomical segments are rigid bodies and the position of tracking markers is invariant relative to bones. Soft tissue artefact (STA) is the error in pose estimation due to markers secured to soft tissue that moves relative to bones. STA is a major source of pose estimation error and is most prevalent when markers are placed over joints. Mocap and bi-plane videoradiography data were recorded synchronously while three individuals walked on a treadmill. For all three, pose of the thigh and shank, and movement of markers relative to the bones, were determined from the videoradiography data (DSX, C-Motion). Independently, pose of thighs and shanks was estimated using mocap data (Visual3D, C-Motion). Our measures of error in the mocap pose estimation were the relative thigh and shank translations. X-ray data from two subjects were used to generate a regression model for the antero/posterior movement of the lateral knee marker against internal/external hip rotation. The mocap translation errors of the third subject, attributed to STA of the knee marker, were 15.6mm and 32.0mm respectively. The pose of the third subject was then estimated using a probabilistic algorithm incorporating our regression model. Mocap translation errors were reduced to 10.6mm (thigh) and 4.4mm (shank). The results from these data suggest that errors in pose estimation due to STA may possibly be reduced via the application of algorithms based on probabilistic inference to mocap data.
Fabrication of biogenic coatings with suitable mechanical properties is a key goal in orthopedics, to overcome the limitations of currently available coatings and improve the clinical results of coated implants compared to uncoated ones. In this paper, biological-like apatite coatings were deposited from a natural bone-apatite source by a pulsed electron deposition technique (PED). Bone apatite-like (BAL) films were deposited directly from bone targets, obtained by standard deproteinization of bovine tibial cortical shafts and compared to films deposited by sintered stoichiometric-hydroxyapatite targets (HA). Deposition was performed at room temperature by PED in the Ionized Jet Deposition (IJD) version. Half of the samples was annealed at 400°C for 1h (BAL_400 and HA_400). As-deposited and annealed coatings were characterized in terms of composition and crystallinity (XRD, FT-IR), microstructure and morphology (SEM-EDS, AFM) and mechanical properties (nanoindentation and micro-scratch). For the biological tests, human dental pulp stem cells (hDPSCs) were isolated from dental pulp from patients undergoing a routine tooth extraction, plated on the samples (2500 cells/cm2) and cultured for 3 weeks, when the expression of typical osteogenic markers Runx-2, osteopontin, Osx and Osteocalcin in hDPSCs was evaluated. Results showed that deposition by PED allows for a close transfer of the targets” composition. As-deposited coatings exhibited low cristallinity, that was significantly increased by post-deposition annealing, up to resembling that of biogenic apatite target. As a result of annealing, mechanical properties increased up to values comparable to those of commercial plasma-sprayed HA-coatings.
In conclusion, bone-like apatite coatings were deposited by PED, which closely resembled composition and structure of natural-apatite. Upon annealing at 400°C, the coatings exhibited satisfactory mechanical properties and were capable of providing a suitable microenvironment for hDPSCs adherence and proliferation and for them to reach osteogenic commitment. These results suggest that bone apatite-like thin films obtained by biogenic source may represent an innovative platform to boost bone regeneration in the orthopedic, maxillofacial and odontoiatric field.
The goal of this study was (1) to investigate the relationships between the bony contours of the knee and the popliteus tendon before and after TKA and (2) to analyse the influence of implant sizing. Our hypothesis was that an apparently well-sized prosthesis, will modify the position or the tracking of popliteus tendon. 4 fresh frozen cadavers were selected. The popliteus tendon was injected with contrast dye and a CT-scan was performed from full extension to full flexion with increments of 20°. Afterwards a total knee arthroplasty (TKA) was performed. Each cadaver received either a normal-sized, oversized, undersized or mobile bearing prosthesis. After TKA the limb was scanned again using the same protocol as before. 3D-reconstructions were created using Materialise Mimics software. These 3D-models were then imported into custom made Matlab software to measure and compare the deviation of the popliteus tendon before and after TKA.Background
Methods
Systemic metal ion monitoring (Co;Cr) has proven to be a useful screening tool for implant performance to detect failure at an early stage in metal-on-metal hip arthroplasty. Several clinical studies have reported elevated metal ion levels after total knee arthroplasty (TKA), with fairly high levels associated with rotating hinge knees (RHK) and megaprostheses1. In a knee simulator study, Kretzer2, demonstrated volumetric wear and corrosion of metallic surfaces. However, prospective in vivo data are scarce, resulting in a lack of knowledge of how levels evolve over time. The goal of this study was to measure serum Co and Cr levels in several types TKA patients prospectively, evaluate the evolution in time and investigate whether elevated levels could be used as an indicator for implant failure. The study was conducted at Ghent University hospital. 130 patients undergoing knee arthroplasty were included in the study, 35 patients were lost due to logistic problems. 95 patients with 124 knee prostheses had received either a TKA (primary or revision) (69 in 55 patients), a unicompartimental knee arthroplasty (7 UKA), a RHK (revision −7 in 6 patients) or a megaprosthesis (malignant bone tumours − 28 in 27 patients) (Fig 1). The TKA, UKA and RHK groups were followed prospectively, with serum Co and Cr ions measured preoperatively, at 3,6 and 12 months postoperatively. In patients with a megaprosthesis, metal ions were measured at follow-up (cross-sectional study design).Introduction
Patients and Methods
To determine the mechanisms and extents of popliteus impingements before and after TKA and to investigate the influence of implant sizing. The hypotheses were that (i) popliteus impingements after TKA may occur at both the tibia and the femur and (ii) even with an apparently well-sized prosthesis, popliteal tracking during knee flexion is modified compared to the preoperative situation. The location of the popliteus in three cadaver knees was measured using computed tomography (CT), before and after implantation of plastic TKA replicas, by injecting the tendon with radiopaque liquid. The pre- and post-operative positions of the popliteus were compared from full extension to deep flexion using normosized, oversized and undersized implants (one size increments). At the tibia, TKA caused the popliteus to translate posteriorly, mostly in full extension: 4.1mm for normosized implants, and 15.8mm with oversized implants, but no translations were observed when using undersized implants. At the femur, TKA caused the popliteus to translate laterally at deeper flexion angles, peaking between 80º-120º: 2.0 mm for normosized implants and 2.6 mm with oversized implants. Three-dimensional analysis revealed prosthetic overhang at the postero-superior corner of normosized and oversized femoral components (respectively, up to 2.9 mm and 6.6 mm). A well-sized tibial component modifies popliteal tracking, while an undersized tibial component maintains more physiologic patterns. Oversizing shifts the popliteus considerably throughout the full arc of motion. This study suggests that both femoro- and tibio-popliteus impingements could play a role in residual pain and stiffness after TKA.
Systemic metal ion monitoring (Co;Cr) has proven to be a useful screening tool for implant performance to detect failure at an early stage in metal-on-metal hip arthroplasty. Several clinical studies have reported elevated metal ion levels after total knee arthroplasty (TKA), with fairly high levels associated with rotating hinge knees (RHK) and megaprostheses1. In a knee simulator study, Kretzer2, demonstrated volumetric wear and corrosion of metallic surfaces. However, prospective in vivo data are scarce, resulting in a lack of knowledge of how levels evolve over time. The goal of this study was to measure serum Co and Cr levels in several types TKA patients prospectively, evaluate the evolution in time and investigate whether elevated levels could be used as an indicator for implant failure. The study was conducted at Ghent University hospital. 130 patients undergoing knee arthroplasty were included in the study, 35 patients were lost due to logistic problems. 95 patients with 124 knee prostheses had received either a TKA (primary or revision) (69 in 55 patients), a unicompartimental knee arthroplasty (7 UKA), a RHK (revision −7 in 6 patients) or a megaprosthesis (malignant bone tumours − 28 in 27 patients). The TKA, UKA and RHK groups were followed prospectively, with serum Co and Cr ions measured preoperatively, at 3,6 and 12 months postoperatively. In patients with a megaprosthesis, metal ions were measured at follow-up (cross-sectional study design). In primary knees, we did not observe an increase in serum metal ion levels at 3, 6 or 12 months. Two patients with a hip arthroplasty had elevated preTKA Co and Cr levels. There was no difference between unilateral and bilateral knee prostheses. In the revision group, elevated pre-revision levels were found in 2 failures for implant loosening. In both cases, ion levels decreased postoperatively. In revisions with a standard TKA, there was no significant increase in metal ions compared to primary knee arthroplasty. RHK were associated with a significant increase in Co levels even at short-term (3–12 months). The megaprosthesis group had the highest metal ion levels and showed a significant increase in Co and Cr with time in patients followed prospectively. With the current data, we could not demonstrate a correlation between metal ion levels, size of the implant or length of time in situ. In primary knee arthroplasty with a standard TKA or UKA, metal ion levels were not elevated till one year postoperatively. This suggests a different mechanism of metal ion release in comparison to metal-on-metal hip arthroplasties. In two cases of revision for implant loosening, pre-revision levels were elevated, possibly associated with component wear, and decreased after revision. With RHK, slightly elevated ion levels were found prospectively. Megaprostheses had significantly elevated Co and Cr levels, due to corrosion of large metallic surfaces and/or wear of components which were not perfectly aligned during difficult reconstruction after tumour resection. Further research is needed to assess the clinical relevance of metal ion levels in knee arthroplasty.
Failure of the polyethylene glenoid component is the most common complication of Total Shoulder Arthroplasty (TSA) and accounts for a majority of the unsatisfactory results after this procedure. Nowadays, most of the shoulder prostheses consist of metal on polyethylene bearing components. Repetitive contact between the metal ball and the polyethylene socket produces progressive abrasion of the implant if the moving part is made of polyethylene. Its debris may then lead to an active osteolysis and implant loosening. Failure of the glenoid component is often manifested clinically by pain, loss of function, and the presence of a clunking noise and leads to revision surgery. The use of ceramic balls aims at the reduction of this phenomenon. In many studies regarding knee and hip replacement it has been shown that the use of ceramic on polyethylene (CoP) is more beneficial in terms of polyethylene wear and failure, when compared to metal on polyethylene (MoP). Since a human shoulder is very different from a hip and a knee, it is not a self-centering, neither congruent joint. And its stability is provided by healthy muscles of the rotator cuff. We decided to compare CoP against MoP in semi- force controlled test setup. Where, for a given governing angular motion the translational motion was a function of contact (frictional) forces between the tested couple (humeral head and PE). This is to our knowledge the first study to address in direct comparison wear in TSA in semi force controlled test setup. Up today, there is no test standard for wear testing of TSA. A customised joint simulator was used to create worst-case scenario motion allowing for simulation of the muscles in two perpendicular axes: inferior – superior (I-S) and anterior – posterior (A-P). Were a governing angular motion (GAM) was the abduction – adduction (±30°) in I-S. A system of springs was created so that the I-S translation and the A-P rotation were a result of the GAM. The stiffens of the springs was tuned based on the MoP pair initial kinematic (1000 cycles) to result in: about 2mm I-S translation, and about ±10° A-P rotation. All samples were tested at the same test station in order to obtain maximal repeatability. Axial load was in range of 100N to 750 N. Three articulating couples for each material were tested for total of 2M cycles. Standard midterm gravimetric measurements were conducted at each 0.5 M cycles.Introduction
Materials and methods
External rotation of the femoral component is one factor that favors a satisfactory clinical result. New technologies have been developed to precisely implant the components of a total knee arthroplasty, including computer-assisted surgery (CAS) and patient-specific instruments (PSIs). The aim of this study was to compare the precision of CAS and PSIs when determining the orientation of the femoral component. A total of 65 patients operated on in 2008 with CAS had pre- and post-operative computed tomography (CT) in which the posterior condylar angle (PCA) was measured. The same pre- and post-operative measurements were performed for 27 patients operated on in 2010 with the assistance of PSI. For both populations, the antero-posterior femoral cuts were directed to implant the femoral component 3° of external rotation from the pre-operative posterior condylar line (PCL).Purpose
Methods
(1) to investigate the relationships between the bony contours of the knee and the Popliteus Tendon (PT) in the healthy knee and after implantation of a TKA and (2) to analyze the influence of implant sizing. With an apparently well-sized TKA, the position of the PT during knee flexion is modified compared with the preoperative situation.Goals of the study
Hypothesis
Obesity is known to influence surgical risk in total hip replacement (THR), with increased Body Mass Index (BMI) leading to elevated risk of complications and poorer outcome scores. Using a multinational trial data of a single implant, we assess the impact of BMI and regional variations on Harris Hip scores (HHS). We assessed BMI in 11 regional centres and associations with HHS at one year. Data were collected from 744 patients prospectively from 11 centres in the UK, Germany, Switzerland, Austria, New Zealand and Netherlands as part of a multicentre outcome trial. All Arthroplasties used RM Pressfit vitamys components (Mathys, Switzerland). Demographic, operative data and HHS were analysed with General Linear Model Anova, Minitab 16 (Minitab Inc, Pennsylvania).Introduction
Method
Fractures are the second commonest presentation of non-accidental injury (NAI) in children. Approximately one third of abused children will present to Acute Trauma Services (ATS) with fractures. Any cases of suspected child maltreatment should be referred to Safeguarding Services for follow-up, as outlined by Trust Guidelines. Our aim was to examine the referral of children with suspicious fractures to safeguarding and assess if cases with high risk of abuse are being missed by ATS. A comprehensive literature review identified commonly cited indicators of abuse. Inclusion criteria included age less than 18 months seen in A&E or Fracture Clinic with a long bone fracture. Patient notes were analysed to identify occurrence of these risk factors and findings cross-referenced with Safeguarding Services' records to verify whether high-risk patients were detected. The origin of each referral was also noted.Aim
Method
Assessment for and treatment of osteoporosis is recommended following hip fracture. All forms of osteoporosis treatment require an adequate calcium intake and normal vitamin D levels. This study assesses vitamin D levels in patients with hip fractures and describes guidelines on how to manage low vitamin D levels with high dose oral vitamin D3 (cholecalciferol). Circulating 25-hydroxyvitamin D levels were measured in consecutive patients with a hip fracture over an 18 month period. Substitution therapy with high dose oral cholecalciferol was started in 2 selected cohorts; one group received substitution therapy for 3 days, the second group for 7 days.Introduction
Materials and methods
compare the radiological results in sagittal balance correction obtained with pedicle subtraction osteotomy (PSO) versus anterior-posterior osteotomy (APO) by double approach in adults. between January of 2001 and July of 2009, fifty-eight vertebral osteotomies were carried out in fifty-six patients: 9 Smith-Petersen osteotomy (SPO), one vertebral resection osteotomy (VRO), 30 anterior-posterior osteotomies (APO) and 18 pedicle subtraction osteotomies (PSO), being the lasts two groups the sample studied (48 osteotomies). The mean age of the patients was 56.3 years (17–72). Initial diagnose was: 28 posttraumathic kyphosis, 7 postsurgical kyphosis, 7 adult degenerative disease, 4 ankylosing spondylitis and 2 congenital kyphoscoliosis. We evaluated the preoperative standing radiographs, the postoperative and at final follow-up by digital measurements with iPACS system viewer (© Real Time Image, USA, 2001). The mean follow-up was 54 months (6–98), and complications were analized.Purpose
Material and Methods
Despite proven advantages, pulsatile lavage seems to be used infrequently during preparation in cemented total knee arthroplasty. This remains irritating, as the technique has been suggested to improve radiological survival in cemented TKA, where aseptic loosening of the tibial component represents the main reason for revision. Furthermore, there may be a potential improvement of fixation strength for the tibial tray achieved by increased cement penetration. In this study, the influence of pulsed lavage on mechanical stability of the tibial component and bone cement penetration was analyzed in a cadaveric setting. Six pairs of cadaveric, proximal tibia specimen underwent computed tomography (CT) for assessment of bone mineral density (BMD) and exclusion of osseous lesions. Following surgical preparation, in one side of a pair, the tibial surface was irrigated using 1800ml normal saline and pulsatile lavage, while in the other side syringe lavage using the identical amount of fluid was applied. After careful drying, bone cement was hand-pressurized on the bone surface, tibial components were inserted and impacted in an identical way. After curing of cement, specimen underwent a postimplantation CT analysis). Cement distrubution was then assessed using a three-dimenionsional visualization software. Trabecular bone, cement and implant were segmented based on an automatic thresholding algorithm, which had been validated in a previous study. This allowed to determine median cement penetration for the entire cemented area. Furthermore, fixation strength of the tibial trays was determined by a vertical pull-out test using a servohydraulic material testing machine. Testing was performed under displacement control at a rate of 0,5mm/sec until implant failure. Data was described by median and range. Results were compared by a Wilcoxon matched pairs signed rank test with a type 1 error probability of 5 %. Median pull-out forces in the pulsed lavage group were 1275N (range 864–1391) and 568N (range 243–683) in the syringe lavage group (p=0.031). Cement penetration was likewise increased (p=0.031) in the pulsed lavage group (1.32mm; range 0.86–1.94), when compared to the syringe irrigated group (0.79mm; range 0.51–1.66). Failure occurred in the pulsatile lavage group at the implant-cement interface and in the syringe lavage group at the bone-cement interface, which indicates the weakness of the latter. Altogether, improved mechanical stability of the tibial implant and likewise increased bone cement interdigitation could be demonstrated in the current study, when pulsed lavage is implemented. Enhanced fixation strength was suggested being a key to improved survival of the implant. If this is the case, pulsatile lavage should be considered being a mandatory preparation step when cementing tibial components in TKA.
To document the success rate of closed reduction and soft tissue release in the treatment of bilateral true dislocation in developmental dysplasia of the hip (DDH). Case-note review of 22 children (44 hips) with idiopathic bilateral hip dislocation referred to a tertiary centre before walking age. The management protocol was as follows:
Examination under general anaesthesia, arthrogram, closed reduction and appropriate soft tissue release (adductors/psoas), application of a ‘frog’ cast. CT scan at 2 weeks to confirm reduction. Change of cast and arthrogram at 6 weeks to confirm improving position and stability. Cast removal at 12 weeks, and application of an abduction brace for 6 weeks. Treatment failure could occur on day 1 (failure of reduction), at week 2 (failure to maintain reduction), at week 6, or after cast removal.Purpose
Methods
To document the incidence and nature of complications associated with hemiepiphysiodesis using a screw and plate device (8-plate, Orthofix). We reviewed case notes and radiographs of 71 children (130 segments) with lower limb deformities treated with temporary hemiepiphyseal arrest using the 8-plate. 96% of deformities were in the coronal plane, 4% sagittal. 72% of coronal deformities demonstrated valgus malalignment. We defined three types of complications: complications Complications were related to variables of patient age, gender, diagnosis, location of deformity and associated surgery.Purpose
Methods
Sleep disturbance is frequently reported by people with chronic low back pain (CLBP >12 weeks), but there is limited knowledge of their sleep quality compared to healthy people. While disturbed sleep influences patients' mood, quality of life and recovery, few studies have comprehensively investigated sleep in CLBP. This study investigated differences in sleep profiles of people with CLBP, compared to age- and gender matched controls over seven consecutive nights. Thirty-two consenting subjects (n=16 with CLBP, n=16 matched controls), aged 24-65 years (43.8% male) underwent an interview regarding sleep influencing variables (e.g. mattress firmness, caffeine consumption), completed the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Pittsburgh Sleep Diary, SF36-v2, Hospital Anxiety and Depression Scale, and CLBP measures (i.e. Oswestry Disability Index and Numerical Pain Scales), recorded seven consecutive nights of sleep in their home using actigraphy, and completed a Devices Utility Questionnaire.Background and purpose
Methods
Cadeveric studies showed that single bundle ACL reconstructions were successful in limiting anterior tibial translation but were insufficient to control a combined rotatory load of internal and valgus torque. One possible cause of these condition could be that current single bundle procedures cannot realistically reproduce the complex anatomy of the ACL, especially the different function of its anteromedial(AM)and posterolateral(PL)bundle. The hypothesis of our study is that the addition of the PL bundle to the AM bundle, in an “in vivo” double bundle computer assisted ACL reconstruction, is actually able to reduce the internal rotation of the tibia at 30° degrees of knee flexion. Computer assisted ACL reconstruction has been used because it could be very effective in evaluating the global performance of the reconstructed knee. Ten consecutive doble bundle ACL reconstructions were performed in our Hospital using hamstrings graft and the 2.0OrthoPilot-B. Braun-Aesculap ACLnavigation system. The average age of patients was 27.8 years. The double-looped semitendinosus tendon replicating the AM bundle was fixed first at 60° of knee flexion. Than the gracilis tendon replicating the PL bundle was fixed at 15° of knee flexion. Maximum manual A–P displacement at 30° of flexion, maximum internal and external rotation of the knee were evaluated using the navigation system before surgery and after single(A–M)and double (AM+PL)bundle reconstruction. Statystical anlisys was done using paired T-test. Before ACL reconstruction mean manual maximum AP displacement was 17.2mm;mean manual maximum internal rotation was 19.8mm and mean manual maximum external rotation was 16.8mm. After AM bundle reconstruction mean manual maximum AP displacement was 6.1mm;mean manual maximum internal rotation was 17.0mm and mean manual maximum external rotation was 16.3mm. After AM+PL bundles reconstruction mean manual maximum AP displacement was 5.3mm;mean manual maximum internal rotation was 16.2mm and mean manual maximum external rotation was 14.6mm. There was no statistically significant difference in the tibial internal rotation at 30° after single bundle(AM)and double bundle(AM+PL)reconstruction. In this study the effectiveness of the PL bundle in controlling the internal rotation of the tibia, responsible of rotational instability of the knee, was evaluated in “in vivo” ACL reconstruction. The navigator system allowed us to obtain “in vivo” the real and correct value of AP displacement and internal and external rotation of the tibia before and after reconstruction. Our hypothesis that the addition of the PL bundle to the AM bundle is actually able to reduce the internal rotation of the tibia at 30° degrees of knee flexion, minimizing the pivot shift phenomenon, on the basis of our study has not been confirmed.
The aim of this study was to determine if the exposure to patient and surgeon was decreased with use of the mini C arm.
The purpose of this paper is to investigate the relative contribution of each component in the ultimate strength and stiffness of the Evolgate (Citieffe), which is presently a widely used fixation device in DGST ACL reconstruction. The three components of the Evolgate were tested using fresh frozen animal tissue stored at −20° Celsius. Common extensor tendons were harvested from 20-month-old bovine forelimbs. Twenty-four tests were performed for each of the following configurations: six tests using Evolgate complete, six tests using screw alone, six tests using screw and washer and six tests using screw and coil. A randomised t-test was used; differences were considered significant when p<
0.05. The mean strength was: Evolgate complete 1314±194N; coil and screw 700±152N; screw alone 408±86N; and screw and washer 333±93N. There was a significant difference between fixation strength of Evolgate and the other devices, none between screw alone and screw and washer. The mean slippage of the Evolgate was significantly lower than the other devices. The mean stiffness of the Evolgate (269±14 N/mm) was significantly greater than the other devices. On the basis of the results of the present study, the coil appears to be the most important component of the Evolgate, resulting in a significant increase of the fixation strength of the screw. However, it is important to note that, as the washer alone does not improve the strength of the screw, if a washer is associated with a coil a further significant increase in strength and stiffness of the device is observed.
The purpose of this study is to biomechanically evaluate how four different fixation devices (two femoral and two tibial) associated in three different combinations, using cyclic loading with final pull-out test, affect the strength and the stiffness of the femur-graft-tibia complex. We conducted a controlled laboratory study and tested, using cyclic loading with final pull-out, two femoral devices (Swing- bridge and Endobutton CL) and two tibial device (Evolgate and BioRCI screw) in three different combinations: Group A, EB-Bio RCI; Group B, EB-Evolgate; and Group C, SB- Evolgate. We used porcine knees and bovine digital extensor tendons and evaluated the stiffness and strength at the final pull-out, and the displacement at the 1st, 100th, 300th, 500th and 1000th cycle. A t-test was used for statistical evaluation. There was a statistically significant difference in ultimate failure load between group A and group B (p=0.03) and group A and group C (p=0.0007) but no difference between group B and group C (p=0.72). There was a statistically significant difference in ultimate failure load between group A and group C (p=0.02) and group B and group C (p=0.01) but no difference between group A and group B (p=0.88). Due to the biomechanical properties of the F-G-T complex the combination of Swing-Bridge and Evolgate seems to be a good alternative when an accelerated post-operative rehabilitation is planned after ACL reconstruction using DGST.
Maintenance of the bone stock is a primary goal in hip surgery. The idea of a resurfacing hip prosthesis had already been proposed in the past without success. The improvement in prosthetic materials, however, has mades it possible to reconsider the use of resurfacing prostheses. We report our experience with the Birmingham hip resurfacing (BHR) prosthesis. We operated on 58 patients (60 hips, two bilaterally), 31 men, 27 women, with a mean age of 47.9 years (25–76) and a mean follow-up of 27 months (1–42). We used the posterolateral approach with the patient in lateral decubitus. We performed a clinical and radiographic examination before surgery and at 1 and 6 months postoperatively. We recorded a statistically significant improvement in the clinical score at 6 months after surgery, with respect to the preoperative examination. Major complications were two fractures of the femoral neck and one infection. We recorded also peri-prosthetic calcifications in two patients, calcifications of the ileopsoas in two and ileopsoas tendinitis in one. In conclusion, in our experience, the BHR prosthesis reproduced the biomechanics of the hip and minimised the risk of luxation. The preliminary clinical results are encouraging, also for difficult cases.
The purpose of our study was to determine the effect of 4 weeks and 12 weeks of implantation on the strength of a tendon graft in a bone tunnel using a low-profile fixation device, Evolgate, in an extra-articular ovine model. Moreover, we evaluated the histological changes. The common digital extensor tendon was detached from the lateral femoral condyle and fixed with the Evolgate device in a 30-mm-long tunnel placed obliquely across the dense metaphyseal bone of the proximal tibia. We performed either biomechanical or histological study. Three sheep were sacrified at time 0 and their posterior limbs were used for biomechanical tests. Six sheep were used for biomechanical tests at time 1 (4 weeks) and at time 2 (12 weeks). The other three sheep were used for histological evaluation after 4 and 12 weeks of implantation. The biomechanical tests included a 50 N preload applied for 10 s and a cyclic load test in 50-N increments until failure to evaluate the ultimate failure load. We used a paired t-test to evaluate the difference between group at T1 and group at T2 with the control group at time 0, respectively. Tests were performed using an electromechanic machine (Zwick-Roell Z010, Zwick-Roell, Ulm, Germany). Data were recorded with dedicated software (Textexpert 8.1, Zwick-Roell). The biomechanical results show an improvement of about 50% in strength after 4 and 12 weeks post-implantation, respectively. The histological evaluation shows a layer of cellular, fibrous tissue between the tendon and the bone, along the length of the bone tunnel; this layer progressively matured and reorganised during the healing process. The collagen fibres that attached the tendon to the bone resembled Sharpey fibres. The strength of the interface was noted to have significantly and progressively increased between the second and the 12th week after the transplantation. The progressive increase in strength was correlated with the degree of bone ingrowth, mineralisation, and maturation of the healing tissue, noted histologically.
The use of conventional stems in hip arthroplasty may be difficult in cases of dysplasia, coxa vara or coxa valga, after fracture or proximal femur osteotomy. In fact the morphologic alterations of the proximal femur might require prosthetic components characterised by small size and different neck angles to restore correct joint biomechanics. In these cases we are often compelled to compromise between the ideal implant aneiversion and fit and what we can really achieve. An alternative to conventional prostheses is represented by custom-made prostheses. For 3 years we have been using the Modulus stem in the treatment of morphologic disorders of the hip. The conic shape of the stem easily fits the different morphologies of the proximal femur, whereas the modularity of the neck makes it possible to correct length, inclination and declination of the femural neck. We studied 59 patients by clinical and radiographic examination before surgery and 1, 3, 6 and 12 months postoperatively. We recorded a statistically significant improvement in the clinical score already at 1 month but this was even better at 6 months after surgery, with respect to the pre-operative examination. With the use of this prosthesis, the recovery of correct joint biomechanics together with high tribologic standards could improve the implant survival, leading to cost reduction and patient satisfaction.
Secure tendon-to-bone fixation is essential for successful rotator cuff repair. Thus, the biomechanical properties of devices used in rotator cuff repair should be better understood. This controlled laboratory study was performed to evaluate response to incremental cyclic loading of six different anchor-wire complexes commonly used in rotator cuff repair. Two absorbable anchors 5 and 6.5 mm in diameter and one metallic anchor, coupled with both ethibond or fibrewire (FW) were tested on five pairs of fresh-frozen human cadaveric shoulders. An incremental cyclic load was applied until failure using a Zwich-Roell Z010 electromechanical testing machine. The ultimate failure load and mode of failure were recorded. A t-test was used for statistical analysis. The FW suture coupled both with absorbable and metallic anchors provides a statistically significant stronger fixation. However, while the metallic anchors in most cases fail due to the slippage of the anchor, absorbable anchors fail due to rupture of the loop. The FW seems to increase the strength of fixation devices under cyclic load both using absorbable or metallic anchors with relevant differences in failure mode (slippage of the metallic anchor and loop failure in absorbable ones). Using a FW suture, the risk of metallic anchor migration might increase.