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Background Psychological risk factors have shown to be important prognostic indicators of back surgery outcome. Prevalence of these risk factors has rarely been examined in an outpatient clinic population. Furthermore, it is unclear to which extent they play a role, in absence of routinely used psychological screening tools, in treatment assignment. Objective First aim of this study was to examine the prevalence of psychological risk factors in back pain patients at an orthopaedic outpatient clinic. Second aim was to investigate the prognostic value of these identified risk factors in treatment assignment by the orthopaedic surgeons (conservative vs. surgery). Methods Sixty-six adult back pain patients were included. Psychological risk factor prevalence was determined with the Hospital Anxiety and Depression Scale, Tampa Scale of Kinesiophobia and Pain Catastrophizing Scale. Prognostic value of these risk factors in treatment assignment was examined using statistics. Results Respectively, 30 (45% HADS Anxiety), 27 (41%, HADS Depression), 19 (29%, PCS) and 37 (56%, TSK) patients scored above cut-off. No prognostic value of risk factors in treatment assignment, was found. Conclusions The majority of patients in our study is at risk of poor surgical outcome due to presence of psychological risk factors. Future studies should target the development of screening tools for an early identification of those at risk.

Contains fulltext : 191246.pdf (Publisher’s version ) (Open Access) BACKGROUND: Roentgen stereophotogrammetric analysis (RSA) is used to measure early prosthetic migration and to predict future implant failure. RSA has several disadvantages, such as the need for perioperatively inserted tantalum markers. Therefore, this study evaluates low-field MRI as an alternative to RSA. The use of traditional MRI with prostheses induces disturbing metal artifacts which are reduced by low-field MRI. The purpose of this study is to assess the feasibility to use low-field (0.25 Tesla) MRI for measuring the precision of zero motion. This was assessed by calculating the virtual prosthetic motion of a zero-motion prosthetic reconstruction in multiple scanning sessions. Furthermore, the effects of different registration methods on these virtual motions were tested. RESULTS: The precision of zero motion for low-field MRI was between 0.584 mm and 1.974 mm for translation and 0.884 degrees and 3.774 degrees for rotation. The manual registration method seemed most accurate, with mu

Item does not contain fulltext Total hip arthroplasty (TGA) is a successful surgical procedure to treat patients with hip osteoarthritis. Clinicians use different questionnaires to evaluate these patients. Gait velocity and these questionnaires; usually show significant improvement after TGA . This clinical evaluation does, however, not provide objective, quantifiable information about the movement patterns underlying the functional capacity, which is clinically important and can currently only be obtained in a gait laboratory. There is a need to improve patient instructions and to quantify the rehabilitation process. The sit-to-stand (STS) movement is an objective performance-based task, whose assessment is related with the evaluation of functional recovery. Twenty two patients with hip osteoarthritis participated in this study. For each patient, validated questionnaires were administered and gait velocity was measured. Time, ground reaction forces, and lower limb asymmetry parameters were calculated using the instrumented force shoes (IFS) during STS movement with and without armrest. Significant inter-limb asymmetry was observed. No correlation was found between any parameter and gait velocity and questionnaires outcomes. Significant differences in time and force parameters between with/without armrest were found. Concluding, inter-limb asymmetry can be evaluated with the IFS supplying important additional information not represented by gait velocity and questionnaires usually used.

Item does not contain fulltext OBJECTIVES: Intramedullary nailing has been accepted as the treatment of choice for femoral shaft fractures. The aim of our study was to determine the incidence and implications of rotational malalignment after intramedullary nailing using computed tomography measurements. DESIGN: Cohort study. SETTING: Patients who postoperatively visited the orthopaedic outpatient and radiology clinics. PATIENTS: Seventy-six patients, 59 men and 17 women, with a mean age of 28.4 years (15-88). INTERVENTION: Patients treated on a fracture table with an antegrade reamed AO nail (n = 46) or Grosse Kempf nail (n = 30) for a unilateral femoral shaft fracture between 1988 and 1998 were included in the study. MAIN OUTCOME MEASUREMENTS: Patients filled out a questionnaire concerning pain, daily activities, and sport. Oxford, Western Ontario and McMaster University osteoarthritis index, and Harris Hip and Knee Society scores were obtained. Physical exams and computed tomography measurements were established. RESULTS: Twenty-one patients (28%) were found to have a rotational malalignment of 15degrees or more. There was no significant difference in rotational deformity with either the AO or Grosse Kempf nail. The incidence of malrotation was independent of the fracture level. Patients with a torsional deformity had difficulties with more demanding activities like running, sports, and climbing stairs. Patients with an external rotational malalignment (n = 12) have more functional problems than patients with an internal rotational malalignment (n = 9). Clinically determined rotation differences are not accurate (+/-20degrees) compared with the established computed tomography measurements. CONCLUSIONS: Rotational malalignment after intramedullary nailing for femoral fractures is found in 28% of the patients in this study. These patients have difficulties with more demanding activities, especially when they have an external torsional deformity.

Background: Total hip arthroplasty is a successful surgical treatment in patients with osteoarthritis of the hip. Different questionnaires are used by the clinicians to assess functional capacity and the patient's pain, despite these questionnaires are known to be subjective. Furthermore, many studies agree that kinematic and kinetic parameters are crucial to evaluate and to provide useful information about the patient’s evolution for clinicians and rehabilitation specialists. However, these quantities can currently only be obtained in a fully equipped gait laboratory. Instrumented shoes can quantify gait velocity, kinetic, kinematic and symmetry parameters. The aim of this study was to investigate whether the instrumented shoes is a sufficiently sensitive instrument to show differences in mobility performance before and after total hip arthroplasty. Methods: In this study, patients undergoing total hip arthroplasty were measured before and 6–8 months after total hip arthroplasty. Both measurement sessions include 2 functional mobility tasks while the subject was wearing instrumented shoes. Before each measurement the Harris Hip Score and the Traditional Western Ontario and McMaster Universities osteoarthritis index were administered as well. Results: The stance time and the average vertical ground reaction force measured with the instrumented shoes during walking, and their symmetry index, showed significant differences before and after total hip arthroplasty. However, the data obtained with the sit to stand test did not reveal this improvement after surgery. Conclusions: Our results show that inter-limb asymmetry during a walking activity can be evaluated with the instrumented shoes before and after total hip arthroplasty in an outpatient clinical setting. The first author gratefully acknowledges the Spanish Department of Health and Institute Carlos III of the Government of Spain [Spanish Net on Aging and frailty; (RETICEF)], and Economy and Competitivity Department of the Government of Spain, under grants numbered RD12/043/0002 and DEP2011-24105, respectively, for financing this research.

Acetabular stress shielding may be a failure mechanism of acetabular constructs promoting osteolysis, aseptic loosening and failure. We used three-dimensional finite element analysis (FEA) to evaluate the effect of flexible sockets on acetabular stress shielding. The sockets were made of (1) full polyethylene (PE), (2) PE with a metal bearing and (3) a PE insert with a metal backing was used as a traditional stiff implant. We compared the strain energy density and interfacial micro-motions between bone and cementless sockets during walking. In our FEA model, the most elastic socket (case 1) showed the highest levels of micro-motion during walking (400 μm). The most rigid socket (case 3) showed smaller areas of high micro-motions. Assuming a threshold for ingrowth of 50 microns, the flexible cup showed an ingrowth area of almost 40%, whereas the other two cases showed stable areas covering 60% of the total bone–component interface. Furthermore, we found that the introduction of an implant generates a very different strain pattern directly around the implant as compared with the intact case, which has a horse-shoe shaped cartilage layer in the acetabulum. This difference was not affected much by the stiffness of the implant; a more flexible implant resulted in only slightly higher strain levels. Bone strains over 1.5 mm from the cup showed physiological values and were not affected by the stiffness of the implant. Hence, this study shows that the physiological strain patterns are not obtained in the direct periprosthetic bone, regardless of the stiffness of the material.

Total hip arthroplasty has been a very succesful orthopaedic procedure. The optimal fixation method of the acetabular component however, has not yet been defined.We performed a systematic review using the Medline and Embase databases to find evidence for the superiority of cemented or cementless acetabular components on short- and long-term clinical and radiological parameters. Methodological quality for randomised trials was assessed using the van Tulder checklist, and for the non randomised studies we used the Newcastle-Ottawa quality assessment scale.Our search strategy revealed 16 randomised controlled trials (RCT) and 19 non RCT studies in which cemented and cementless acetabular components are compared. A best evidence analysis for complications, wear, osteolysis, migration and clinical scores showed no superiority for either cemented or cementless socket in the RCTs. A best evidence analysis for non RCT studies revealed better osteolysis, migration properties and aseptic loosening survival for cementless sockets; however, wear and overall survival favoured the cemented sockets.We recommend that an orthopaedic surgeon should choose an established cemented or cementless socket for hip replacement based on patient characteristics, knowledge, experience and preference.

Item does not contain fulltext INTRODUCTION: Computed tomography (CT) is considered the method of choice for detecting rotational malalignment of the femur. However, it is unclear how reliable the method is, and what the causes are of potential inaccuracies. MATERIALS AND METHODS: To address these issues three observers measured the CT images of the femur of 76 patients on two separate occasions. The images were made during follow-up of a unilateral femoral shaft fractures. Rotational malalignment was determined by comparing the torsion angle of the injured to the noninjured leg. RESULTS: The pooled intraobserver variance was 3.9 degrees and interobserver variance 4.1 degrees. Of the two measurements of one observer 95% were up to 10.8 degrees different, and between observers 95% of the measurements were up to 15.6 degrees different. CONCLUSIONS: CT measurements of rotational malalignment of the femur are not accurate. This is due principally to the difficulty in defining a line through the axis of the femoral neck. The accuracy can be improved by taking the average of two measurements.

Background: Total hip arthroplasty is a successful surgical procedure to treat hip osteoarthritis. Clinicians use different questionnaires to assess the patient’s pain and functional capacity. Furthermore, they assess the quality of gait in a very global way. This clinical evaluation usually shows significant improvement after total hip arthroplasty, however, does not provide objective, quantifiable information about the movement patterns underlying the functional capacity, which can currently only be obtained in a gait laboratory. Instrumented force shoes can quantify gait velocity, ground reaction forces and the gait pattern easily in an outpatient setting. The main goal of this study was to investigate how mobility characteristics during walking, relate to gait velocity and questionnaire outcomes of patients with hip osteoarthritis in an outpatient setting. Methods: 22 patients with primary osteoarthritis of the hip selected for a total hip arthroplasty participated in this study. For each patient the Harris Hip Score, the Traditional Western Ontario and the McMaster Universities osteoarthritis index were administered. Subsequently, the patients were instructed to walk through the corridor while wearing instrumented shoes. The gait velocity estimated with the instrumented force shoes was validated measuring the time required to walk a distance of 10 m using a stopwatch and a measuring tape as a reference system. A regression analysis between spatial, temporal, ground reaction force parameters, including asymmetry, and the gait velocity and the questionnaires outcomes was performed. Results: The velocity estimated with the instrumented shoes did not differ significantly from the velocity measured independently. Although gait parameters correlated significantly with velocity, symmetry index parameters were not correlated with velocity. These symmetry index parameters show significant inter-limb asymmetry during walking. No correlation was found between any of the variables studied and questionnaires outcomes. Conclusion: Inter-limb asymmetry can be evaluated with the instrumented shoes supplying important additional information about the individual gait pattern, which is not represented by gait velocity and questionnaires usually used. Therefore, this new ambulatory measurement system is able to provide complementary information to gait velocity and questionnaires outcomes to assess the functional capacity of patients with hip osteoarthritis. The first author gratefully acknowledges the Spanish Ministry of Health, Institute Carlos III, and Government of Spain, with Grant RD06/013/1003, and the Group Theory branch of algebra from Public University of Navarre for financing this research.