Publications
284 results found
Riviere C, Lazic S, Dagneaux L, et al., 2018, Spine-hip relations in patients with hip osteoarthritis, EFORT OPEN REVIEWS, Vol: 3, Pages: 39-44, ISSN: 2058-5241
Riviere C, Lazic S, Boughton OR, et al., 2018, Current concepts for aligning knee implants: patient-specific or systematic?, EFORT Open Reviews, Vol: 3, Pages: 1-6, ISSN: 2058-5241
Clarke S, Cobb J, Jaere M, et al., 2018, Osteotomies: Advanced and complex techniques, ESSKA Instructional Course Lecture Book: Glasgow 2018, Pages: 129-151, ISBN: 9783662561263
We started performing precise surgery based upon CT plans in the last century - the first embodiment of this approach was a robotic assistant built for total knee replacement, the “Acrobot” [1]. Abundant evidence now exists to confirm that assistive technologies enable surgeons to achieve their preoperative goals [2]. The concept of planned surgery is therefore not novel. Patient-matched instruments share several key elements with the robotic platform, and these formed the basis of this current project. The essential elements include image segmentation, planning, and registration. We applied the know-how of these dimensions to design and build patient-matched guides for a range of tasks using biocompatible polymer 3D printers. Having established a workflow for arthroplasty, the adaptation of the same principles to osteotomy was a short step, requiring software to be developed to deliver semiautomated useful information regarding limb segment alignment and the shapes of bones.
Newman SDS, Altuntas A, Alsop H, et al., 2017, Up to 10 year follow-up of the Oxford Domed Lateral Partial Knee Replacement from an independent centre, KNEE, Vol: 24, Pages: 1414-1421, ISSN: 0968-0160
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- Citations: 18
Ma S, Hansen U, Cobb J, et al., 2017, Long-term effects of bisphosphonate therapy: perforations, microcracks and mechanical properties., Annual Meeting of the American-Society-for-Bone-and-Mineral-Research (ASBMR), Publisher: WILEY, Pages: S106-S107, ISSN: 0884-0431
Rivière C, Iranpour F, Auvinet E, et al., 2017, Mechanical alignment technique for TKA: Are there intrinsic technical limitations?, Revue de Chirurgie Orthopedique et Traumatologique, Vol: 103, Pages: 762-772, ISSN: 1877-0517
Rivière C, Iranpour F, Harris S, et al., 2017, The kinematic alignment technique for TKA reliably aligns the femoral component with the cylindrical axis, Revue de Chirurgie Orthopedique et Traumatologique, Vol: 103, Pages: 773-777, ISSN: 1877-0517
Riviere C, Iranpour F, Auvinet E, et al., 2017, Alignment options for total knee arthroplasty: A systematic review, ORTHOPAEDICS & TRAUMATOLOGY-SURGERY & RESEARCH, Vol: 103, Pages: 1047-1056, ISSN: 1877-0568
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- Citations: 167
Riviere C, Iranpour F, Harris S, et al., 2017, The kinematic alignment technique for TKA reliably aligns the femoral component with the cylindrical axis, ORTHOPAEDICS & TRAUMATOLOGY-SURGERY & RESEARCH, Vol: 103, Pages: 1069-1073, ISSN: 1877-0568
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- Citations: 26
Jin A, Cobb JP, Hansen U, et al., 2017, The effect of long term bisphosphonate therapy on trabecular bone strength and microcrack density, Bone & Joint Research, Vol: 6, Pages: 602-609, ISSN: 2046-3758
ObjectivesBisphosphonates (BP) are the first-line treatment for preventing fragility fractures. However, concern regarding the efficacy is growing because bisphosphonate is associated with over-suppression of remodelling and accumulation of microcracks. While DEXA scanning may show a gain in bone density the impact of this class of drug on mechanical properties remains unclear. We therefore sought to quantify the mechanical strength of bone treated with BP (oral alendronate for this study), and correlate this with the microarchitecture and density of microcracks in comparison with untreated controls. MethodsTrabecular bone from hip-fracture patients treated with BP (n=10) was compared to naïve fractured (n=14) and non-fractured controls (n=6). Trabecular cores were synchrotron and micro-CT scanned for microstructural analysis including quantification of bone volume fraction, micro-architecture and microcracks, then mechanically tested in compression. ResultsBP bone was 28% lower in strength than untreated hip-fracture bone and 48% lower in strength than and non-fracture control bone (4.6 vs 6.4 vs 8.9 MPa). BP treated bone had 24% more microcracks than naïve fractured bone and 51% more than non-fractured control (8.12 vs 6.55 vs 5.25 /cm2). BP and naïve fracture bone exhibited similar trabecular microarchitecture, with significantly lower bone volume fraction and connectivity than non-fractured controls. ConclusionsBP therapy had no detectable mechanical benefit. Instead its use was associated with substantially reduced bone strength. This low strength was probably due to the greater accumulation of microcracks and a lack of any discernible improvement in bone volume or microarchitecture. This preliminary study suggests that the clinical impact of BP induced microcrack accumulation may be substantial and long term.
Arnold M, Zhao S, Ma S, et al., 2017, Microindentation: a tool for measuring cortical bone stiffness? A systematic review, Bone & Joint Research, Vol: 6, Pages: 542-549, ISSN: 2046-3758
Objectives: Microindentation hasthe potential to measuretheelasticity(stiffness)of individualpatients’bone. Bone elasticity plays a crucial role in the press-fit stability of orthopaedic implants.Arming surgeons with accuratebone elasticityinformation may reduce surgical complicationsincluding peri-prosthetic fractures. The question we address with this systematicreview is whether microindentation can accurately measure cortical bone stiffness.Methods: A systematic review of all English language articles using a keyword search was undertaken in Medline, Embase, PubMed, Scopus and Cochrane databases. Studies thatonly used nanoindentation, cancellous boneoranimal tissue were excluded.Results: 1094abstracts were retrieved and 32papers were included in the analysis, 20 of which used reference point indentation and 12of which used traditional depth sensing indentation.There are a number of factors thatmust be taken into account when using microindentation such as tip size, depth and method of analysis.Only two studies validated microindentation againsttraditional mechanical testing techniques. Bothstudies used reference point indentation(RPI) with one showing that RPI parameters correlate well with mechanical testing, butanother suggestedthatthey do not. Conclusion: Microindentation has been used in various studies to assess bone elasticity but only two studies with conflicting results compared microindentation to traditional mechanical testing techniques. Further research,includingmore studies comparingmicroindentationto other mechanical testing methodsare needed,before microindentation can be reliably used to calculate cortical bone stiffness.
Arnold M, Zhao S, Ma S, et al., 2017, Microindentation - a tool for measuring cortical bone stiffness?, BONE & JOINT RESEARCH, Vol: 6, Pages: 542-549, ISSN: 2046-3758
Rivière C, FarhadIranpour, Auvinet E, et al., 2017, Mechanical Alignment Technique For TKA: Are there Intrinsic Technical Limitations?, Orthopaedics and Traumatology: Surgery and Research, ISSN: 1877-0568
BACKGROUND: Mechanically aligned (MA) total knee arthroplasty (TKA) is affected by disappointing functional outcomes in spite of the recent improvements in surgical precision and implant designs. This might suggest the existence of intrinsic technical limitations. Our study aims to compare the prosthetic and native trochlear articular surfaces and to estimate the extent of collateral ligament imbalance which is technically un-correctable by collateral ligament release when TKA implants are mechanically aligned. STUDY HYPOTHESIS: conventional MA technique generates a high rate of prosthetic overstuffing of the distal groove, distal lateral trochlear facet and distal lateral femoral condyle (Hypothesis 1), and technically un-correctable collateral ligament imbalance (hypothesis 2)? Disregarding the distal femoral joint line obliquity (DFJLO) when performing femoral cuts explainsdistal lateral femoral prosthetic stuffing and un-correctable imbalance (hypothesis 3)? METHODS: Twenty patients underwent a conventional MA TKA. Pre-operative MRI-based 3D knee models were generated and MA TKA was simulated. Native and prosthetic trochlear articular surfaces were compared using in-house analysis software.Following the automatic determination by the planning software of the size of the extension and flexion gaps, an algorithm was applied to balance the gaps and the frequency and amplitude of technically un-correctable knee imbalance wereestimated. RESULTS: The conventional MA technique generateda significant slight distal lateral femoral prosthetic overstuffing (mean 0.6mm, 0.8mm, 1.25 mmfor the most distal lateral facet point, groove, and at the most distal point of lateral femoral condyle, respectively) and a high rate of type 1 and 2 un-corretable knee imbalance (30% and 40%, respectively). The incidence of distal lateral prosthetic overstuffing (trochlea and condyle) and un-correctable knee imbalance were strongly to very strongly correlated with the DFJLO (r=0.53 to 0.89).
Aframian A, Auvinet E, Iranpour F, et al., 2017, O95: An instrumented treadmill shows excellent reliability and repeatability at a range of speeds to maximal walking speedover a range of inclines and declines, Gait and Posture, Vol: 57, ISSN: 0966-6362
Wiik AV, Logishetty K, Boughton O, et al., 2017, Letter to the Editor regarding 'How symmetric are metal-on-metal hip resurfacing patients during gait? Insights for the rehabilitation'., Journal of Biomechanics, Vol: 63, Pages: 203-203, ISSN: 0021-9290
Li J, Clarke S, Cobb JP, et al., 2017, Novel curved surface preparation technique for knee resurfacing, Medical Engineering and Physics, Vol: 49, Pages: 89-93, ISSN: 1350-4533
Conventional tools are incapable of preparing the curved articular surface geometry required during cartilage repair procedures. A novel curved surface preparation technique was proposed and tested to provide an accurate low-cost solution. Three shapes of samples, with flat, 30 mm radius and 60 mm radius surfaces, were manufactured from foam bone substitute for testing. Registering guides and cutting guides were designed and 3-D printed to fit onto the foam samples. A rotational cutting tool with an adapter was used to prepare the surfaces following the guidance slots in the cutting guides. The accuracies of the positions and shapes of the prepared cavities were measured using a digital calliper, and the surface depth accuracy was measured using a 3-D scanner. The mean shape and position errors were both approximately ± 0.5 mm and the mean surface depth error ranged from 0 to 0.3 mm, range − 0.3 to + 0.45 mm 95% CI. This study showed that the technique was able to prepare a curved surface accurately; with some modification it can be used to prepare the knee surface for cartilage repair.
Ridzwan M, Sukjamsri C, Pal B, et al., 2017, Femoral fracture type can be predicted from femoral structure: a finite element study validated by digital volume correlation experiments, Journal of Orthopaedic Research, Vol: 36, Pages: 993-1001, ISSN: 1554-527X
Proximal femoral fractures can be categorized into two main types: Neck and intertrochanteric fractures accounting for 53% and 43% of all proximal femoral fractures, respectively. The possibility to predict the type of fracture a specific patient is predisposed to would allow drug and exercise therapies, hip protector design, and prophylactic surgery to be better targeted for this patient rendering fracture preventing strategies more effective. This study hypothesized that the type of fracture is closely related to the patient-specific femoral structure and predictable by finite element (FE) methods. Fourteen femora were DXA scanned, CT scanned, and mechanically tested to fracture. FE-predicted fracture patterns were compared to experimentally observed fracture patterns. Measurements of strain patterns to explain neck and intertrochanteric fracture patterns were performed using a digital volume correlation (DVC) technique and compared to FE-predicted strains and experimentally observed fracture patterns. Although loaded identically, the femora exhibited different fracture types (six neck and eight intertrochanteric fractures). CT-based FE models matched the experimental observations well (86%) demonstrating that the fracture type can be predicted. DVC-measured and FE-predicted strains showed obvious consistency. Neither DXA-based BMD nor any morphologic characteristics such as neck diameter, femoral neck length, or neck shaft angle were associated with fracture type. In conclusion, patient-specific femoral structure correlates with fracture type and FE analyses were able to predict these fracture types. Also, the demonstration of FE and DVC as metrics of the strains in bones may be of substantial clinical value, informing treatment strategies and device selection and design.
Ali AM, Newman S, Hooper P, et al., 2017, The effect of implant position on bone strain following lateral unicompartmental knee arthroplasty. A biomechanical model using digital image correlation, Bone and Joint Research, Vol: 6, Pages: 522-529, ISSN: 2046-3758
ObjectivesUnicompartmental knee arthroplasty (UKA) is a demanding procedure, with tibial component subsidence or pain from high tibial strain being potential causes of revision. The optimal position in terms of load transfer has not been documented for lateral UKA. Our aim was to determine the effect of tibial component position on proximal tibial strain.MethodsA total of 16 composite tibias were implanted with an Oxford Domed Lateral Partial Knee implant using cutting guides to define tibial slope and resection depth. Four implant positions were assessed: standard (5° posterior slope); 10° posterior slope; 5° reverse tibial slope; and 4 mm increased tibial resection. Using an electrodynamic axial-torsional materials testing machine (Instron 5565), a compressive load of 1.5 kN was applied at 60 N/s on a meniscal bearing via a matching femoral component. Tibial strain beneath the implant was measured using a calibrated Digital Image Correlation system.ResultsA 5° increase in tibial component posterior slope resulted in a 53% increase in mean major principal strain in the posterior tibial zone adjacent to the implant (p = 0.003). The highest strains for all implant positions were recorded in the anterior cortex 2 cm to 3 cm distal to the implant. Posteriorly, strain tended to decrease with increasing distance from the implant. Lateral cortical strain showed no significant relationship with implant position.ConclusionRelatively small changes in implant position and orientation may significantly affect tibial cortical strain. Avoidance of excessive posterior tibial slope may be advisable during lateral UKA.
Duffell LD, Jordan SJ, Cobb JP, et al., 2017, Gait adaptations with aging in healthy participants and people with knee joint osteoarthritis, Gait and Posture, Vol: 57, Pages: 246-251, ISSN: 0966-6362
The relationship between age and gait characteristics in people with and without medial compartment osteoarthritis (OA) remains unclear. We aimed to characterize this relationship and to relate biomechanical and structural parameters in a subset of OA patients. Twenty five participants with diagnosed unilateral medial knee OA and 84 healthy participants, with no known knee pathology were recruited. 3D motion capture was used to analyse sagittal and coronal plane gait parameters while participants walked at a comfortable speed. Participants were categorized according to age (18–30, 31–59 and 60+ years), and those with and without OA were compared between and within age groups. In a subset of OA patients, clinically available Computed Tomography images were used to assess joint structure. Differences in coronal plane kinematics at the hip and knee were noted in participants with OA particularly those who were older compared with our healthy controls, as well as increased knee moments. Knee adduction moment correlated with structural parameters in the subset of OA patients. Increased knee moments and altered kinematics were observed in older participants presenting with OA only, which seem to be related to morphological changes in the joint due to OA, as opposed to being related to the initial cause of medial knee OA.
Riviere C, Hardijzer A, Lazennec J-Y, et al., 2017, Spine-hip relations add understandings to the pathophysiology of femoro-acetabular impingement: A systematic review, ORTHOPAEDICS & TRAUMATOLOGY-SURGERY & RESEARCH, Vol: 103, Pages: 549-557, ISSN: 1877-0568
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- Citations: 35
Ng CTJ, Newman S, Harris S, et al., 2017, Patient-specific instrumentation improves alignment of lateral unicompartmental knee replacements by novice surgeons., International Orthopaedics, Vol: 41, Pages: 1379-1385, ISSN: 0341-2695
PurposePatient-specific instrumentation (PSI) has the potential to offer numerous benefits—not least of all, improved resection accuracy; but its potential has not been realised in clinical studies. An explanation may be the focus of such studies on the total knee replacement (TKR—a common procedure, with which surgeons are generally very familiar. Consequently, we sought to investigate the potential role of PSI in guiding novice surgeons to perform the more technically demanding and less familiar lateral unicondylar knee replacement (LUKR).MethodsTwelve orthopaedic trainees naive to LUKR were instructed to perform the procedure according to a pre-operative plan. These were carried out on synthetic sawbones and were completed once with conventional instrumentation alone and once with the adjunct of PSI, allowing a comparison of the plan adherence achieved by the two sets of instrumentation.ResultsThere was a tendency for PSI to demonstrate improved plan adherence, though a statistically significant improvement was only seen in compound rotational error of the femoral implant (p = 0.004). PSI was, however, able to produce narrower standard deviations in the mean translational displacement of the femoral implant and also the mean rotational displacement of both implants, suggesting a higher degree of precision.ConclusionsOur study provides some evidence that PSI can improve the ability of novice surgeons to replicate a pre-operative plan, but our results suggest the need for larger-scale clinical studies to establish the role of PSI in this procedure.
Wiik AV, Aqil A, Brevadt M, et al., 2017, Abnormal ground reaction forces lead to a general decline in gait speed in knee osteoarthritis patients., World Journal of Orthopedics, Vol: 8, Pages: 322-328, ISSN: 2218-5836
AIM: To analyse ground reaction forces at higher speeds using another method to be more sensitive in assessing significant gait abnormalities. METHODS: A total of 44 subjects, consisting of 24 knee osteoarthritis (OA) patients and 20 healthy controls were analysed. The knee OA patients were recruited from an orthopaedic clinic that were awaiting knee replacement. All subjects had their gait patterns during stance phase at top walking speed assessed on a validated treadmill instrumented with tandem force plates. Temporal measurements and ground reaction forces (GRFs) along with a novel impulse technique were collected for both limbs and a symmetry ratio was applied to all variables to assess inter-limb asymmetry. All continuous variables for each group were compared using a student t-test and χ(2) analysis for categorical variables with significance set at α = 0.05. Receiver operator characteristics curves were utilised to determine best discriminating ability. RESULTS: The knee OA patients were older (66 ± 7 years vs 53 ± 9 years, P = 0.01) and heavier (body mass index: 31 ± 6 vs 23 ± 7, P < 0.001) but had a similar gender ratio when compared to the control group. Knee OA patients were predictably slower at top walking speed (1.37 ± 0.23 m/s vs 2.00 ± 0.20 m/s, P < 0.0001) with shorter mean step length (79 ± 12 cm vs 99 ± 8 cm, P < 0.0001) and broader gait width (14 ± 5 cm vs 11 ± 3 cm, P = 0.015) than controls without any known lower-limb joint disease. At a matched mean speed (1.37 ± 0.23 vs 1.34 ± 0.07), ground reaction results revealed that push-off forces and impulse were significantly (P < 0.0001) worse (18% and 12% respectively) for the knee OA patients when compared to the controls. Receiver operating characteristic curves analysis demonstrated total impulse to be the best discriminator of asymmetry, with an area under the curve of 0.902, with a cut-off
Rivière C, Lazennec J-Y, Van Der Straeten C, et al., 2017, The influence of spine-hip relations on total hip replacement: A systematic review., Orthopaedics and Traumatology: Surgery and Research, Vol: 103, Pages: 559-568, ISSN: 1877-0568
Sagittal pelvic kinematics along with spino-pelvic angular parameters have recently been studied by numerous investigators for their effect on total hip replacement (THR) clinical outcomes, but many issue of spine-hip relations (SHR) are currently unexplored. Therefore, our review aims at clarifying the following questions: is there any evidence of a relationship between articular impingement/dislocation risk in primary THR and (1) certain sagittal pelvic kinematics patterns, (2) pelvic incidence, and (3) types of SHRs? A systematic review of the existing literature utilising PubMed and Google search engines was performed in January 2017. Only clinical or computational studies published in peer-reviewed journals over the last five years in either English or French were reviewed. We identified 769 reports, of which 12 met our eligibility criteria. A review of literature shows that sagittal pelvic kinematics, but not the pelvic incidence, influences the risk of prosthetic impingement/dislocation. We found no study having assessed the relationship between this risk and the types of SHRs. Sagittal pelvic kinematics is highly variable among individuals and certain kinematic patterns substantially influences the risk of prosthetic impingement/dislocation. Recommendations for cup positioning are therefore switching from a systematic to a patient-specific approach, with the standing cup orientation Lewinneck safe zone progressively giving way to a new parameter of interest: the functional orientation of the cup. Based on a recently published classification for SHRs, We propose a new concept of "kinematically aligned THR" for the purposes of THR planning. Further studies are needed to investigate the relevance of such a classification towards the assumptions and hypothesis we have made. Level of evidence,- Level IV, systematic review of level III and IV studies.
Iranpour F, Merican AM, Teo SH, et al., 2017, Femoral articular geometry and patellofemoral stability, KNEE, Vol: 24, Pages: 555-563, ISSN: 0968-0160
Background:Patellofemoral instability is a major cause of anterior knee pain. The aim of this study was to examine how the medial and lateral stability of the patellofemoral joint in the normal knee changes with knee flexion and measure its relationship to differences in femoral trochlear geometry.Methods:Twelve fresh-frozen cadaveric knees were used. Five components of the quadriceps and the iliotibial band were loaded physiologically with 175 N and 30 N, respectively. The force required to displace the patella 10 mm laterally and medially at 0°, 20°, 30°, 60° and 90° knee flexion was measured. Patellofemoral contact points at these knee flexion angles were marked. The trochlea cartilage geometry at these flexion angles was visualized by Computed Tomography imaging of the femora in air with no overlying tissue. The sulcus, medial and lateral facet angles were measured. The facet angles were measured relative to the posterior condylar datum.Results:The lateral facet slope decreased progressively with flexion from 23° ± 3° (mean ± S.D.) at 0° to 17 ± 5° at 90°. While the medial facet angle increased progressively from 8° ± 8° to 36° ± 9° between 0° and 90°. Patellar lateral stability varied from 96 ± 22 N at 0°, to 77 ± 23 N at 20°, then to 101 ± 27 N at 90° knee flexion. Medial stability varied from 74 ± 20 N at 0° to 170 ± 21 N at 90°. There were significant correlations between the sulcus angle and the medial facet angle with medial stability (r = 0.78, p < 0.0001).Conclusions:These results provide objective evidence relating the changes of femoral profile geometry with knee flexion to patellofemoral stability.
Ma S, Goh EL, Jin A, et al., 2017, Long-term effects of bisphosphonate therapy: perforations, microcracks and mechanical properties, Scientific Reports, Vol: 7, Pages: 1-10, ISSN: 2045-2322
Osteoporosis is characterised by trabecular bone loss resulting from increased osteoclast activation and unbalanced coupling between resorption and formation, which induces a thinning of trabeculae and trabecular perforations. Bisphosphonates are the frontline therapy for osteoporosis, which act by reducing bone remodelling, and are thought to prevent perforations and maintain microstructure. However, bisphosphonates may oversuppress remodelling resulting in accumulation of microcracks. This paper aims to investigate the effect of bisphosphonate treatment on microstructure and mechanical strength. Assessment of microdamage within the trabecular bone core was performed using synchrotron X-ray micro-CT linked to image analysis software. Bone from bisphosphonate-treated fracture patients exhibited fewer perforations but more numerous and larger microcracks than both fracture and non-fracture controls. Furthermore, bisphosphonate-treated bone demonstrated reduced tensile strength and Young’s Modulus. These findings suggest that bisphosphonate therapy is effective at reducing perforations but may also cause microcrack accumulation, leading to a loss of microstructural integrity and consequently, reduced mechanical strength.
Boughton OR, Zhao S, Arnold M, et al., 2017, Measuring bone stiffness using microindentation, British Orthopaedic Research Society (BORS) 2016 Conference, Publisher: British Editorial Society of Bone and Joint Surgery, Pages: 31-31, ISSN: 2049-4416
Hurst S, 2017, Electronic patient centred outcomes in orthopaedic surgery
This thesis primarily reports on the national pilot of an electronic patient reported outcomes (ePRO) system for orthopaedic patients. Also reported on within the pilot is a new electronic patient centred outcome measure (ePCO) with focus on activity participation, and aspiration. At the time of publishing the pilot remains the largest of its kind within the speciality, and the first of its kind with respect to ePCOs. A background with historical perspective is provided for the use of outcomes in orthopaedic surgery, including a discussion surrounding current practices, and controversies. The engineering principles behind the construction of an ePCO/PCO system are also explained, along with the current regulatory guidelines governing them in Europe and the United States. The development and piloting of three individual software platforms are explained, evaluated, and discussed. This includes in the appendix a discussion on their wider context within industry, and within an increasingly technological able society. The final platform (Software C) is piloted in a large cohort both nationally, and internationally. Results from the pilot are presented and discussed in terms of the software usability, the ability for PROs to be successfully digitalised to ePROs within the software, and patient’s opinion of the technology. Objective outcome data obtained from a instrumented treadmill is used as an adjunct to the analysis of the impact of ePROs collected during the pilot, and also helping to address the validation parameters for the ePCO. Finally, the PCO is reported on. This includes the principles providing its conception, and foundation. It is tested using parameters for outcome score validation in both an initial paper-based pilot study, and in a national pilot using a modified digitalised format of the PCO
Nazruzov T, Van Der Straeten C, Iranpour Boroujeni F, et al., 2017, REGISTRATION OF PRE- AND POST-OPERATIVE CT DATA USING ICP FOR PATIENTS UNDERGOING TOTAL KNEE ARTHROPLASTY (TKA), Bone & Joint Journal, ISSN: 2049-4394
Ma S, Goh EL, Patel B, et al., 2016, Are the cracks starting to appear in bisphosphonate therapy?, British Orthopaedic Research Society (BORS) 2016 Conference, Publisher: British Editorial Society of Bone and Joint Surgery, Pages: 53-53, ISSN: 2049-4416
Jones G, Kotti M, Wiik A, et al., 2016, Gait comparison of unicompartmental and total knee arthroplasties with healthy controls, Bone & Joint Journal, Vol: 98-B, Pages: 16-21, ISSN: 2049-4394
Aims:To compare the gait of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) patients with healthy controls, usinga machine learning approach.Patients:145 participants (121 healthy controls, 12 cruciate retaining TKA patients, and 12 mobile bearing UKA patients) were recruited. The TKAand UKA patients were a minimum of 12 months post-op, and matched for pattern and severity of arthrosis, age, and BMI.Methods:Participants walked on an instrumented treadmill until their maximum walking speed was reached. Temporospatial gait parameters, andvertical ground reaction force data was captured at each speed. Oxford knee scores (OKS) were also collected. An ensemble of treesalgorithm was used to analyse the data: 27 gait variables were used to train classification trees for each speed, with a binary outputprediction of whether these variables were derived from a UKA or TKA patient. Healthy control gait data was then tested by the decisiontrees at each speed and a final classification (UKA or TKA) reached for each subject in a majority voting manner over all gait cycles andspeeds. Top walking speed was also recorded.Results:92% of the healthy controls were classified by the decision tree as a UKA, 5% as a TKA, and 3% were unclassified. There was nosignificant difference in OKS between the UKA and TKA patients (p=0.077). Top walking speed in TKA patients (1.6 m/s [1.3-2.1]) wassignificantly lower than that of both the UKA group (2.2 m/s [1.8-2.7]) and healthy controls (2.2 m/s [1.5-2.7]) (p<0.001).Conclusion:UKA results in a more physiological gait compared to TKA, and a higher top walking speed. This difference in function was not detectedby the OKS.
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