Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleChen A, Sabharwal S, Akhtar K, et al., 2015,
Time-driven activity based costing of total knee replacement surgery at a London teaching hospital
, KNEE, Vol: 22, Pages: 640-645, ISSN: 0968-0160- Author Web Link
- Cite
- Citations: 38
-
Journal articleAqil A, Wiik A, Clarke S, et al., 2015,
Resurfacing head size and femoral fracture: Are registry conclusions on head size justified?
, Eur J Orthop Surg Traumatol, Vol: 25, Pages: 1301-1305BACKGROUND: Joint registries report that peri-prosthetic fractures are the most common reason for early revision of a hip resurfacing arthroplasty (HRA) and are twice as likely with small implant sizes. However, a national survey found peri-prosthetic fracture to be strongly associated with surgical accuracy. We therefore asked whether the force required to induce a peri-prosthetic fracture: (1) was significantly lower when using smaller implants and (2) correlated to the size of implant used, when surgery was performed accurately. METHODS: To ensure an adequate power, we calculated our sample size from pilot data. Forty-four femurs were tested in two experiments. The first experiment tested femurs with either a small (48 mm) or a large (54 mm) HRA implant. The second involved testing femurs with a range of implant sizes. A rapid prototyped femur-specific guide ensured accurate implantation. Specimens were then vertically loaded in a servo-hydraulic testing machine till fracture. Displacement (mm) and force (N) required for fracture were recorded. RESULTS: A median force of 1081 N was required to fracture specimens implanted with small 48-mm heads, while 1134 N was required when a 54-mm head was used (U = 77, z = -0.054, p = 0.957). Implant head size and force required to fracture were not related, r = 0.12, p = 0.63. CONCLUSIONS: The force required to induce a resurfacing peri-prosthetic fracture was not related to the size of the implant. The increased failure rate seen in all registries is unlikely to be directly the result of this single variable. Correctly performed resurfacing arthroplasty is highly resistant to fracture.
-
Journal articleSugand K, Akhtar K, Khatri C, et al., 2015,
Training effect of a virtual reality haptics-enabled dynamic hip screw simulator.
, Acta Orthopaedica, Vol: 86, Pages: 695-701, ISSN: 1745-3682Background and purpose - Virtual reality (VR) simulation offers a safe, controlled, and effective environment to complement training but requires extensive validation before it can be implemented within the curriculum. The main objective was to assess whether VR dynamic hip screw (DHS) simulation has a training effect to improve objective performance metrics. Patients and methods - 52 surgical trainees who were naïve to DHS procedures were randomized to 2 groups: the training group, which had 5 attempts, and the control group, which had only one attempt. After 1 week, both cohorts repeated the same number of attempts. Objective performance metrics included total procedural time (sec), fluoroscopy time (sec), number of radiographs (n), tip-apex distance (TAD; mm), attempts at guide-wire insertion (n), and probability of cut-out (%). Mean scores (with SD) and learning curves were calculated. Significance was set as p < 0.05. Results - The training group was 68% quicker than the control group, used 75% less fluoroscopy, took 66% fewer radiographs, had 82% less retries at guide-wire insertion, achieved a reduced TAD (by 41%), had lower probability of cut-out (by 85%), and obtained an increased global score (by 63%). All these results were statistically significant (p < 0.001). The participants agreed that the simulator provided a realistic learning environment, they stated that they had enjoyed using the simulator, and they recognized the need for the simulator in formal training. Interpretation - We found a significant training effect on the VR DHS simulator in improving objective performance metrics of naïve surgical trainees. Patient safety, an important priority, was not compromised.
-
Journal articleChawla A, McGregor A, 2015,
Highlights from day three of the EuroSciCon 2015 Sports Science Summit.
, Future Science OA, Vol: 1, ISSN: 2056-5623This EuroSciCon Sports Science Summit represented a significant gathering of leading professionals in the field of sports science. The conference was held on 13-15 January 2015 at the O2 arena, London, UK. The chairman on the third day was Mr Greg Robertson, a specialist trainee Orthopedic surgeon from Edinburgh. The conference attracted over 80 attendants from all over the world, with 32 presentations from invited speakers and peer-reviewed submissions. This meeting report provides a summary of the best abstracts from the conference.
-
Journal articleSugand K, Mawkin M, Gupte C, 2015,
Validating Touch Surgery™: A cognitive task simulation and rehearsal app for intramedullary femoral nailing
, INJURY-INTERNATIONAL JOURNAL OF THE CARE OF THE INJURED, Vol: 46, Pages: 2212-2216, ISSN: 0020-1383- Author Web Link
- Cite
- Citations: 40
-
Journal articleAthwal KK, Daou HE, Kittl C, et al., 2015,
The superficial medial collateral ligament is the primary medial restraint to knee laxity after cruciate-retaining or posterior-stabilised total knee arthroplasty: effects of implant type and partial release.
, Knee Surgery, Sports Traumatology, Arthroscopy, Vol: 24, Pages: 2646-2655, ISSN: 0942-2056PURPOSE: The aim of this study was to quantify the contributions of medial soft tissues to stability following cruciate-retaining (CR) or posterior-stabilised (PS) total knee arthroplasty (TKA). METHODS: Using a robotic system, eight cadaveric knees were subjected to ±90-N anterior-posterior force, ±5-Nm internal-external and ±8-Nm varus-valgus torques at various flexion angles. The knees were tested intact and then with CR and PS implants, and successive cuts of the deep and superficial medial collateral ligaments (dMCL, sMCL) and posteromedial capsule (PMC) quantified the percentage contributions of each structure to restraining the applied loads. RESULTS: In implanted knees, the sMCL restrained valgus rotation (62 % across flexion angles), anterior-posterior drawer (24 and 10 %, respectively) and internal-external rotation (22 and 37 %). Changing from CR TKA to PS TKA increased the load on the sMCL when resisting valgus loads. The dMCL restrained 11 % of external and 13 % of valgus rotations, and the PMC was significant at low flexion angles. CONCLUSIONS: This work has shown that medial release in the varus knee should be minimised, as it may inadvertently result in a combined laxity pattern. There is increasing interest in preserving constitutional varus in TKA, and this work argues for preservation of the sMCL to afford the surgeon consistent restraint and maintain a balanced knee for the patient.
-
Journal articleWeinert-Aplin RA, Bull AM, McGregor AH, 2015,
Orthotic Heel Wedges Do Not Alter Hindfoot Kinematics and Achilles Tendon Force During Level and Inclined Walking in Healthy Individuals.
, Journal of Applied Biomechanics, Vol: 32, Pages: 160-170, ISSN: 1543-2688Conservative treatments such as in-shoe orthotic heel wedges to treat musculoskeletal injuries are not new. However, weak evidence supporting their use in the management of Achilles tendonitis suggests the mechanism by which these heel wedges work remains poorly understood. It was the aim of this study to test the underlying hypothesis that heel wedges can reduce Achilles tendon load. A musculoskeletal modelling approach was used to quantify changes in lower limb mechanics when walking due to the introduction of 12mm orthotic heel wedges. 19 healthy volunteers walked on an inclinable walkway while optical motion, forceplate and plantar pressure data were recorded. Walking with heel wedges increased ankle dorsiflexion moments and reduced plantar flexion moments. This resulted in increased peak ankle dorsiflexor muscle forces during early stance and reduced Tibialis Posterior and toe flexor muscles forces during late stance. Heel wedges did not reduce overall Achilles tendon force during any walking condition, but did redistribute load from the medial to lateral triceps surae during inclined walking. These results add to the body of clinical evidence confirming that heel wedges do not reduce Achilles tendon load and our findings provide an explanation as to why this may be the case.
-
Journal articleBergmann JHM, Goodier H, Spulber I, et al., 2015,
The "Wear and Measure" Approach: Linking Joint Stability Measurements from a Smart Clothing System to Optical Tracking
, Journal of Sensors, Vol: 2015, ISSN: 1687-7268Joint stability is essential for maintaining normal everyday function. However, assessment of stability often still relies on subjective or obtrusive methods. An unobtrusive approach would be to have our clothes assess our joint stability. Methods. A new application consisting of an attachable clothing sensing system (ACSS), constructed from a flexible carbon black and polyurethane composite film, was tested against an optical tracking system to assess if the ACSS placed across the knee could provide stability results that correlate with the optical tracking outcomes. Stability was challenged by reducing the base of support and by removing vision generating different experimental conditions. Results. Bland and Altman plots indicated a general proportional error between the measurement systems within each stability condition. However, across all conditions a Spearman correlation coefficient of 0.81 () was found between the displacement values and ACSS, showing a good association between stability measurements. Electromyography (EMG) also indicated that joint stability was challenged between the different conditions. The ACSS was experienced by users as comfortable and hardly noticeable. Conclusions. This study indicates that smart clothing can measure important physiological parameters in an unobtrusive manner. This “wear and measure” approach might change how we gather relevant clinical data in the future.
-
Journal articleAkhtar K, Sugand K, Wijendra A, et al., 2016,
The Transferability of Generic Minimally Invasive Surgical Skills: Is There Crossover of Core Skills Between Laparoscopy and Arthroscopy?
, JOURNAL OF SURGICAL EDUCATION, Vol: 73, Pages: 329-338, ISSN: 1931-7204- Author Web Link
- Cite
- Citations: 9
-
Book chapterMasouros S, Halewood C, Bull A, et al., 2015,
Biomechanics
, Expertise orthopadie und unfallchirurgie: Knie, Editors: Kohn, ISBN: 978-3-1317500-1-3 -
Conference paperGeraldes D, Hansen U, Amis A, 2015,
An automated framework for parametric analysis glenoid implant design
, Bath Biomechanics Symposium 2015 -
Conference paperGeraldes D, Hansen U, Amis A, 2015,
Parametric analysis of glenoid implant design
, International Society of Biomechanics 2015 -
Conference paperBrevadt MJ, manning V, wiik A, et al., 2015,
The Impact of Stem Length on Function Following Hip Arthroplasty: Are Long Stems Still Required?
, International Society for Technology in Arthroplasty -
Conference paperDeane JA, McGregor AM, 2015,
Clinical Interpretations of Degenerative Lumbar Disc Disease
, Society of Back Pain Research, Publisher: British Editorial Society of Bone and Joint Surgery, ISSN: 2049-4408 -
Journal articleSukjamsri C, Amis A, Hansen UN, et al., 2015,
Digital volume correlation and micro-CT: an in-vitro technique for measuring full-field interface micromotion around polyethylene implants
, Journal of Biomechanics, Vol: 48, Pages: 3447-3454, ISSN: 0021-9290Micromotion around implants is commonly measured using displacement-sensor techniques. Due to the limitations of these techniques, an alternative approach (DVC-μCT) using digital volume correlation (DVC) and micro-CT (μCT) was developed in this study. The validation consisted of evaluating DVC-μCT based micromotion against known micromotions (40, 100 and 150 μm) in a simplified experiment. Subsequently, a more clinically realistic experiment in which a glenoid component was implanted into a porcine scapula was carried out and the DVC-μCT measurements during a single load cycle (duration 20 min due to scanning time) was correlated with the manual tracking of micromotion at 12 discrete points across the implant interface. In this same experiment the full-field DVC-μCT micromotion was compared to the full-field micromotion predicted by a parallel finite element analysis (FEA). It was found that DVC-μCT micromotion matched the known micromotion of the simplified experiment (average/peak error=1.4/1.7 μm, regression line slope=0.999) and correlated with the micromotion at the 12 points tracked manually during the realistic experiment (R2=0.96). The DVC-μCT full-field micromotion matched the pattern of the full-field FEA predicted micromotion. This study showed that the DVC-μCT technique provides sensible estimates of micromotion. The main advantages of this technique are that it does not damage important parts of the specimen to gain access to the bone–implant interface, and it provides a full-field evaluation of micromotion as opposed to the micromotion at just a few discrete points. In conclusion the DVC-μCT technique provides a useful tool for investigations of micromotion around plastic implants.
-
Journal articleSabharwal S, Wilson H, Reilly P, et al., 2015,
Heterogeneity of the definition of elderly age in current orthopaedic research
, SpringerPlus, Vol: 4, Pages: 1-7, ISSN: 2193-1801Medical research often defines a person as elderly when they are 65 years of age or above, however defining elderly age by chronology alone has its limitations. Moreover, potential variability in definitions of elderly age can make interpretation of the collective body of evidence within a particular field of research confusing. Our research goals were to (1) evaluate published orthopaedic research and determine whether there is variability in proposed definitions of an elderly person, and (2) to determine whether variability exists within the important research sub-group of hip fractures. A defined search protocol was used within PubMed, EMBASE and the Cochrane Library that identified orthopaedic research articles published in 2012 that stated within their objective, intent to examine an intervention in an elderly population. 80 studies that included 271,470 patients were identified and subject to analysis. Four (5 %) studies failed to define their elderly population. The remaining 76 (95 %) studies all defined elderly age by chronology alone. Definitions of an elderly person ranged from 50 to 80 years and above. The most commonly used age to define an elderly person was 65, however this accounted for only 38 (47.5 %) of studies. Orthopedic research appears to favor defining elderly age by chronology alone, and there is considerable heterogeneity amongst these definitions. This may confuse interpretation of the evidence base in areas of orthopaedic research that focus on elderly patients. The findings of this study underline the importance of future research in orthopaedics adopting validated frailty index measures so that population descriptions in older patients are more uniform and clinically relevant.
-
Journal articlePapi E, Belsi A, McGregor AH, 2015,
A knee monitoring device and the preferences of patients living with osteoarthritis: A qualitative study
, BMJ Open, Vol: 5, ISSN: 2044-6055 -
Journal articleJones C, Aqil A, Clarke S, et al., 2015,
Short uncemented stems allow greater femoral flexibility and may reduce peri-prosthetic fracture risk: a dry bone and cadaveric study
, Journal of Orthopaedics and Traumatology, Vol: 16, Pages: 229-235, ISSN: 1590-9921BackgroundShort femoral stems for uncemented total hip arthroplasty have been introduced as a safe alternative to traditional longer stem designs. However, there has been little biomechanical examination of the effects of stem length on complications of surgery. This study aims to examine the effect of femoral stem length on torsional resistance to peri-prosthetic fracture.Materials and methodsWe tested 16 synthetic and two paired cadaveric femora. Specimens were implanted and then rapidly rotated until fracture to simulate internal rotation on a planted foot, as might occur during stumbling. 3D planning software and custom-printed 3D cutting guides were used to enhance the accuracy and consistency of our stem insertion technique.ResultsSynthetic femora implanted with short stems fractured at a significantly higher torque (27.1 vs. 24.2 Nm, p = 0.03) and angle (30.3° vs. 22.3°, p = 0.002) than those implanted with long stems. Fracture patterns of the two groups were different, but showed remarkable consistency within each group. These characteristic fracture patterns were closely replicated in the pair of cadaveric femora.ConclusionsThis new short-stemmed press-fit femoral component allows more femoral flexibility and confers a higher resistance to peri-prosthetic fracture from torsional forces than long stems.
-
Journal articleAkhtar K, Sugand K, Sperrin M, et al., 2015,
Training safer orthopedic surgeons Construct validation of a virtual-reality simulator for hip fracture surgery
, ACTA ORTHOPAEDICA, Vol: 86, Pages: 616-621, ISSN: 1745-3674Background and purpose — Virtual-reality (VR) simulation inorthopedic training is still in its infancy, and much of the work hasbeen focused on arthroscopy. We evaluated the construct validityof a new VR trauma simulator for performing dynamic hip screw(DHS) fixation of a trochanteric femoral fracture.Patients and methods — 30 volunteers were divided into 3groups according to the number of postgraduate (PG) years andthe amount of clinical experience: novice (1–4 PG years; less than10 DHS procedures); intermediate (5–12 PG years; 10–100 procedures);expert (> 12 PG years; > 100 procedures). Each participantperformed a DHS procedure and objective performancemetrics were recorded. These data were analyzed with each performancemetric taken as the dependent variable in 3 regressionmodels.Results — There were statistically significant differences inperformance between groups for (1) number of attempts at guidewireinsertion, (2) total fluoroscopy time, (3) tip-apex distance,(4) probability of screw cutout, and (5) overall simulator score.The intermediate group performed the procedure most quickly,with the lowest fluoroscopy time, the lowest tip-apex distance,the lowest probability of cutout, and the highest simulator score,which correlated with their frequency of exposure to running thetrauma lists for hip fracture surgery.Interpretation — This study demonstrates the construct validityof a haptic VR trauma simulator with surgeons undertakingthe procedure most frequently performing best on the simulator.VR simulation may be a means of addressing restrictionson working hours and allows trainees to practice technical taskswithout putting patients at risk. The VR DHS simulator evaluatedin this study may provide valid assessment of technical skill.
-
Journal articleAqil A, Sheikh HQ, Masjedi M, et al., 2015,
Birmingham Mid-Head Resection Periprosthetic Fracture.
, Clin Orthop Surg, Vol: 7, Pages: 402-405Total hip arthroplasty in the young leads to difficult choices in implant selection. Until recently bone conserving options were not available for younger patients with deficient femoral head bone stock. The novel Birmingham Mid-Head Resection (BMHR) device offers the option of bone conserving arthroplasty in spite of deficient femoral head bone stock. Femoral neck fracture is a known complication of standard resurfacing arthroplasty and is the most common reason for revision. It is unknown whether this remains to be the case for the BMHR neck preserving implants. We report a case of a 57-year-old male, who sustained a periprosthetic fracture following surgery with a BMHR arthroplasty. This paper illustrates the first reported case of a BMHR periprosthetic fracture. The fracture pattern is spiral in nature and reaches to the subtrochanteric area. This fracture pattern is different from published cadaveric studies, and clinicians using this implant should be aware of this as revision is likely to require a distally fitting, rather than a metaphyseal fitting stem. We have illustrated the surgical technique to manage this rare complication.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.