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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_18 | Pages 6 - 6
1 Dec 2023
Allott N Banger M Korgaonkar J Thomas R McGregor A
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Introduction

Anterior tibial translation (ATT) is assessed in the acutely injured knee to investigate for ligamentous injury and rotational laxity. Specifically, there is a growing recognition of the significance of anterior medial rotary laxity (AMRI) as a crucial element in assessing knee stability. Anterior cruciate ligament (ACL) injuries are often accompanied with medial collateral ligament (MCL) damage. It has been suggested that Deep MCL (dMCL) fibres are a primary restraint in rotational displacement. This research aims to quantify the difference in rotational laxity of patients with ACL and MCL injuries to deem if the Feagin-Thomas test can robustly capture metrics of AMRI. 2.

Methods

AMRI was assessed using the Feagin-Thomas test in 7 isolated ACL (iACL) injured participants, 3 combined ACL and superficial fibre MCL (sMCL) injuries, 5 combined ACL and deep fibre MCL injuries, and 21 healthy controls. Displacement values were recorded using an optical motion capture (OMC) system and bespoke processing pipeline which map and model the knee's anterior displacement values relative to the medial compartment. Since absolute values (mm) of rotational laxity vary dependant on the person, values were recorded as a proportion of the rotational laxity obtained from the subject's contralateral leg. Values were compared between each patient group using an ANOVA test and Tukey's honesty significant difference post hoc test. 3.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_16 | Pages 34 - 34
17 Nov 2023
Elliott M Rodrigues R Hamilton R Postans N Metcalfe A Jones R McGregor A Arvanitis T Holt C
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Abstract

Objectives

Biomechanics is an essential form of measurement in the understanding of the development and progression of osteoarthritis (OA). However, the number of participants in biomechanical studies are often small and there is limited ways to share or combine data from across institutions or studies. This is essential for applying modern machine learning methods, where large, complex datasets can be used to identify patterns in the data. Using these data-driven approaches, it could be possible to better predict the optimal interventions for patients at an early stage, potentially avoiding pain and inappropriate surgery or rehabilitation. In this project we developed a prototype database platform for combining and sharing biomechanics datasets. The database includes methods for importing and standardising data and associated variables, to create a seamless, searchable combined dataset of both healthy and knee OA biomechanics.

Methods

Data was curated through calls to members of the OATech Network+ (https://www.oatechnetwork.org/). The requirements were 3D motion capture data from previous studies that related to analysing the biomechanics of knee OA, including participants with OA at any stage of progression plus healthy controls. As a minimum we required kinematic data of the lower limbs, plus associated kinetic data (i.e. ground reaction forces). Any additional, complementary data such as EMG could also be provided. Relevant ethical approvals had to be in place that allowed re-use of the data for other research purposes. The datasets were uploaded to a University hosted cloud platform. The database platform was developed using Javascript and hosted on a Windows server, located and managed within the department.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_16 | Pages 63 - 63
17 Nov 2023
Bicer M Phillips AT Melis A McGregor A Modenese L
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Abstract

OBJECTIVES

Application of deep learning approaches to marker trajectories and ground reaction forces (mocap data), is often hampered by small datasets. Enlarging dataset size is possible using some simple numerical approaches, although these may not be suited to preserving the physiological relevance of mocap data. We propose augmenting mocap data using a deep learning architecture called “generative adversarial networks” (GANs). We demonstrate appropriate use of GANs can capture variations of walking patterns due to subject- and task-specific conditions (mass, leg length, age, gender and walking speed), which significantly affect walking kinematics and kinetics, resulting in augmented datasets amenable to deep learning analysis approaches.

METHODS

A publicly available (https://www.nature.com/articles/s41597-019-0124-4) gait dataset (733 trials, 21 women and 25 men, 37.2 ± 13.0 years, 1.74 ± 0.09 m, 72.0 ± 11.4 kg, walking speeds ranging from 0.18 m/s to 2.04 m/s) was used as the experimental dataset. The GAN comprised three neural networks: an encoder, a decoder, and a discriminator. The encoder compressed experimental data into a fixed-length vector, while the decoder transformed the encoder's output vector and a condition vector (containing information about the subject and trial) into mocap data. The discriminator distinguished between the encoded experimental data from randomly sampled vectors of the same size. By training these networks jointly using the experimental dataset, the generator (decoder) could generate synthetic data respecting specified conditions from randomly sampled vectors. Synthetic mocap data and lower limb joint angles were generated and compared to the experimental data, by identifying the statistically significant differences across the gait cycle for a randomly selected subset of the experimental data from 5 female subjects (73 trials, aged 26–40, weighing 57–74 kg, with leg lengths between 868–931 mm, and walking speeds ranging from 0.81–1.68 m/s). By conducting these comparisons for this subset, we aimed to assess the synthetic data generated using multiple conditions.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 50 - 50
1 Mar 2021
Favier C McGregor A Phillips A
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Abstract

OBJECTIVES

Bone health deterioration is a major public health issue. General guidelines for the limitation of bone loss prescribe a healthy lifestyle and a minimum level of physical activity. However, there is no specific recommendation regarding targeted activities that can effectively maintain lumbar spine bone health. To provide a better understanding of such influencing activities, a new predictive modelling framework was developed to study bone remodelling under various loading conditions.

METHODS

The approach is based on a full-body subject-specific musculoskeletal model [1] combined with structural finite element models of the lumbar vertebrae. Using activities recorded with the subject, musculoskeletal simulations provide physiological loading conditions to the finite element models which simulate bone remodelling using a strain-driven optimisation algorithm [2]. With a combination of daily living activities representative of a healthy lifestyle including locomotion activities (walking, stair ascent and descent, sitting down and standing up) and spine-focused activities involving twisting and reaching, this modelling framework generates a healthy bone architecture in the lumbar vertebrae. The influence of spine-focused tasks was studied by adapting healthy vertebrae to an altered loading scenario where only locomotion activities were performed.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 37 - 37
1 Mar 2021
Kaufmann J McGregor A Phillips A
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Abstract

Objectives

Osteoporosis of the pelvis and femur is diagnosed in a high proportion of lower-limb amputees which carries an increased fracture risk and subsequently serious implications on mobility, physical dependency and morbidity. Through the development of biofidelic musculoskeletal and finite element (FE) models, we aim to determine the effect of lower-limb amputation on long-term bone remodelling in the hip and to understand the potential underpinning mechanisms for bone degradation in the younger amputee population.

Methods

Our models are patient specific and anatomically accurate. Geometries are derived from MRI-scans of one bilateral, above-knee, amputee and one body-matched control subject. Musculoskeletal modelling enables comparison of muscle and joint reaction-forces throughout gait. This provides the loading scenario implemented in FE. FE modelling demonstrates the effect of loading on the amputated limb via a prosthetic socket by comparing bone mechanical stimulation in amputee and control cases.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_9 | Pages 10 - 10
1 Sep 2019
Deane J Lim A Strutton P McGregor A
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Introduction

Patients with recurrent low back pain (LBP) exhibit changes in postural control. Stereotypical muscle activations resulting from external perturbations include anticipatory (APAs) and compensatory (CPAs) postural adjustments. This study aimed to determine differences in postural control strategies (APAs and CPAs) between those with and without lumbar disc degeneration (LDD) and LBP.

Methods

Ninety-seven subjects participated in the study (mean age 50 years (SD 12)). 3T MRI was used to acquire T2 weighted images (L1-S1). LDD was determined using Pfirrmann grading and LBP using the numerical rating scale (NRS). A bespoke perturbation platform was designed to deliver postural perturbations. Electrical activity was analysed from 16 trunk and lower limb muscles during four typical APA and CPA epochs. A Kruskal-Wallis H test with Bonferroni correction for multiple comparisons was conducted.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_9 | Pages 5 - 5
1 Sep 2019
Greenwood J Hurley M McGregor A Jones F
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Purpose

The behavioural change wheel methodology and social cognitive theory were combined to inform and develop a rehabilitation programme following lumbar fusion surgery (REFS).

This qualitative study evaluated participant's experiences of lumbar fusion surgery, including REFS, to identify valued programme content (‘active ingredients’).

Background

A feasibility-RCT suggested REFS achieved a meaningful impact in disability and pain self-efficacy compared to ‘usual care’ (p=0.014, p=0.007).

In keeping with MRC guidance a qualitative evaluation was undertaken to understand possible mechanisms of action.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_10 | Pages 18 - 18
1 May 2017
Deane J Papi E Phillips A McGregor A
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Introduction

Low back pain (LBP) is the top leading global cause of years lived with disability. In order to examine LBP, researchers have typically viewed the spine in isolation. Clinically, it is imperative that the lower limbs are also considered. The aim of this study was to design a holistic and reliable multi-segmental kinematic model of the spine and lower limbs.

Method

The spine was modelled according to easily identifiable anatomical landmarks, including upper thoracic (T1-T6), lower thoracic (T7-T12) and lumbar (L1-L5) segments. Pelvis, thigh, shank and foot segments were included. A 10-camera 3D motion capture system was used to track retro-reflective markers, which were used to define each segment of 10 healthy participants as they walked 3 times at a comfortable speed over a 6km walkway. The relative peak angles between each segment were calculated using the Joint Coordinate System convention and Intraclass Correlation Coefficients (ICCs) were used to determine intra-rater and inter-rater reliability (between an experienced clinician and biomechanical scientist).


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_10 | Pages 19 - 19
1 May 2017
Deane J Joyce L Wang C Wiles C Lim A Strutton P McGregor A
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Introduction

The usefulness of markers of non-specific low back pain (NSLBP), including MRI derived measurements of cross-sectional area (CSA) and functional CSA (FCSA, fat free muscle area) of the lumbar musculature, is in doubt. To our knowledge, such markers remain unexplored in Lumbar Disc Degeneration (LDD), which is significantly associated with NSLBP, Modic change and symptom recurrence. This exploratory 3.0-T MRI study addresses this shortfall by comparing asymmetry and composition in asymptomatic older adults with and without Modic change.

Methods

A sample of 21 healthy, asymptomatic subjects participated (mean age 56.9 years). T2-weighted axial lumbar images were obtained (L3/L4 to L5/S1), with slices oriented through the centre of each disc. Scans were examined by a Consultant MRI specialist and divided into 2 groups dependent on Modic presence (M) or absence (NM). Bilateral measurements of the CSA and FCSA of the erector spinae, multifidus, psoas major and quadratus lumborum were made using Image-J software. Muscle composition was determined using the equation [(FCSA/CSA)*100] and asymmetry using the equation [(Largest FCSA-smallest FCSA)/largest FCSA*100]. Data were analysed using Mann-Whitney U tests (p value set at). Intrarater reliability was examined using Intraclass Correlations (ICCs).


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_10 | Pages 15 - 15
1 May 2017
Poyton R Cowell I Hall T Drew P Murtagh G McGregor A
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Background

Persistent low back and leg pain is a common and highly disabling musculoskeletal condition. Many patients seek the opinion of a neurosurgeon with a view to surgical intervention. Few data are available which document the experiences of patients at these consultations.

Aims

To investigate the experiences of patients seeking a neurosurgical opinion for back and leg pain.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_6 | Pages 32 - 32
1 Feb 2016
Deane J McGregor A
Full Access

Purpose and Background:

Clinical interpretations of Degenerative Lumbar Disc Disease are not described in the literature. The purpose of this study was to establish a consensus of expert clinical opinion in order to fuel further research.

Methods:

A reliable and valid electronic survey was designed to include theoretical constructs relating to training and education, general knowledge, assessment and management practices. Clinicians from the Society of Back Pain Research U.K. were invited to take part. Quantitative data was collated and coded using Bristol on-line survey software, and content analysis was used to systematically code and categorize qualitative data.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_14 | Pages 12 - 12
1 Dec 2015
Berwin J Burton T Taylor J McGregor A Roche A
Full Access

Background

The current ‘gold standard’ method for enabling weightbearing during non-invasive lower limb immobilisation is to use a Patella Tendon-Bearing (PTB) or Sarmiento cast. The Beagle Böhler Walker™ is a non-invasive frame that fits onto a standard below knee plaster cast. It is designed to achieve a reduction in force across the foot and ankle.

Our objective was to measure loading forces through the foot to examine how different types of casts affect load distribution. We aimed to determine whether the Beagle Böhler Walker™ is as effective or better, at reducing load distribution during full weightbearing.

Methods

We applied force sensors to the 1st and 5th metatarsal heads and the plantar surface of the calcaneum of 14 healthy volunteers. Force measurements were taken without a cast applied and then with a Sarmiento Cast, a below knee cast, and a below knee cast with Böhler Walker™ fitted.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_4 | Pages 10 - 10
1 Feb 2014
Sperry M Phillips A McGregor A
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Statement of Purpose

It is well known that individuals with a history of low back pain (hLBP) exhibit altered movement patterns that are caused by changes in neuromuscular control. Postural disturbance provides an effective method for creating these differentiable movement patterns. This study has explored the response of the lower limb and spine to a translational perturbation similar to that experienced on public transport in healthy volunteers and those with hLBP.

Methods

Healthy volunteers (n=16) and subjects with hLBP (n=10) were subjected to 31 identical postural disturbances at varying time intervals while standing atop a moving platform. Skeletal kinematics and muscle activation were recorded using a 10-camera Vicon system (Oxford, UK) and Myon electromyography (EMG) at the trunk (lumbar, lower thoracic, and upper thoracic segments), pelvis, thigh, calf, and foot. Joint angles were calculated using Body Builder (Vicon) and a unilateral seven-segment custom model.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_17 | Pages 26 - 26
1 Apr 2013
Buisson Y McGregor A Strutton P
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Introduction

Changes in central nervous system (CNS) pathways controlling trunk and leg muscles in patients with low back pain(LBP) and lumbar radiculopathy have been observed and this study investigated whether surgery impacts upon these changes in the long term.

Methods

80 participants were recruited into the following groups: 25 surgery(S), 20 chronic LBP(CH), 14 spinal injection(SI), and 21 controls(C). Parameters of corticospinal control were examined before, at 6, 26 and 52 weeks following lumbar decompression surgery and equivalent intervals. Electromyographic(EMG) activity was recorded from tibialis anterior(TA), soleus(SOL), rectus abdominis(RA), external oblique(EO) and erector spinae(ES) muscles at the T12&L4 levels in response to transcranial magnetic stimulation of the motor cortex. Motor evoked potentials (MEP) and cortical silent periods(cSP) recruitment curves(RC) were analysed.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 32 - 32
1 Mar 2013
Gulati V McGregor A Bergmann J
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Gathering reliable information about joint movement during activities of daily living is of clinical interest. Here we present pilot data regarding a new wearable knee joint sensing system by comparing the outcomes of this device to a gold standard. Initial results show a complex, but repetitive pattern. These outcomes generate potential for future work.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_4 | Pages 34 - 34
1 Jan 2013
Borhani M Bull A McGregor A
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Background

The measurement of pelvic kinematics is key to the analysis of aberrant movement patterns of lower back, yet to date technical issues of skin artefacts, body composition and optical motion tracking sensor occlusion [1] are unresolved.

Methods

In this study, an alternative technical pelvic coordinate system to the standard right and left anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) is developed and evaluated in two healthy male subjects (slim and overweight). The alternative system consists of a cluster of 3 retro-reflective markers attached to the Sacrum, thus allowing position and motion of the pelvis to be measured. In order to use these technical markers a static trial must be performed. The ASISs were calibrated relative to the technical frame; and the anatomical frame of the pelvis was defined relative to the technical coordinate frame. Each participant completed 5 walking trials and the angular rotations of the two methods were investigated using Euler angles.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_4 | Pages 25 - 25
1 Jan 2013
McGregor A Doré C Morris T Morris S Jamrozik K
Full Access

Introduction

This study sought to determine whether the functional outcome of two common spinal operations could be improved by a programme of post-operative rehabilitation and/or an educational booklet each compared with usual care.

Methods

This was a multi-centre, factorial, randomised controlled trial on the post operative management of spinal surgery patients, with randomisation stratified by surgeon and operative procedure. The study compared the effectiveness of a rehabilitation programme and an education booklet for the postoperative management of patients undergoing discectomy or lateral nerve root decompression surgery, each compared with “usual care” using a 2 × 2 factorial design, randomising patient to four groups; rehabilitation-only, booklet-only, rehabilitation-plus-booklet, and usual care only. The primary outcome measure was the Oswestry Disability Index (ODI) at 12 months, with secondary outcomes including visual analogue scale measures of back and leg pain. An economic analysis was also performed.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_I | Pages 33 - 33
1 Jan 2012
Carslake R McGregor A
Full Access

Background

Several theories have been put forward with respect to the mechanical role of the thoracolumbar fascia (TLF) but none have been substantiated in part due to an inability to explore its function in vivo. This study explored the use of ultrasound to image the layers of the TLF in vivo.

Methods

Initially a cadaveric dissection of the fascia was performed to gain an appreciation of the 3-D orientation and representation of the TLF in the lumbar region. A conventional ultrasound system (Diasus, Dynamic Imaging Ltd) was then used to image the 3 layers of the fascia on 40 normal subjects (18 males and 22 females, mean age 27.3±5.8 years) and the reliability of these measures was investigated on a subset of this population.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_I | Pages 17 - 17
1 Jan 2012
Chhikara A McGregor A Rice A Bello F
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Background

The clinical assessment of Chronic Low Back Pain (CLBP) is usually undertaken at a single time point at clinic rather than through continuous monitoring. To address this, a wearable prototype sensor to monitor motion of the lumbar spine and pelvis has been developed.

Sensor Development, Testing and Results

The system devised was based on inertial sensor technology combined with wireless Body Sensor Network (BSN) platform. This was tested on 16 healthy volunteers for ten common movements (including sit to stand, lifting, walking, and stairs) with results validated by optical tracking.

Preliminary findings suggest good agreement between the optical tracker and device with mean average orientation error (°) ranging from 0.1 ± 2.3 to 4.2 ± 2.6. The sensor repeatability errors range from 0 to 4° while subject movement variability ranged from 4% to 14%. Parameters of angular motion suggest greater movement of the lumbar spine compared to the pelvis with mean velocities (°/s) for lumbar spine ranging from 15.3 to 74.13 and pelvis ranging from 5.6 to 40.74. Further analysis revealed the extent to which the pelvis was engaged, as a proportion of the total movement. This demonstrated that the pelvis underwent smooth transitions from low (0.02), moderate (0.4) to high (0.99) use during different movement phases.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_I | Pages 27 - 27
1 Jan 2012
Buisson Y Catley M Lopez JG McGregor A Strutton P
Full Access

Introduction

Changes in the central nervous system (CNS) pathways controlling trunk and leg muscles in patients with low back pain and radiculopathy have been observed and this study investigated whether surgery impacts upon these changes.

Methods

Parameters of corticospinal control were examined on 3 occasions in 22 patients prior to, at 6 and 26 weeks following lumbar decompression surgery and in 14 control subjects at the same intervals. Electromyographic activity was recorded from tibialis anterior (TA), soleus (SOL), rectus abdominis (RA), external oblique (EO) and erector spinae (ES) muscles at the T12 & L4 levels in response to transcranial magnetic stimulation of the motor cortex.