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Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_10 | Pages 16 - 16
1 Aug 2021
Gupta V Thomas C Parsons H Metcalfe A Foguet P King R
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Total hip arthroplasty (THA) is one of the most successful surgical procedures of modern times, however debate continues as to the optimal orientation of the acetabular component and how to reliably achieve this. We hypothesised that functional CT-based planning with patient specific instruments using the Corin Optimised Positioning System (OPS) would provide more accurate component alignment than the conventional freehand technique using 2D templating.

A pragmatic single-centre, patient-assessor blinded, randomised control trial of patients undergoing THA was performed. 54 patients (age 18–70) were recruited to either OPS THA or conventional THA. All patients received a cementless acetabular component. Patients in both arms underwent pre- and post-operative CT scans, and four functional x-rays (standing and seated). Patients in the OPS group had a 3D surgical plan and bespoke guides made. Patients in the conventional group had a surgical plan based on 2D templating x-rays, and the pre-operative target acetabular orientation was recorded by the surgeon. The primary outcome measure was the difference between planned and achieved acetabular anteversion and was determined by post-operative CT scan performed at 6 weeks. Secondary outcome measures included Hip disability and Osteoarthritis Outcome Score (HOOS), Oxford Hip Score (OHS), EQ-5D and adverse events.

In the OPS group, the achieved acetabular anteversion was within 10° of the plan in 96% of cases, compared with only 76% of cases in the conventional group. For acetabular inclination, the achieved position in the OPS group was within 10° of the plan in 96% of cases, compared with in only 84% of cases in the conventional group. These differences were not statistically significant. The clinical outcomes were comparable between the two groups.

Large errors in acetabular orientation appear to be reduced when functional CT-based planning and patient-specific instruments are used compared to the freehand technique, but no statistically significant differences were seen in the difference between planned and achieved angles. Larger studies are needed to analyse this in more detail and to determine whether the reduced numbers of outliers lead to improved clinical outcomes.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 5 - 5
1 Feb 2021
Burson-Thomas C Browne M Dickinson A Phillips A Metcalf C
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Introduction

An understanding of anatomic variability can help guide the surgeon on intervention strategies. Well-functioning thumb metacarpophalangeal joints (MCPJ) are essential for carrying out typical daily activities. However, current options for arthroplasty are limited. This is further hindered by the lack of a precise understanding of the geometric variation present in the population. In this paper, we offer new insight into the major modes of geometric variation in the thumb MCP using Statistical Shape Modelling.

Methods

Ten participants free from hand or wrist disease or injury were recruited for CT imaging (Ethics Ref:14/LO/1059)1. Participants were sex matched with mean age 31yrs (range 27–37yrs). Metacarpal (MC1) and proximal phalanx (PP1) bone surfaces were identified in the CT volumes using a greyscale threshold, and meshed. The ten MC1 and ten PP1 segmented bones were aligned by estimating their principal axes using Principal Component Analysis (PCA), and registration was performed to enable statistical comparison of the position of each mesh vertex. PCA was then used again, to reduce the dimensionality of the data by identifying the main ‘modes’ of independent size and shape variation (principal components, PCs) present in the population. Once the PCs were identified, the variation described by each PC was explored by inspecting the shape change at two standard deviations either side of the mean bone shape.


Bone & Joint Open
Vol. 1, Issue 11 | Pages 697 - 705
10 Nov 2020
Rasidovic D Ahmed I Thomas C Kimani PK Wall P Mangat K

Aims

There are reports of a marked increase in perioperative mortality in patients admitted to hospital with a fractured hip during the COVID-19 pandemic in the UK, USA, Spain, and Italy. Our study aims to describe the risk of mortality among patients with a fractured neck of femur in England during the early stages of the COVID-19 pandemic.

Methods

We completed a multicentre cohort study across ten hospitals in England. Data were collected from 1 March 2020 to 6 April 2020, during which period the World Health Organization (WHO) declared COVID-19 to be a pandemic. Patients ≥ 60 years of age admitted with hip fracture and a minimum follow-up of 30 days were included for analysis. Primary outcome of interest was mortality at 30 days post-surgery or postadmission in nonoperative patients. Secondary outcomes included length of hospital stay and discharge destination.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 391 - 391
1 Jul 2008
Thomas C Whittles C Fuller C Sharif M
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Apoptosis of articular chondrocytes may play an important role in the pathogenesis of osteoarthritis (OA). The aim of this study was to investigate the incidence of chondrocyte apoptosis in equine articular cartilage (AC) specimens and examine the relationship between the process of cell death and the degree of cartilage degradation.

The study comprised 2 populations of equine cartilage taken from the left forelimb. Population 1 (n=10) consisted of full depth cartilage from weight-bearing regions of equine metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints. Population 2 (n=9) comprised cartilage from 6 different regions of the MCP joint: dorsomedial, dorsolateral, centromedial, centrolateral, palmarome-dial and palmarolateral areas. Cartilage from each horse for each of the joints and joint regions was not always available. Seven micrometre cryostat sections were obtained. Haematoxylin and Eosin with Safranin-O stained sections were used to score structural differences between samples for features of cartilage pathology using a ‘modified’ Mankin scoring system. Two methods were used to quantify apoptotic chondrocytes: a direct method in which chondrocytes were assessed for morphological features of apoptosis using a light microscope and an immunohistochemical staining technique to detect the expression of active caspase-3 using a commercially available monoclonal antibody.

Apoptosis assessed by the direct method did not show any association with increasing severity of OA (r=0.11, p=0.7205). Overall there was a positive correlation between caspase-3 expression and cartilage damage (r= 0.44, p=0.0043). Caspase-3 expression was found to increase linearly with increasing severity of OA in the superficial, middle and deep zones of AC (r=0.36, p=0.0198; r=0.49, p=0.0011 and r=0.37, p=0.0237 respectively). Moreover, caspase-3 expression was higher in the superficial and middle zones than in the deep zone (p< 0.001). In the superficial, middle and deep zones the expression of caspase-3 was higher in the MCP joint than the PIP joint (p< 0.05, p< 0.01 and p< 0.05 respectively).

The significant positive correlation between disease severity and chondrocyte apoptosis, suggests that this process plays an important role in the pathogenesis of OA. The differences in the extent of apoptosis observed in different joints could be explained by the biomechanical environment of the joints.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 308 - 308
1 Jul 2008
Thomas C Bhutta M Johnson D
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Introduction: The aim of this study was to assess the practice of obtaining informed consent for Total Hip Replacement Surgery in the United Kingdom.

Methods and results: 1571 consultant members of the BOA were surveyed by postal questionnaire regarding their practice towards obtaining informed consent for total hip replacement surgery. 524 (33.3%) replies were received. 368 (23.4%) of the 524 consultants who replied still performed total hip replacement surgery. In obtaining informed consent for hip replacement surgery consultants warned of the following complications: Infection 99.7%, Dislocation 98.9%, Leg length discrepancy 75.2%, Aseptic loosening 85.8%, neurovascular damage 61.9%, Wear 63.2%, DVT 96.0%, PE 89.0% and Mortality 71.6%. Consent was routinely obtained by Senior House Officers in 38.7%, by Pre-Registration House Officer in 3.8% and by specialist nurses in 5.4% of cases. Patient information leaflets were provided by 72.0% of consultants for Hip Replacement.

Discussion: We recommend national guidelines relating to obtaining consent for hip replacement should be published by the British Hip Society. This should be incorporated into their best practice documents regarding Hip replacement Surgery. Consent should also be obtained by a suitably experienced practitioner.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 382 - 382
1 Oct 2006
Mayhew P Thomas C Loveridge N Clement J Reeve J
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Introduction: Femoral neck (FN) fragility has been attributed to age-related bone loss, with increased loss in women. It has been shown that the mechanical properties of a supporting structure will also change with any alteration to the structure’s dimensions. The purpose of this study was to identify the age-related changes that take place in the morphology of the mid cross-section of the FN, and the implications for its mechanical properties in the different regions around the mid FN cross-section.

Materials and Methods: Measurements were taken from peripheral quantitative computed tomogram (pQCT) images of 81 cadaveric femurs (36 F, 45 M). The mid FN cross-section was segmented radially into eight regions and the cortical bone thickness (CT) and change of the centroid position (CP) of the FN cross-section were measured. The age-related effects of the corresponding changes in the proportion of cortical bone and the “resistance to bending” (section modulus, (Z)) were also measured.

Results: Four femurs were excluded because there were clear signs of OA being present. The maximum difference in regional CT between men and women, was less than 7% (Female: 3.07 ± 0.108mm; Male: 3.28 ± 0.123 mm (mean ± SEM) p =0.21). However, there were regional differences in CT between the young under fifty, (Un50, n=26) and the old, (Abv50), (ANOVAs for young vs old: CT p = 0.001 t 0.01). These effects were attributable to differences in the inferior region, where there was an increase in thickness of the cortical bone of 27% with senior status (Abv50: 3.44 ± 0.09mm; Und50: 2.70 ± 0.12mm. p = 0001) counter balanced by anterior and posterior loss. There was a corresponding change in CP, the distance of the superior, posterior, and superoposterior regions to the FN cross-section’s centroid, 7.6% (Abv50: 20.88 ± 0.28mm; Und50: 19.40 ± 0.47mm; p = 0.005); 6.7% (Abv50: 14.67 ± 0.2mm; Und50: 13.74 ± 0.32mm; p = 0.01); and 8%(Abv50: 17.95 ± 0.24; Und50: 16.61 ± 0.37), respectively. When these two measurements were combined (CP divided by CT) to provide the Local Buckling Ratio (BLR), where the higher the ratio the more unstable the structure, there were significant differences in superoanterior, 30%(Abv50: 15.8 ± 0.52; Und50: 12.1 ± 0.59;p=0.0001); anterior, 20%(Abv50: 10.1 ± 0.32; Und50: 8.3 ± 0.4; p=0.001); inferior, 35%(Abv50: 4.37 ± 0.14; Und50: 5.8 ± 0.34; p=0.0001); inferoposterior 18%(Abv50 8.6 ± 0.27: Und50: 7.36 ± 0.41; p=0.008); posterior, 29%(Abv50: 14.0 ± 0.33; Und50: 10.8 ± 0.5; p=0.0001) and superoposterior, 14%(Abv50: 14.6 ± 0.3; Und50: 12.8 ± 0.4; p=0.001), regions. There was no significant difference in bending resistance nor in the proportion of cortical bone.

Conclusions: A more uniform cortical thickness, seen in the young, would optimise fracture resistance to overloading from unusually loaded directions. Ageing was associated with a thickening of the inferior cortex and thinning of the cortex elsewhere. This effects the location of the area that is least susceptible to the loading forces experienced in stance – that is of the FN mid cross-section’s neutral bending axis – as it will be nearer to the inferior region. Such a change in the morphology will produce deterioration in the FN’s capacity to take a load as shown by the detrimental change in the LBR. This change may indicate that the potential for femoral neck fracture increases with age when load is applied in a direction different to normal stance eg through the greater trochanter.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 253 - 253
1 May 2006
Bhutta M Thomas C Johnson D
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Purpose: The aim of this survey was to assess the practice of obtaining informed consent for Total Knee Replacement Surgery in the United Kingdom.

Method: A postal questionnaire was distributed to consultant members of the British Orthopaedic Association. They were questioned regarding their practice for obtaining informed consent for Total Knee Replacement Surgery.

Results: Of the 1571 consultant members contacted 34% (526) replied. From these 76% (400) performed total knee replacements. Informed consent was obtained in a pre-operative assessment clinic in 64%, on admission in 32.5% and during the first clinic visit in 3.5% of cases. Consent was routinely obtained by Consultants in 76%, Senior House Officers in 38%, Pre-Registration House Officers in 4% and Specialist Nurses in 5% of cases. Consultants warned of the following complications: Infection 99.2%, Stiffness 70.5%, Aseptic loosening 81.6%, neurovascular damage 56.9%, DVT 96.5%, PE 88.5%, Wear 61.2% and Mortality 67.4%. Patient information leaflets were provided by 71.5% of consultants for Total Knee Replacement.

Conclusions: This survey has identified inconsistencies in the complications described to patients. Junior practitioners are continuing to obtain informed consent. Informed consent should be obtained by a suitably experienced practitioner. Patient information leaflets should be provided to patients at the time of listing. We recommend national guidelines relating to obtaining consent for Total Knee Replacement should be published by the BASK. These could be incorporated into their best practice document regarding Total Knee Replacement Surgery.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 395 - 396
1 Sep 2005
Paton R Hinduja K Thomas C
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Introduction: The results of a 10 year prospective hip ultrasound surveillance programme of ‘at risk’ or clinically unstable hips are analysed.

Method: Between June 1992 and may 2002, there were 34723 births in the Blackburn area. Over this period 2,578 infants with unstable hips and or risk factors for developmental dysplasia of the hip were assessed with bilateral hip ultrasound scans. Clinically unstable hips were imaged within two weeks post natally and those with ‘at risk’ groups within eight weeks. All results were collected prospectively by the senior author. The degree of Dysplasia was classified using Graf’s alpha angle. Dynamic instability or irreductable dislocation was recorded.

Results: Early dislocation was present in 77 patients of which 53 (68.8%) were referred as being Ortolani-positive or unstable, only 24 were identified from the screening programme alone. The dislocation rate was 2.6 per 1000 live births. There were 21 irreducible dislocations in 19 infants, a rate of 0.54 per 1000 live births.

Only 31.2 % of the dislocated hips belonged to the major ‘at risk’ group. In infants referred for possible clinical instability one dislocation was detected for every 8.5 infants screened, whereas in the ‘at risk’ group this number rose to 1 in 88. From the ‘at risk’ groups those with breech and a positive family history were most likely to reveal a dislocation. There was a 1:45 chance of instability/irreducibility in family history, compared with a 1:70 chance in breech presentation or 1:71 chance in foot abnormality. No patients with oligohydramnios alone had evidence of hip instability or dislocation. If type III dysplasia is assessed there is a 1:22 chance in family history, a 1:43 chance in breech presentation and a 1:61 chance in foot deformity.

Discussion: Screening groups with possible risk factors such as oligohydramnios or Caesarian section cannot be justified. Selective ultrasound screening of the clinical instability, family history, breech presentation and foot abnormality groups looking for dislocation or type III dysplasia may be justified on a National basis.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 160 - 160
1 Feb 2003
Paton R Thomas C
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There have been major changes in practice in Orthopaedics and Anaesthetics in Britain over recent years. The Royal College of Anaesthetists in Britain in its document on the provision of paediatric services stated that the anaesthetic service for children should be led by consultants who anaesthetise children regularly. This has affected the range of conditions that Orthopaedic Surgeons in District General Hospitals have been able to operate.

The Children’s Orthopaedic Group in the North West Region of England was surveyed in 1996 and 2001. Age limits for elective procedures and the range of procedures performed were analysed. The orthopaedic procedures looked at were for scoliosis, DDH / Dysplasia, Perthes’ disease, CTEV, Leg lengthening and genu varum/valgum.

The demographic map of the region was studied. This highlighted the variation in Children’s Orthopaedic Services in the region. Some large population centres had minimal Paediatric Orthopaedic Services.

In 1996, 91% of non children’s hospitals could perform elective surgery on children under 1 compared to 60% in 1996. The average minimum age for elective surgery in District General Hospitals increased from 8.5 months in 1996 to 17 months in 2001.

Baseline services are needed at each DGH to support the paediatric units. These services should include gait abnormalities, conservative treatment of CTEV, postural problems, straight forward cerebral palsy, assessment of hip instability and Perthes disease. Paediatric physiotherapists and Community Paediatricians may be involved in this aspect of care as part of the Multidisciplinary team. A hub and spoke regional service may be required where paediatric orthopaedic specialists undertake outreach clinics in District General Hospitals in order to assess more complex problems such as resistant CTEV, DDH and complex Cerebral Palsy. Such a system already exists in other specialities such as paediatric neurology. Clinical networks may improve service standards.