Nuffield Orthopaedic Centre

About: Nuffield Orthopaedic Centre is a healthcare organization based out in Oxford, United Kingdom. It is known for research contribution in the topics: Population & Arthroplasty. The organization has 2082 authors who have published 2920 publications receiving 145718 citations.

Transmission of Rapidly Applied Loads Through Articular Cartilage Part 2: Cracked Cartilage

Abstract: A model of articular cartilage suffering rapidly applied loads and containing splits and fissures is presented. The possibility of cracks propagating through the cartilage collagen network is analysed using elastic fracture mechanics. Cracks are modelled using the distributed dislocation technique and the crack tip stress intensity factors are thereby evaluated. The mode I (tensile) stress intensity factors are generally much larger than the mode II (shearing) factors for cracks at the articular surface and close to, and at oblique angles to, the cartilage-bone interface, two regions where cartilage cracks have been observed. This suggests an opening, tensile mode of failure. The mode II factors are larger for cracks running along the interface. The rapidly loaded cracked cartilage model may explain the splits observed in osteoarthrotic cartilage.

In vivo measurement of volumetric wear of a total knee replacement.

Abstract: A new Roentgen Stereophotogrammetric Analysis (RSA) system is reported; it can measure penetration of the metallic femoral component of a Total Knee Replacement (TKR) prosthesis into the polyethylene bearing on the tibial component. This system was used to analyse a study group of six Anatomic Graduated Components (AGC) knee prostheses more than 6 years post-implantation, and to compare with a control group of six newly implanted AGC prostheses. The volumetric loss of polyethylene was estimated by imaging each prosthesis at a series of different knee flexion angles. The mean difference between the RSA measured polyethylene bearing thickness and the manufacturer's quoted values for the control group was -0.03 mm (SD 0.17). The estimated linear penetration at 6.4 years in this prosthesis was determined to be 0.1 mm/year. Volumetric wear was estimated to be 600-700 mm(3)/year at 6.4 years, equating to approximately 100 mm(3)/year. This does not appear to be clinically significant amount of wear as this prosthesis has excellent survival at 10 years.

Can radiological results be surrogate markers of functional outcome in distal radial extra-articular fractures

Abstract: The purpose of this study was to evaluate the relationship between radiological and functional results in patients with extra-articular fractures of the distal radius. We conducted a prospective study of radiological and functional assessment in 95 consecutively selected extra-articular distal radius fractures. There were two patient groups: more than 60 and less than 60 years of age. The final fracture union radiographs were analysed for their functional outcome using the Michigan Hand Outcomes Questionnaire (MHQ) and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. In patients with acceptable radiological results, 62% (MHQ group) and 72% (DASH group) of patients had satisfactory functional outcome. Analysing patients with satisfactory functional results, 56% (MHQ group) and 59% (DASH group) had satisfactory radiological results. There was a higher proportion of patients with better functional results, despite poor radiological results, in both of the age groups. There was a statistically significant correlation between satisfactory radial tilt and functional outcome in the younger patients. In the older age group, patients with satisfactory radiological results had satisfactory functional outcome (p < 0.05). However, in the older age group, satisfactory functional results were achieved, despite unsatisfactory radiological results.

Meta-ethnography to understand healthcare professionals' experience of treating adults with chronic non-malignant pain.

Abstract: Objectives We aimed to explore healthcare professionals’ experience of treating chronic non-malignant pain by conducting a qualitative evidence synthesis. Understanding this experience from the perspective of healthcare professionals will contribute to improvements in the provision of care. Design Qualitative evidence synthesis using meta-ethnography. We searched five electronic bibliographic databases from inception to November 2016. We included studies that explore healthcare professionals’ experience of treating adults with chronic non-malignant pain. We used the GRADE-CERQual framework to rate confidence in review findings. Results We screened the 954 abstracts and 184 full texts and included 77 published studies reporting the experiences of over 1551 international healthcare professionals including doctors, nurses and other health professionals. We abstracted six themes: (1) a sceptical cultural lens, (2) navigating juxtaposed models of medicine, (3) navigating the geography between patient and clinician, (4) challenge of dual advocacy, (5) personal costs and (6) the craft of pain management. We rated confidence in review findings as moderate to high. Conclusions This is the first qualitative evidence synthesis of healthcare professionals’ experiences of treating people with chronic non-malignant pain. We have presented a model that we developed to help healthcare professionals to understand, think about and modify their experiences of treating patients with chronic pain. Our findings highlight scepticism about chronic pain that might explain why patients feel they are not believed. Findings also indicate a dualism in the biopsychosocial model and the complexity of navigating therapeutic relationships. Our model may be transferable to other patient groups or situations.

The Oxford Ankle Foot Questionnaire for children: responsiveness and longitudinal validity.

Abstract: To evaluate how scores from the Oxford Ankle Foot Questionnaire change over time and with treatment using both distribution-based and anchor-based approaches. Eighty children aged 5–16 and their parent or carer completed questionnaires at orthopaedic or trauma outpatient clinics. They were asked to complete and return a second set of questionnaires again within 2 weeks (retest), and then mailed a third set of questionnaires to complete again after 2 months (follow-up). The follow-up questionnaires included a global rating of change ‘transition’ item. Child- and parent-reported mean domain scores (Physical, School & Play, and Emotional) were all stable at retest, whereas positive mean changes were observed at follow-up. As we hypothesised, trauma patients had poorer scores than elective patients at baseline, and showed greater improvement at follow-up. For trauma patients, mean changes in per cent scores were large (scores improved between 40 and 56 for the Physical and School & Play domains, and 17 and 21 for Emotional); all effect sizes (ES) were large (>0.8). For elective patients, the mean improvement in per cent scores were more moderate (Physical: child 10, ES = 0.4, parent 11, ES = 0.5; School & Play child 0, ES = 0, parent 9 ES = 0.4; Emotional: child 6, ES = 0.2; parents 8, ES > 0.3). Minimal detectable change (MDC90), an indication of measurement error, ranged from 6 to 8. Half the standard deviation of baseline scores ranged from 11 to 18. Minimal important difference could only be calculated for elective patients (9 child and 13 parent ratings), these ranged from 7 to 17. The findings support the responsiveness and longitudinal validity of the scales. Changes in domain scores of, or exceeding, the MDC90 (6–8) are likely to be beyond measurement error; further work is required to refine the estimate of change that can be considered important.