Title: Risk stratification of lower limb osteoarthritis and arthroplasty to optimise patient pathways
Funder: Department of Health and Social Care

Abstract: With the impact of covid and the increase in elective patients awaiting surgery, there is a need for appropriate patient selection and streamlining of orthopaedic elective surgery patient pathways. There are a significant number of osteoarthritis patients who have not presented to primary or secondary care and who are likely to present in the next few years. These 'hidden' osteoarthritis patients are expected to cause a huge burden on health services. More than ever, understanding osteoarthritis disease trajectory and appropriate patient surgical selection is key to maximising healthcare utilisation and patient outcomes. This research will look at the patient features and healthcare burden from initial presentation in primary care with osteoarthritis to the downstream post-operative course after joint replacement surgery, with an emphasis on day-case surgery. This research will provide a greater understanding of the pre-and post-operative course of lower limb joint replacement surgery. Objectives: To provide an epidemiological description of the natural history of hip and knee osteoarthritis and hip and knee arthroplasty patients in the UK To risk stratify knee osteoarthritis patients and identify those who are appropriate candidates for day-case Fast Track hip and knee joint replacement surgery To explore the post-operative healthcare burden after day-case elective hip and knee joint replacement surgery using data describing both primary and secondary care. To compare UK elective Fast Track day surgery pathways and arthroplasty outcomes with Danish day-case surgery outcomes and pathways.Methods: Analysis of over 300,000 orthopaedic patients from different datasets (Table 1) will be undertaken to outline the baseline characteristics of the hip and knee replacement surgery patients. Descriptive statistics and machine learning methods will be used to describe NHS hip and knee osteoarthritis patients. Regression models will be used on national data to understand the patient factors for successful day-case surgery. Statistical models will be used to determine the need for repeat imaging and the healthcare burden following lower limb arthroplasty. Dataset Number of Patients Ethical Approval Status Access Ready for analysis Clinical Research Practice Datalink(CPRD) Aurum +CPRD Patients Reported Outcome Measure Database(PROMS) >39,555,354 Not required To be submitted Pending Multicentre Osteoarthritis Initiative 3000 Not required Granted Yes Osteoarthritis Initiative 4000 Not required Granted Yes Imperial College NHS Trust Imaging Dataset 2000 Not required Granted Yes Danish Integrated Healthcare records 20000 Not required To be submitted Pending Table 1. A summary highlighting the different datasets TimelineAs identified in the Gantt chart(attachment). There are no ethical applications required. The lead applicant is familiar with most of the databases to be used in the study. The timeline provides a contingency for project over-running. Impact and disseminationThis research will provide a risk stratification model to aid patients, service providers, policymakers, and surgeons to plan safe and effective orthopaedic services. It will aim to provide a greater understanding of the healthcare burden of the patient pathway in the elective hip and knee osteoarthritis pathway at a critical period for the NHS to aid elective surgery recovery. The findings will be presented nationally and published in high-impact peer-reviewed journals.

Lay abstract: Covid has created a significant impact on the lives of musculoskeletal patients. There are a significant number of patients who have not presented to General Practice or hospital services and who are likely to present in the next few years. These Hidden patients are expected to cause a huge burden on health services. Furthermore, in 2021, there were 4.7 million people waiting for elective surgery in the UK. The British Broadcasting Corporation (BBC) alone published 10 articles in 2020 related to the waiting times for elective surgery. Whilst there are clear plans for the recovery of the more urgent procedures, such as cancer surgery, non-emergency procedures have been sent to the back of the queue. Orthopaedics has been one of the worst affected specialities. To plan safe and efficient orthopaedic surgery we require a better understanding of the patients undergoing surgery. There is a need to identify which types of patients could safely be operated on and sent home the same day ('day cases'). Furthermore, more than 10% of all surgery patients will have some sort of complication after an operation. We do not know the effects of day case surgery after an operation. Some surgeons feel that patients are discharged too early, and some are discharged too late. There is a need to identify which patients would benefit from day case surgery.This PhD aims to use available national data and the latest mathematical techniques to help understand more about day-case joint replacement surgery, streamline knee osteoarthritis patients experiences and improve understanding of patients undergoing hip and knee joint replacement surgery. Aims and Objectives: To find out more about UK patients with hip and knee osteoarthritis and hip and knee replacements and the number of GP visits and hospital visits they have To understand the mechanical factors about why some patients may develop more rapidly worsening knee osteoarthritis and hence would benefit from early referral To understand the complications after daycase and non-daycase hip and knee replacements with emphasis on A&E attendance, readmission and clinic visits To compare UK Day case surgery complications with the Danish day-case surgery complicationsExpected Outcomes:This project will aim to provide an up to date understanding of the UK hip and knee osteoarthritis patients and those undergoing joint replacement surgery and improve our understanding of the effect of these patients on the National Health Service. This will aid in COVID-19 elective orthopaedic surgery recovery and future orthopaedic surgery service planning. Patient Public InvolvementFocus groups have been conducted on patient and public views of using Artificial Intelligence in Healthcare, the results of which have been published. Two PPI members(Ms Rose Stallwood and Ms Tina Thomas )who have Total Knee Replacements have provided critical feedback on this PhD which has resulted in a change to the secondary outcome measure for the day case study. Ms Stallwood has kindly agreed to review the progress of the PhD and provide feedback at 3-time points. PPI focus groups in the 2nd year and 3rd year are planned.This project also meets several key research priorities from the patient-led PPI James Lind Alliance priority setting partnership in hip and knee replacements and perioperative care, e.g., the second and third and ninth James Lind Alliance points, covering 'What is the optimal timing for hip and knee replacement surgery for best post-operative outcomes? What are the pre-operative predictors of post-operative success and risk factors for poor outcomes? What are ideal post-operative follow-up periods and the best long term care model for people with osteoarthritis that have had hip and knee replacements?

Research activity codes: 6.4 SURGERY
Health categories: MUSCULOSKELETAL