A comparative study of patients presenting for revision of hip or knee replacements, based on whether they were or were not under long term follow-up

Background: This prospective cohort study explored differences in symptoms, healthcare use, reason for revision, and the revision surgery (surgical time, components, length-of-stay) between patients having regular follow-up and those without. Methods: Data were collected from participants and medical records for the 12 months prior to revision. Patients with previous revision, metal-on-metal or hip hemi-arthroplasty were excluded. Participants were retrospectively classified to a ‘follow-up’ or ‘no follow-up’ group. Multi-level regression and propensity score matching compared the 2 groups. Results: 568 patients were enrolled at 35 UK secondary care sites between October 2017 and October 2018 (43.5% male; mean (SD) age 71.86 (9.93) years; 305 hips, 263 knees). No significant inclusion differences were identified between the Follow-up and No Follow-up groups. For hip revision, male gender (OR 1.975, 95%CI[1.083-3.602], p=0.026) and time-to-revision>10 years (OR 3.804, 95%CI[1.353-10.694], p=0.011) were associated with Follow-up. Periprosthetic fracture (OR 20.309, 95%CI[4.574-90.179], p10 years (OR 2.337, 95% CI[1.007-5.419], p=0.048) and infection (OR 2.946, 95%CI[1.046-8.298], p=0.041) were associated with No Follow-up. No other significant differences in cost outcomes, length of surgery time and access to a health professional in the 12 months prior to revision were found between the two groups for either hip or knee patients. However, there was a trend for increased length-of-stay and increased surgery time for hip revisions in the No Follow-up group, which was retained when periprosthetic fractures were excluded. Conclusion: There are differences between patients presenting for revision through follow-up and no follow-up routes. Possible reasons for these differences will be presented. Implications: This study formed part of the evidence used to inform the development of recommendations for follow-up of hip and knee surgery patients as part of the UKSAFE programme (HS&DR 14/170/96).