Outcomes of patellofemoral joint arthroplasties compared to total knee arthroplasties
File(s)
Author(s)
Vella Baldacchino, Martinique
Type
Thesis or dissertation
Abstract
Patellofemoral joint arthroplasty (PFA) and total knee arthroplasty (TKA) are established treatment options for patients with isolated patellofemoral osteoarthritis. PFA is considered a small, bone-preserving procedure that maintains native knee kinematics through preservation of the cruciate ligaments. Due to its historically high revision rates, which have been reported as high as 35%, surgeons have been cautious in adopting PFA. This may explain why PFAs still account for 1% in most national joint registries worldwide.
A comparison of matched patients undergoing PFA and TKA was performed using data from the National Joint Registry for England and Wales. Complications, revision reasons, and patient-reported outcome measures were analysed. While TKA patients were more likely to experience complications within 30 days, they were less likely to undergo revision surgery. Gender differences in revision risk and reasons for revision were evaluated across different age groups. To further understand the factors influencing revision rates, the impact of surgical experience was also examined.
Although there was a statistically significant difference in Oxford Knee Score and EQ-5D-3L outcomes, with TKA faring better, the difference did not reach the minimal clinical difference when taken as 5 and 0.085, respectively. For further comparison, differences in function were examined to delineate functional differences between the two procedures. A 10-year follow up of an international randomised controlled trial was conducted to assess differences in activity levels and gait analysis patterns between PFA and TKA in patients with isolated patellofemoral osteoarthritis.
Although limited by a small sample size, PFA patients demonstrated higher total physical activity time per week, though this did not reach statistical significance. Gait analysis revealed a more physiological pattern in PFA patients, likely reflecting the preservation of normal knee kinematics. However, further work is needed to establish if there is an objective difference in activity levels in the short term.
A comparison of matched patients undergoing PFA and TKA was performed using data from the National Joint Registry for England and Wales. Complications, revision reasons, and patient-reported outcome measures were analysed. While TKA patients were more likely to experience complications within 30 days, they were less likely to undergo revision surgery. Gender differences in revision risk and reasons for revision were evaluated across different age groups. To further understand the factors influencing revision rates, the impact of surgical experience was also examined.
Although there was a statistically significant difference in Oxford Knee Score and EQ-5D-3L outcomes, with TKA faring better, the difference did not reach the minimal clinical difference when taken as 5 and 0.085, respectively. For further comparison, differences in function were examined to delineate functional differences between the two procedures. A 10-year follow up of an international randomised controlled trial was conducted to assess differences in activity levels and gait analysis patterns between PFA and TKA in patients with isolated patellofemoral osteoarthritis.
Although limited by a small sample size, PFA patients demonstrated higher total physical activity time per week, though this did not reach statistical significance. Gait analysis revealed a more physiological pattern in PFA patients, likely reflecting the preservation of normal knee kinematics. However, further work is needed to establish if there is an objective difference in activity levels in the short term.
Version
Open Access
Date Issued
2025-11-10
Date Awarded
2026-08-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Cobb, Justin
Liddle, Alexander
Sponsor
Orthopaedic Research UK
International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine
Grant Number
ORUK 551
Publisher Department
Department of Surgery & Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)