Subgroup analysis on pain and function outcomes of pre-operative exercise therapy in patients with knee osteoarthritis after knee replacement surgery


Knee pain is considered as the most disabling OA symptom in people with knee joint osteoarthritis (OA). Several treatment options are available for different stages of OA. Exercise therapy (ET) is one of the non-surgical and non-pharmacological therapy intervention with beneficial effects, recommended by international clinical guidelines. Although, patients might have improvement of pain and function pre-operative due to pre-operative ET, the primary purpose is to have better outcomes on pain and function postoperatively. The overall effects of pre-operative ET are rather small and the population of patients with knee OA is heterogeneous, therefore it is still unknown which patients benefit from exercise therapy given pre-surgery.

This study aims to identify subgroups of patients with knee OA who have better outcome after pre-operative exercise therapy compared to usual care after total knee joint replacement.


We will conduct an individual patient data (IPD) analysis by collecting IPD of relevant published randomized controlled trials (RCTs). A systematic literature search will be performed through several literature databases. We will include interventions involving any form of supervised, repetitive and structured pre-operative exercise therapy in comparison to usual care. The primary outcome will be self-reported pain and knee function 3 months post-surgery on a WOMAC scale and the secondary outcomes are pain and physical function measured at other time points and scales, hospital stay duration, adverse events, analgesic use and quality of life.

Subgroups that will be evaluated, will be defined based on age, sex, body mass index (BMI), severity of pain and physical disability, muscle strength, mental health complaints, presence of comorbidities, daily physical activity, and radiographic involvement of patellofemoral compartment.

For all included studies, the lead investigators will be invited to share anonymized IPD. We will follow a two-stage approach, analyzing each trial separately first, then analyzing across trials, to evaluate the treatment effect in different subgroups.


Ongoing. We are currently screening studies for inclusion to our review

Protocol and publications


R.U. (Upasna) Sharma 1
J. (Jos) Runhaar1
K. (Koen) P. Bos 2
D. (Desirée) M.J. Dorleijn 3
M. (Marijn) Vis 4
P. (Patrick) J.E. Bindels 1
M. (Max) Reijman 2
M. (Marienke) van Middelkoop 1, 5
S. (Sita) M.A. Bierma-Zeinstra 1, 2

1. Erasmus MC Medical University Center Rotterdam, Department of General Practice, The Netherlands
2. Erasmus MC Medical University Center Rotterdam, Department of Orthopedics & Sports Medicine, The Netherlands
3. University Hospital Ghent, Department of Orthopedics, Belgium
4. Erasmus MC Medical University Center Rotterdam, Department of Rheumatology, The Netherlands
5. OA Trial Bank Steering Group, Rotterdam, Netherland