FIDELITY is a randomized, placebo-surgery controlled trial comparing arthroscopic partial meniscectomy with diagnostic arthroscopy, a placebo surgical comparator, in patients with degenerative meniscus tear.

Why was this trial needed?

Meniscal damage in MRI imaging is a common finding in middle-aged and older patients with knee pain. Conventional wisdom dictates that these ‘meniscal tears’ are the origin for knee pain. Following this rationale, arthroscopic partial meniscectomy (APM) to trim the lesions became the most common orthopedic procedure with approximately two million such procedures each year. Remarkably, there was no convincing evidence to justify the practice.

A series of randomized controlled trials, including the FIDELITY, established that APM has minimal or no beneficial effects on patients’ symptoms. High prevalence of knee osteoarthritis (OA) among patients having undergone APM prompted concerns about APM potentially accelerating the progression of knee degeneration.


What is the primary objective of the FIDELITY trial?

In the original FIDELITY trial, we showed that APM was not any better than placebo surgery in relieving knee pain and other symptoms in patients with a degenerative meniscus tear in short-term (1- and 2-year follow-up).

The objective of our 5- and 10-year follow-up extensions, the FIDELITY-OA, is to determine the possible effect of APM on the knee symptoms and development of knee OA.

Where are we now?

We have already published the following articles:

The 5-year follow-up examinations are completed and we are working with the data!

Principal investigators

Teppo Järvinen

Professor, Head

Raine Sihvonen

MD, PhD, Orthopedic surgeon, Senior researcher

Pirjo Toivonen

Physiotherapist, Project manager

Project team

Mika Paavola – Antti Malmivaara – Simo Taimela – Pasi Aronen – Roope Kalske


Ari Itälä – Antti Joukainen – Heikki Nurmi – Juha Kalske – Martin Englund – Anna Ikonen – Timo Järvelä – Tero Järvinen – Kari Kanto – Janne Karhunen – Jani Knifsund – Heikki Kröger – Jaanika Kumm – Tommi Kääriäinen – Janne Lehtinen – Jukka Nyrhinen – Juha Paloneva – Outi Päiväniemi – Marko Raivio – Janne Sahlman – Roope Sarvilinna – Aleksandra Turkiewicz – Sikri Tukiainen – Ville-Valtteri Välimäki – Ville Äärimaa


by Sihvonen R, Paavola M, Malmivaara A, Itälä A, Joukainen A, Nurmi H, Kalske J, Ikonen A, Järvelä T, Järvinen TA, Kanto K, Karhunen J, Knifsund J, Kröger H, Kääriäinen T, Lehtinen J, Nyrhinen J, Paloneva J, Päiväniemi O, Raivio M, Sahlman J, Sarvilinna R, Tukiainen S, Välimäki VV, Äärimaa V, Toivonen P, Järvinen TL