One of our Elf friends has had a three year history of knee pain with some episodes of flare ups causing him to be absent from work for several weeks at a time. His pain is aggravated by descending stairs and kneeling. He is keen to return to work and his usual hobby of attending the gym and wonders what is the best way to treat his condition. So, we set to work finding the latest evidence to help him.

We found a new systematic review that examined the literature to determine whether exercise therapy is an effective intervention to reduce pain and patient-reported measures of activity limitations and participation restrictions (PRMALP) in patients with patellofemoral pain.

Here’s what they did

They looked for randomized controlled trials in English and German languages published in the MEDLINE, Physiotherapy Evidence Database (PEDro), International Clinical Trials Registry Platform, and Cochrane databases using a comprehensive search strategy.

The methodological quality of the studies was rated using the PEDro scale.

Here’s what they found

• Fifteen studies, with a total of 748 participants compared exercise with – control group receiving neither exercise therapy nor another intervention (n=6); additive therapy (n=4); different exercise interventions (n=5).
• Exercise – 4 studies patients were instructed to exercise daily, 9 studies 3 to 5 weekly, 2 studies 2 sessions or less per week. Four studies used home-based exercise therapy interventions.
• Pain reduction – Significant short-term effects (less than 12 weeks) Hedges’ g 1.18 (95% CI 1.86 to 0.51) circa 40 mm on the 100-mm VAS pain scale after re-expression.
• Patient-reported measures of activity limitations and participation restrictions (PRMALP) – Significant short-term effects (less than 12 weeks) Hedges’ g 1.30 (95% CI2.11, 0.50) and long-term effects (more than 26 weeks) Hedges’ g 0.99 (95% CI2.28, 1.51).

 The author’s concluded

Exercise therapy has a strong pain-reducing effect and decreases PRMALP in patients with patellofemoral pain.

The Musculoskeletal Elf’s view

A criterion for a good systematic review is the need to undertake a comprehensive search for evidence. The authors of this review elected to search a range of databases but CINAHL was not inclcuded. The CINAHL databse includes specialist nursing and allied health professionals literature. However, they did utilise the PEDro database. The autors also elected to only include studies published in English or German and this may have introduced bias.

Interestingly the included studies involved 539 females and 209 males, 2 studies only included women and one study only men. This may have influenced the results.

There was a wide variety of exercise types and durations described by studies and of the 15 included studies, only 6 provided sufficient information regarding the exercise therapy load.

This review also used Hedges’ g to calculate effect sizes (this is a method of Standarised Mean Differences). In this method the original units are replaced by standardized units. However, for the purpose of a better clinical understanding, these values were re-expressed as the original pain scale scores.

What do you think?

• Does the proportion of females to males refect presentation in clinical practice for this condition?
• What exercise regime would you recommend for our friend?

Send us your views on this blog and become part of the ever expanding Musculoskeletal Elf community. Post your comment below, or get in touch via social media (Facebook, Twitter, LinkedIn, Google+).

Links

• Effectiveness of exercise therapy in treatment of patients with patellofemoral pain syndrome: systematic review and meta-analysis. Clijsen R, Fuchs J, Taeymans J. Phys Ther. 2014 Dec;94(12):1697-708. doi: 10.2522/ptj.20130310. Epub 2014 Jul 31. [Abstract]