One article on PainSci cites Pattyn 2011: The Complete Guide to Patellofemoral Pain Syndrome
PainSci notes on Pattyn 2011:
It is an article of faith for many professionals that the inner portion of the quadriceps muscle group (VMO) is weak and atrophied in patients with patellofemoral pain, “despite very little objective evidence” according to this paper. For the first time, researchers used MRI to measure the size of the vastus medialis obliquus muscle in patients with and without patellofemoral pain syndrome, and found that it was 9% smaller in PFPS patients. The results are just barely statistically significant, and of course it is “not clear whether this atrophy is a result or a cause of PFPS.” However, that wise disclaimer is contradicted by the following statement that VMO is a “contributing factor in PFPS” — a troubling inconsistency in the paper’s abstract.
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
BACKGROUND: Quadriceps atrophy and in particular atrophy of the vastus medialis obliquus (VMO) muscle have been frequently related with patellofemoral pain syndrome (PFPS), despite very little objective evidence.
HYPOTHESIS: Patients with PFPS exhibit atrophy of the VMO in comparison with healthy controls.
STUDY DESIGN: Case-control study; Level of evidence, 3.
METHODS: Forty-six patients with PFPS and 30 healthy control persons with similar age, gender, body mass index, and activity index distributions underwent magnetic resonance imaging (MRI) of the quadriceps. The muscle size was determined by calculating the cross-sectional area of the total quadriceps and its components.
RESULTS: The cross-sectional area (CSA) of the VMO was significantly smaller in the PFPS group than in the control group (16.67 ± 4.97 cm(2) vs 18.36 ± 5.25 cm(2)) (P = .040). A tendency was noted for a smaller total quadriceps CSA for the PFPS patients at midthigh level (66.99 ± 15.06 cm(2) vs 70.83 ± 15.30 cm(2)) (P = .074).
CONCLUSION: This is the first study to examine VMO size in PFPS patients by MRI. Patients with patellofemoral problems exhibited atrophy of the VMO. Although it is not clear whether this atrophy is a result or a cause of PFPS, the results of this study do show that atrophy of the VMO is a contributing factor in PFPS. Longitudinal, prospective studies are needed to establish the cause-effect relation of VMO atrophy and PFPS.
- “Structural parameters of the vastus medialis muscle and its relationship to patellofemoral joint deterioration,” J Peeler and J E Anderson, Clinical Anatomy, 2007.
- “Vastus medialis obliquus muscle morphology in primary and recurrent lateral patellar instability,” Peter Balcarek, Swantje Oberthür, Stephan Frosch, Jan Philipp Schüttrumpf, and Klaus Michael Stürmer, Biomed Res Int, 2014.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- No long-term effects after a three-week open-label placebo treatment for chronic low back pain: a three-year follow-up of a randomized controlled trial. Kleine-Borgmann 2022 Pain.
- Exercise and education versus saline injections for knee osteoarthritis: a randomised controlled equivalence trial. Bandak 2022 Ann Rheum Dis.
- Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-based Cohort Study. Kasch 2022 Spine (Phila Pa 1976).
- A double-blinded randomised controlled study of the value of sequential intravenous and oral magnesium therapy in patients with chronic low back pain with a neuropathic component. Yousef 2013 Anaesthesia.
- Is Neck Posture Subgroup in Late Adolescence a Risk Factor for Persistent Neck Pain in Young Adults? A Prospective Study. Richards 2021 Phys Ther.