Differences in Pain Intensity in Anti- and Pro-Nociceptive Pain Profile Subgroups in Patients with Knee Osteoarthritis

Abstract

Aim: Facilitated temporal summation is one component of central sensitization. The aim of this exploratory study was to classify pro-, eu- and antinociceptive subgroups based on wind-up ratio cut-off scores in patients with knee osteoarthritis (OA). Patients & methods: A total of 56 patients with knee OA met the inclusion criteria. Temporal summation was measured and wind-up ratio was calculated. Reference values of 180 healthy subjects were used to define wind-up ratio cut-off scores. Results: Twenty-seven percent of patients showed a pro-nociceptive pain profile. Sixteen percent of patients showed an anti-nociceptive pain profile. A eu-nociceptive pain profile was present in 57% of patients. Conclusion: Central pain sensitization was present in approximately a third of knee OA patients. The results should be confirmed in larger studies.

Keywords::

• pain profile
• temporal summation
• wind-up ratio

Acknowledgements

This research project would not have been possible without the support of many people. The authors wish to express their gratitude to the colleagues from our co-operating hospitals for their valuable support during the research process: B Michel and M Kley (endogap Kinik für Gelenkersatz, Klinikum Garmisch-Partenkirchen); R Eisenhart-Rothe and N Harrasser (Klinik und Poliklinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar, Technische Universität München); S Horn (Krankenhaus Barmherzige Brüder München, Abteilung Orthopädie und Unfallchirurgie).

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The study was approved by the ethics committee of the faculty of medicine, Technical University Munich (TUM; project number: 5498/12) and is indexed within the German Clinical Trials Register (DRKS00005147).