File
A. Koufogianni1, A.K. Kanellopoulos2,3, K. Vassis1, I.A. Poulis1
1Human Performance and Rehabilitation Laboratory, University of Thessaly, Department of Physiotherapy, School of Health Sciences, Lamia, Greece, 2University of Thessaly, Department of Physiotherapy, School of Health Sciences, Lamia, Greece, 3Health Assessment and Quality of Life Laboratory, University of Thessaly, Department of Physiotherapy, School of Health Sciences, Lamia, Greece
Background: Osteoarthritis (OA) is one of the most common conditions in our society. There is an ongoing debate nowadays, on whether an association between radiographic and clinical findings exists in OA, as chronic pain does not always correspond to structural damage. A growing number of studies suggest the existence of central sensitization (CS) in a subgroup of osteoarthritic patients. As a result of CS, the patient continues to perceive pain, with exactly the same pain characteristics that are directly caused by a stimulus, but in this case the primary painful stimulus may have disappeared leading to a secondary hyperalgesia.
One of the criteria included for the classification of CS pain is the expanded distribution of pain, presented as a percentage of the whole-body area, with a neuroanatomically illogical distribution. As this criterion is a well-recognized sign of CS, a digital pain drawing (DPD) analysis would be useful to easily identify possible extended areas of pain distribution in patients with OA.
One of the criteria included for the classification of CS pain is the expanded distribution of pain, presented as a percentage of the whole-body area, with a neuroanatomically illogical distribution. As this criterion is a well-recognized sign of CS, a digital pain drawing (DPD) analysis would be useful to easily identify possible extended areas of pain distribution in patients with OA.
Purpose: Τo study the relationship between the percentage of distribution of pain that holds for the lower limb generally for both knee and hip, in patients before hip or knee arthroplasty, in relation with the Central Sensitization Inventory questionnaire.
Methods: 20 women (mean age = 64.78 ± 9.5 years) with diagnosed chronic (over 3 months) knee (11 patients) or hip (9 patients) OA participated in the study, with intensity of pain from mild to severe, meaning pain >5/10 using the Numeric Pain Rating Scale (NPRS). The pain distribution was analysed with the help of a software created for this research, called “Pain Distribution Application”, which is freely available to the public (https://www.hprl.physio.uth.gr/pain-distribution), in combination with the use of a tablet and the application “Autodesk Sketchbook”, where a digital body diagram appeared on the subject, on which the participant marked the places where he felt pain.
Results: A statistically significantly positive correlation between CSI and pain distribution to the lower extremity OA (hip and knee) (r = 0.775, sig <0.01) was found. We found that the distribution of pain has a linear correlation with the results in CSI, of patients who tested positive for CS, i.e. with a score of ≥40.
A finding seems to be that the threshold to be positive in the CSI (cut off score ≥ 40), corresponds in a distribution of pain in the body at the level of 10% of the body surface. Above this threshold, as the score in CSI increases, meaning more severe conditions, the percentage of pain distribution, as expressed in percentage of the whole-body area, also increases, in a positive linear correlation.
A finding seems to be that the threshold to be positive in the CSI (cut off score ≥ 40), corresponds in a distribution of pain in the body at the level of 10% of the body surface. Above this threshold, as the score in CSI increases, meaning more severe conditions, the percentage of pain distribution, as expressed in percentage of the whole-body area, also increases, in a positive linear correlation.
Conclusion(s): As the distribution of pain on the surface of the body (diffusion) increases, so does the score of people who test positive for CSI.
Implications: Our results showed that calculating the distribution of pain with our application may have a utility as a CS screening tool. The pain distribution threshold of 10% of the body area is an index for Central Sensitization for chronic pain lower limb OA patients.
Funding, acknowledgements: This study does not involve any external research grant support.
Keywords: Central Sensitization, Pain distribution, Lower Limp Osteoarthritis
Topic: Pain & pain management
Did this work require ethics approval? Yes
Institution: School of Health Sciences, University of Thessaly
Committee: Research Ethics Committee of Department of Physiotherapy
Ethics number: Protocol number 15/04-9-2019
All authors, affiliations and abstracts have been published as submitted.
