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Alaiti R.K.1,2, Gasparin J.T.2, de Sousa M.F.d.C.2, Pompeu J.E.2,3, Gracitelli M.E.4, Malavolta E.A.4, Neto A.A.4, Costa M.F.d.1,2
1University of São Paulo, Experimental Psychology, São Paulo, Brazil, 2University of São Paulo, Neuroscience and Behavior, São Paulo, Brazil, 3University of São Paulo, Physical Therapy and Occupational Therapy, São Paulo, Brazil, 4Orthopaedics Institute of the University of São Paulo, Shoulder and Elbow Group, São Paulo, Brazil
Background: A growing body of the literature is reconceptualising our understanding of the painful phenomenon, since the old structural-pathology model is no longer able to explain the many new findings in the fields of study of perception, cognitive neuroscience and behavior in individuals with chronic pain that have emerged in recent years. Nevertheless, many researches and clinical interventions are still based on the assumption that the source of the chronic pain is related to structural and anatomical factors.
Purpose: The purpose of the presente study was to verify the correlation between pain perception and the severity of the rotator cuff tear in individuals with shoulder pain.
Methods: 85 patients (61,65 ±8,77 years old) diagnosed with rotator cuff dysfunction (tendinopathy, partial or a full-thickness tear) from traumatic or degenerative etiology, right-handed, symptomatic, sedentary and with the beginning of the complaint in the shoulder region for at least 3 months were randomly selected between the patients in care in the Shoulder and Elbow Group of the IOTFMUSP. Their shoulder pain were accessed in a nominal level, by the binary verbal report of the presence/absence of pain; in a ordinal level, by the pain assessment used in the Constant-Murley questionnaire; in an interval level, by the Visual Numeric Scale used in the ASES questionnaire; in a pseudo-ratio level, by a 10 cm Visual Analog Scale with the left extremity labeled as "no pain" and the right as "worst pain possible" and in a ratio level using the power function exponent of the functional pain derived from the numerical magnitude estimations made for the pain percept at rest and during the 10 movements of The Psychophysical Scale for Functional Shoulder Pain Evaluation developed by our research group. The severity of the injury was classified according to the Thomazeau criterion modified by Boileau. This study was approved by the Ethics Committee on Human Research of the Psychology Institute of the University of São Paulo and written consent was obtained from each participant prior to the experiments.
Results: Only the correlations between the degenerative etiology and the Goutallier classification of the supraspinatus (r=-0,45) and the duration of symptoms and the retraction of the subscapularis tendon (r=0,46) were significant. No measure of rotator cuff tear severity correlated with pain, regardless of the level of measurement used to access it.
Conclusion(s): Anatomic features that define the severity of the rotator cuff tears are not associated with the pain felt by the patient, regardless of the level of measurement used to access the pain.
Implications: These findings corroborate with the new bio-psicossocial model, suggesting that we have to go beyond the anatomical level if we realy want to understant the pain phenomenon in order to find more efficient forms of treatment for the chronic pain population.
Funding acknowledgements: This paper was supported by the scholarship 130699/2016-0 from the CNPq and FAPESP #04049-4.
Topic: Pain & pain management
Ethics approval: This study was approved by the Ethics Committee of the Psychology Institute of the University of São Paulo, protocol 49635115.5.0000.5561.
All authors, affiliations and abstracts have been published as submitted.
