Local Anesthetic Injection Resolves Movement Pain, Motor Dysfunction, and Pain Catastrophizing in Individuals With Chronic Achilles Tendinopathy: A Nonrandomized Clinical Trial

• Published in: The journal of orthopaedic and sports physical therapy 2020-06, Vol.50 (6), p.334-343
• Main Authors: Chimenti, Ruth L, Hall, Mederic M, Dilger, Connor P, Merriwether, Ericka N, Wilken, Jason M, Sluka, Kathleen A
• Format: Article
• Language: English
• Subjects: Achilles Tendon - diagnostic imaging; Adult; Anesthetics, Local - administration & dosage; Catastrophization; Chronic Disease; Female; Humans; Male; Middle Aged; Movement; Nociceptive Pain - prevention & control; Nociceptive Pain - psychology; Ropivacaine - administration & dosage; Tendinopathy - diagnostic imaging; Tendinopathy - physiopathology; Ultrasonography
• ISSN: 0190-6011; 1938-1344
• DOI: 10.2519/jospt.2020.9242

Peripherally directed treatments (targeted exercise, surgery) can reduce, but not fully eliminate, pain for up to 40% of patients with Achilles tendinopathy. The objectives of the present study were (1) to identify indicators of altered central processing in participants with Achilles tendinopathy compared to controls, and (2) to determine which indicators of altered central processing would persist after a local anesthetic injection in patients with Achilles tendinopathy. Mechanistic clinical trial. Forty-six adults (23 with chronic Achilles tendinopathy, 23 matched controls) repeated (1) a movement-evoked pain rating, (2) motor performance assessment, (3) pain psychology questionnaires, and (4) quantitative sensory testing. Participants with Achilles tendinopathy received a local anesthetic injection before repeat testing and controls did not. Mixed-effects analyses of variance examined the effects of group, time, and group by time. The Achilles tendinopathy group had movement-evoked pain, motor dysfunction, and higher pain psychological factors (pain catastrophizing, kinesiophobia) compared to controls ( .05). In those with Achilles tendinopathy, local anesthetic injection eliminated pain and normalized the observed deficits in heel-raise performance and pain catastrophizing (group-by-time effect, .05). People with Achilles tendinopathy had elevated pain psychological factors and motor dysfunction but no signs of nociplastic pain with quantitative sensory testing. Removal of nociceptive input normalized movement-evoked pain and some indicators of altered central processing (motor dysfunction, pain catastrophizing), but not kinesiophobia. .