title: Muscle-tendon glucose uptake in Achilles tendon rupture and tendinopathy before and after eccentric rehabilitation: Comparative case reports.
abstract: Achilles tendon rupture (ATR) is the most common tendon rupture injury. The consequences of ATR on metabolic activity of the Achilles tendon and ankle plantarflexors are unknown. Furthermore, the effects of eccentric rehabilitation on metabolic activity patterns of Achilles tendon and ankle plantarflexors in ATR patients have not been reported thus far. We present a case study demonstrating glucose uptake (GU) in the Achilles tendon, the triceps surae, and the flexor hallucis longus of a post-surgical ATR patient before and after a 5-month eccentric rehabilitation. At baseline, three months post-surgery, all muscles and Achilles tendon displayed much higher GU in the ATR patient compared to a healthy individual despite lower plantarflexion force. After the rehabilitation, plantarflexion force increased in the operated leg while muscle GU was considerably reduced. The triceps surae muscles showed similar values to the healthy control. When compared to the healthy or a matched patient with Achilles tendon pain after 12 weeks of rehabilitation, Achilles tendon GU levels of ATR patient remained greater after the rehabilitation. Past studies have shown a shift in the metabolic fuel utilization towards glycolysis due to immobilization. Further research, combined with immuno-histological investigation, is needed to fully understand the mechanism behind excessive glucose uptake in ATR cases.
authors.affiliation: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland; Isra Institute of Rehabilitation Sciences, Isra University, Islamabad Campus, Islamabad, Pakistan. Electronic address: tahirphysio@gmail.com.
authors.forename: Tahir
authors.initials: T
authors.lastname: Masood
authors.affiliation: Turku PET Centre, Turku, Finland. Electronic address: Kari.Kalliokoski@tyks.fi.
authors.forename: Kari
authors.initials: K
authors.lastname: Kalliokoski
authors.affiliation: Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway. Electronic address: jens.bojsen-moller@nih.no.
authors.forename: Jens
authors.initials: J
authors.lastname: Bojsen-Møller
authors.affiliation: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland. Electronic address: taija.finni@jyu.fi.
authors.forename: Taija
authors.initials: T
authors.lastname: Finni
mesh_terms: D000125:Achilles Tendon / Q000000981:diagnostic imaging / Q000293:injuries* / Q000378:metabolism*; D000328:Adult; D001265:Athletic Injuries / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000534:rehabilitation*; D001696:Biomechanical Phenomena; D003952:Diagnostic Imaging; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000378:metabolism*; D012421:Rupture; D013708:Tendon Injuries / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000534:rehabilitation*
chemical_list: D005947:Glucose
keywords: Biomechanics; Glucose uptake; Immobilization; Positron emission tomography