Associations between abnormal ultrasound color Doppler measures and tendon pain symptoms in badminton players during a season: a prospective cohort study.
BACKGROUND
Color Doppler ultrasound is widely used to examine intratendinous flow in individuals with overuse tendon problems, but the association between color Doppler and pain is still unclear.


OBJECTIVE
Intratendinous flow is present and associated with pain in badminton players, and intratendinous flow and pain increase during a badminton season.


METHODS
Cohort study (prognosis); Level of evidence, 2.


METHODS
Ninety-five semiprofessional badminton players were included in the study at a tournament at the start of the badminton season. All players were interviewed regarding pain. The anterior knee tendons and Achilles tendons were studied. Each tendon was scored using a quantitative grading system (grades 0-5) and a qualitative scoring system (color fraction) using color Doppler ultrasound. Eight months later, 86 of the players (91%) were retested by the same investigators during an equivalent badminton tournament (including 1032 tendon regions; 86 players with 4 tendons each with 3 regions), thus forming the study group.


RESULTS
At the start of the season, 24 players (28%) experienced pain in 37 tendons (11%), and at the end of the season, 31 players (36%) experienced pain in 51 tendons (15%), which was a statistically significant increase (P = .0002). Abnormal flow was found in 230 tendon regions in 71 players (83%) at the start of the season compared with 78 tendon regions in 41 players (48%) at the follow-up. The decrease in abnormal flow was statistically significant (P < .0001). Of the 37 painful tendons at the start of the season, 25 had abnormal flow (68%). In contrast, 131 tendons (85%) with abnormal flow at the start of the season were pain free. At the end of the season, 18 of the 51 painful tendons (35%) had abnormal flow. Ninety-six of the 131 pain-free tendons (73%) with abnormal flow at the start of the season were normalized (no pain and normal flow) at the end of the season.


CONCLUSIONS
It was not possible to verify any association between intratendinous flow and pain at the start of the season or at the follow-up (end of the season). Intratendinous flow at the start of the season could not predict symptomatic outcome at the end of the season. The decrease in Doppler flow during the season might suggest that intratendinous flow could be part of a physiological adaptive response to loading and that intratendinous flow as previously believed is not always a sign of pathological changes.
Institute of Sports Medicine, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark. boesenanders@hotmail.com
Anders Ploug
AP
Boesen
Morten Ilum
MI
Boesen
Soren
S
Torp-Pedersen
Robin
R
Christensen
Lars
L
Boesen
Per
P
Hölmich
Michael Bachmann
MB
Nielsen
Merete Juhl
MJ
Koenig
Andreas
A
Hartkopp
Karen
K
Ellegaard
Henning
H
Bliddal
Henning
H
Langberg
D000125:Achilles Tendon / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D056352:Athletes; D001265:Athletic Injuries / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging; D008297:Male; D010146:Pain / Q000000981:diagnostic imaging; D011446:Prospective Studies; D015865:Racquet Sports / Q000293:injuries*; D052256:Tendinopathy / Q000000981:diagnostic imaging*; D018615:Ultrasonography, Doppler, Color; D055815:Young Adult