Patellar tendon morphology in volleyball
athletes with and without patellar tendinopathy.

Kulig K, Chang TJ, Hannanvash
N, Reischl SF, Song P, and Bashord GR. Scand J Med Sci Sports. 2012: 1-8.

Patellar tendinopathy is common in athletics, especially among
volleyball players. The condition occurs due to degeneration and/or
inflammation secondary to physical activity. Additionally, clinical imaging
struggles to distinguish between inflammatory and degenerative conditions
further complicating diagnosis and thus, management. Therefore, Kulig and
colleagues sought to perform a detailed analysis of patellar tendon collagen
bundle organization in elite male volleyball athletes. The authors recruited 94
male participants (10 controls and 84 NCAA Division I or Olympic volleyball
players) over 6 feet tall. The 84 volleyball players were divided into those
with anterior knee pain near the patellar tendon (symptomatic, 44 players) and
those without (asymptomatic, 40 players). All participants completed a
questionnaire (lower VISA-P score indicated more pain and restrictions).
Furthermore, the researchers collected anthropometric data (body mass, height,
etc.) and conducted personal interviews. Lastly, the researchers performed
B-mode ultrasound imaging to assess the collagen organization
and thickness of the patellar tendons. While B-mode ultrasound cannot
specifically identify inflammation, the researchers considered inflammation to
be the cause of the tendinopathy if the athlete was symptomatic, yet did not demonstrate
collagen disorganization, thus ruling out degenerative changes to the tendon.
Overall, patellar tendons of asymptomatic athletes, and athletes with
tendinopathy, demonstrated greater proximal tendon thicknesses compared to
control participants; however VISA-P scores were significantly lower in
symptomatic athletes than asymptomatic athletes. Symptomatic athletes also had
greater collagen bundle disorganization (degeneration) compared to both control
participants and asymptomatic volleyball players.

The presence of collagen
bundle disorganization and lower VISA-P scores suggests that symptoms of
tendinopathy are associated with tendon degeneration rather than inflammatory
responses, although all athletes displayed morphological changes to the tendon
compared to control participants. While interesting one should be cautious not
to generalize these findings to the general population. The current study
observed only elite male volleyball players. These athletes may be unique
because of their high volume of training, which may explain why athletes had
thicker tendons than control participants. In order to increase
generalizability, future research should compare various levels of competition
(recreational, high school) and sports to healthy controls. Further, it would
be interesting to follow athletes over time to determine when and how certain
aspects of training begin to induce healthy adaptation (thickness) and
degenerative changes. Eventually, this data conceivably could optimize training
regiments for volleyball athletes so as to prevent tendinopathy from occurring.
In the meantime, given this information, clinicians should be aware that
volleyball athletes (as well as possibly other athletes) who present with recurrent
patellar tendon pain may be experiencing tendonosis rather than tendonitis and
could respond to a change in treatment approach. Tell us what you think. Have
you seen athletes which, given this information may be experiencing patellar
tendonosis rather than tendonitis? Further, do you see this evidence changing
how you treat tendinopathies which may be degenerative changes more so than
inflammatory change?

Written by: Kyle Harris
Reviewed by: Laura McDonald

Related Posts:

Kulig K, Landel R, Chang YJ, Hannanvash N, Reischl SF, Song P, & Bashford GR (2012). Patellar tendon morphology in volleyball athletes with and without patellar tendinopathy. Scandinavian Journal of Medicine & Science in Sports PMID: 23253169