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Anterior cruciate ligament tear induces a sustained loss of muscle fiber force production
Author(s) -
Gumucio Jonathan P.,
Sugg Kristoffer B.,
Enselman Elizabeth R Sibilsky,
Konja Alexis C.,
Eckhardt Logan R.,
Bedi Asheesh,
Mendias Christopher L.
Publication year - 2018
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.26075
Subject(s) - medicine , anterior cruciate ligament , contractility , muscle weakness , neurophysiology , muscle contraction , weakness , anatomy , physical medicine and rehabilitation , cardiology , psychiatry
ABSTRACT Introduction : Patients with anterior cruciate ligament (ACL) tears have persistent quadriceps strength deficits that are thought to be due to altered neurophysiological function. Our goal was to determine the changes in muscle fiber contractility independent of the ability of motor neurons to activate fibers. Methods : We obtained quadriceps biopsies of patients undergoing ACL reconstruction, and additional biopsies 1, 2, and 6 months after surgery. Muscles fiber contractility was assessed in vitro , along with whole muscle strength testing. Results : Compared with controls, patients had a 30% reduction in normalized muscle fiber force at the time of surgery. One month later, the force deficit was 41%, and at 6 months the deficit was 23%. Whole muscle strength testing demonstrated similar trends. Discussion : While neurophysiological dysfunction contributes to whole muscle weakness, there is also a reduction in the force generating capacity of individual muscle cells independent of alpha motor neuron activation. Muscle Nerve 58 : 145–148, 2018