Insufficient recovery of neuromuscular activity around the knee after experimental anterior cruciate ligament reconstruction.
BACKGROUND
Operative and nonoperative treatment of anterior cruciate ligament (ACL) injuries is often associated with a lack of proprioception and persistent muscle weakness of unknown origin.


METHODS
This long-term study in the cat experimentally compares both neural and muscular activity in the articular nerves of the knee (PAN and MAN), quadriceps and hamstrings, in the chronic unstable knee, and in the reconstructed knee. We also investigated changes in neuromuscular response due to the mechanical competence of the graft, comparing stable and unstable reconstructed knees.


RESULTS
We found increased periarticular muscle activity during anterior tibial translation in chronically unstable knees. Both reconstructed and non-reconstructed knees lost fast reactive activity in the articular nerves. When stability was recovered after reconstruction, the knees showed a more adjusted - although incomplete - muscular reaction.


CONCLUSIONS
ACL-injured knees in the cat, with or without reconstruction, show definite abnormalities in neuromuscular reaction in the long term. Regaining stability with a competent graft in the reconstructed knee is crucial for reduction of this anomalous reaction.
Gómez-Barrena
Enrique
E
Department of Surgery (Orthopedics), Universidad Autónoma de Madrid, Madrid, Spain. enrique.gomezbarrena@uam.es
Bonsfills
Nuria
N
Martín
José G
JG
Ballesteros-Massó
Rafael
R
Foruria
Antonio
A
Núñez-Molina
Angel
A
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D002415:Cats; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000517:prevention & control; D007719:Knee Joint / Q000294:innervation / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D011434:Proprioception / Q000502:physiology; D052097:Quadriceps Muscle / Q000502:physiology; D019651:Plastic Surgery Procedures / Q000379:methods*; D020127:Recovery of Function