The effect of anterior cruciate ligament reconstruction on stride-to-stride variability.
OBJECTIVE
The purpose of our study was to investigate the functional outcome after anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) and quadrupled semitendinosus and gracilis tendon (ST/G) autografts by evaluating stride-to-stride variability.


METHODS
Six patients with BPTB and 6 patients with STG ACL reconstruction, 2 years postoperatively, and 6 healthy control subjects walked on a treadmill at a self-selected pace while 2 minutes of continuous kinematic data were recorded with a 6-camera optoelectronic system. Stride-to-stride variability was calculated from the knee flexion/extension data using the nonlinear measure of approximate entropy, which estimates the regularity of movement patterns over time.


RESULTS
ACL reconstruction affects stride-to-stride variability. Both the BPTB and the ST/G groups had significantly larger approximate entropy values than the healthy controls. No differences were found between the BPTB and the ST/G approximate entropy values.


CONCLUSIONS
After ACL reconstruction using either BPTB or quadrupled ST/G, there is increased gait variability as compared to healthy individuals. This could be caused by the altered neuromuscular activity found in ACL-reconstructed limbs.


METHODS
Level III, case control study.
Moraiti
Constantina O
CO
Orthopaedic Sports Medicine Center of Ioannina, Department of Orthopaedic Surgery, University of Ioannina, Ioannina, Greece.
Stergiou
Nicholas
N
Ristanis
Stavros
S
Vasiliadis
Haris S
HS
Patras
Kostas
K
Lee
Cassandra
C
Georgoulis
Anastasios D
AD
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D005684:Gait; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D019651:Plastic Surgery Procedures / Q000379:methods; D020127:Recovery of Function; D016896:Treatment Outcome