Isokinetic evaluation of internal/external tibial rotation strength after the use of hamstring tendons for anterior cruciate ligament reconstruction.
BACKGROUND
Evaluation of the knee after an anterior cruciate ligament reconstruction with the use of the semitendinosus and gracilis (hamstring) autografts has primarily focused on flexion and extension strength. The semitendinosus and gracilis muscles contribute to internal tibial rotation, and it has been suggested that harvest of these tendons for the purpose of an anterior cruciate ligament reconstruction contributes to internal tibial rotation weakness.


OBJECTIVE
Internal tibial rotation strength may be affected by the semitendinosus and gracilis harvest after anterior cruciate ligament reconstruction.


METHODS
Prospective evaluation of internal and external tibial rotation strength.


METHODS
Inclusion criteria for subjects (N = 30): unilateral anterior cruciate ligament reconstruction at least 2 years previously, a stable anterior cruciate ligament (<5-mm side-to-side difference) at time of testing confirmed by surgeon and KT-1000 arthrometer, no history of knee problems after initial knee reconstruction, a normal contralateral knee, and the ability to comply with the testing protocol. In an attempt to minimize unwanted subtalar joint motion, subjects were immobilized using an ankle brace and tested at angular velocities of 60 degrees /s, 120 degrees /s, and 180 degrees /s at a knee flexion angle of 90 degrees .


RESULTS
The mean peak torque measurements for internal rotation strength of the operative limb (60 degrees /s, 17.4 +/- 4.5 ft-lb; 120 degrees /s, 13.9 +/- 3.3 ft-lb; 180 degrees /s, 11.6 +/- 3.0 ft-lb) were statistically different compared to the nonoperated limb (60 degrees /s, 20.5 +/- 4.7 ft-lb; 120 degrees /s, 15.9 +/- 3.8 ft-lb; 180 degrees /s, 13.4 +/- 3.8 ft-lb) at 60 degrees /s (P = .012), 120 degrees /s (P = .036), and 180 degrees /s (P = .045). The nonoperative limb demonstrated greater strength at all speeds. The mean torque measurements for external rotation were statistically similar when compared to the nonoperated limb at all angular velocities.


CONCLUSIONS
We have shown through our study that patients who undergo surgical intervention to repair a torn anterior cruciate ligament with the use of autogenous hamstring tendons demonstrate with weaker internal tibial rotation postoperatively at 2 years when compared to the contralateral limb.
Armour
Tanya
T
Fowler Kennedy Sport Medicine Clinic, London, Ontario, Canada.
Forwell
Lorie
L
Litchfield
Robert
R
Kirkley
Alexandra
A
Amendola
Ned
N
Fowler
Peter J
PJ
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000534:rehabilitation / Q000601:surgery; D008297:Male; D018908:Muscle Weakness; D011446:Prospective Studies; D016059:Range of Motion, Articular; D019651:Plastic Surgery Procedures / Q000379:methods*; D013710:Tendons / Q000637:transplantation*; D013977:Tibia / Q000502:physiology*; D019415:Torque; D016896:Treatment Outcome