Comparison of clinical and dynamic knee function in patients with anterior cruciate ligament deficiency.
BACKGROUND
Whether passive measures of isokinetic muscle strength deficits and knee laxity are related to the dynamic function of the anterior cruciate ligament-deficient knee remains unclear.


OBJECTIVE
Arthrometer measurements are not predictive of peak external knee flexion moment (net quadriceps muscle moment), isokinetic quadriceps muscle strength correlates with peak external knee flexion moment (net quadriceps muscle moment), and isokinetic hamstring muscle strength correlates with peak external knee extension moment (net flexor muscle moment).


METHODS
Cross-sectional study.


METHODS
Gait analysis was used to assess dynamic function during walking, jogging, and stair climbing in 44 subjects with unilateral anterior cruciate ligament deficiency and 44 control subjects. Passive knee laxity and isokinetic quadriceps and hamstring muscle strength were also measured.


RESULTS
Arthrometer measurements did not correlate with peak external flexion or extension moments in any of the activities tested or with isokinetic quadriceps or hamstring muscle strength. Test subjects also had a significantly reduced peak external flexion moment during all three jogging activities and stair climbing compared with the control subjects and this was correlated with significantly reduced quadriceps muscle strength.


CONCLUSIONS
Absolute knee laxity difference did not correlate with dynamic knee function as assessed by gait analysis and should not be used as a sole predictor for the outcome of treatment. Patients with greater than normal strength in the anterior cruciate ligament-deficient limb performed low- and high-stress activities in a more normal fashion than those with normal or less-than-normal strength.
Patel
Rohita R
RR
Department of Orthopedic Surgery, Rush Medical College of Rush University, Rush-Presbyterian-St Luke's Medical Center, Chicago, Illinois 60612, USA.
Hurwitz
Debra E
DE
Bush-Joseph
Charles A
CA
Bach
Bernard R
BR
Andriacchi
Thomas P
TP
D000328:Adult; D000704:Analysis of Variance; D016118:Anterior Cruciate Ligament / Q000503:physiopathology*; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005080:Exercise Test / Q000379:methods; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology*; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D000070600:Tibial Meniscus Injuries