Knee strength after total knee arthroplasty.
Fifty-two knees in normal healthy subjects and 32 knees more than 2 years after total knee arthroplasty (TKA) were evaluated. Average isometric extension peak torque values in TKA patients were reduced by up to 30.7% (P=.01). Isometric flexion peak torque values in patients with TKA were, on average, 32.2% lower than those from control subjects throughout the motion arc (P=.004). Knee Society Functional Scores were positively correlated to the average isometric extension peak torque (r=0.57; P=.004) and negatively correlated to the average isometric hamstring to quadriceps (H/Q) ratio (r=-0.78, P<.0001). Relatively greater quadriceps strength was associated with a better functional score. Older TKA patients (>/=70 years) generated lower isometric extension peak torque values in terminal extension than younger TKA patients (>24.2%; P=.05). Higher body mass index (BMI) was associated with relative quadriceps weakness (r=0.44; P=.007). These results suggest that more thorough rehabilitation after TKA would improve functional outcomes.
Silva
Mauricio
M
Joint Replacement Institute at Orthopaedic Institute, Los Angeles, CA 90007, USA.
Shepherd
Eric F
EF
Jackson
Walter O
WO
Pratt
Jeffrey A
JA
McClung
Christian D
CD
Schmalzried
Thomas P
TP
D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000534:rehabilitation; D001696:Biomechanical Phenomena; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology