Knee joint muscle function after patellectomy: how important are the hamstrings?
Twenty-three patients who had undergone unilateral patellectomy were tested using the Cybex II isokinetic dynamometer 9 years postoperatively. The results were compared with the performance of the uninvolved joint. There was a good correlation between loss of the quadriceps muscle function and loss of the hamstrings muscle function at 60 deg/s (R = 0.7, P < 0.001). Patients who showed a loss of quadriceps function of less than 40% also maintained good hamstrings function. A good or excellent functional result could be expected in these patients. If the loss of quadriceps function was more than 40%, a proportional loss of flexion torque was seen, indicating a functional impairment of the knee joint muscles not solely attributable to the loss of the lever arm. Furthermore, all patients with a loss of peak flexion torque of more than 30% showed an unsatisfactory clinical result. The evaluation of the hamstrings muscles by measuring the peak flexion moment at 60 deg/s can therefore be used as a preoperative assessment and as a guideline for rehabilitation after patellectomy.
Kuster
M
M
Klinik für Orthopädische Chirurgie, Kantonsspital, St. Gallen, Switzerland.
Blatter
G
G
D000203:Activities of Daily Living; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010329:Patella / Q000601:surgery*; D016059:Range of Motion, Articular; D011795:Surveys and Questionnaires; D013848:Thigh; D019415:Torque; D017211:Treatment Failure