TY - JOUR
T1 - The optimum position of arthrodesis of the ankle. A gait study of the knee and ankle
AU - Buck, P.
AU - Morrey, B. F.
AU - Chao, E. Y.S.
PY - 1987/1/1
Y1 - 1987/1/1
N2 - Findings from biomechanical analyses of gait were used to estimate the optimum position of arthrodesis of the ankle. Nineteen patients who were followed for an average of 10.4 years (range, four to seventeen years) were studied. By including the knee in the analysis as well as studying the effects on gait of different ground conditions, objective data for the weight-bearing extremities in the transverse, sagittal, and coronal planes were generated. Genu recurvatum was shown to be associated with a plantar-flexion position of fusion of the ankle. Laxity of the medial collateral ligament of the knee was noted in twelve patients (63 per cent). Among these patients, in three (16 per cent) the laxity was graded as moderate to severe, possibly due to external rotation of the extremity during gait to avoid rolling over the rigid plantar-flexed ankle. The patterns of gait showed that a valgus position of the arthrodesis is more advantageous and provides more normal gait, particularly on uneven ground. To attain more normal function of the knee and improve performance on rough ground, the optimum position of arthrodesis of the ankle appears to be neutral flexion, slight (zero to 5 degrees) valgus angulation, and approximately 5 to 10 degrees of external rotation. Posterior displacement of the thalus under the tibia tends to produce a more normal pattern of gait and decreases the stress at the knee.
AB - Findings from biomechanical analyses of gait were used to estimate the optimum position of arthrodesis of the ankle. Nineteen patients who were followed for an average of 10.4 years (range, four to seventeen years) were studied. By including the knee in the analysis as well as studying the effects on gait of different ground conditions, objective data for the weight-bearing extremities in the transverse, sagittal, and coronal planes were generated. Genu recurvatum was shown to be associated with a plantar-flexion position of fusion of the ankle. Laxity of the medial collateral ligament of the knee was noted in twelve patients (63 per cent). Among these patients, in three (16 per cent) the laxity was graded as moderate to severe, possibly due to external rotation of the extremity during gait to avoid rolling over the rigid plantar-flexed ankle. The patterns of gait showed that a valgus position of the arthrodesis is more advantageous and provides more normal gait, particularly on uneven ground. To attain more normal function of the knee and improve performance on rough ground, the optimum position of arthrodesis of the ankle appears to be neutral flexion, slight (zero to 5 degrees) valgus angulation, and approximately 5 to 10 degrees of external rotation. Posterior displacement of the thalus under the tibia tends to produce a more normal pattern of gait and decreases the stress at the knee.
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U2 - 10.2106/00004623-198769070-00014
DO - 10.2106/00004623-198769070-00014
M3 - Article
C2 - 3654697
AN - SCOPUS:0023488463
VL - 69
SP - 1052
EP - 1062
JO - Journal of Bone and Joint Surgery - American Volume
JF - Journal of Bone and Joint Surgery - American Volume
SN - 0021-9355
IS - 7
ER -