What exactly is "foot abduction" during management of idiopathic clubfoot in clinical practice?

PURPOSE: There is however gross ambiguity regarding the use of term "foot abduction" in clubfoot treatment. We measured below defined angles at different stages of clubfoot treatment to decipher their precise interpretation. METHODS: In a prospective evaluation of 25 unilateral clubfeet in infants' age less than six months treated with Ponseti technique, clinical leg foot and thigh foot angle were measured at talar head reduction (LHT0), pre-tenotomy, and post-tenotomy stage. A "normal" reference was available in the form of measurements of contralateral limb. RESULTS: Talar head (LHT0) was reduced at mean leg foot angle of 26 degrees. The corresponding pre- and post-tenotomy angles were 42.6 and 50.0 degrees, respectively. The reference leg foot angles for contralateral limb were 49.8 degrees. The thigh foot angle for LHT0, pre-tenotomy, post-tenotomy, and contralateral side were, respectively, 39.2, 56, 68, and 65.6 degrees. There was an additional tibial external rotation component of mean 13.4 degrees (SD 4.5) in the thigh foot angle when compared to the leg foot angle at tenotomy. This increased to 18 degrees (SD 3.4) post-tenotomy. CONCLUSIONS: The study suggested that the foot abduction described in the "Ponseti Manual" probably intends thigh foot rather than leg foot angles. There was a significant difference in the angles when talar head reduced and tenotomy was decided. The foot abduction is an ambiguous term which should be replaced by the more specific leg or thigh foot abduction angle.

A study of normal foot abduction across various age groups in children.

INTRODUCTION: The relapse rate after Ponseti method of correction has reduced in recent years which is attributable to the better appreciation of the need to achieve the correct degree of abduction. Ponseti recommended clinical 'overcorrection' of the foot to 700 of abduction. However, no scientific basis for this figure was found in literature. As the indications of Ponseti method extend to older children, we conducted a study to find out the amount of foot abduction to be achieved before applying a foot abduction brace in various age groups. METHODS: The normal 197 feet of children up to eight years of age were considered for study. The measurements included foot-bimalleolar angle in neutral and maximum possible abduction, thigh foot angle and leg foot angle. RESULTS AND DISCUSSION: The foot bimalleolar angle in neutral had a mean of 82.6 degrees and in maximum abduction a mean of 99.0 degrees. The mean leg foot angle was 66.4 degrees and the mean thigh foot angle was 60.5 degrees. It was found that these variables do not change with age. From the study we concluded that achieved abduction should be about 60-70 degrees before applying foot abduction brace in all children till age eight years with clubfeet treated with Ponseti technique, keeping the leg foot angle or the thigh foot angle as a guideline. This is against the common perception of keeping the abduction at 70 degrees for infants and reducing the abduction to 30 to 40 degrees for older children. Both the leg foot angle and thigh foot angles are reliable indicators of correction.

Relationship between Physical Examinations and Two-Dimensional Computed Tomographic Findings in Children with Intoeing Gait.

OBJECTIVE: To evaluate the validity of physical examinations by assessment of correlation between physical examinations and CT measurements in children with intoeing gait and the causes of intoeing gait by age using CT measurements. METHOD: Twenty-six children with intoeing gait participated in this study. The internal and external hip rotation, thigh-foot angle and transmalleolar angle were measured. In addition, femoral anteversion and tibial torsion of the subjects were assessed using a CT scan. The measurements of torsional angles were performed twice by two raters. The correlation coefficients between physical examinations and CT measurements were calculated using Pearson correlation. The data was analyzed statistically using SPSS v12.0. RESULTS: The correlation coefficients between physical examinations and CT measurements were not high. Before 5 years of age, intoeing gait was caused by femoral anteversion in 17.86%, tibial torsion in 32.29% and the combination of causes in 35.71% of cases. After 6 years of age, the contributions changed to 29.17%, 8.33% and 45.83%, respectively. CONCLUSION: Before 5 years of age, the common cause of an intoeing gait was tibial torsion, whereas after 6 years of age it was femoral anteversion. Regardless of age, the most common cause of intoeing gait was a combination of causes. This study shows poor correlation between physical examinations and CT. Therefore, it is limiting to use physical examination only for evaluating the cause of intoeing gait in clinical practice.

Relationship between Physical Examinations and Two-Dimensional Computed Tomographic Findings in Children with Intoeing Gait

OBJECTIVE: To evaluate the validity of physical examinations by assessment of correlation between physical examinations and CT measurements in children with intoeing gait and the causes of intoeing gait by age using CT measurements. METHOD: Twenty-six children with intoeing gait participated in this study. The internal and external hip rotation, thigh-foot angle and transmalleolar angle were measured. In addition, femoral anteversion and tibial torsion of the subjects were assessed using a CT scan. The measurements of torsional angles were performed twice by two raters. The correlation coefficients between physical examinations and CT measurements were calculated using Pearson correlation. The data was analyzed statistically using SPSS v12.0. RESULTS: The correlation coefficients between physical examinations and CT measurements were not high. Before 5 years of age, intoeing gait was caused by femoral anteversion in 17.86%, tibial torsion in 32.29% and the combination of causes in 35.71% of cases. After 6 years of age, the contributions changed to 29.17%, 8.33% and 45.83%, respectively. CONCLUSION: Before 5 years of age, the common cause of an intoeing gait was tibial torsion, whereas after 6 years of age it was femoral anteversion. Regardless of age, the most common cause of intoeing gait was a combination of causes. This study shows poor correlation between physical examinations and CT. Therefore, it is limiting to use physical examination only for evaluating the cause of intoeing gait in clinical practice.

The influence of tibial positioning on the diagnostic accuracy of combined posterior cruciate ligament and posterolateral rotatory instability of the knee.

BACKGROUND: To determine if tibial positioning affects the external rotation of the tibia in a dial test for posterolateral rotatory instability combined with posterior cruciate ligament (PCL) injuries. METHODS: Between April 2007 and October 2007, 16 patients with a PCL tear and posterolateral rotatory instability were diagnosed using a dial test. The thigh-foot angle was measured at both 30 degrees and 90 degrees of knee flexion with an external rotation stress applied to the tibia in 2 different positions (reduction and posterior subluxation). The measurements were performed twice by 2 orthopedic surgeons. RESULTS: In posterior subluxation, the mean side-to-side difference in the thigh-foot angle was 11.56 +/- 3.01 degrees at 30 degrees of knee flexion and 11.88 +/- 4.03 degrees at 90 degrees of knee flexion. In the sequential dial test performed with the tibia reduced, the mean side-to-side difference was 15.94 +/- 4.17 degrees (p < 0.05) at 30 degrees of knee flexion and 16.88 +/- 4.42 degrees (p = 0.001) at 90 degrees of knee flexion. The mean tibial external rotation was 5.31 +/- 2.86 degrees and 6.87 +/- 3.59 degrees higher in the reduced position than in the posterior subluxation at both 30 degrees and 90 degrees of knee flexion. CONCLUSIONS: In the dial test, reducing the tibia with an anterior force increases the ability of an examiner to detect posterolateral rotary instability of the knee combined with PCL injuries.

The Influence of Tibial Positioning on the Diagnostic Accuracy of Combined Posterior Cruciate Ligament and Posterolateral Rotatory Instability of the Knee

BACKGROUND: To determine if tibial positioning affects the external rotation of the tibia in a dial test for posterolateral rotatory instability combined with posterior cruciate ligament (PCL) injuries. METHODS: Between April 2007 and October 2007, 16 patients with a PCL tear and posterolateral rotatory instability were diagnosed using a dial test. The thigh-foot angle was measured at both 30degrees and 90degrees of knee flexion with an external rotation stress applied to the tibia in 2 different positions (reduction and posterior subluxation). The measurements were performed twice by 2 orthopedic surgeons. RESULTS: In posterior subluxation, the mean side-to-side difference in the thigh-foot angle was 11.56 +/- 3.01degrees at 30degrees of knee flexion and 11.88 +/- 4.03degrees at 90degrees of knee flexion. In the sequential dial test performed with the tibia reduced, the mean side-to-side difference was 15.94 +/- 4.17degrees (p < 0.05) at 30degrees of knee flexion and 16.88 +/- 4.42degrees (p = 0.001) at 90degrees of knee flexion. The mean tibial external rotation was 5.31 +/- 2.86degrees and 6.87 +/- 3.59degrees higher in the reduced position than in the posterior subluxation at both 30degrees and 90degrees of knee flexion. CONCLUSIONS: In the dial test, reducing the tibia with an anterior force increases the ability of an examiner to detect posterolateral rotary instability of the knee combined with PCL injuries.