Correlation of postoperative midfoot position with outcome following reconstruction of the stage II adult acquired flatfoot deformity.

BACKGROUND

No studies investigating the effect of the midfoot (talonavicular joint) position on clinical outcomes following flatfoot reconstruction have been performed. The purpose of our study was to determine whether a postoperative abducted or adducted forefoot alignment, as determined from anteroposterior (AP) radiographs, was associated with a difference in outcomes using the Foot and Ankle Outcome Score (FAOS).

METHODS

Midfoot abduction was defined on postoperative AP radiographs, evaluated at a mean of 1.9 years in 55 patients from the authors' institution who underwent flatfoot reconstruction for a stage II adult acquired flatfoot deformity (AAFD), as a lateral incongruency angle greater than 5 degrees, a talonavicular uncoverage angle greater than 8 degrees, and a talo-first metatarsal angle greater than 8 degrees based on previously reported measurements. Patients with 2 or more measurements in the abduction category were classified as the abduction group (n = 30); those with 1 or fewer measurements in the abduction category were placed in the adduction group (n = 25). The preoperative and postoperative FAOS values with a mean follow-up of 3.1 years were compared using Wilcoxon rank-sum tests.

RESULTS

Patients corrected to a position of adduction showed significantly lower improvement in the FAOS daily activities (P = .012) and quality of life subscales (P = .046). The mean improvement in subscale scores for the adducted group was lower for pain (P = .052) and sports activities (P = .085) but did not reach statistical significance. No significant difference in the FAOS symptoms subscale (P = .372) between groups was found.

CONCLUSION

Correction of the talonavicular joint to a position of adduction following a stage II AAFD was associated with decreased patient outcomes in daily activities and quality of life compared with an abducted position. These results suggest that overcorrection to a position of midfoot adduction leads to a lesser amount of individual patient improvement in reconstruction of a stage II AAFD.