Medial double arthrodesis with lateral column sparing and arthrodiastasis: a radiographic and medical record review.

Correction of valgus hindfoot deformity can be successfully achieved with arthrodesis of the subtalar and talonavicular joints through a single medial based incision. The advantages of medial double arthrodesis compared with the standard triple arthrodesis 2-incision approach include the absence of a lateral incision and a few degrees of residual mobility through the unfused calcaneocuboid joint (CCJ). The CCJ has often been noted to distract and decompress with the abduction correction achieved through medial double fusion. The primary goal of the present retrospective study was to identify the frequency of CCJ decompression, measure the radiographic changes at the CCJ, and evaluate the flatfoot correction using this operative approach. A total of 46 patients (47 feet) were identified as possible subjects. Twenty patients (20 feet) with a mean follow-up period of 9.2 ± 4.1 (range 6 to 21) months met our inclusion criteria. Distraction of the CCJ using medial double fusion resulted in increased joint space and improvement of at least 1 grade of arthritis in 50% of the patients. In the patients with severe CCJ arthrosis, the improvement was less predictable, with only 20% showing radiographic improvement. Correction of flatfoot as measured on standard radiographs showed excellent results. Subchondral bone changes as measured by the CCJ arthrosis scale improved in patients with mild to moderate arthritis after distraction arthrodiastasis. However, those with severe preoperative CCJ had less predictable improvement. Medial double arthrodesis for severe flatfoot deformity provides predictable correction of the deformity and improvement in the CCJ arthritis scale when the preoperative arthritis of the CCJ is mild to moderate.