Calcaneal Lengthening after Tarsal Bone Fusion for Massive Calcaneus Defect Reconstruction

Calcaneus defect remains challenging with limited strategies for reconstruction. Current methods, including graft transplantation, substitution, and distraction osteogenesis, showed limited advantages with certain shortcomings. Current calcaneus lengthening for partial calcaneus loss reconstruction requires bone loss of less than 35%. We introduced our combination of tarsal bone fusion and gradual lengthening method in treating massive calcaneus loss.

From January 2015 to December 2021, tarsal bone fusion and calcaneus gradual lengthening were performed in six patients with unilateral massive traumatic loss of the calcaneal tuberosity. A retrospective study was held to evaluate the outcomes of this novel technique. Clinical outcomes were assessed based on the American Orthopedic Foot and Ankle Score (AOFAS). Radiological data were assessed, which included tibio-calcaneal angle (TCA), calcaneal interface angle (CIA), metatarsal declination angle (MDA), angle of longitudinal arch (ALA), and the amount of calcaneus axial lengthening (CAL).

The mean calcaneal axial lengthening was 43.8 ± 3.1 mm (range, 39-49.5 mm), and the mean proportion of the lengthened calcaneus was 47.8% ± 3.7% (range, 42.8-55.3%). The mean external fixation time was 104.8 ± 67.5 days (range, 69 to 242 days), and the mean external fixation index was 2.4 ± 1.6 days/cm. All patients stuck to the postoperative follow-up plan with an average follow-up time (FT) of 35.0 ± 6.7 months (range, 26-40 months). Deformities of the injured limbs were all corrected according to radiography. Based on the AOFAS, three excellent and three good results were achieved.

The Ilizarov technique remains an option for calcaneus reconstruction with a great amount of loss once combined with tarsal bone fusion. The function of the injured foot and ankle can be satisfactorily restored using these techniques in our study. Apart from calcaneus elongation, tarsal bone fusion is somehow necessary to reinforce the proximal segment of the distracted calcaneus for creating a larger distraction callus, correcting concomitant foot deformities, and enhancing hindfoot stability. It is necessary to choose flexibly when tarsal bones should be fused.