[Reconstruction-arthrodesis of the first metatarsophalangeal joint iatrogenic bone defects]

Arthrodesis-reconstruction for metatarsophanlangeal bone defects of the great toe after hallux valgus or hallux rigidus is rarely performed and only a few series are found in the literature. In these series, retarded bone fusion, skin rupture, and interphalangeal intolerance (both clinically and radiologically) have been frequent. The purpose of this work was to determine what parameters contribute to minimizing these postoperative risks.

Thirteen patients, mean age 60 years, were reviewed at a mean follow-up of 7 years. Mean delay from initial surgery to revision surgery was greater than 6 years. Preoperative complaints included metatarsophalangeal pain and especially transfer metatarsalgia. The procedure used corticocancellous bone grafting associated with osteosynthesis and unloading of the forefoot for three months.

Eleven of the 13 patients achieved full relief of their metatarsophalangeal pain and metatarsalgia. Twelve of the 13 patients had a satisfactory great toe axis, including 2 who had a secondary osteotomy for correction. Bone fusion was achieved in all 13 patients; one at 8 months. Mean lengthening was 5.1 mm; reconstruction with the corticocancellous graft reconstruction generally filled the bone defect resulting from ablation of the joint prosthesis in 7 cases. The interphalangeal joint was pain free at last follow-up in all cases despite radiological evidence of suffering in one (similar to the situation before the revision surgery).

Correct position of the arthrodesis is essential to alleviate transfer metatarsalgia. A moderate lengthening of the great toe can minimize the risk of skin rupture. In order to preserve the interphalangeal joint, the position of the arthrodesis must be precise both in the sagittal and horizontal plane, leaving sufficient valgus and avoiding the need for temporary interphalangeal pinning.