Modified Technique of Single-Bone Forearm in the Treatment of Deformities.

Abstract

The single-bone forearm is a salvage technique for massive loss of bone due to serious trauma, malignant tumors, infections or congenital deformity. It is also described to treat the sequelae of hereditary multiple exostoses disease that affects the distal end of the ulna. We present the case of a 29-year-old patient, operated for sequelae of hereditary multiple exostoses disease of the left forearm by a modified single-bone forearm technique. The patient, right-handed, operated on twice in childhood for a hereditary multiple exostoses disease of the left forearm: incomplete excision of the exostosis of the distal end of the ulna and lengthening of this last on external fixator, without improvement. The patient presented for a deformation of the left forearm with shortening compared to the right side‌. Significant limitation of prono-supination (pronation 15°, supination 20°). Elbow flexion at 110° and extension with deficit of 15°. Wrist flexion at 50° and extension at 50°, radial inclination at 25° and ulnar at 30°. The pain score was 3 according to the Visual Analogue Scale (VAS), especially on effort. Dash score was 31,82/100. We chose the forearm technique with a single bone. The immediate postoperative result found a realignment of the forearm, without neurological or vascular damages. Consolidation was obtained in four months. At five months, the patient recovered elbow flexion at 110° and full extension, wrist flexion at 45° and extension at 50°. Radial inclination at 20° and ulnar at 25°. The single-bone forearm technique has been described, not only for the treatment of hereditary multiple exostoses disease, but also for serious trauma or tumors with massive loss of bone. The technique generally consists of an osteotomy of the radius as well as the ulna, fixing the radius to the ulna creating a synostosis, with or without resection of part of one or both bones of the forearm. The most described complications of single-bone forearm procedure are pain, complications related to soft tissue secondary to the previous injury, and infections. The one-bone forearm remain a salvage technique for massive loss of bone of the forearm, or large deformities due to congenital malformations. This technique could allow the excision of massive bone and keep only a part of the ulna and the radius, with function maintenance and aesthetic forearm preservation.