[Cup & cone reamers for arthrodesis of the first metatarsophalangeal joint].

THE PROBLEM: Individual optimized positioning of arthrodesis of the first metatarsophalangeal joint (fusion of MTP1 joint) as well as presumable shortage of the first ray using precalculated osteotomies often unpredictable. THE SOLUTION: Preparation of accurately fitting broad contact surfaces for MTP1 joint fusion with maximum flexibility of intraoperative decision-making for an optimized position. ADVANTAGES OF THE INSTRUMENTS: Semi-open or open systems of motor powered Cup & Cone reamers allow removal of remaining cartilage intended for MTP1 joint fusion with checkable shortage of the first ray, creation of exactly congruent concave-convex surfaces for an optimized position of MTP1 joint fusion. SURGICAL TECHNIQUE: Medial longitudinal incision for exposure of MTP1 joint. Removal of osteoarthrophytes, cartilage, and sclerotic bone from the first metatarsal head and the base of proximal phalanx, using a motorized Cup & Cone reamer set over axially directed guide wires to cancellous bone. Provisional positioning of the fragments in an optimized position. Clinical and fluoroscopic control. Definite internal fixation using a plantar lag screw and superelastic bone staples or a locking-plate system. PERSONAL EXPERIENCE: Allows the surgeon to prepare congruent and broad metatarsal and phalangeal cancellous bone surfaces for an optimized position of MTP1 joint fusion. Reamer-induced thermal damage and osteonecrosis were not encountered.