First carpometacarpal joint osteoarthritis (CMC-1) may develop first metacarpophalangeal joint hyperextension (MCP-1). We enrolled patients with CMC-1 osteoarthritis and MCP-1 hyperextension ≥40 degrees treated with resection-suspension arthroplasty and MCP-1 intramedullary arthrodesis with XMCP™ system. Minimum follow-up was five years. We evaluated: thumbinterphalangeal (IP) range ofmotion, key pinch, hand grip, Kapandji, VAS and Quick DASH. Wilcoxon test was uses for statistical analysis.Nineteen patients were reviewed. We found improvement in key pinch, hand grip, VAS and Quick DASH; statistical difference (p < 0.05) was observed in all of them except key pinch. IF thumb range of motion and Kapandji decreased.TMC arthrodesis with XMCP™ system associated with resection-suspension arthroplasty, as a treatment for CMC-1 osteoarthritis and MCP-1 hyperextension ≥40 degrees, achieves good functional results in the medium term.