Background Bone loss at the metacarpophalangeal joint (MCP) after trauma is difficult to treat. Objective We aimed to investigate the effectiveness of Swanson's arthroplasty and the reason for implant fracture. Methods We retrospectively analyzed the data of 175 patients who underwent emergency MCP arthroplasty between 2013 and 2016. Some patients used a orthosis to limit the radioulnar movement of the metacarpal joint for eight weeks after surgery (Group A), while the other patients underwent only hand rehabilitation after surgery (Group B). The basic information and perioperative data of the patients were compared. The patients were followed up clinically for an average of 65±19 months. Postoperative and follow-up complications and functional parameters were recorded and compared. Stress model of implant fracture had been analyzed in order to mark the frequent area. Results A total of 162 patients were followed up, 4 of whom were lost to follow-up completely and 9 of whom were followed up by telephone only. There were 11 and 26 implant fractures in groups A and B, respectively (P=0.019), and the degrees of radioulnar movement were 2±1° and 7±4°, respectively (P<0.01). The disabilities of the arm, shoulder, and hand (DASH) score and MCP joint range of motion (ROM) did not significantly differ. Conclusion The effect of Swanson’s arthroplasty for bone loss at MCP joint is useful. The radioulnar stress may be the reason for implant fracture. Joint orthosis can reduce the incidence of implant fractures.