Background:To avoid the irritation of tendons and soft tissues as well as hardware-related problems,we designed an intramedullary fixation with bioabsorbable rods for the treatment of the metacarpal shaft fractures.Methods:Five patients with nine shaft fractures of the fourth and fifth metacarpi were treated with intramedullary absorbable implants and followed up with an average of 4.2 months postoperatively.Results:At final follow-up,all patients achieved fracture union with no signs of inflammatory or subcutaneous effusion.There was no shortening,angulatory,or rotatory deformity.There was almost full active extension range of motion (ROM) of the metacarpophalangeal joints while the active flexion ROM of these joints was 80.7 ± 9.6°.Compared with the contralateral hand,the grip strength of the injured hand was 94.0 ± 9.6％.X-rays showed that the arch of the second to fifth metacarpal heads was smooth.There were no intramedullary lytic changes and soft tissue swellings.Conclusion:The intramedullary absorbable implants are a safe,simple,and practical treatment for fourth and fifth metacarpal fractures with good early clinical outcomes and no significant complications.