The fifth metacarpal neck fracture treated by closed reduction and intramedullary fixation with antegrade Kirschner wire plus rod rotation technique

Objective To assess the clinical effects of closed reduction and intramedullary fixation with antegrade Kirschner wire plus rod rotation technique in the treatment of the fifth metacarpal neck fracture. Methods In this retrospective study, 26 patients with the fifth metacarpal neck fracture were treated by closed reduction and intramedullary fixation with antegrade Kirschner wire plus rod rotation technique at Department of Orthopaedics, Central Hospital of Karamay from August 2015 to October 2017. They were 23 males and 3 females, aged from 12 to 53 years with an average age of 25.2 years. In the intramedullary nailing, a Kirschner wire pre-bent by 10° to 15° was inserted from the base of the fifth metacarpal into the medullary canal before closed reduction. After satisfactory reduction was achieved, the Kirschner wire was inserted across the fracture site into the metacarpal head for further reduction and fixation using rod rotation technique. After operation, a plaster was applied to protect the fixation for 2 weeks. Functional exercise was started after removal of the plaster. The Kirschner wire was not removed under local anaesthesia at the outpatient department until about 10 to 16 weeks postoperation when X-ray showed fracture healing. Records of their operation time, head/shaft angle of the fifth affected metacarpal, active range of motion of the metacarpophalangeal joints and Total Active Movement (TAM) of hand function at the last follow-up were collected. Results Their operation time averaged 21 minutes (from 12 to 35 minutes). Anatomical reduction was achieved in 23 cases but not in 3 ones whose metacarpal head/shaft angle and alignment were obviously improved. Follow-ups for 6 to 29 months (average, 15.8 months) showed all the patients obtained solid fracture healing with no infection or delayed fracture healing. The head/shaft angle was improved significantly from preoperative 61.2°±11.2° to postoperative 14.7°±3.5° (P 0.05). The active range of motion of the metacarpophalangeal joint was 89.3°±4.2° after fixation removal, not significantly different from that of the healthy side (90.7°±1.5°) (P>0.05). According to TAM scores at the last follow-up, 22 cases were rated as excellent, 3 as good and one as fair. Conclusion In the treatment of the fifth metacarpal neck fracture, closed reduction and intramedullary fixation with antegrade Kirschner wire plus rod rotation technique is effective, because it is simple and limitedly invasive, and leads to limited complications, low costs and secondary reduction. Key words: Metacarpal bone; Fracture fixation, intramedullary; Bone nail; Fifth metacarpal neck fracture; Rod rotation