Abstract: Abstract:Objective To explore the surgical method of bony mallet finger  and to evaluate the clinical effect of fixed needle extrusion in treatment of bony mallet finger.Methods 28 patients with bony mallet finger were treated with kirschner needle extrusion to  reset the fracture fragments and fix　the fracture.The flexion or extension of  distal interphalangeal joint (DIP),fracture healing and postoperative complications of the patients were observed.Results 27 patients were followed-up for 14 months.Crawford assessment standard was used to assess the efficacy.Before operation,the DIP extension limitation of 10 °-25 ° or obvious  flexion  obstacles existed in 8 cases (29.6%);the DIP extension limited by greater than 25 ° or the presence of persistent pain existed in 20 patients (70.4%).After operation,the fully active flexion and extension of DIP without pain in resting or action existed in 21 cases (77.8%);the  full flexion of DIP,extension limitation from 0 ° to 10 °without pain in  resting state  existed in 6 cases (22.2%).All fractures in the patients healed,and the joint face apposition was good without osteomyelitis and wound complications such as infection,necrosis and recurrence of mallet finger deformity.Conclusion Kirschner needle extrusion  fixation method  for the treatment of bony mallet finger is a simple method with satisfatory curative effect.  

Key words: finger injury, mallet finger, avulsion fracture, kirschner