Objective To evaluate the clinical outcome of reconstruction of traumatic digital arthritis by transfer of free proximal interphalangeal joint of the second toe with toe reserving technique.Methods The study enrolled nineteen patients with traumatic digital arthritis treated from May 2013 to April 2016.The patients consisted of fifteen males and four females,and mnean age was 27.3 years (range,18-52 years).Finger involved included index fingers in 10 patients,middle fingers in seven and ring fingers in two.The joint of digit was reconstructed by transplanting the proximal interphalangeal joint of the second toe with a monitoring flap,and bone defect of the second toe was repaired with autogenous iliac bone graft.Wound was closed directly in six patients and covered by island flap from the foot dorsurn in 13 patients.Evaluation indicators contained survival rate of the free joint and island flap,appearance and fracture healing of the finger and toe and mnotion of the proximal digital joint.Finger function was studied using the evaluation standard of upper limb function set up by hand surgery branch of Chinese Medical Association.Healing in the donor site,foot function and related complications were observed.Results All the free joint and island flap survived.Period of follow-up was 6-30 months (mean,14 months).The fractured finger healed at 2.5 months on average,and appearance of the finger was good.Flexion range of the proximal digital joint was 63 °-80° (mean,74°) and extension range was-20°--10° (mean,-14°).Finger function was excellent in eleven patients and good in eight patients,with the excellent-good rate of 100％.Hematoma of the dorsal region of the foot occurred in one patient and the cut healed well after taking out some stitches and drainage.All fractured toe healed at 2.6 months.Except that one patient had fracture malunion with minor outward inclination,all presented good appearance of the toe without influencing walking and running.On the part of iliac,there was only one inconspicuous linear scar without any discomfort.Conclusions Transfer of free proximal interphalangeal joint of the second toe with toe preservation restores the anatomy structure and function of the digital joint.Meantime,autogenous iliac bone grafting combined with island flap from the foot dorsum for coverage of donor site defect retains the toe length and reduces injury of the donor site.