Objective: To investigate current status and latest progress of clinical research on distal femoral fractures.

Objective To evaluate the clinical efficacy of single plate,double plates,and intramedullary nail in treating medial cortical comminuted fractures of the medial distal femur.Methods A retrospective case control study was conducted on 63 cases of medial cortical comminuted fractures of the medial distal femur treated from November 2011 through October 2016.According to the type of internal fixation,19 cases of middle and distal shaft fractures were divided into the single plate group (n =11) comprising four males and seven females,aged averagely 57.5 years,and intramedullary nail group (n =8) comprising five males and three females,aged averagely 56.4 years.Forty-four cases of distal femoral fractures were divided into the single plate group (n =14) comprising six males and eight females,aged averagely 57.6 years,intramedullary nail group (n =9) comprising five males and four females,aged averagely 56.6 years,and double plates group (n =21) comprising 14 males and seven females,aged averagely 55.1 years.The rate and period of racture healing,distal femoral valgus resection (DFVR),femoral angle,change of DFVR and femoral angle,and complications were compared within and between groups.Results All the cases were followed up for 6-37 months (mean,13.4 months).Of 19 cases of middle and distal shaft fractures,there were no statistically significant differences in fracture healing rate and period,DFVR after operation and at the last follow-up,and the amount of change of DFVR between the single plate and double plates group (P ＞ 0.05).With respect to postoperative complications of the two groups,no significant difference was found for the rate of nonunion,infection,internal fixation failure,and mal union (P ＞ 0.05).However,the incidence rate of adverse events in single plate group (46％) was significantly higher than that in intramedullary nail group (0) (P ＜0.05).Of the 44 cases of distal femoral fractures,the pairwise comparisons among three groups showed no statistically significant differences in fracture healing rate,healing period,and the post operative femoral angle (P ＞ 0.05).The femoral angle at the last follow-up in intramcdullary nail group was (80.80 ± 2.93) °,significantly lower than (85.28 ± 5.89) ° in single plate group and (83.55 ± 3.51) ° in double plates group (P ＜ 0.05).Within the intramedullary nail group,no significant difference was found between the femoral angle immediately after operation and at the last follow-up (P ＞ 0.05),but significant difference was detected in both single plate group and double plates group (P ＜ 0.05).The amount of change of the femoral angle in intramedullary nail group [(0.25 ± 1.95) °] was significantly lower than (4.03 ± 3.78) ° in single plate group and (2.60 ± 2.24) ° in double plates group (P ＜ 0.05).With respect to post operative complications in the three groups,no significant difference was found for the rate of nonunion,infection,internal fixation failure,and malunion (P ＞ 0.05).The malunion rate in single plate group (36％) was significantly higher than that in double plates group (14％).The incidence rate of adverse events in single plate group (50％) was significantly higher than that in double plates group (14％) (P ＜ 0.05).Conclusions Three internal fixations have similar clinical results in fracture healing rate and period.For medial cortical comminuted middle and distal shaft fractures,and distal femoral fractures without involving articular surface,intramedullary nail has better results than locking plate.For medial cortical comminuted distal femoral fractures involving articular surface,double plates fixation might be a better option.