The clinical evidence behind the current implants used for proximal femoral fractures is weak considering the number of implants used worldwide .
Sporadic evaluation is not sufficient to identify long term problems .
INTRODUCTION Evaluation of the long-term performance of  implants used in trauma surgery relies on post-marked clinical studies since no registry based implant assessment exists .
The purpose of this study was to evaluate the evidence of performance of implants  currently used for treating proximal femoral fractures ( PFF ) in Denmark .
Is the lag screw sliding effective in the intramedullary nailing in A1 and A2 AO-OTA intertrochanteric fractures? A prospective study of Sliding and None-sliding lag screw in Gamma-III nail
ObjectTo compare the Sliding with Non-sliding lag screw of a gamma nail in the treatment of A1 and A2 AO-OTA intertrochanteric fractures . Material s and methods 80 patients were prospect ively collected . In each group , AO/OTA 31-A were classified into group A. AO/OTA 31-A2.1 was classified as group B. We classified the A2.2 and A2.3 as group C. According to the set-screw locking formation of Gamma-III , the cases were r and omly allocated to Sliding subgroup and Non-sliding subgroup in A , B and C groups . Follow-ups were performed 1 , 3 , 6 and 12 months postoperatively . Results In the Sliding group , the bone healing rate 3 , 6 , 12 months postoperatively reached 85.00 % , 97.50 % , 100 % in group A , B and C. Meanwhile , in Non-sliding group , postoperatively , bone healing rate were 90.00 % , 95.00 % and 97.50 % in group A , B and C , respectively . Both differences were not significant . Lower limb discrepancy between  Sliding and Non-sliding pattern was significantly different in group C which represent fracture types of AO/OTA 31-A2.2 and A2.3 ( 0.573 ± 0.019 mm in Non-sliding group , 0.955 mm ± 0.024 mm in Sliding group , P < 0.001 ) . Difference of sliding distance among the three groups was significant among group A , B and C : 0.48 mm ± 0.04 mm , 0.62 mm ± 0.07 mm and 0.92 mm ± 0.04 mm ( P < 0.001 ) . Differences in average healing time and Harris scores also presented no significance in the three groups . Conclusions As a result , we can conclude that the sliding distance is minimal in Gamma nails and it is related to the comminuted extent of the intertrochanteric area in A1 and A2 AO-OTA intertrochanteric fractures . For treating these kinds of fractures , the sliding of the lag screw of an Gamma nail does not improve any clinical results and in certain cases , such as highly comminuted A1 and A2 fractures , can therefore even benefit from a locked lag screw by tightening the set-screw
The clinical evidence behind the current implants used for proximal femoral fractures is weak considering the number of implants used worldwide .
Sporadic evaluation is not sufficient to identify long term problems .
INTRODUCTION Evaluation of the long-term performance of  implants used in trauma surgery relies on post-marked clinical studies since no registry based implant assessment exists .
The purpose of this study was to evaluate the evidence of performance of implants  currently used for treating proximal femoral fractures ( PFF ) in Denmark .