Can TAD and CalTAD predict cut-out after extra-medullary fixation with new generation devices of proximal femoral fractures? A retrospective study.

Background: Intramedullary and extramedullary strategies of pertrochanteric fracture fixation are still controversial, but new percutaneous devices may give advantages regarding operative time, blood loss and rate of cardiovascular complications. We retrospectively analyze our cases regarding Anteversa plate (Intrauma, Turin, Italy) fixation of pertrochanteric femoral fractures, focusing on the correlation between two radiographical parameters (tip-apex distance "TAD" and calcar referenced tip-apex distance "CalTAD") and the occurrence of cut-out. The purpose of this study was to determine if these predicting factors of cut-out are reliable in the treatment of proximal femoral fractures with the Anteversa plate.

Methods: A series of 77 patients with 53 31-A1 fracture types and 24-A2 fractures completed a 12-month-follow-up. Clinical outcomes were evaluated according to Parker-Palmer Mobility Score at the final follow-up. TAD and CalTAD were considered to determine their correlation with cut-out events.

Results: The mean Parker-Palmer Score was 6.94 in A1 group and 7.41 in A2 group ( = 0.47). Mean value of TAD index was 29.58, 29.81 in the A1 group and 29.08 in the A2 group, and mean value of CalTAD index was 30.87, 31.03 in the A1 group and 30.50 in the A2 group. We observed 3 cases of implant cut-out. We shared our sample in two groups, one group with TAD and CalTAD indices lower than 25 mm and another group higher than 25 mm to evaluate how the Palmer Parker score changed and no statistical differences were found between the two groups.

Conclusions: Taking into consideration that good clinical results were obtained for TAD and CalTAD values superior to 25 mm, the prognostic value of 25 mm of TAD and CalTAD indices might not be appropriate to this new percutaneous plate.