Fit assessment of two different anatomically contoured distal femur plate sets on cadaveric bones

This study aims to investigate the fitness of two anatomic distal femoral plates with cadaveric femurs and to show whether current plates optimally match each femur.

Two different sets of plates with five, seven and nine shaft holes were applicated on 62 cadaveric femurs. Ball clay was molded onto the entire inner surfaces of the plates and then the plates were fixed to the bones using two self-locking nylon cable zip ties. The volume of ball clay sandwiched in between the plate and bone was calculated and used as a quantitative fit parameter. Data of each plate were analyzed separately.

Using Double Medical Technology IncorporatedTM plates, the mean plate to bone volumes were calculated as 8.4 mL (range, 5-14 mL), 10.0 mL (range, 6-17 mL), and 13.1 mL (range, 7-25 mL) in five, seven and nine-hole plates, respectively. Using Zimmer Biomet IncorporatedTM plates, the mean volumes were 10.5 mL (range, 6-21 mL), 12.7 mL (range, 7-22 mL) and 16.3 mL (range, 8-30 mL) in five, seven and nine-hole plates, respectively. Within each group, the measurements were significantly correlated positively with femoral length.

Optimal fit may not be achieved in each femur using current distal femoral plate implant sets. Thus additional sizes of plates should be supplied in the implant sets.