Delayed Structural Failure Following Medial Femoral Condyle Flap Reconstruction of the Distal Radius: A Report of Two Cases.

Vascularized medial femoral condyle (MFC) flap transfer is a technique that may be used to reconstruct recalcitrant distal radius nonunion. Although union rates are high, the flap provides thin cortical bone requiring rigid fixation. The long-term strengthening and structural integrity of the MFC flap bone remains understudied. We describe two cases of delayed structural failure following distal radius MFC reconstruction. Two patients underwent distal radius reconstruction using vascularized corticocancellous MFC flaps stabilized with spanning fixed-angle volar plates. Both achieved radiographic union. Clinical records and radiographs were retrospectively reviewed following low-energy injuries. Late failure occurred 7 and 9 years after flap incorporation, involving deformity through the MFC bone segment. The spanning plates bent without evidence of screw loosening or hardware failure. These cases highlight a rare pattern of delayed structural failure following MFC reconstruction. Radiographic union alone may not predict long-term structural durability. Rigid fixed-angle fixation may influence load distribution and adaptive remodeling.