Isolated depression fractures of the femoral condyle are rare, but severe injuries due the destroyed congruency of the articular
surface in the weight-bearing region of the joint. In most cases, an arthrotomy with fragment reduction and internal fixation
by screws buttress or plates is performed. Disadvantages of this procedure are the approach-related complications. Furthermore,
an implant removal is necessary, if a secondary osteoarthrosis develops. We present a female patient with a hyperflexion trauma
of her right knee, resulting in an isolated depression fracture of the medial femoral condyle. To avoid arthrotomy-related
morbidity, the impressed fragment was retrograde addressed using navigated guidance and reduced indirectly under arthroscopic
control. Via the retrograde intraosseous tunnel a biodegradable screw was used as a buttress against the fragment to prevent
a re-dislocation. The fracture healed without any complications and the patient re-administered her sports activities at 10 weeks
follow-up. This procedure enables an accurate reduction and stable fixation of joint depression fragments via a minimal invasive
approach.
Keywords Fluoro-free navigation – Arthroscopy – Retrograde drilling – Femoral fracture – Biodegradable screws – Medial femoral notch sign