Background: Injuries to the posterolateral corner of the knee can lead to chronic degenerative changes, external rotation instability, and varus instability if not repaired adequately. A proximal fibula avulsion fracture, referred to as an arcuate fracture, has been described in the literature, but a definitive repair technique has yet to be described.
Purpose: The objective of this study was to present a novel arcuate fracture repair technique, using a spiked-washer with an intramedullary screw, and to compare its biomechanical integrity to a previously described suture and bone tunnel method.
Methods: Ten fresh-frozen cadaveric knees underwent a proximal fibula osteotomy to simulate a proximal fibula avulsion fracture. The lateral knee capsule and posterior cruciate ligament were also sectioned to create maximal varus instability. Five fibulas were repaired using a novel spiked-washer technique and the other 5 were repaired using the suture and bone tunnel method. The repaired knees were subjected to a monotonic varus load using a mechanical testing system instrument until failure of the repair or associated posterolateral corner structures.
Results: Compared with the suture repair group, the spiked-washer repair group demonstrated a 100% increase in stiff- ness, 100% increase in yield, 110% increase in failure force, and 108% increase in energy to failure.
Conclusions: The spiked-washer technique offers superior quasi-static biomechanical performance compared with suture repair with bone tunnels for arcuate fractures of the proximal fibula. Further clinical investigation of this technique is war- ranted and the results of this testing may lead to improved outcomes and patient satisfaction for proximal fibula avulsion fractures.
