The biomechanical study in the July JOT evaluating posterior medial fragment stability in complex tibial plateau fractures emphasizes the importance of this fracture component when considering fixation strategies for the treatment of these intricate fracture patterns. The authors provide valuable data on the morphology of the critical posterior medial fragment size and at which point the fragment is likely displace with motion. The authors state ‘Certain sizes of posteromedial fragments may be inherently stable through a defined arc of motion and may not require direct surgical attention.” However, I would urge the readers to be very cautious if actually considering any non op management of these coronal plane components based on the authors results. The 10mm post medial fracture fragment evaluated was essentially an extra articular fragment. Contact pressure results largely demonstrated no significant differences between an intact condyle and the idealized 10-mm fracture fragment when tested in compression, internal rotation, and posterior shear loading.
These small coronal plane fractures are rare and occur infrequently in the clinical setting when treating these complex fracture patterns. The larger 20 mm fracture fragment specimens were thru the weight bearing portion of the medial condyle and displacement of this fragment increased progressively for all loading conditions, demonstrating the requirement for fragment stabilization. These larger fragments are the clinical norm. I would encourage clinicians to employ the column classification with transverse CT cuts to evaluate the size and overall morphology of these specific components with the realization that very few of these will be amenable to non op management.
J. Tracy Watson, MD
Professor and Chief of Orthopaedic Traumatology
Saint Louis University