The orthopaedic community began to move away from individual fracture classifications in the mid-1980s. The basis for that shift was the need for wider recognition that fractures represent a “continuous variable,” with infinite varieties of orientations and combinations of fracture lines. Trying to fit fractures into a narrow classification system can lead to confusion and misinformation. Furthermore, surgeons often disagree when determining a fracture’s classification and, therefore, which treatment is best.
To move away from individual classification systems, orthopaedic journals have generally moved toward the compendium of fracture classifications approved by the OTA and AO. Still, there are times when a new fracture classification seems appropriate, and in the June 5, 2019 issue of The Journal, Pieroh et al. have provided us with an example that classifies fragility fractures of the pelvis (FFP). The 4-group FFP classification is based on fracture morphology with different degrees of instability and includes treatment recommendations.
The authors collected the CT scans of 60 patients from 6 different hospitals who were ≥60 years old and had sustained a pelvic fracture from low-energy trauma. These CT scans were shown to 6 experienced surgeons, 6 inexperienced surgeons, and 1 surgeon who had direct experience/training with the FFP system. Each surgeon was asked to classify the pelvic fractures according to the FFP classification. Inter- and intra-rater reliabilities for the fracture classifications were calculated from these readings, and the overall inter-rater Kappa coefficient was found to be 0.53, while the overall intra-rater Kappa coefficient was 0.46 (Kappa coefficients of 0.61 to 0.41 constitute “moderate” reliability). In terms of percent agreement, there was greater agreement between surgeons when it came to classifying FFP Group 1 fractures than for FFP Group 2 and 3 fractures. This is noteworthy because Group 3 fractures are thought to require surgical treatment, while primary treatment for Group 2 fractures is usually nonoperative.
Pelvic fractures that are associated with low bone density and low-energy trauma are becoming increasingly frequent as our population continues to skew older. Having a validated, relatively straightforward classification system like the FFP to assist us in managing these patients will be of great assistance. The sound methodology used to develop the FFP classification system and its decent reliability, face validity, and construct and criterion validity can assure all of us about the usefulness of the FFP classification as the basis for future clinical investigations and to advance the care of these patients.
Marc Swiontkowski, MD