BACKGROUND : The Schatzker classification is the most widely accepted system used to classify tibial plateau fractures. The presence of
posteromedial fragments in the more severe fracture types is known, but the presence of posteromedial fragmentation in the less severe
fracture types is unknown. The ability of the Schatzker classification to predict posteromedial fragmentation was evaluated.
METHODS : Two hundred patients were reviewed of which only 67 met the inclusion criteria. The X-rays were reviewed by three independent
orthopaedic surgeons and classified according to the Schatzker classification. A radiologist reviewed the CT scans and noted the presence
or absence of a posteromedial fragment and if present, the largest diameter of the fragment was measured.
RESULTS : The mean age of the sample was 44.79 (SD: 14.03) years. Seventy-five per cent of the females (n=33) presented with
posteromedial fragmentation compared to 65.20% of the males (n=44) (chi²-test, P=0.399). The incidence of posteromedial fragmentation
varied between 15.8 and 26.3% for Schatzker 1 and 2 fractures and 73.7 and 84.2% for Schatzker 3 to 6 (chi2-test, p<0.001) based on
the three independent assessments. The mean length of the posteromedial fragmentation ranged from 41.87 to 47.77 mm for Schatzker
1 and 2 fractures, and 44.74 to 46.12 mm for Schatzker 3 to 6 for the three assessors (statistically not significant [T-test, P=0.536,
P=0.551 and P=0.652]).
CONCLUSION : The Schatzker classification by itself is not adequate to identify all fractures with posteromedial fragmentation. There is a
higher association of posteromedial fragmentation with fracture types 3 to 6. There is a high probability of missing a significantly sized
posteromedial fragment in Schatzker type 1 and 2 fractures if a CT scan is not performed which might influence and compromise fracture
stability, joint congruency and the ability to rehabilitate optimally.