Outcome validation of the AO/OTA fracture classification system

Objectives: To determine whether a greater severity of injury as documented by the AO/OTA code would correlate with poor scores of impairment, functional performance, and self-reported health status. Design: Prospective, functional outcome. Setting: Three Level One Trauma Centers. Patients/Participants: Two hundred patients with unilateral and isolated lower extremity fractures. Main Outcome Measurements: Six- and twelve-month SIP, AMA impairment, and functional performance measures of self-selected walking speed, stair climbing, heel raises, rising from a chair, balance work. Results: At six months post injury, overall impairment was significantly (p < 0.05) higher for patients with Type C versus Type B fractures. A significant difference was found among the A, B, C types and the ROM impairment rating at six months (p = 0.004). Using the Schaffe method, the significant difference was determined to be between the B- and C-type fractures. Overall functional performance scores at six months were shown to have significant (p = 0.01) variation using an ANOVA with the significant variation being between the B and C type. At twelve months, the overall functional performance was significant (p = 0.05). Conclusion: Patients with C-type fractures had significantly worse functional performance and impairment compared with patients with B-type fractures but were not significantly different from patients with A-type fractures. AO/OTA code may not be a good predictor of six- and twelve-month functional performance and impairment for patients with isolated unilateral lower extremity fractures.