Abstract Objective To compare clinical, functional, and quality of life outcomes between patients with tibial plateau fractures operated with locked or conventional plates, and to compare the costs of these implants. Methods This was a comparative cross-sectional study of a consecutive series of patients with tibial plateau fractures treated surgically from August 2015 to June 2016. Patients < 18 years old, those unable to answer the questionnaires or to attend the outpatient reassessment, polytrauma patients, those with associated injuries on the ipsilateral limb, and patients who had not undergone treatment with bone plates were excluded. The present study compared the costs of the implants for the hospital, quality of life (with the 12-Item Short Form Health Survey [SF-12]), Lysholm score, pain scale, and clinical and radiological parameters. Results A total of 45 patients with tibial plateau fractures were admitted, and 11 cases were excluded. Two cases were lost to follow-up; therefore, 32 remained for the analysis (94%). The mean follow-up time was of 15.1 months (standard deviation [SD] = 4.8 months). In group A (locked plates), there were 22 patients (69%), at an average hospital cost of BRL 4,125.39/patient (SD = 1,634.79/patient) for the implants. In group B (conventional plates) there were 10 patients (31%), at an average cost of BRL 438.53 (SD = 161.8/patient) (p < 0.00001). For the other parameters, no differences were observed, except for a greater articular depression in group A (2.7 mm ± 3.3 mm versus 0.5 mm ± 1.6 mm; p = 0.02; TE = 0.90). Conclusion The costs of locked implants for the treatment of tibial plateau fractures are significantly higher than those of conventional implants, without any clinical, quality of life, radiological, or functional advantages of the locked implants demonstrated in the present series.