Comparison of radiographic parameters of limb alignment and TKA component placement in patients treated with PSI and CI. Radiographic parameters of limb alignment and component placement were measured on anteroposterior knee-rays of patients who underwent TKA with the use of conventional instrumentation (CI) or patient-specific instrumentation (PSI). A) The medial tibio-femoral axis angle (TFA) was measured in anteroposterior knee X-ray and was considered accurate when it lay between 182° and 188°. B) Femoral component placement in the coronal plane was assessed by the α angle and was considered accurate when the α angle lay between 92° and 98°. C) Tibial component placement in the coronal plane was assessed by the β angle and was considered accurate when the β angle lay between 87° and 93°. D) Accurate radiological outcome was considered when the TFA, the α angle, and the β angle were measured within respective limits. Comparison by Fisher’s exact test; ns: non-significant.