Depression and anxiety before and after limb length discrepancy correction in patients with unilateral developmental dysplasia of the hip

•Depression and anxiety levels before THA were significantly higher in DDH patients with perceived LLD than in those with non-perceived LLD.•In patients with LLD, perception of LLD changed dynamically after it was corrected.•Changes in the perception of LLD play an essential role in the improvement of depression and anxiety in DDH patients with perceived LLD.