summary THA Leg Length Discrepancy is a common finding following THA that may be transient due to weakness of the abductors or permanent due to intentional limb lengthening. Diagnosis can be made clinically with comparison of the measurement from the anterior superior iliac spine to the medial malleolus. Pelvic radiographs can also be used to determine and compare limb lengths. Treatment is generally observation as most cases resolve with relaxation of the abductor muscles over time. Shoe-lifts may be indicated if leg length discrepancy persists after 6 months. Epidemiology Associated conditins 2nd most common reason for litigation following total hip arthroplasty (following nerve injury) Etiology Mechanism contracture leads to pelvic obliquity login to view 2 more bullets weakness login to view 2 more bullets Prevention pre-operative planning reduces incidence of post-operative discrepancies Presentation Symptoms patient may feel perceived LLD despite anatomic equality Physical exam post-operative assessment of limb-length discrepancy login to view 5 more bullets Imaging Radiographs recommended views login to view 1 more bullet findings login to view 3 more bullets Treatment Nonoperative shoe-lift login to view 3 more bullets Operative revisions THA - rare login to view 3 more bullets