Hip-Sparing Equalization Procedures for Leg-Length Discrepancy After Total Hip Arthroplasty: A Retrospective Case Series

Leg-length discrepancy (LLD) after primary THA is not uncommon. Little is known, however, about the role of hip-sparing procedures for equalization of LLD after THA.The aim of this study is to report our experiences with these techniques in patients presenting at one institution over a 10-year period.We retrospectively reviewed records at one institution to find patients who had sought surgical treatment for LLD after THA between January 2007 and August 2017. Patients who had LLD related to conditions other than the THA, such as bone loss or traumatic defects, were excluded. We recorded the time after THA, laterality, and LLD. Assessment of LLD was performed using clinical and radiographic examinations. Patient demographics and true LLD were recorded, as were prior conservative treatment, equalization procedure performed, final leg length after equalization surgery, time to healing, and complications.After exclusion of patients with LLD related to other causes, eight patients in whom conservative treatment had failed and who had undergone hip-sparing leg-length equalization surgery were included in the study. The average age was 44.6 years (range, 18 to 66 years). Seven of the patients were female. The pre-operative mean LLD was 3.1 cm (range 1.5 to 7 cm). In those who were long after THA, ipsilateral (THA-side) shortening of femur with a retrograde intramedullary nail (IMN; n = 1) or with a plate (n = 1) was performed. In those who were short after THA, ipsilateral femur lengthening with retrograde Precice nails (n = 2), ipsilateral tibial lengthening with Precice nails (n = 2), or contralateral femur shortening with a retrograde IMN (n = 2) was performed. The average time to full consolidation or union was 6.6 months (range, 2 to 19 months). Two patients had delayed union. All patients but one were satisfied with final results.We believe that hip-sparing equalization procedures can be part of the treatment algorithm of LLD after THA. These advancements in the field are promising and might expand the indications of lengthening and equalization procedures to include LLD after THA.