Outcome measures and survivorship following total hip arthroplasty in adolescent population

Background The most frequent indication for total hip arthroplasty (THA) in adolescent patients has been juvenile idiopathic arthritis (JIA). However, in recent years, other causes have become more prevalent. Questions/Purposes: ( 1) What is the survivorship following THA across the diagnostic spectrum in adolescent population? (2) How are quality of life results affected by systemic medical conditions? Methods We retrospectively reviewed all consecutive THA in patients under 21 years of age, performed at our Institution between 1993 and 2018. There were 34 prostheses implanted in 26 patients with a mean age of 18.4 years (range 11 to 21). The most frequent diagnosis was JIA (14 hips), followed by avascular necrosis (10 hips). Patient reported outcomes were assessed using Harris and Oxford Hip Scores (HHS and OHS), Visual Analogue Scale (VAS) and EuroQol-5D. Survivorship for revision and aseptic loosening was determined with Kaplan Meier analysis. Results At final follow-up, the overall survival rate was of 89.3% at 12-year follow-up. Three acetabular components underwent revision surgery for aseptic loosening. Clinical HHS significantly improved from 37.5 to 90.6 points (p < 0.001). Mean OHH was 37.4 points, with a final VAS of 1.64 points. Mean 5Q-5D was 0.704 with an interquartile range of 0.4 to 1.0. JIA patients displayed worse pre-operative HHS scores, and at final follow-up had worse HHS, OHS, VAS and EQ-5D scores compared to the rest of the patients. Complications included three intra-operative femoral fractures, one sciatic nerve palsy and one adductor contracture. Conclusion THA in adolescent patients provides improved functional outcomes with acceptable revision rates at mid-term follow-up.