Temporal Trends and Survivorship of Total Hip Arthroplasty in Very Young Patients

Nicholas D Peterson, David Metcalfe, JM Wilkinson, Daniel Perry

Background: In this study, we aimed to describe temporal trends and survivorship of total hip arthroplasty (THA) procedures in very young patients (aged ≤20 years).

Methods: A descriptive observational study was undertaken using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man. All patients aged ≤20 years at the time of undergoing primary THA were included and the primary outcome was revision surgery. Descriptive statistics were used to summarise the data and Kaplan-Meier estimates calculated for cumulative implant survival.

Results: There were 769 arthroplasty procedures performed in 703 patients. Seven patients died and 35 THAs were revised during the follow-up period. Uncemented implants and ceramic-on-ceramic (CoC) bearing surfaces were most commonly used. The use of metal-on-metal (MoM) bearings and resurfacing procedures declined from 2008. The most frequently recorded indications for revision were loosening (20%) and infection (20%), although the absolute risk of these events occurring within the cohort was low at 0.9%. Factors associated with lower THA survival were MoM and metal-on-polyethylene (MoP) bearings and resurfacing arthroplasty (versus ceramic-on-polyethylene [CoP] and CoC bearings, p=0.002), and operations performed by surgeons with a lower frequency of very young patient THAs recorded in the NJR (versus those with >5 recorded operations, p=0.030). Kaplan-Meier estimates suggested 96.2% (95% confidence interval [CI] 94.2-97.6%) survivorship of implants across the cohort at 5 years.

Conclusion: Within the NJR, the overall survival for very young patients undergoing THA exceeded 96% over the subsequent five years. Surgeons should consider the increased risk of early revision with implant type, volume of young hip arthroplasties performed and bearing surface when performing THA in children and young adults.