• BACKGROUND
    • Dislocation remains a leading cause of revision following primary and revision total hip arthroplasty (THA). The aim of the present study was to compare the rate of second revision THA following a major first revision for the treatment of dislocation using an implant with a standard, large head, dual-mobility, or constrained acetabular liner.
  • METHODS
    • Data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1999 through December 2018. All primary THAs that had been performed for the treatment of osteoarthritis and subsequently revised for dislocation were included. All revision THA prostheses with a standard head (≤32 mm), large head (≥36 mm), dual-mobility, or constrained acetabular liner that were used for the first revision procedure were identified. The primary outcome measures were the cumulative rates of second revisions for all causes and for a subsequent diagnosis of dislocation for the 4 different constructs used in the first revision.
  • RESULTS
    • A total of 1,275 hips underwent a major first revision because of prosthesis dislocation, with 203 of these hips going on to have a second revision. The rate of all-cause second revision was significantly higher in the standard-head group compared with the constrained-acetabular-liner group (hazard ratio [HR], 1.53 [95% confidence interval (CI), 1.01 to 2.30]; p = 0.044). There was no difference in the rates of revision between other articulations. The most common cause of second revision for all implants was dislocation. There were a total of 91 second revisions for a diagnosis of dislocation. Standard heads had a higher rate of second revision compared with constrained acetabular liners (HR, 2.44 [95% CI, 1.30 to 4.60]; p = 0.005), dual-mobility implants (HR, 2.04 [95% CI, 1.03 to 4.01]; p = 0.039), and large heads (HR, 1.80 [95% CI, 1.09, 2.99]; p = 0.022). There was no difference in the rates of second revision between other articulations.
  • CONCLUSIONS
    • Surgeons have a number of options for prostheses when performing a first revision for the treatment of dislocation following a primary THA. The most common cause of a second revision is recurrent dislocation. The use of constrained acetabular liners, dual-mobility liners, and large heads (≥36 mm) are options for reducing subsequent dislocation. Standard head sizes have a higher rate of second revision for further dislocation.
  • LEVEL OF EVIDENCE
    • Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.