Background and purpose - The shelf
arthroplasty was the regular treatment for residual
hip dysplasia before it was substituted by the peri-acetabular
osteotomy. Yet, evidence regarding the survival of shelf
arthroplasty surgery has never been systematically documented. Hence, we investigated the survival time of the shelf procedure until revision to THA in patients with primary
hip dysplasia. Factors that influenced survival and complications were also examined, along with the accuracy of correcting radiographic parameters to characterize dysplasia.Material and methods - The inclusion criteria were studies of human adolescents and adults (> 16 years) with primary or
congenital hip dysplasia who were treated with a shelf
arthroplasty procedure. Data were extracted concerning patient characteristics, survival time, complications, operative techniques, and accuracy of correcting radiographic parameters.Results - Our inclusion criteria were applicable to 9 studies. The average postoperative Center-Edge Angle and Acetabular Head Index were mostly within target range, but large variations were common. Kaplan-Meier curves (endpoint: conversion to THA) varied between 37% at 20 years' follow-up and 72% at 35 years' follow-up. Clinical failures were commonly associated with
pain and radiographic
osteoarthritis. Only minor complications were reported with incidences between 17% and 32%.Interpretation - The shelf
arthroplasty is capable of restoring normal radiographic hip parameters and is not associated with major complications. When carefully selected on minimal osteoarthritic changes,
hip dysplasia patients with a closed triradiate cartilage may benefit from the shelf procedure with satisfactory survival rates. The importance of the shelf
arthroplasty in relation to peri-acetabular
osteotomies needs to be further (re)explored.