Abstract
Introduction: Failure to restore offset in severe protrusio defects in revision total hip replacement can lead to impingement and loss of limb length. The purpose of this study was to determine the initial results obtained with a novel cup in cup technique utilizing two porous tantalum acetabular shells, one placed onto supportive host bone in a cementless fashion, the other cemented in to this shell.
Methods: Porous tantalum hemispherical shells were implanted in 4 revision total hip replacements in 3 patients with an average age of 73 years at the time of the procedure.
Bony defects per the Paprosky classification were one IIC, two IIIA, and one IIIB. All patients were followed clinically and radiographically.
Results: The patients were followed for an average of 25.5 months (range, 17 to 29 months). Abductor strength improved by one grade in all patients. In the non-bilateral reconstruction patients horizontal offset was increased compared to the normal hip by 6 mm (IIIB) and 8 mm (IIC). For the bilateral reconstruction patient (IIIA) horizontal offset compared to pre-op was increased by 13–16 mm. There was no evidence of loosening or migration at the time of final follow-up.
Conclusions: At short term follow-up the early experience cautiously supports the use of this construct. Long term follow-up and a larger patient experience will be required to evaluate the results of this novel technique.
Correspondence should be addressed to Diane Przepiorski at ISTA, PO Box 6564, Auburn, CA 95604, USA. Phone: +1 916-454-9884; Fax: +1 916-454-9882; E-mail: ista@pacbell.net
