Abstract
Introduction
The rise of the anterior approach (AA) in primary surgery has led to enthusiasm for using this approach in revision surgery, especially because head and liner exchanges have been accompanied by a high dislocation rate when the posterior approach (PA) is used. The aim of this study was to compare the institutional dislocation rate comparing the PA and AA in isolated head and liner exchange.
Methods
A retrospective institutional database query was done to identify all aseptic head and liner exchanges between the years 2010- June, 2020. 186 hips were identified with an average age of 64.8+/−10.8 yrs (27.9–87.6) and average BMI of 28.7+/−6.3 kg/m2 (16.2–52). The reason for revision was polyethylene wear and osteolysis in 105 hips (56.5%), adverse tissue reaction to metal on metal (MOM) in 43 hips (23.1%), and recurrent instability in 38 hips (20.4%). The approach used for the revision surgery was PA in 128 hips (68.8%) and AA in 58 hips (31.2%). The mean follow-up for this cohort is 1.9±2 yrs (0.0–8.6).
Results
The overall dislocation rate for the entire cohort was 28/186 (15%). There was no difference in the dislocation rate whether the revision surgery was performed by the PA 19/128 (15%) or the AA 9/58 (16%) (p=0.9). With the numbers available, there was no difference in dislocation rates when comparing reason for revision: poly wear/osteolysis 12/105 (11%), MOM 8/43 (19%) or recurrent instability 8/38 (21%) (p=0.28). The head size used in the exchange did not influence the dislocation rate; 28 mm-2/11 (18%), 32 mm-6/56 (11%), 36 mm-16/91 (18%), 40 mm-4/26 (15%) (p=0.89).
Conclusion
The use of either the PA or AA did not alter the dislocation rate in our cohort. While there was a trend towards a higher dislocation rate when liner exchange was performed for MOM or recurrent instability, no statistical difference was shown with the numbers available. The head size used in the revision did not influence the rate of dislocation.
