Anti-rotation pins for the compress implant do not increase risk of mechanical failure or impair osseointegration

Sean T. Campbell, Robert J. Steffner, Andrea Finlay, David G. Mohler, Raffi S. Avedian

Abstract

Background: The use of compliant fixation for endoprosthetic implants is gaining popularity. Previous work has shown that anti-rotation pins improve rotational stability at the bone-implant interface, but there is concern that these pins lead to increased risk of mechanical failure. We asked: (I) are anti-rotation pins used with the Compress implant associated with mechanical failure? (II) Are anti-rotation pins associated with less effective osseointegration?
Methods: We performed retrospective review of cases using a Compress implant from 2004–2016. Mechanical failure rates and bone growth at the bone-implant interface were compared between pin and no-pin cohorts. Regression models were used to examine patient and surgical factors associated with mechanical failure.
Results: Anti-rotation pins were not associated with mechanical failure (P=1.0, odds ratio 1.17, 95% confidence interval: 0.12–15.40). Anti-rotation pins were not associated with impaired osseointegration at any time point (P=1.0 at 3–6 months, P=0.33 at 6-9 months, P=0.34 at 9–12 months, P=0.40 at 12–24 months, P=0.28 at 24–48 months, P=1.0 at >48 months). No patient or surgical variables were predictors of mechanical failure.
Conclusions: Anti-rotation pins were not associated with mechanical failure or impaired osseointegration.