Hydroxyapatite-Coated Pins Versus Titanium Alloy Pins in External Fixation at the Wrist: A Controlled Cohort Study

Abstract

In external fixation of the wrist, the use of HA-coated pins yields no clinical advantages: there is a trend toward a superior pin-bone anchorage, but a tendency of increased susceptibility for minor pin-track infections.

Clinical Benefit of Hydroxyapatite-Coated Versus Uncoated External Fixation: A Systematic Review

“…Pieske et al [25] , 2011 Pieske et al [26] , 2010 Placzek et al [16] Prospective nonrandomised comparative study . loosening (extraction torque < 150 Nmm per degree).…”

“…Five of the studies in this review found that HA-coating of pins improves bone fixation and therefore reduces loosening in patients undergoing external fixation. However, the results of the studies of Pieske et al [25,26] found that although there was a trend towards a superior clinical outcome, the results showed no significant superiority of HA-coated pins against uncoated pins and that the majority of clinical pin-site parameters were comparable in both groups. At the end of the fixator therapy, Pieske et al [26] , found there were a total of 9 loose pins out of 76 in the steel group (11.8%) compared to 6 loose pins out of 76 in the HA-coated group (7.9%), whilst Pieske et al [25] , showed there were 10 loose pins in the titanium group (12.5%) compared to 6 loose pins in the HAcoated group (7.9%).…”

“…However, the results of the studies of Pieske et al [25,26] found that although there was a trend towards a superior clinical outcome, the results showed no significant superiority of HA-coated pins against uncoated pins and that the majority of clinical pin-site parameters were comparable in both groups. At the end of the fixator therapy, Pieske et al [26] , found there were a total of 9 loose pins out of 76 in the steel group (11.8%) compared to 6 loose pins out of 76 in the HA-coated group (7.9%), whilst Pieske et al [25] , showed there were 10 loose pins in the titanium group (12.5%) compared to 6 loose pins in the HAcoated group (7.9%). Pieske et al [26] found that although there was a lower rate of loose pins in the HA group, this was not significant (P = 0.864) and that the benefit of advanced pin-bone bonding in the HA group was clinically irrelevant.…”

“…Furthermore the fixation therapy in both of these studies was only for a period of 6 weeks. In other studies which have demonstrated a significant improvement in bone fixation, such as for lower leg lengthening, external fixation treatment time is much longer, extending on average up to 500 days [25] . During long-term fixator treatment, the beneficial effects of HA-coated pins becomes more evident, with improved bone fixation and low rates of pin-loosening seen, compared with the shorter duration of fixation therapy used for this wrist study.…”

Complications of transcutaneous metal devices

“…This material produces a reduced susceptibility to bacterial adhesion. In a study by Pieske et al [24], titanium alloy pins were compared with stainless pins in 80 patients. There was no difference in the incidence of pin-tract infection.…”