Pin-site related outcomes after temporary staging external fixator pin placement using the self-drilling pin insertion technique.

Abstract

Objectives: To report on pin-related complications in patients who underwent temporary staging external fixation using a self-drilling pin insertion technique.

Design: Retrospective cohort study.

Setting: Single tertiary referral level one trauma center.

Patient selection criteria: Adult patients were included who underwent temporary spanning external fixation of the lower extremity (AO/OTA 32, 33, 41, 42, 43, 44, 81, 82, 83, 84, and 85 fractures) using self-drilling and self-tapping pins placed using the self-drilling technique (Stryker Hoffman External Fixation System, Kalamazoo, MI, USA) between August 1st, 2015, and December 31st, 2022, with minimum follow up of 90 days. The self-drilling technique included use of a soft tissue sleeve for pin protection in the femur and tibia, release of the tourniquet if inflated, and full speed insertion with the final turns completed by hand. Irrigation of the pin-bone interface was not typically used.

Outcome measures: Outcome measures included pin-site infection, pin loosening, loss of reduction in external fixator, and deep infection of the primary surgical site.

Results: 265 patients were included with a mean follow-up of 556 days. Mean age was 50 years (range 18-86 years). 155 patients (59%) were male. 1154 total pins were placed: 289 (25%) in the femur (one metaphyseal), 527 (46%) in the tibia (12 metaphyseal), 161 (14%) transfixion pins in the calcaneus, and 171 (15%) in the midfoot/forefoot. 7 patients (2.6%) developed a pin site infection. The infection rate for the total number of pins placed was 7/1154 (0.6%). 1 patient sustained a loss of reduction in the external fixator and 3 pins were noted to be loose at the time of definitive fixation (two in the tibial diaphysis and one in the 1st metatarsal shaft). 35/265 (13.2%) patients developed deep fracture related infection or septic nonunion in the post-operative period, none of which were associated with prior pin site infection.

Conclusions: The self-drilling technique for temporary external fixator pin insertion in the present study demonstrated low rates of pin site infection, pin loosening, and loss of reduction.

Level of evidence: Level III Therapeutic Study.