Distal targeting device for long Gamma nail(®). Monocentric observational study.

Introduction: Intramedullary nail distal locking screws make it possible to control length and rotation but include an increased risk of radiation exposure. A distal targeting device was recently developed for long Gamma(®) nails (Stryker(®)). The aim of this practical observational study was to evaluate the reliability of this system. Our hypothesis was that the targeting device would be systematically used without conversion or complications.

Materials And Methods: All of the long Gamma(®) nails implanted between November 2011 and October 2012 were recorded: 91 nails (59W/32M, mean age 73.5years old) for 68 traumatic fractures, 14 preventive nailings and nine pathological fractures. A junior surgeon performed the procedure in 45 cases and a senior in 46 cases. The number of times the device was used, the difficulties and complications encountered, the duration of fluoroscopy and the dose of radiation were noted. Risk factors were looked for.

Results: The targeting device was used 79 times (the surgeon chose not to use it 11 times, and it was not available in one case). There was a measurement error in one case, therefore 78 nails could be evaluated. Three wrong positions of the distal locking screw occurred. No statistically significant risk factors were identified. Distal locking screw corresponded to 18% of the entire procedure at a radiation dose of 7.44% (this was higher with titanium nails and pathological fractures). Total fluoroscopy time was longer with junior than with senior surgeons but the dose and duration for distal locking were not different.

Discussion: The hypothesis was not confirmed. The device was not systematically used and the risk of complications was not null. No risk factors were identified. The distal locking screw is a difficult step but the use of the targeting device can limit the dose of radiation. This device is effective and allows young surgeons to perform distal locking without increasing the dose of radiation compared to senior surgeons.

Level Of Evidence: Level IV, cohort study, observational prospective follow-up.