Higher than expected incidence of femoral neck shortening seen among young patients after fracture fixation

TAMPA, Fla. — Research presented here from a prospective trauma database showed femoral neck shortening of at least 5 mm following internal fixation in 54% of patients aged 60 years or younger.

“A majority of our cases did experience early shortening greater than 5 mm. The clinical significance of this remains undetermined, but recent literature suggests significant associations between shortening and functional outcome. The sliding hip screw was associated with increased shortening, but this likely represents selection biases,” Gerard P. Slobogean, MD, MPH, FRCSC, said during his presentation at the Orthopaedic Trauma Association Annual Meeting. “Ultimately, the optimum implant for fixation remains controversial and the topic of a future clinical trial.”

Gerard P. Slobogean

To describe the incidence and magnitude of femoral neck shortening in young patients and to find variables associated with femoral neck shortening, Slobogean and his colleagues identified 65 patients with a mean age of 51 years who had femoral neck fractures treated with either sliding hip screws or multiple cancellous screws. Overall, 51 patients were treated with multiple cancellous screws. Open reduction was performed in 15% of all cases, and a sliding hip screw plus derotation screw was used in 22% of cases. Most patients had displaced Garden type 2 or 3 fractures, and Pauwel type 2 and 3 fractures. The patients had a minimum follow-up of 6 months with X-rays evaluated by two independent reviewers.

“We recognize that shortening would only increase with time and, if anything, our results would potentially be of conservative or underestimated value,” Slobogean said.

“Strikingly, I would say that 32% of patients had shortening greater than 1 cm,” he said. “An additional 22% had shortening between 5 mm and 10 mm.”

A regression analysis revealed fixation implant and the initial displacement were independently associated with femoral neck shortening. After adjustment for initial fracture displacement, investigators found cases treated with a sliding hip screw construct shortened an average of 2.2 mm more than patients treated with cancellous screws alone.

“I do need to mention, of course, that we were unable to find any associations between the implant selected and the fracture characteristics.” Slobogean said. – by Gina Brockenbrough, MA

Reference:

GP Slobogean. Paper #45. Presented at: Orthopaedic Trauma Association Annual Meeting; Oct. 16-18, 2014; Tampa, Fla.

Disclosure: Slobogean has no relevant financial disclosures.