Association of Long Versus Standard-Length Cephalomedullary Nail Constructs with Posterior Sagging in Intertrochanteric Fractures with Posteromedial Comminution: A Retrospective Comparative Study.

Background

Posterior sagging (PS) of the proximal fragment after cephalomedullary nailing (CMN) of intertrochanteric fractures leads to loss of anteromedial cortical support.

Methods

We retrospectively reviewed 118 patients with AO/OTA 31-A2 intertrochanteric fractures (2007 classification). After an institutional protocol change, standard-length constructs with one distal screw were used until March 2019 (n = 65) and long constructs (≥300 mm) with two distal screws from June 2019 (n = 53); the cohorts were consecutive, not concurrent.

Results

PS occurred in 23/118 patients (19.5%): 21/65 (32.3%) with standard-length versus 2/53 (3.8%) with long constructs (p < 0.001; adjusted odds ratio (OR) 0.08, 95% confidence interval (CI) 0.02-0.37). With standard-length constructs, PS was more frequent with big lesser trochanteric (LT) fragments (42.9% vs. 13.0%, p = 0.014); the interaction was not significant (p = 0.092). Long-construct use and a higher reduction score were associated with lower odds of PS, and older age and a big LT fragment with higher odds. Greater trochanter (GT) separation was present in 114 of 118 fractures and could not be evaluated as a risk factor.

Conclusions

PS was associated with the standard-length construct and, within this group, with a big LT fragment. Nail length, distal locking, and treatment era could not be separated, so these findings show an association, not a causal effect of nail length. Functional outcomes were not assessed.