Nail Alone Results in Similar Clinical Outcomes with Less Perioperative Morbidity Compared to Nail Plate Combination In Treatment of Native Distal Femur Fractures

Objectives: To compare outcomes and complications of retrograde intramedullary nailing (rIMN), plating, and combined rIMN+plate constructs for native distal femur fractures. Methods: Design: Retrospective review of operative distal femur fractures, 2018-2022. Setting: Urban level one trauma center. Patient Selection Criteria: Included were patients >18 years-old with AO/OTA 33A or 33C distal femur fractures and >=6 months follow-up. Outcome Measures and Comparisons: Demographics, fracture type, operative time, estimated blood loss (EBL), changes in radiographic alignment, union rates (mRUST ≥10), re-operations, complications, and return to weightbearing. were collected and compared between the three fixation constructs. Results: 137 patients were included (71 rIMN, 27 plate, 39 rIMN+plate). Median age was older for rIMN+plate compared to rIMN (61 vs 54 years, P =0.015) and similar between rIMN+plate and plate groups (61 years for both, P = 0.68) . There were no other differences in demographics among groups (P>0.05). The rIMN+plate group had longer operative time (256 min) and higher EBL (250cc) compared to rIMN alone (150 min, P = 0.0006 and 200cc, P = 0.023) and similar operative time and EBL compared to plate alone (168 min, P = 0.071 and 250cc, P = 0.73) There were no differences in final coronal or sagittal alignment (P=0.78, P=0.87 respectively) or reoperation rates (P=0.74) among groups. The rIMN+plate group showed a higher rate of radiographic union (66.7%) compared to the rIMN (42.3%) and plate (44.4%) groups (P=0.042) . When controlling for patient age, time to weight bearing was similar among the groups (P =0.79). Conclusions: While the rIMN+plate combination led to higher rates of union, it did not decrease time to weightbearing or re-operation rates compared to rIMN alone, and was associated with longer operative time and greater blood loss. Level of Evidence: Level III