OBJECTIVES: To compare implant failure rates, reoperations, and postoperative mobilization between lateral locked plate (LLP), retrograde intramedullary nail (rIMN), and nail-plate combination (NPC) constructs in treating distal femur fractures. METHODS: Design : Retrospective cohort study Setting: Single level 1 trauma center Patient Selection Criteria: Adult patients treated operatively for distal femur fractures (OTA/AO 33A and 33C) from 2019 to 2024 were included. Patients were excluded if they sustained partial articular injuries, pathologic fractures, multifocal femoral injuries, or critical bone defects. Outcome Measures and Comparisons: Construct failure was the primary outcome, defined as displaced implant breakage, gross loss of fracture reduction, or any reoperation for nonunion. Secondary outcomes included all-cause reoperation, deep infection, death within 90 days, and mobilization status at the time of discharge. RESULTS: 196 distal femur fractures in 188 patients were included. There were 83 fractures treated with NPC fixation (mean age 70 years, 24% male, BMI 31), 37 fractures treated with rIMN (mean age 55 years, 54% male, BMI 28), and 76 fractures treated with LLP (mean age 65 years, 29% male, BMI 32). Across the three treatment groups, rIMN patients were younger (p<0.001) and had a higher proportion of males (p=0.004). Immediate weightbearing was allowed in 70% of NPC constructs, 32% of rIMN constructs, and 3% of LLP constructs, respectively (p<0.001). After controlling for age, BMI, and open fracture status, NPC was associated with a lower risk of construct failure, occurring in 1/83 (1.2%) cases, compared with LLP, which failed in 15/76 (19.7%) cases (HR 17.43 95% CI: 2.23, 136.10, p=0.006). While NPC had the lowest rate of failure among the three constructs, the difference between NPC and rIMN, which failed in 2/37 (5.4%) cases, was not statistically significant (HR 7.62 95% CI 0.66, 88.24, p=0.104). All-cause reoperation occurred in 7 (8.4%) patients in the NPC group, 4 (10.8%) patients in the rIMN group, and 18 (24.7%) patients in the LLP group. Deep infection occurred in 6 (7.2%) patients in the NPC group, 1 (2.7%) patient in the rIMN group, and 1 (1.3%) patient in the LLP group (p=0.085). There were no differences in EBL (p=0.137), or death (p=0.999) between groups. Geriatric patients (age ≥60 years) with NPC fixation were more likely to discharge within a higher mobilization strata relative to single implant constructs (OR 2.93, p=0.049). CONCLUSIONS: NPC and rIMN demonstrated a lower hazard of construct failure and reoperation than LLP in the treatment of acute distal femur fractures. While NPC had a higher number of deep infection cases, controlling for multiple comorbidities found no statistical difference in infection rates between NPC, LLP, and rIMN, but rather an increased risk of infection in smokers and patients with high BMI. NPC fixation was associated with improved postoperative mobilization in geriatric patients compared to single implant constructs. LEVEL OF EVIDENCE: Therapeutic Level III
Verlinsky et al. (2026) studied this question.