Comparison of retrograde vs. antegrade intramedullary nailing for extra-articular distal tibial fracture: a retrospective matched case-control study.

OBJECTIVE

To compare the clinical efficacy of retrograde vs. antegrade intramedullary nailing(RIN vs. AIN)for extra-articular distal tibial fracture.

METHODS

This retrospective matched case-control study included 42 patients treated between April 2020 and April 2024-21 with RIN and 21 with AIN. Patients were matched by age and sex. Perioperative parameters, radiographic reduction quality, malunion rate, time to weight-bearing, functional outcomes (Baird-Jackson and AOFAS scores), and complications were assessed. Pain at the knee and ankle was also recorded. All patients were followed for at least 12 months. A post hoc power analysis was performed based on key outcome variables. Binary outcomes were analyzed using conditional logistic regression accounting for the matched design, with sensitivity analyses adjusting for fracture type and fibular fracture. A post-hoc power analysis based on discordant pairs was performed.

RESULTS

Both groups had comparable baseline characteristics. RIN resulted in significantly lower intraoperative blood loss (34.38 ± 2.27 mL vs.49.38 ± 7.00 mL, P < 0.05), shorter hospital stays (8.00 ± 2.07 days vs.11.00 ± 2.10 days, P < 0.05), earlier weight-bearing (11.86 ± 0.96 days vs.12.76 ± 1.04 days, P < 0.05). The RIN group showed a numerically higher rate of excellent fracture reduction (90.5% vs. 76.2%), though this difference was not statistically significant in the matched-pair analysis (OR = 3.50, 95% CI: 0.73-16.85, P = 0.119). post-hoc power analysis indicated that this non-significant finding likely reflected insufficient power (<10%) due to a limited number of discordant pairs. Functional scores improved significantly over time in both groups, with no inter-group differences at any time point. The incidence of anterior knee pain was significantly lower in the RIN group (9.5% vs. 47.6%, OR = 0.10, 95% CI: 0.01-0.82, P = 0.032), whereas malunion rates and other complications were comparable.

CONCLUSION

Both RIN and AIN provide reliable fixation and satisfactory functional outcomes for extra-articular distal tibial fracture. RIN significantly reduces the incidence of anterior knee pain compared to AIN, a finding supported by adequate statistical power. RIN also reduces intraoperative blood loss and shortens hospital stay. The observed numerical advantage in excellent reduction requires further confirmation in larger, appropriately powered studies. RIN may be the preferred approach in selected patients, especially those with high functional demands or preexisting anterior knee pathology.