The relevance of the number of distal locking planes and nail to canal ratio in bone healing after intramedullary nailing in tibial shaft fractures

Do two distal locking screws in two planes offer the best option in the nailing of diaphyseal tibial fractures?

Background

Although the intramedullary nail represents the treatment for most tibia diaphyseal fractures, there is no agreement on the configuration of the distal locking screws. Therefore, this study aimed to investigate the impact of the configuration of distal locking bolts on the healing of a tibial shaft fracture.

Methods

We retrospectively analyzed 170 closed fractures of the tibia diaphyseal operated consecutively between 2018 and 2021. Patients with postoperative unacceptable reduction (>5° in any plane or gap >4 mm), nail-canal ratio <0.78, and less than 12 months of follow-up were excluded. Using a univariate and multivariate analysis, we analyzed comorbidities (smoking, Body mass index >30, diabetes), fracture type (OTA/AO), the number (one, two, three distal locking screws), and configuration (uniplanar, biplanar, triplanar) of distal locking screws between patients with and without a bone union.

Results

One hundred and forty-two fractures were available for analysis. The bone union and non-union rates were 89.4 % (n = 127) and 10.6 % (n = 15), respectively. The multivariate analysis showed that type A fractures (OR 6.67, p = 0.010) and using two distal locking screws with a biplanar configuration (OR 3.63, p = 0.036) were independent variables related to bone union. In contrast, smoking habit (OR 0.12, p = 0.041), fractures type B (OR 0.22, p = 0.013), and uniplanar fixation (OR 0.51, p = 0.003) were related to non-union.

Conclusion

The findings of this study suggest that using two distal locking screws (anteroposterior + mediolateral) in the nailing of closed tibial diaphyseal fracture represents the optimal configuration, offering a higher likelihood of healing compared to other locking options.

Does the distal nail position impact the rates of misalignment and bone union in distal tibial fractures?

PURPOSE

This retrospective study aimed to assess the impact of distal nail placement on misalignment and healing rates in distal tibial fractures.

METHODS

We reviewed all patients with distal tibial fracture treated with intramedullary nailing between 2015 and 2021, and a minimum follow-up of 12 months. Distal nail positioning was determined according to the Triantafillou zones. We related these positioning zones to misalignments (alignment ≥ 3°) and too bony union disorders (delayed union, non-union).

RESULTS

Out of the 62 patients included, 56 (90.3%) show bone union without additional procedure, 3 (4.8%) with dynamization, and 3 (4.8%) showed non-union. Twenty-one (33.8%) presented misalignment, with valgus in the coronal plane being the most frequent (76.19%). In patients with and without misalignment, the most frequent distal nail position was 2-2 in 47.6% and 80.5%, respectively (p = 0.01). In multivariate analysis, distal nail positioning in the 2-2 zone showed a significant protective effect against misalignment (OR 0.18; p = 0.018), while nail positioning in the 3-2 zone generated a significant risk of misalignment (OR 18.55; p = 0.009).

CONCLUSION

In intramedullary nailing of distal tibial fractures, distal positioning of the nail slightly lateral to the center of the talus in the coronal plane and slightly posterior in the sagittal plane (zone 2-2) allows high alignment percentages to be obtained. Positioning medial to this point in the coronal plane (zone 3) is associated with more significant misalignment and should be avoided.