Effect of dorsoplantar miniscrew fixation of the second metatarsal base fracture on residual diastases in acute lisfranc fracture-dislocation.

PURPOSE: This study aimed to evaluate and compare the clinico-radiographic outcomes between two techniques for acute Lisfranc fracture-dislocation with a large, displaced second metatarsal base plantar fracture: isolated Lisfranc screw fixation versus Lisfranc joint fixation with dorsoplantar miniscrew fixation of the second metatarsal base.

METHODS

We retrospectively compared the clinico-radiographic outcome between patients who underwent isolated Lisfranc screw fixation (Group 1, 26 patients) and those who underwent Lisfranc joint fixation with dorsoplantar miniscrew fixation of the second metatarsal base (Group 2, 23 patients). The main outcome measurements were the postoperative distance between the medial cuneiform and second metatarsal base on standing anteroposterior foot radiographs, known as the C1-M2 distance. Residual diastasis was defined as C1-M2 distance ≥ 2 mm on the affected side compared with that on the contralateral side. We also assessed the Foot and Ankle Ability Measure (FAAM)-activities of daily living (ADL) and sports subscale scores at three, six and ≥ 18 months postoperatively.

RESULTS

At the final follow-up, the mean C1-M2 distance on the affected side compared with that on the contralateral side was significantly greater in Group 1 than in Group 2 (3.9 versus 0.7 mm, P = 0.027). Furthermore, Group 1 showed a higher incidence of residual diastases at the final follow-up (69.2%) than the Group 2 (13.0%, P < 0.001). The FAAM-ADL scores at the final follow-up did not differ significantly between the groups (P = 0.518), but the FAAM Sports score was significantly higher in Group 2 than in Group 1 (P = 0.001).

CONCLUSIONS

The postoperative C1-M2 distance was better maintained with Lisfranc joint fixation with dorsoplantar miniscrew fixation of the second metatarsal base than with isolated Lisfranc screw fixation. We recommend that surgeons exercise caution when dealing with a second metatarsal plantar fracture and consider performing secure fixation using the dorsoplantar miniscrew technique for improved clinical outcomes.