Analysis of risk factors for sagittal plane malpositioning during primary ankle arthrodesis.

OBJECTIVE

This study aimed to identify specific risk factors for sagittal plane malpositioning following primary ankle arthrodesis in patients with end-stage ankle joint diseases.

METHODS

A retrospective cohort analysis was conducted on 166 patients who underwent primary ankle arthrodesis between January 2010 and December 2019. Sagittal plane malpositioning was defined as postoperative talar anterior translation > 5 mm or sagittal plane angulation > 10° on lateral radiographs. Potential risk factors analyzed included age, gender, affected side, primary disease, preoperative alignment, surgical approach combined with fixation system, concomitant procedures, and surgeon experience. Binary logistic regression was used to evaluate associations with postoperative malpositioning.

RESULTS

The incidence of sagittal plane malpositioning was 16.3 % (27/166). Preoperative pes equinus and/or anterior talar subluxation (OR = 6.887, 95 % CI: 1.375-34.50, p = 0.019) and surgery performed by mid-senior surgeons (vs. senior surgeons; OR = 3.210, 95 % CI: 1.039-9.919, p = 0.043) were significant risk factors. Compared with the anterior approach + cannulated screws, the lateral approach + lateral plate plus cannulated screws was associated with a lower risk (OR = 0.105, 95 % CI: 0.012-0.953, p = 0.045). No significant associations were found with gender, age, affected side, primary disease, preoperative anteroposterior alignment, or concomitant subtalar arthrodesis.

CONCLUSION

Preoperative sagittal deformities, use of the anterior approach with cannulated screws alone, and less experienced surgeons increase the risk of sagittal malpositioning after primary ankle arthrodesis. The lateral approach with lateral plate fixation may reduce this risk. Thorough preoperative planning, appropriate surgical technique selection, and surgeon training are crucial to improving outcomes.

LEVEL OF EVIDENCE: Ⅲ, Retrospective Comparative Study.