Metatarsophalangeal arthrodesis of the hallux: A clinical comparison of fixation methods and a review of the literature.

BACKGROUND

First metatarsophalangeal joint arthrodesis (FMTPA) reliably treats severe hallux deformities. While fixation techniques differ biomechanically, there is no evidence that this influences clinical outcomes. This study compares clinical and radiologic results across three fixation methods.

METHODS

One hundred and ten FMTPA were performed, followed for a mean of 41 months (range, 12-156). Plate-and-screws were used in 74 feet, staples in 28 and crossed-screws in 8. Diagnoses included advanced hallux rigidus (72%), hallux valgus with severe deformity (19%) and rheumatoid foot with advanced osteoarthritis (9%). Clinical outcomes included transfer metatarsalgia, pain and functionality (assessed with the European Foot and Ankle Society (EFAS) score). Radiological analysis studied union rate and hallux alignment, assessed using the hallux valgus (HVA), intermetatarsal (IMA) and dorsiflexion angles (DFA) of the first metatarsophalangeal joint.

RESULTS

Twenty-five patients (23%) experienced pain in the operated hallux and 22 (20%) developed transfer metatarsalgia. Mean EFAS score was 29 ± 6, with no differences between techniques (p = 0.95). Eleven patients showed nonunion (10%), without differences (p = 0.46), but 3 patients needed revision surgery due to symptoms. Mean HVA was 10.4º ± 10º, with no differences between groups (p = 0.18) and mean IMA was 6º ± 3º, also with no significant differences (p = 0.38). At the end of follow-up, the mean DFA was 18° ± 11°, with a significant difference between groups (p = 0.03), indicating greater correction in hallux dorsiflexion in patients treated with plates and screws. Twelve patients (11%) required hardware removal, most of them in the plate group.

CONCLUSIONS

FMTPA is an effective procedure without major clinical differences between fixation techniques. Plate-and-screws fixation allows for a more predictable alignment of the hallux and, even with a higher number of reoperations, presents comparable functional results.

LEVEL OF CLINICAL EVIDENCE: III; Retrospective Cohort Comparison.