Radiographic Changes in Central Tarsometatarsal Arthritis Following Flatfoot Reconstruction

Area of Science:

• Orthopedic Surgery
• Foot and Ankle Reconstruction
• Biomechanical Engineering

Background:

• Progressive collapsing flatfoot deformity (PCFD) frequently leads to non-traumatic degenerative midfoot arthritis.
• Arthrodesis (joint fusion) is a conventional treatment for symptomatic arthritis unresponsive to conservative care.
• Restoring the medial longitudinal arch is hypothesized to improve associated tarsometatarsal (TMT) arthritis.

Purpose of the Study:

• To evaluate the clinical and radiographic outcomes of medial longitudinal arch reconstruction in patients with PCFD and central TMT arthritis.
• To determine if arch reconstruction can improve TMT joint arthritis without the need for arthrodesis.
• To assess the efficacy of flexor hallucis longus (FHL) transfer for arch restoration.

Main Methods:

• A prospective study included 18 patients (21 feet) with PCFD and central TMT arthritis from April 2017 to December 2022.
• Medial longitudinal arch reconstruction was performed using flexor hallucis longus (FHL) transfer.
• Clinical outcomes were assessed using the visual analog scale (VAS) and Foot Function Index (FFI). Radiographic parameters, including TMT joint stage and lateral talo-first metatarsal angle, were evaluated via CT scans.

Main Results:

• Significant improvements were observed in clinical outcomes: VAS scores decreased from 7.1 to 1.6, and FFI scores decreased from 53.3 to 12.2 (P < .001).
• Radiographic evaluation showed significant improvement in the second TMT joint stage (from 3.4 to 1.2) and the lateral talo-first metatarsal angle (from 33.3 to 16.8 degrees) (P < .001).
• The study demonstrated radiographic improvement in TMT arthritis without the need for TMT joint arthrodesis.

Conclusions:

• Medial longitudinal arch reconstruction effectively improved radiographic findings of non-traumatic central TMT arthritis in patients with PCFD.
• While radiographic improvements were noted, the direct attribution of clinical outcome improvements specifically to TMT joint changes requires further investigation.
• Flexor hallucis longus (FHL) transfer is a viable surgical option for medial longitudinal arch reconstruction in this patient population.