Flexor hallucis longus augmentation for Achilles tendon – is pre-operative evaluation of flexor hallucis longus by MRI required?

Abstract

Objectives: Flexor hallucis longus (FHL) tendon transfer is the method of choice in reconstructing chronic neglected Achilles tendon rupture. We performed a retrospective study to assess the incidence and degree of fatty degeneration of FHL. Material and Methods: Two hundred and twenty-five consecutive MR of ankles were reviewed retrospectively and assessed for fatty atrophy based on Goutallier classification. Results: About 42.7% had Grade 1, 8.4% had Grade 2, 3.1% had Grade 3, and 1.8% had Grade 4 fatty atrophy of FHL. Other lesions identified included posterior ankle impingement, tenosynovitis, loose bodies, and giant cell tumors of the tendon sheath. Conclusion: We suggest pre-operative radiological assessment of the FHL to establish that the FHL muscle and tendon are normal and intact and suitable for transfer surgery. We also discuss the spectrum of pathologies affecting FHL.