Cervical Ligament Insufficiency in Progressive Collapsing Foot Deformity: It May Be More Important Than We Know.

BACKGROUND

Subluxation at the subtalar joint is one of the major radiographic features that characterize progressive collapsing foot deformity (PCFD). Although it is recognized that the cervical ligament plays an important function in maintaining the subtalar joint's stability, its role and involvement in PCFD is largely unknown. The purpose of this study was to assess the prevalence of cervical ligament insufficiency in patients with PCFD and to establish if the degree of its pathology changes with increasing axial plane deformity.

METHODS

This study retrospectively reviewed magnetic resonance imaging (MRI) of 78 PCFD patients and age- and gender-matched controls. The structures evaluated were the cervical, spring, and talocalcaneal interosseous ligaments. Structural derangement was graded on a 5-part scale (0-4), with grade 0 being normal and grade 4 indicating a tear of greater than 50% of the cross-sectional area. Plain radiographic parameters (talonavicular coverage angle [TNC], lateral talo-first metatarsal [Meary] angle, calcaneal pitch, and hindfoot moment arm) as well as axial plane orientation of the talus (TM-Tal) and calcaneus (TM-Calc) relative to the transmalleolar axis and talocalcaneal subluxation (Diff Calc-Tal) were correlated with the cervical ligament MRI grading system.

RESULTS

The overall distribution of the degree of cervical ligament involvement was significantly different between the PCFD and control groups (

CONCLUSION

This study found that cervical ligament insufficiency is more often than not associated with PCFD, and that an increasing axial plane deformity appears to be associated with a greater degree of insufficiency.

LEVEL OF EVIDENCE

Level III, case-control study.

Déclaration de conflit d'intérêts

Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. ICMJE forms for all authors are available online.