PERINAVICULAR ARTHROGRAPHY AND TIBIALIS POSTERIOR INSERTION IN THE ASSESSMENT OF ROTATORY NAVICULAR DEFORMITY AT SEQUENTIAL CLUBFOOT CORRECTION

Abstract

Introduction: Intra-operative visualisation of talonavicular reduction does not exclude the possibility of persistent navicular rotatory subluxation as cause of persistent cavus or adductus deformity. Open perinavicular arthrography accurately defines navicular rotatory status. Similarly, inferior navicular insertion of the tibialis posterior tendon is a reliable predictor of correction of navicular rotation.

Methods: Six operated clubfeet, aged six to ten months and operated on from March 2001 to September 2001, were included in this study. Correction was obtained using a sequential release and reduction was held with talonavicular and calcaneocuboid pinning. Simultaneous perinavicular arthrography was done using contrast soaked surgical patties inserted into the opened talonavicular and naviculocuneiform joints. Naviculocuneiform status and navicular insertion of the tibialis posterior were observed and conventional intra-operative clinical- and radiographic assessment of clubfoot correction was compared with perinavicular arthrographic findings.

Results: Naviculocuneiform displacement was not observed. Visual and arthrographic assessment of talonavicular reduction showed a correlation of 100%, but such reduction often necessitated joint incongruence. Arthrography showed persistent navicular rotatory subluxation after adequate release and talonavicular reduction in 2 cases. Anteroposterior and lateral talar-first metatarsal angles fail to identify inadequate plantar fascia release, failure of talonavicular reduction or persistent navicular rotation as cause of persistent deformity. After adequate plantar fascia release, visual confirmation of talonavicular reduction and arthrographic confirmation of navicular rotatory reduction successfully corrected persistent midfoot deformities. Medial navicular insertion of the tibialis posterior tendon was observed in all cases of navicular rotatory subluxation, while restored inferior navicular insertion of this tendon was confirmed in all cases where navicular rotation was corrected. Recurrent navicular rotation after confirmed correction was observed in one case after single pinning of both talonavicular and calcaneocuboid joints.

Conclusions: The naviculocuneiform joint should not be addressed at clubfoot surgery. Inferior navicular tibialis posterior insertion confirms correction of navicular rotation as cause of persistent midfoot deformity and should be routinely assessed. Recurrent navicular rotatory subluxation suggests double pinning of the talonavicular joint.