Subtalar and talonavicular arthrodesis through a single medial approach for the correction of severe planovalgus deformity

Triple arthrodesis

Triple arthrodesis is largely used to restore painful hindfoot deformity. However, the procedure has been connected to several postoperative complications. Therefore, an isolated fusion of the talonavicular and the subtalar joint through a single medial approach has gained popularity. This "diple" arthrodesis provides effective correction of deformities and reduces the risk of wound healing problems on the lateral side of the foot.

Talonavicular joint fixation using augmenting naviculocalcaneal screw in modified double hindfoot arthrodesis

BACKGROUND

Triple arthrodesis and combined talonavicular/subtalar arthrodesis are procedures for hindfoot disorders. Achieving talonavicular joint fusion can be problematic. We hypothesized that talonavicular joint fixation bending stiffness could be increased by adding a fully-threaded screw inserted through the lateral navicular into the calcaneus.

MATERIALS AND METHODS

We used ten fresh-frozen cadaver hindfeet. The calcaneus and talus were immobilized, and talonavicular joint stripped of cartilage. Two partially-threaded 4.5-mm cannulated screws were placed across the talonavicular joint, one traversing the central third of the navicular and a second through the medial third of the navicular. We quantified talonavicular fixation bending stiffness and angulation in response to 4N-m bending moments applied to the navicular in four directions: plantar-to-dorsal (P-D), medial-to-lateral (M-L), dorsal-to-plantar (D-P), and lateral-to-medial (L-M). An augmenting fully-threaded 4.5 mm cannulated screw was then placed through the lateral third of the navicular into the calcaneus and the specimens retested.

RESULTS

The mean bending stiffness in each direction increased significantly after addition of the third screw. The stiffness increase in each direction was: P-D 92%, D-P 39%, L-M 108%, and M-L 56%. Correspondingly, mean talonavicular angulation significantly decreased in each direction: P-D 43%, D-P 28%, L-M 47%, and M-L 34%.

CONCLUSION

A third, fully-threaded screw from the lateral navicular into the calcaneus significantly increases talonavicular bending stiffness and decreases angulation.

CLINICAL RELEVANCE

The increased resistance to arthrodesis site motion afforded by the addition of a naviculocalcaneal screw may improve the likelihood of achieving successful talonavicular fusion in combined talonavicular/subtalar arthrodesis.

Total ankle replacement in association with hindfoot fusion

We report the clinical and radiological outcome of total ankle replacement performed in conjunction with hindfoot fusion or in isolation. Between May 2003 and June 2008, 60 ankles were treated with total ankle replacement with either subtalar or triple fusion, and the results were compared with a control group of 288 ankles treated with total ankle replacement alone.

After the mean follow-up of 39.5 months (12 to 73), the ankles with hindfoot fusion showed significant improvement in the mean visual analogue score for pain (p < 0.001), the mean American Orthopaedic Foot and Ankle Society score (p < 0.001), and the mean of a modified version of this score (p < 0.001). The mean visual analogue pain score (p = 0.304) and mean modified American Orthopaedic Foot and Ankle Society score (p = 0.119) were not significantly different between the hindfoot fusion and the control groups. However, the hindfoot fusion group had a significantly lower mean range of movement (p = 0.009) and a higher rate of posterior focal osteolysis (p = 0.04). Both groups showed various complications (p = 0.131) and failure occurring at a similar rate (p = 0.685).

Subtalar or triple fusion is feasible and has minimal adverse effects on ankles treated with total ankle replacement up to midterm follow-up. The clinical outcome of total ankle replacement when combined with hindfoot fusion is comparable to that of ankle replacement alone. Thus, hindfoot fusion should be performed in conjunction with total ankle replacement when indicated.

Arthrodesis of the subtalar and talonavicular joints through a medial surgical approach: a series of 15 cases

INTRODUCTION

We report a series of 15 double-hindfoot (subtalar and talonavicular joint) arthrodeses through a single medial approach on 14 patients. Mean age at surgery was 59.3 years. The chosen surgical technique was always identical using a medial approach and performed by a single surgeon. The average follow-up was 20.6 months.

METHOD

The mean Kitaoka score increased from 44 to 75, axis of the hindfoot decreased from 21 degrees to 11 degrees in valgus, arch foot angle decreased from 142 degrees to 134.4 degrees . Two failures have led to a secondary complementary arthrodesis of the talocrural joint.

RESULTS

Throughout our study, subtalar and talonavicular arthrodesis in the treatment of painful valgus deformities of the hindfoot reveals to be a valuable and safe alternative. The chosen fixation method combined with a good articular surface avivement through medial approach guarantee a long-term fusion. Moreover, resort to a medial approach significantly reduces wound complications.

CONCLUSION

This medial approach procedure permits the fusion without developing non-union and provides a significant correction of the fixed deformities.