A Closer Look At The Medial Double Fusion And Extending The Medial Column

Noting the medial double fusion can be a viable treatment for patients with severe valgus, this author explores using the procedure in a 62-year-old patient with bilateral flexible flatfoot.

Arthrodesis of the subtalar joint and talonavicular joint has gained recent popularity as an alternative to the triple arthrodesis.^1,2

There appear to be many advantages for the medial double fusion. The medial incision typically has redundant and ample soft tissue to facilitate an incision closure without tension. Classically, when it comes to the laterally approach to the subtalar joint, there have been reported difficulties with soft tissue breakdown due to the tension created during hindfoot realignment.³ Furthermore, during the medial double approach realignment, surgeons often distract the calcaneocuboid joint, which decompresses the joint, potentially providing lateral column pain relief and sparing motion.³ Finally, choosing to fuse just two joints saves operating time and cost, and offers one less joint to fuse, decreasing the chance of nonunion of the calcaneocuboid joint.⁴

The double fusion appears to be as powerful as the triple arthrodesis. However, as with the triple arthrodesis, one may need to correct the extended medial column at the same time as the subtalar joint and talonavicular joint. The surgeon should be prepared to extend correction down the medial column after correcting the hindfoot. Uncovering forefoot varus is common during flatfoot correction. Additionally, one may need to address a concomitant angular first ray deformity.

What You Should Know About The Patient Presentation

I present a case study as an example of the choice to add a first tarsometatarsal fusion as this can help correct any remaining varus, helps support the forefoot by extending the stability down the medial column and corrects the medial eminence deformity. Plantar first tarsometatarsal ligament laxity may be present from longstanding valgus stress and one can also address this with this extended medial column first tarsometatarsal fusion.

A 62-year-old healthy male presented with painful bilateral flexible flatfoot. The patient had failed attempts at orthotics and physical therapy. His pain was focused at the posterior tibial tendon, subfibular area and medial eminence of the first ray. Preoperative radiographs correlated with clinical complaints. I chose a medial double fusion with extended medial column fusion and tendo-Achilles lengthening. I performed surgery on the right foot first and addressed the left foot six months later.

The bilateral operative procedures were the same. The patient had a preoperative popliteal block and was in supine position. After the administration of general anesthesia and application of a thigh tourniquet, I performed a triple hemisection Achilles lengthening to alleviate the contracted lateralizing pull of the Achilles. The medial approach involves an incision from the tip of the medial malleolus to the distal navicular in line with the posterior tibial tendon. Access the talonavicular joint and perform standard joint fusion preparation. Then utilize a Cobb elevator or osteotome to access the subtalar joint from the anterior medial aspect of the joint, following the medial subtalar joint line as a guide. Place a lamina spreader deep in the joint and transect the interosseous ligament to allow better access. Then prep the joint in standard fashion.

Fixation includes a single or double screw approach to the subtalar joint followed by a single compression screw and medial locking plate at the talonavicular joint. Achieving the ideal hindfoot position is required prior to fixation.

Verify forefoot alignment at this time. If a medial column fault is present, continue correction to the affected joint. In this case, identify the first tarsometatarsal and extend the incision, or create a second, more distal incision. Prep the first tarsometatarsal in standard fashion. What was unique to this case was the medial cuneiform being a bilateral bipartite bone, which required fixation of both the superior and inferior aspect to the first metatarsal.

The patient followed a standard postoperative course. He demonstrates maintenance of clinical correction and radiographic fusion. He is pain-free and performs farm labor without complaint.

In Conclusion

The medial double fusion with an extended medial column fusion is a useful option for severe valgus. Surgeons can combine this procedure with other procedures for extended medial column needs.

Dr. Bussewitz is a fellowship-trained foot and ankle surgeon, who is in private practice at Steindler Orthopedic Clinic in Iowa City, Iowa.

References

1. Lee MS. Medial approach to the severe valgus foot. Clin Pod Med Surg. 2007; 24(4):735-44.

2. Weinraub GM, Schuberth JM, Lee MS, Rush S, Ford L, Neufeld, Yu J. Isolated medial incisional approach to subtalar and talonavicular arthrodesis. J Foot Ankle Surg. 2010; 49(4):326-30.

3. Berlet GC, Hyer CF, Scott RT, Galli MM. Medial double arthrodesis with lateral column sparing and arthrodiastasis: a radiographic and medical record review. J Foot Ankle Surg. 2015; 54(3):441-4.

4. Galli MM, Scott RT, Bussewitz BW, Hyer CF. A retrospective comparison of cost and efficiency of the medial double and dual incision triple arthrodesis. Foot Ankle Spec. 2014; 7(1):32–6.