Staged Revision Surgery for Failed Cavovarus Hindfoot Reconstruction

Mark C. Drakos, MD; Austin T. Fragomen, MD

Disclosures

March 15, 2017

Case Report

A 27-year-old female presented to the Hospital for Special Surgery for evaluation of her left ankle in 2013, reporting a long-standing history of left ankle problems. She initially sprained her ankle in 2009 and went on to experience recurrent ankle sprains and chronic ankle instability. The patient was initially diagnosed with a cavovarus foot deformity, which likely predisposed her to this condition. She eventually had a foot and ankle reconstruction in May 2011, performed by an outside physician. This procedure consisted of cavovarus foot reconstruction with a lateralizing calcaneal osteotomy, first ray dorsiflexion osteotomy, Brostrom Gould type ankle stabilization with suture anchors,[1] peroneus longus to brevis transfer and exostectomy. The patient denied any postoperative complications, but experienced persistent pain in the ankle after surgery. In spite of treatment with various braces and orthotics, the patient reported that the condition was getting progressively worse. In addition to persistent discomfort, the patient experienced frequent episodes of instability as well as clicking, catching and locking.

On physical examination, the patient's gait was heel to toe, but severely antalgic and she walked on the lateral border of her foot. She had a significant callous pattern along the lateral border of her foot. The patient was unable to toe walk and heel walk without difficulty.

The patient had functional range of motion of the hips, knees and ankles. The hindfoot alignment was significant cavovarus. Ankle strength testing revealed 3/5 strength in dorsiflexion, 5/5 plantar flexion, 5/5 inversion and 4/5 eversion. The patient pointed to the anterior ankle joint line as the predominant site of pain and had positive signs of anterior impingement. Peroneal tendons were located. She had a 2+ anterior drawer.

X-rays of the lower extremity (Figure 1) and MRI (Figure 2) revealed cavovarus alignment. The patient had a 20° varus deformity at the ankle. She has significant ankle instability with a positive stress testing. There were also full thickness osteochondral defects on the medial talar dome and medial tibial plafond, as well as marginal osteophytes and loose bodies. There was also an adduction deformity of the midfoot.

Figure 1

AP standing radiograph demonstrating a severe varus deformity of the ankle, narrowing of the joint space over the medial talar dome and hardware from the prior procedure.

Figure 2

Sagittal fat suppressed MRI demonstrating severe cartilage loss, subchondral edema and anterior ankle osteophytes. Arrow points to a large anterior osteophyte and corresponding ankle effusion.

We recommended surgical management beginning with ankle arthroscopy and cartilage repair using denovo allograft with bone marrow aspirate concentrate from the patient's iliac crest. In addition, a supramalleolar osteotomy with ankle distraction to be performed with a Taylor spatial frame.[2] We also recommended staging a lateral ligament reconstruction with hamstring autograft, revision calcaneal osteotomy and posterior tibial lengthening to address the adduction deformity.

The patient underwent arthroscopy with removal of loose body and articular cartilage repair with a denovo allograft, along with a distal tibial osteotomy and distraction as described (Figure 3). She was initially non-weight bearing; at 6 weeks, progressing weight bearing as tolerated. The valgus producing supramalleolar osteotomy healed and the frame was removed at 3 months.

Figure 3

Mortise standing radiograph demonstrating the ankle status post supramalleolar osteotomy and distraction with the Taylor spatial frame in place.

When the frame pin sites healed, the patient was reassessed. Although her overall alignment was improved, she still had some hindfoot varus and a 2+ anterior drawer (Figure 4). At approximately 6 months after the initial procedure, a second stage procedure was performed. This consisted of lateral ligament reconstruction with hamstring autograft and posterior tibial tendon lengthening. Revision lateralizing calcaneal osteotomy and peroneal tendon repair where performed as well.

Figure 4

AP standing radiograph demonstrating correction of the varus deformity of the ankle, improved medial joint space and a plantigrade foot.

The patient was initially treated in a cast, and then advanced to a CAM boot with partial weight bearing at 2 months, followed by a Ritchie Brace at 4 months. She was able to walk without any assistive devices by 6 months.

Her pain was minimal. Radiographs of the lower extremity revealed a slight valgus alignment at the ankle, as intended to overcorrect at this level. The patient's foot was plantigrade, with neutral heel alignment and good stability on stress testing (Figure 5).

Figure 5

Lateral standing radiograph demonstrating reduction of the calcaneal pitch, elimination of anterior osteophytes and plantigrade alignment.

Discussion

This case illustrates several key concepts when addressing chronic ankle instability in a mal-aligned foot. Although a neurologic cause has been evaluated and ultimately ruled out, this patient had significant muscle imbalance, which may have contributed to the malalignment. Sometimes in severe cases such as this one, the conventional cavovarus foot reconstructions are inadequate to address the deformity. Moreover, this was a young patient with early arthritis, in which reconstruction options such as fusion or ankle replacement are less than ideal with potential long-term ramifications.

This multifaceted, staged approach allowed for joint preservation and realignment with less morbidity than some of the other potential options. Given the patient's young age, she would have likely worn out an ankle replacement and require a revision in the future.[3] If we had chosen a fusion for this individual, she would have a 90% chance of adjacent joint arthritis (Talonavicular or subtalar joint) within 10 years.[4] The lack of other long-term viable options was the main reason we chose a joint preserving approach. Furthermore, it did not preclude other procedures in the future should the cartilage ultimately continue to degrade over time necessitating other procedures such as ankle replacement when the patient is older and potentially has less demand on the implant.

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