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February 17, 2021
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68-year-old man with severe ankle deformity, 3 weeks of medial-sided pain

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A 68-year-old man presented to our outpatient orthopedic department with a complicated history of chronic ankle pain and deformity, as well as a right ankle injury sustained 3 weeks earlier.

He noted ankle pain with walking for many years, use of ambulatory aids including a cane and decreased activity secondary to pain. He also reported trauma to the right ankle 3 weeks ago from a ground-level fall. He had been placed in a splint and referred to our clinic for specialty care. His medical history includes psoriatic arthritis and a myocardial infarction with previous stent placement. He is a non-diabetic patient. His medications are notable for methotrexate and ticagrelor.

Doctor Name, MD
Travis Frantz
Doctor Name, MD
Ian Savage-Elliott

On clinical examination, he had an obvious varus deformity and his right ankle was severely tender to palpation over the medial malleolus (Figure 1.) The patient’s deformity was fixed on examination. There were no open wounds or skin lesions. His leg compartments were soft and compressible, his posterior tibial and dorsalis pedis pulses were strong and his neurologic exam was normal. He was unable to ambulate or weight-bear on the right lower extremity at the time of examination. Dynamic maneuvers and ligamentous examination were deferred secondary to his discomfort.

1. Right ankle deformity is shown on preoperative examination.

Source: Ian Savage-Elliott, MD

Radiographs of the right ankle were obtained and were significant for a severe tibiotalar varus deformity and a vertical shear fracture of the medial malleolus with incongruity of the talus within the ankle mortise. There was also significant osteoarthritis of the tibiotalar joint with osteophytosis of the medial and lateral gutter. Hindfoot varus and mild subtalar arthritis was also noted. (Figure 2).

2. AP, mortise and lateral X-rays of the right ankle are shown.

What are the treatment options?

See answer below.

TAA, possibly with closing wedge osteotomy, lateral ligament reconstruction, medial malleolus fracture treatment

A thorough discussion was held with the patient regarding operative and nonoperative management.

Given the medial malleolus fracture and obvious talar incongruity and displacement within the ankle mortise, operative fixation of the fracture in the form of open reduction and internal fixation (ORIF) was recommended. Given our patient’s severe post-traumatic arthritis, a discussion of concomitant ankle fusion, tibiotalocalcaneal fusion or total ankle arthroplasty (TAA) was discussed. The patient wanted to avoid any ankle arthrodesis (AA) procedure secondary to loss of ankle motion. Therefore, the decision was made for the patient to undergo a TAA with possible closing wedge osteotomy, possible lateral ligament reconstruction and concomitant ORIF of the medial malleolus fracture. Given its minimal arthritis, it was decided the subtalar joint was to be treated nonoperatively.

In determining simultaneous vs. staging of the operative procedures, multiple factors were considered. The patient stated his preference for concomitant procedures in one operation. Blood loss in an anticoagulated patient was a concern, however, this was believed to be manageable through meticulous dissection, a minimal number of incisions and use of a tourniquet. Furthermore, given the patient’s cardiological status and the risks of withholding anticoagulation, it was elected to undergo all procedures in a single surgical event.

Surgical technique

General anesthesia was used with a regional block. The patient was positioned in a supine position with his operative extremity on a ramp. A nonsterile tourniquet was used. A standard anterior approach to the ankle was completed between extensor hallucis longus and tibialis anterior. This was about 15 cm in length, which also allowed access to the medial malleolus fracture (Figure 3). This was cleared of debris and provisionally fixed using an antiglide plate with an axillary screw followed by multiple percutaneously placed screws that were proximal and distal to the fracture. Reduction of the vertical shear fracture was satisfactory on intraoperative fluoroscopic imaging.

3. An anterior approach to the ankle and visualization of the medial malleolus fracture are shown.

The varus deformity was then addressed. The ankle was pinned in neutral alignment at the tibiotalar joint and the calcaneus was found to remain in cavus. A lateral approach was made to the calcaneus and a closing wedge osteotomy was performed with compression screws to secure the osteotomy. After this, the intramedullary jig and cutting blocks were applied to the ankle and the pin across the tibiotalar joint was removed demonstrating residual varus ankle alignment. A Schanz pin was placed through the talus and tibia and used to bring the ankle to neutral alignment, after which resection of the distal tibial plafond and talar body was completed. We proceeded to ream and place the stem, as well as the talar component of the implant. The ankle was stressed and found to dorsiflex to neutral. A triple cut of the Achilles tendon was made to release the posterior aspect of the capsule and increase dorsiflexion, which was noted to improve to 20°. Two additional screws were placed into the medial malleolus antiglide plate around the stem of the implant for adequate fixation of the fracture (Figure 4).

Stability with varus stress

The ankle was noted to have chronic insufficiency of the lateral ligaments, which was confirmed with talar tilt testing intraoperatively. Therefore, a modified Brostrom-Gould procedure was performed using a small laterally based incision and advancing the anterior talofibular and calcaneofibular ligaments and securing these with anchor fixation to the extensor retinaculum. Following anchor fixation, there was excellent stability noted to varus stress.

4. Antiglide plate fixation of the medial malleolus fracture is shown (a). Placement of a Schanz pin to bring the ankle to neutral alignment and resection of the distal tibial plafond and talar dome are shown (b). Placement of the tibial stem and talar components of the arthroplasty implant is shown (c). Placement of two additional screws through the medial malleolus antiglide plate around the stem of the implant is shown (d).

Postoperatively, anteroposterior (AP), lateral and mortise views of the ankle were obtained, which demonstrated overall satisfactory reduction and fixation of the fracture, as well as placement of the total ankle prosthesis with significant deformity correction (Figure 5). After discharge, the patient was non-weight-bearing for 6 weeks. He was transitioned from a splint to a short leg cast. At 6 weeks, he began partial weight-bearing. By 3.5 months follow-up, his incisions had healed completely, and he was fully weight-bearing without pain or use of weight-bearing assistive devices (Figure 6). At most recent follow-up, he had resumed normal activity.

Discussion

End-stage tibiotalar joint arthritis is a disabling condition that can result in significant functional impairment and decreased quality of life. For patients who fail conservative treatment, the most commonly used surgical management techniques are AA or TAA. Despite being considered the gold standard for treatment of end-stage arthritis, high nonunion rates, loss of normal ankle motion and concern for acceleration of adjacent joint degeneration have contributed to criticism of AA. TAA was developed as an alternative to AA, although first-generation TAA implants demonstrated an unacceptably high complication rate.

Improvements in newer generations of AA and TAA have included attention to soft tissues, altered fixation constructs and refined surgical techniques. A 2017 meta-analysis by Cort D. Lawton, MD, and colleagues assessed outcomes in new-generation AA vs. TAA. This study revealed the overall complication rate (26.9% vs. 19.7%, respectfully) and non-revision reoperation rate (12.9% vs. 9.5%, respectfully) were higher in AA than TAA, although the revision rate was higher in TAA (5.4% vs. 7.9%, respectfully). Other studies have reported similar rates of degeneration of adjacent joints AA and TAA.

5. Postoperative AP and lateral X-rays of the patient’s right ankle are shown.6. Follow-up imaging at 3.5 months postoperatively is shown. The patient progressed to full weight-bearing without assistive devices.

In addition to making the decision of TAA over AA, we also had to consider the varus deformity in this patient’s ankle and the increased risk of displacement of the medial malleolus fracture. If neutral coronal plane alignment at the level of the tibiotalar joint is not restored, the unbalanced ankle joint prosthesis may cause edge-loading. This, in turn, increases the contact stresses on the polyethylene, which accelerates wear and can result in premature implant failure. Additionally, persistent varus can overload the medial ankle mortise causing chronic pain and, in our patient’s case, fracture displacement or nonunion. In the past, varus or valgus deformity greater than 15° was considered a relative contraindication and greater than 20° of deformity was considered an absolute contraindication for TAA. However, newer studies have demonstrated that corrections up to 20° yielded satisfactory clinical outcomes without an increase in complications. Improvements in surgical technique that allow for these better outcomes have been attributed to thorough preoperative surgical assessment, medial soft-tissue release, correction of varus talar deformity, tendon transfers and ligamentous reconstruction. As seen with our patient, ligamentous insufficiency can be a common, contributing factor to post-traumatic arthritis of the ankle and must be recognized and treated appropriately to obtain a balanced, aligned, ligamentously stable arthroplasty.

In a 2019 study, Gun-Woo Lee, MD, and colleagues found functional outcomes, pain, range of motion, complications and survivorship were similar between patients with severe (20° to 35°) and moderate (5° to 15°) coronal plane deformity after TAA.

Some studies have found that in patients with increasing preoperative deformity, full correction of the deformity is more difficult and residual deformity is more likely to remain. Long-term outcomes of minor residual ankle deformity have not been studied however, intermediate outcomes show comparable clinical outcome scores and complication rates.

Conclusion

This case report presents an uncommon and complex injury pattern that required both TAA and fracture fixation of the medial malleolus, as well as multiple other concomitant procedures. In cases of severe tibiotalar varus deformity as well as a medial malleolus fracture requiring fixation, physicians may consider management of the injury with TAA and concomitant procedures to achieve an improved alignment and stable, pain-free ankle.