Evaluating Prospective Patient-Reported Pain and Function Outcomes After Ankle and Hindfoot Arthrodesis

The Fate of Delayed Unions After Isolated Ankle Fusion

BACKGROUND

Nonunion remains the most common major complication of ankle arthrodesis. Although previous studies have reported delayed union or nonunion rates, few have elaborated on the clinical course of patients experiencing delayed union. In this retrospective cohort study, we sought to understand the trajectory of patients with delayed union by determining the rate of clinical success and failure and whether the extent of fusion on computed tomography scan (CT) was associated with outcomes.

METHODS

Delayed union was defined as incomplete (<75%) fusion on CT between 2 and 6 months postoperatively. Thirty-six patients met the inclusion criterion: isolated tibiotalar arthrodesis with delayed union. Patient-reported outcomes were obtained including patient satisfaction with their fusion. Success was defined as patients who were not revised and reported satisfaction. Failure was defined as patients who required revision or reported being not satisfied. Fusion was assessed by measuring the percentage of osseous bridging across the joint on CT. The extent of fusion was categorized as absent (0%-24%), minimal (25%-49%), or moderate (50%-74%).

RESULTS

We determined the clinical outcome of 28 (78%) patients with mean follow-up of 5.6 years (range, 1.3-10.2). The majority (71%) of patients failed. On average, CT scans were obtained 4 months after attempted ankle fusion. Patients with minimal or moderate fusion were more likely to succeed clinically than those with "absent" fusion (P = .040). Of those with absent fusion, 11 of 12 (92%) failed. In patients with minimal or moderate fusion, 9 of 16 (56%) failed.

CONCLUSION

We found that 71% of patients with a delayed union at roughly 4 months after ankle fusion required revision or were not satisfied. Patients with less than 25% fusion on CT had an even lower rate of clinical success. These findings may help surgeons in counseling and managing patients experiencing a delayed union after ankle fusion.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

Clinical and Radiological Mid- to Long-term Results Following Triple Arthrodesis

BACKGROUND/AIM

Triple arthrodesis (TA) is a common procedure for stabilization of painful and unstable hind foot deformities. The aim of the study was to analyze postoperative changes in function and pain following isolated TA based on clinical outcomes, radiological findings, and pain scores. The study also considered economic aspects, such as the inability to work, before and after surgery.

PATIENTS AND METHODS

This was a single-center retrospective study, with a mean follow-up of 7.8 (range=2.9-12.6) years, of isolated triple fusions was performed. Short-Form 36 (SF-36), Foot Function Index (FFI), American Orthopedic Foot and Ankle Society Score (AOFAS) were analyzed. Clinical examination and standardized radiographs pre- and post-surgery were evaluated.

RESULTS

All 16 patients were very satisfied with the outcome after TA. In patients with secondary arthrosis of the ankle joint, AOFAS scores were significantly lower (p=0.012), whereas arthrosis in tarsal and tarsometatarsal joints did not affect the score. Body mass index (BMI) was associated with lower AOFAS, FFI-pain, FFI-function and increased hindfoot valgus. The non-union rate was approximately 11%.

CONCLUSION

TA leads to good clinical and radiological outcomes. None of the study participants reported a deterioration in their quality of life after TA. Two thirds of the patients reported significant limitations when walking on uneven ground. More than half of the feet developed secondary arthrosis of the tarsal joints and 44% of the ankle joint.

Tibiotalocalcaneal Arthrodesis in Severe Hindfoot Deformities

Tibiotalocalcaneal arthrodesis (TTCA) is the most common and reliable procedure in the treatment of patients with end-stage ankle arthritis combined with severe deformity. Many of these patients present with difficult previous sequelae that include nonunion, malunion, broken implants, vascular deficiencies, skin problems, or a combination of the previous. In that complex scenario, sometimes the only alternative treatment is a below-the-knee amputation. Image studies--weightbearing X-rays, tomography, and magnetic resonance - are fundamental to evaluate alignment and bone stock. When all conservative treatments fail to alleviate pain and dysfunction, the combination of osteotomies and arthrodesis is the procedure of choice. Surgical planning needs to be very detailed and thorough with a special focus on bone loss after debridement of non-healthy tissue and removal of metalwork. TTCA with grafting allows for the preservation of the limb in more than 80% of cases but at the expense of many complications with nonunion rates of approximately 20% of cases. There is controversy about the use of a retrograde nail versus specific TTCA plate and screws but results from biomechanical studies do not show a clear superiority of one specific construct. Amputation rates are close to 5% of cases after repeated failed surgeries. Bulk allografts increase the rate of nonunions but apparently do not have an influence on postoperative infections. Valgus positioning of the ankle/hindfoot is paramount to allow for maximal sagittal plane compensation from the midtarsal joints. Most patients are satisfied with the results of these salvage operations. The studies presented in this article have a considerable wide array of different scenarios that obviously bias some of the results, complications, and outcomes but together they present a persuasive pattern toward considering TTC with grafting and nail or plate fixation as a good salvage procedure that may help the patients to maintain their foot and ankle with a better alignment, function, and pain relief.