What is the recommended postoperative care for subtalar arthrodesis?

Postoperative Care for Subtalar Arthrodesis

The recommended postoperative care for subtalar arthrodesis includes immobilization in a non-weight bearing cast for 6-8 weeks, followed by progressive weight bearing in a protective boot, with radiographic assessment at regular intervals until fusion is confirmed, typically at 12 weeks post-surgery. Based on the available evidence, this approach provides optimal outcomes for patients undergoing subtalar fusion.

Initial Postoperative Phase (0-6 weeks)

• Non-weight bearing immobilization in a cast or removable boot is essential during the initial healing phase to protect the fusion site and promote bone healing 1
• When possible, use removable casts and splints to facilitate wound inspection and care, especially during the COVID-19 pandemic period 2
• Avoid pulse lavage during the procedure to minimize complications 2
• Use clear dressings for easier wound monitoring without frequent dressing changes 2
• Regular wound inspection is recommended to monitor for early complications such as infection or nerve injuries, which occur in approximately 12% of cases 3

Intermediate Phase (6-12 weeks)

• Radiographic assessment should be performed at 6-8 weeks to evaluate fusion progress before advancing weight bearing 2
• Progressive weight bearing in a protective boot can begin once early signs of fusion are evident, typically around 6-8 weeks postoperatively 1
• CT scanning is superior to plain radiographs for assessing fusion status and should be considered when there is uncertainty about fusion progress 2, 4
• Lateral flexion and extension radiography is recommended as an adjunct to determine the presence of fusion, with lack of motion between vertebrae being highly suggestive of successful fusion 2

Late Phase (12+ weeks)

• Full weight bearing can typically begin after radiographic confirmation of fusion, which occurs at an average of 12.1 weeks (range 9-16 weeks) 5
• Hardware removal may be necessary in approximately 9-17% of patients due to symptomatic implants 6, 1
• Physical therapy focusing on gait training, proprioception, and strengthening should begin once fusion is confirmed 6
• Long-term follow-up is recommended as complications can occur even after successful fusion 6

Monitoring for Complications

• Common complications include superficial infection (0.8%), nonunion (4.3%), and need for hardware removal (9.4%) 1
• Delayed union occurs in approximately 1% of cases and requires continued protected weight bearing 1
• Nerve injuries, particularly to the sural nerve, can occur in both open and arthroscopic approaches (approximately 2.8% of cases) 1, 3
• Regular assessment of pain, function, and patient satisfaction should be performed at 3,6, and 12 months postoperatively 3

Special Considerations

• Vitamin D and calcium supplementation should be considered in patients with diabetes mellitus and active Charcot neuro-osteoarthropathy to promote bone healing 2
• For patients with hindfoot instability or deformity with high risk of developing ulcers, additional stabilization measures may be necessary during the postoperative period 2
• Patients who undergo subtalar arthrodesis after initial operative treatment of calcaneal fractures tend to have better functional outcomes than those who had initial nonoperative treatment 7

Expected Outcomes

• Successful union rates range from 95.4-95.8% with proper postoperative care 5, 1
• The American Orthopaedic Foot and Ankle Society (AOFAS) score typically improves from approximately 51.5 points preoperatively to 81.9 points postoperatively 5
• Patient satisfaction rates, including pain relief, are reported at 95.4% with appropriate postoperative management 1