What are the advantages and disadvantages of a single medial incision versus a double incision approach for double hind foot arthrodesis?

Single Medial Incision vs Double Incision in Double Hindfoot Arthrodesis

For double hindfoot arthrodesis, the double incision approach should be preferred over the single medial incision technique due to superior cartilage debridement and lower risk of compromising medial ankle stability, despite the single medial approach offering faster operative times and potentially fewer wound complications.

Key Surgical Considerations

Cartilage Debridement Adequacy

The single medial incision demonstrates significantly inferior cartilage removal compared to the double incision technique 1:

• Talar head: 61.1% vs 88.1% cartilage debrided (p < .001) 1
• Posterior facet of talus: 53.5% vs 73.6% cartilage debrided (p < .001) 1
• Posterior facet of calcaneus: 55.3% vs 81.0% cartilage debrided (p = .001) 1

This incomplete debridement with the single medial approach creates substantial risk for nonunion, as adequate cartilage removal is fundamental to achieving successful arthrodesis 1.

Medial Ankle Stability Risk

Critical concern: 75% of specimens undergoing single medial incision developed increased valgus tibiotalar tilt (average 4.6 degrees), suggesting deltoid ligament compromise, whereas zero specimens with double incision showed this complication (p < .01) 1. This indicates the single medial approach may inadvertently destabilize the ankle joint while attempting to access the subtalar posterior facet 1.

Clinical Outcomes Comparison

Single Medial Incision Approach

Advantages:

• Shorter operative time: 86-110 minutes 2, 3
• No lateral wound complications 4, 5
• Low rate of superficial wound infections (11% resolved with oral antibiotics) 4
• Zero cases of surgical wound dehiscence 4

Disadvantages:

• Union rate only 89% 5
• Patient satisfaction rate only 78% 5
• Risk of talar avascular necrosis (11% in one series) 4
• Development of valgus ankle deformity in some cases 5
• Malunion occurred in 11% of cases 5

Double Incision Approach

Advantages:

• Superior cartilage debridement at all joint surfaces 1
• Preserves medial ankle stability 1
• Better access to posterior facet of subtalar joint 1
• More complete joint preparation 1

Disadvantages:

• Longer operative time: 95-121 minutes 2, 3
• Risk of lateral wound complications 5
• Potential for calcaneocuboid joint issues if triple arthrodesis performed 5

Surgical Decision Algorithm

Choose double incision approach when:

• Rigid deformity requiring maximal correction 2
• Significant posterior facet involvement 1
• Patient has adequate soft tissue envelope laterally 2
• Primary goal is achieving solid fusion 1

Consider single medial incision only when:

• Patient has compromised lateral soft tissue (previous surgery, trauma, vascular insufficiency) 4
• Minimal posterior facet involvement 4
• Surgeon willing to accept potentially incomplete debridement 1
• Patient counseled about higher risk of nonunion and need for revision 5

Technical Modifications to Improve Single Medial Approach

If single medial incision is chosen despite limitations, consider:

• Arthroscopic joint preparation to improve debridement efficiency (110 minutes tourniquet time vs 121 minutes traditional, with union at 6 weeks vs 10 weeks) 3
• Use of osteobiologic agents in all cases 3
• More aggressive soft tissue dissection to access posterior facet, though this increases deltoid ligament injury risk 1

Critical Pitfalls to Avoid

With single medial incision:

• Inadequate visualization of posterior facet leading to incomplete debridement 1
• Excessive medial dissection compromising deltoid ligament 1
• Underestimating difficulty of accessing lateral subtalar joint 1

With double incision:

• Lateral wound complications in patients with peripheral vascular disease 2
• Unnecessary fusion of calcaneocuboid joint (may not be required for symptom relief) 2

Special Population Considerations

Patients with diabetes: Given the 11% rate of talar necrosis with single medial approach 4 and diabetes being a risk factor for complications in ankle fusion 6, the double incision approach with superior debridement may be preferable to minimize nonunion risk, despite wound healing concerns.

Charcot neuroarthropathy: Surgical intervention for hindfoot instability should be considered when conservative management fails 6, and given the already elevated complication rates in this population 6, maximizing fusion success through complete debridement (double incision) outweighs wound complication concerns.