Summary

Osteoarthritis of the Ankle (Tibiotalar Joint) is fundamentally different from hip or knee arthritis. While hip/knee OA is primarily "wear and tear" (primary), 80% of Ankle Arthritis is Post-Traumatic—occurring years or decades after a fracture (Pilon/Ankle) or chronic ligamentous instability. The cartilage of the ankle is thinner but stiffer than the knee, making it resilient to load but intolerant of incongruity. Treatment is a major debate: Arthrodesis (Fusion) remains the gold standard for young, active laborers, providing a painless, durable limb. Total Ankle Replacement (TAR) is gaining ground for older, lower-demand patients to preserve motion and protect adjacent joints. [1,2,3]

Key Facts

• The Etiology Split:
  • Post-Traumatic: 70-80%. (Rotational fractures, Pilon fractures).
  • Primary (Idiopathic): <10%. (Rare!).
  • Inflammatory: 10%. (RA, Hemophilia).
• "Footballer's Ankle": A precursor condition involving anterior osteophytes (spurs) that pinch during dorsiflexion (Anterior Impingement), often seen in athletes long before joint space narrowing occurs.
• The Consequence of Fusion: Fusing the ankle increases stress on the subtalar and agitation joints, causing them to degenerate 10-20 years later.

Clinical Pearls

"Check the Alignment": Ankle arthritis is rarely neutral. It usually tilts into Varus (Lateral ligament failure) or Valgus (Deltoid failure/Fracture malunion). Correcting the deformity is as important as treating the cartilage.

"The Rocker Bottom Shoe": The simplest and most effective conservative measure. A curved sole ("MBT" style) replicates the rocking motion of the ankle, allowing the patient to "roll over" the stiff joint without bening it.

"Supramalleolar Osteotomy": In young patients with asymmetric wear (e.g., medial wear with varus tilt), re-aligning the tibia can offload the bad side and buy 10 years before fusion is needed.

                 ANKLE ARTHRITIS
                        ↓
                  CONSERVATIVE
             (NSAID, Injection, Brace)
                        ↓
                     FAILED?
                        ↓
            AGE / DEMAND / ALIGNMENT?
      ┌─────────────────┼─────────────────┐
    YOUNG            MIDDLE             ELDERLY
   ACTIVE           ALIGNMENT          LOW DEMAND
  DEFORMED            ISSUE             ALIGNABLE
     ↓                  ↓                   ↓
  FUSION           OSTEOTOMY           REPLACEMENT
(Arthrodesis)    (Supramalleolar)        (TAR)

Indications

• Mild to Moderate disease.
• Poor surgical candidates.

Protocol

• Footwear: Rocker bottom soles. High-top boots (lace-up) for stability.
• Bracing: AFO (Ankle Foot Orthosis) or SMO (Supramalleolar Orthosis) to offload the joint. The "Arizona Brace" (leather gauntlet) is the gold standard.
• Injections:
  • Corticosteroid: Relief for 3 months.
  • Hyaluronic Acid: Variable evidence.
  • PRP: Investigational.

1. Arthroscopic Debridement

• Indication: Anterior Impingement (Footballer's ankle) with preserved joint space. Removal of bone spurs can restore dorsiflexion.
• Contraindication: Diffuse arthritis (makes it worse).

2. Supramalleolar Osteotomy

• Indication: Asymmetric arthritis (Varus/Valgus) in young patients with preserved cartilage on the other side.
• Action: Re-align the tibia to shift weight to the healthy side.
• Result: "Buys time" (5-10 years).

3. Arthrodesis (Fusion)

• Indication: Young laborers, heavy deformity, failed TAR, infection history, neuropathic joint.
• Technique: Open or Arthroscopic. Screws/Plates compress the Tibia to the Talus.
• Position: Neutral flexion, 5° Valgus, 5-10° External Rotation.
• Outcome:
  • Pain relief: Excellence.
  • Function: Can walk/run (awkwardly). Heavy labor possible.
  • Downside: Adjacent joint arthritis (Subtalar/Talonavicular) in 10-20 years.

4. Total Ankle Replacement (TAR)

• Indication: Older (>60), low demand, good bone stock, minimal deformity.
• Implants: 3rd Generation (Mobile Bearing vs Fixed Bearing). E.g., Wright Infinity, STAR, Cadence.
• Outcome:
  • Pain relief: Good (slightly less reliable than fusion).
  • Motion: Preserves existing motion (doesn't add much).
  • Survivorship: 85-90% at 10 years (improving, but worse than Hip/Knee).
  • Risks: Aseptic loosening, subsidence, wound healing.

Fusion vs TAR

• COFAS Study: Compared outcomes. Both offer significant improvement. TAR provides better gait symmetry and protects adjacent joints but has a higher re-operation rate. Fusion is more "fire and forget".

Arthroscopic Fusion

• Townshend et al: Arthroscopic fusion has higher union rates (95% vs 85%) and shorter hospital stays than open fusion, provided deformity is minimal.

The Condition

Your ankle joint is worn out. Unlike your knee, which wore out because of age, your ankle wore out because of that break/sprain you had 20 years ago. The cartilage cushion is gone, and bone is rubbing on bone.

The Options

1. The Boot: A brace and steroid injection to soothe it.
2. The Fusion: We glue the bones together. You will never move your ankle again (up and down), but the pain will be gone instantly. You can still walk, hike, and work, but running will be hard.
3. The Replacement: We put in a metal and plastic joint. It keeps your movement, but it is not as tough as a fusion. You can't run on it or jump off trucks. It might loosen up in 15 years.

Q1: What is the most common cause of Ankle Arthritis? A: Post-Traumatic (70-80%). Primary OA is rare (<10%).

Q2: Describe the position of function for Ankle Arthrodesis. A:

• Flexion: Neutral (0°, Plantigrade).
• Valgus: 5° (Prevents locking of subtalar joint).
• Rotation: 5-10° External Rotation (Matches contralateral limb).
• Posterior Translation: Slight posterior shift of talus.

Q3: What are the contraindications for Total Ankle Replacement? A:

• Absolute: Active infection, Charcot neuroarthropathy (instability), severe muscle dysfunction, poor skin envelope.
• Relative: Young age (<50), heavy labor, severe deformity (>15°), AVN of talus.

Q4: What is Anterior Impingement Syndrome? A: The formation of osteophytes on the anterior tibia and dorsal talus groove, caused by repetitive microtrauma (dorsiflexion). Common in footballers. Causes pain on dorsiflexion before widespread arthritis sets in.

(End of Topic)