Subtalar Dislocation: Understanding, Treatment, and Rehabilitation

How Do You Treat a Subtalar Dislocation?

Treating a subtalar dislocation is a medical emergency requiring immediate professional intervention, typically involving prompt closed reduction to realign the bones, followed by a period of immobilization and a comprehensive, progressive rehabilitation program to restore full ankle and foot function.

Understanding Subtalar Dislocation

A subtalar dislocation, also known as a peritalar dislocation, is a rare but severe injury involving the simultaneous dislocation of the talonavicular and talocalcaneal joints. This means the talus bone, which sits atop the calcaneus (heel bone) and articulates with the navicular bone, becomes completely separated from both. The ankle mortise (tibiotalar joint) itself usually remains intact.

Key Anatomical Structures Involved:

• Talus: The central bone, linking the leg to the foot.
• Calcaneus: The heel bone, forming the lower part of the subtalar joint.
• Navicular: A tarsal bone that articulates with the talus anteriorly.
• Ligaments: Numerous strong ligaments, including the talocalcaneal, talonavicular, and calcaneonavicular ligaments, are often torn or severely stretched during this injury.

Common Mechanisms of Injury: Subtalar dislocations typically result from high-energy trauma, often involving a combination of significant axial load, inversion, or eversion forces applied to a plantarflexed foot. Examples include:

• Falls from a height.
• Motor vehicle accidents.
• Sports injuries (e.g., awkward landings in basketball, gymnastics, or football).

Types of Dislocation: Dislocations are classified based on the direction of the foot relative to the talus:

• Medial Dislocation (most common): The foot is dislocated medially and plantarflexed.
• Lateral Dislocation: The foot is dislocated laterally and dorsiflexed.
• Anterior/Posterior Dislocation: Less common, but can occur.

Immediate Management: First Aid and Emergency Care

Given the severity and potential for neurovascular compromise, a subtalar dislocation demands immediate medical attention. Self-treatment is not possible or advisable.

First Aid Principles (Pre-Hospital):

• Do not attempt to reduce the dislocation: Any manipulation by untrained individuals can cause further damage to nerves, blood vessels, or surrounding tissues.
• Immobilize the foot and ankle: If possible, keep the foot and ankle in the position of injury to prevent further movement. A splint or firm padding can help.
• Elevate the limb: If comfortable, elevate the injured foot to help reduce swelling.
• Apply ice (indirectly): Apply ice packs wrapped in cloth to the injured area to help manage pain and swelling.
• Seek emergency medical care immediately: Call emergency services (e.g., 911 or local equivalent) or transport the individual to the nearest emergency department.

Medical Diagnosis

Upon arrival at a medical facility, the diagnosis of a subtalar dislocation is typically confirmed through a combination of physical examination and imaging studies.

Diagnostic Steps:

• Clinical Presentation: The foot will appear grossly deformed, often shortened, and there will be severe pain, swelling, and inability to bear weight. Skin tenting or compromise may be present.
• Neurovascular Assessment: Critical assessment of pulses, capillary refill, sensation, and motor function is performed to rule out nerve or blood vessel damage.
• Radiography (X-rays): Standard anteroposterior, lateral, and oblique views of the ankle and foot are essential to confirm the dislocation, determine its direction, and rule out associated fractures (e.g., talar neck fractures, malleolar fractures).
• Computed Tomography (CT) Scan: Often performed after initial reduction, a CT scan provides detailed 3D images, which are invaluable for identifying subtle fractures, incarcerated soft tissues, and assessing articular congruity. This helps guide rehabilitation and predict prognosis.

Acute Treatment: Reduction

The primary goal of acute treatment is the prompt reduction of the dislocation, meaning realigning the talus with the calcaneus and navicular. Early reduction is crucial to minimize complications such as skin necrosis, neurovascular compromise, and articular cartilage damage.

Reduction Techniques:

• Closed Reduction: This is the preferred method and is typically performed under procedural sedation or general anesthesia due to the significant pain and muscle spasms involved.
  • Procedure: Specific maneuvers are employed, often involving strong traction on the foot, counter-traction on the leg, and direct manipulation to guide the talus back into its anatomical position. The exact maneuver depends on the direction of the dislocation (e.g., for medial dislocations, the foot is typically everted, dorsiflexed, and abducted).
  • Confirmation: Successful reduction is confirmed by a palpable "clunk," restoration of normal foot alignment, and post-reduction X-rays.
• Open Reduction: If closed reduction is unsuccessful, or if there are associated fractures, significant soft tissue interposition (e.g., tendons, ligaments), or neurovascular compromise that does not resolve with closed reduction, surgical open reduction is necessary.
  • Procedure: An incision is made to directly visualize the joint, clear any obstructions, and manually reduce the dislocation. Any associated fractures are then fixed.

Post-Reduction Immobilization

Following successful reduction, the foot and ankle must be immobilized to allow the damaged ligaments and soft tissues to heal and prevent re-dislocation.

Immobilization Protocol:

• Type of Immobilization: Typically, a non-weight-bearing cast (e.g., a short leg cast) is applied immediately after reduction.
• Duration: The duration of immobilization varies but commonly ranges from 4 to 6 weeks. The specific timeline depends on the stability of the reduction, the extent of soft tissue injury, and any associated fractures.
• Purpose: Immobilization promotes initial healing, reduces pain, and protects the vulnerable joint from stress.

Rehabilitation: Restoring Function

Rehabilitation is a critical phase following immobilization, aiming to restore full range of motion, strength, proprioception, and functional mobility. This process is progressive and guided by a physical therapist or exercise physiologist.

Phases of Rehabilitation:

1. Phase 1: Initial (Non-Weight-Bearing to Partial Weight-Bearing, Weeks 0-6/8)

   • Goal: Protect healing tissues, reduce swelling, maintain joint mobility (if allowed), and prevent muscle atrophy.
   • Interventions:
     • Gentle Range of Motion (ROM): Once the cast is removed or replaced with a removable boot, begin gentle, pain-free ankle and subtalar ROM exercises (e.g., ankle pumps, alphabet tracing, inversion/eversion).
     • Non-Weight-Bearing Exercises: Isometric exercises for ankle musculature, hip and knee strengthening exercises, core stability.
     • Swelling Management: Elevation, compression, ice.
     • Gait Training: Learning to walk with crutches safely.

2. Phase 2: Intermediate (Partial Weight-Bearing to Full Weight-Bearing, Weeks 6/8-12)

   • Goal: Gradually increase weight-bearing, improve ROM, restore muscle strength, and begin proprioceptive training.
   • Interventions:
     • Progressive Weight-Bearing: Transition from crutches to partial weight-bearing with the aid of a walking boot or brace, then gradually to full weight-bearing as tolerated.
     • Active ROM: Progress to active and active-assisted ROM exercises for all ankle and foot movements.
     • Strengthening: Introduce progressive resistance exercises for dorsiflexors, plantarflexors, invertors, and evertors (e.g., resistance bands, calf raises, seated heel raises).
     • Proprioception/Balance: Begin with bilateral balance exercises (e.g., standing on stable surface), progressing to single-leg balance and unstable surfaces (e.g., wobble board, foam pad).

3. Phase 3: Advanced (Return to Activity, Weeks 12+ and Beyond)

   • Goal: Restore high-level strength, power, agility, and sport-specific function; prevent re-injury.
   • Interventions:
     • Advanced Strengthening: Plyometric exercises (e.g., hopping, jumping), sport-specific drills, agility ladders, cone drills.
     • Advanced Proprioception: Dynamic balance exercises, reactive drills, sport-specific movements on unstable surfaces.
     • Cardiovascular Fitness: Maintain overall fitness through activities like swimming, cycling, or elliptical training.
     • Gradual Return to Activity: A carefully supervised and progressive return to running, cutting, jumping, and sport-specific activities, ensuring the joint is stable and pain-free. This phase can take several months.

Potential Complications

Despite appropriate treatment, subtalar dislocations can be associated with several potential complications:

• Recurrent Dislocation: Though rare, especially after primary closed reduction.
• Post-Traumatic Arthritis: Damage to the articular cartilage can lead to degenerative changes and chronic pain.
• Chronic Pain and Stiffness: Due to ligamentous laxity, scar tissue formation, or subtle joint incongruity.
• Neurovascular Injury: Damage to nerves (e.g., sural nerve) or blood vessels during the initial injury or reduction.
• Avascular Necrosis of the Talus: Though less common than with talar fractures, compromised blood supply to the talus can lead to bone death.
• Tendon Injuries: Associated tears of surrounding tendons.
• Complex Regional Pain Syndrome (CRPS): A chronic pain condition that can develop after trauma.

Prognosis and Long-Term Outlook

The prognosis for subtalar dislocations is generally good, especially with prompt and effective reduction. However, a full return to pre-injury activity levels can take 6 months to over a year. Persistent pain, stiffness, and some degree of functional limitation are possible, particularly in cases with associated fractures, significant cartilage damage, or delayed reduction. Regular follow-up with the treating physician and continued adherence to the rehabilitation program are crucial for optimal long-term outcomes.

Important Considerations

• Prevention: While high-energy trauma is difficult to prevent, proper footwear, ankle strengthening, and proprioceptive training can contribute to overall ankle stability and potentially reduce the risk of such severe injuries during athletic activities.
• Listen to Your Body: During rehabilitation, it is crucial to respect pain and swelling. Pushing too hard too soon can lead to setbacks or re-injury.
• Multidisciplinary Approach: Successful recovery often involves a team approach, including orthopedic surgeons, physical therapists, and potentially pain management specialists.