Diastasis Ankle (High Ankle Sprain): Symptoms, Diagnosis, and Treatment

What is a Diastasis ankle?

While "diastasis ankle" is not a standard medical or anatomical term, it most likely refers to a high ankle sprain, also known as a syndesmotic ankle injury. This condition involves the disruption or separation of the strong ligaments connecting the two lower leg bones (tibia and fibula) just above the ankle joint.

Understanding the Term "Diastasis" in Context

The term "diastasis" fundamentally means a separation of normally joined parts. A common example is diastasis recti, where the abdominal muscles (rectus abdominis) separate along the midline. When applied to the ankle, the concept of "separation" is relevant to certain types of injuries, particularly those affecting the syndesmosis. While not formally called a "diastasis ankle," the injury it describes involves a widening or separation of the tibiofibular joint, which aligns with the general meaning of diastasis.

What a "Diastasis Ankle" Most Likely Refers To: The High Ankle Sprain (Syndesmotic Injury)

A high ankle sprain is an injury to the syndesmosis, a complex of fibrous ligaments that bind the distal (lower) ends of the tibia (shin bone) and fibula (calf bone) together. This joint is crucial for maintaining the stability of the ankle mortise – the socket that the talus (ankle bone) fits into.

• Anatomy of the Syndesmosis: The primary ligaments comprising the syndesmosis include:

  • Anterior Inferior Tibiofibular Ligament (AITFL): Located at the front of the joint.
  • Posterior Inferior Tibiofibular Ligament (PITFL): Located at the back of the joint.
  • Interosseous Membrane (IOM): A strong sheet of connective tissue running between the tibia and fibula along their length, contributing to syndesmotic stability distally.
  • Transverse Tibiofibular Ligament: A deeper, smaller ligament often considered part of the PITFL complex. These ligaments work in concert to prevent excessive separation or rotation of the tibia and fibula, ensuring the ankle joint remains stable during movement.

• Mechanism of Injury: High ankle sprains typically occur due to forceful external rotation and/or dorsiflexion (foot pointing upwards) of the foot relative to the lower leg. This action can force the talus bone upwards and outwards, wedging between the tibia and fibula and causing the syndesmotic ligaments to stretch or tear. Common scenarios include:

  • Getting tackled or falling with the foot planted and twisted outwards.
  • Landing awkwardly from a jump.
  • Direct impact to the outside of the lower leg while the foot is fixed. These injuries are common in sports that involve sudden changes in direction, pivoting, or contact, such as football, soccer, basketball, and hockey.

Symptoms of a High Ankle Sprain

The symptoms of a high ankle sprain can differ from a more common lateral ankle sprain (which affects ligaments on the outside of the ankle). Key indicators include:

• Pain Location: Pain is typically felt higher up the ankle, above the ankle bone, and sometimes extending up the lower leg along the shin.
• Pain Character: Pain is often sharp and worsens with movements that stress the syndesmosis, such as external rotation of the foot, pushing off the toes, or walking up stairs.
• Difficulty with Weight-Bearing: Significant pain and instability may make it difficult or impossible to put weight on the affected foot.
• Swelling and Bruising: While present, swelling and bruising may be less pronounced or spread out compared to a lateral ankle sprain.
• Tenderness: Localized tenderness when pressing on the syndesmotic ligaments between the lower tibia and fibula.

Diagnosis

Accurate diagnosis of a high ankle sprain is crucial due to its often longer recovery time and potential for chronic instability if not properly managed.

• Clinical Examination: A healthcare professional will perform a thorough physical examination, including:
  • Palpation: Feeling for tenderness along the syndesmotic ligaments.
  • External Rotation Stress Test: The doctor stabilizes the lower leg and externally rotates the foot, looking for increased pain.
  • Squeeze Test: The doctor squeezes the tibia and fibula together higher up the leg; pain in the ankle indicates a positive test.
• Imaging:
  • X-rays: Used to rule out fractures and to assess for widening of the syndesmotic space, especially with stress views (X-rays taken while applying stress to the ankle).
  • MRI (Magnetic Resonance Imaging): Often the gold standard for visualizing soft tissue injuries, an MRI can clearly show the extent of ligament damage and any associated bone bruising.

Treatment and Rehabilitation

Treatment for a high ankle sprain depends on the severity of the injury (grade I, II, or III, indicating mild stretch to complete rupture with instability). Unlike lateral ankle sprains, high ankle sprains often require a longer period of immobilization and rehabilitation.

• Initial Management (Acute Phase):

  • R.I.C.E.: Rest, Ice, Compression, and Elevation to control pain and swelling.
  • Immobilization: For moderate to severe high ankle sprains, a walking boot, cast, or brace may be used to restrict ankle movement and protect the healing ligaments.
  • Non-Weight Bearing: Crutches are often necessary, and weight-bearing may be restricted for several weeks to prevent further separation of the tibia and fibula.

• Rehabilitation Phases: A structured physical therapy program is vital for full recovery.

  • Phase 1 (Protection & Pain Control): Focus on reducing pain and inflammation, maintaining immobilization, and performing gentle, pain-free range of motion exercises as permitted.
  • Phase 2 (Restoration of Motion & Early Strength): Once pain allows, gradually increase ankle range of motion, introduce isometric strengthening exercises (muscle contraction without movement), and light resistance exercises.
  • Phase 3 (Progressive Strengthening & Proprioception): Advance to more challenging resistance exercises for all ankle muscles, incorporate balance and proprioception training (e.g., balance boards, single-leg stands), and begin agility drills.
  • Phase 4 (Return to Activity): Progress to sport-specific drills, plyometrics, and gradual return to full activity under the guidance of a physical therapist or athletic trainer. This phase is carefully managed to prevent re-injury.

• Surgical Intervention: In cases of significant syndesmotic instability (a wide separation of the tibia and fibula) or if conservative treatment fails, surgery may be recommended. This typically involves using screws or a special suture-button device to stabilize the tibia and fibula while the ligaments heal.

When to Seek Medical Attention

If you suspect you have a high ankle sprain or any significant ankle injury, it is crucial to seek medical attention promptly. Consult a doctor if you experience:

• Inability to bear weight on the injured ankle.
• Severe pain, especially higher up the ankle or along the lower shin.
• Significant swelling or bruising.
• Any visible deformity of the ankle or foot.
• Persistent pain, instability, or difficulty with daily activities weeks after an initial ankle injury.

Prevention Strategies

While not all high ankle sprains can be prevented, certain strategies can reduce the risk, especially for athletes:

• Ankle Strengthening: Regularly perform exercises that strengthen the muscles surrounding the ankle, including dorsiflexors, plantarflexors, invertors, and evertors.
• Proprioceptive Training: Improve balance and coordination through exercises like single-leg stands, wobble board exercises, and agility drills.
• Proper Footwear: Wear supportive athletic shoes appropriate for your activity.
• Taping or Bracing: For individuals with a history of ankle injuries or those participating in high-risk sports, ankle taping or bracing can provide additional support and stability.
• Warm-up and Cool-down: Always include dynamic warm-ups before activity and static stretches during cool-down.

Conclusion

While "diastasis ankle" is a non-standard term, it aptly describes the core issue in a high ankle sprain – a separation or widening of the distal tibiofibular joint. These injuries are more severe and typically require a longer, more structured rehabilitation process than common lateral ankle sprains. Understanding the anatomy, mechanism of injury, and the importance of professional diagnosis and a comprehensive rehabilitation program is key to achieving a full recovery and preventing chronic instability.