No, not all high ankle sprains require surgery, with the necessity for an operation depending entirely on the stability of the ankle joint after the injury. These injuries, also known as syndesmotic injuries, are less frequent than typical lateral ankle sprains but often present a more serious concern for full recovery. Determining whether the bones remain properly aligned is the factor that guides treatment, which can range from non-surgical immobilization to complex surgical fixation.
What Defines a High Ankle Sprain
A high ankle sprain involves the syndesmosis, a fibrous joint located just above the ankle where the tibia and the fibula are connected by strong ligaments. This group includes the anterior inferior tibiofibular ligament (AITFL) and the interosseous ligament, which keep the tibia and fibula tightly compressed to maintain the structural integrity of the ankle joint.
The mechanism of injury is typically a forceful external rotation of the foot while the ankle is bent upwards (dorsiflexed), often seen in contact sports. This twisting motion forces the tibia and fibula apart, stressing or tearing the stabilizing syndesmotic ligaments. Damage is commonly graded: Grade I is a mild stretch, Grade II is a partial tear (stable or unstable), and Grade III represents a complete tear resulting in joint instability.
The injury is inherently more severe than a standard lateral ankle sprain. Since the syndesmosis keeps the lower leg bones compressed, any instability can significantly compromise the ankle’s ability to bear weight and function correctly.
Conservative Treatment for Stable Injuries
For high ankle sprains classified as stable injuries—typically Grade I or Grade II injuries where the tibia and fibula remain correctly aligned—the standard approach is non-surgical, or conservative, treatment. This pathway focuses on protecting the healing ligaments and gradually restoring the ankle’s function without surgical intervention. The initial phase of recovery involves a period of immobilization and protection to allow the injured ligaments to begin their repair process.
Immobilization often involves using a controlled ankle motion (CAM) boot or a short-leg cast for a brief period, typically ranging from a few days up to two weeks, to minimize stress on the syndesmosis. During this acute period, patients are placed on weight-bearing restrictions, using crutches to prevent excessive force on the joint. This initial rest helps control pain and swelling, which are common symptoms located higher up the leg.
Once pain and swelling subside, the focus shifts to a progressive physical therapy regimen. The goal is to restore the ankle’s full range of motion through gentle, pain-free exercises. Strengthening exercises for the calf and ankle muscles are then introduced to rebuild support around the joint.
Indicators That Require Surgical Intervention
The primary indicator for surgical intervention is instability of the syndesmosis, a condition where the tibia and fibula separate too much, often referred to as diastasis. This instability is usually seen with severe Grade III sprains or unstable Grade II injuries where ligament damage compromises joint integrity. When the joint is unstable, the bones cannot be held in proper alignment, leading to significant functional impairment and a risk of long-term arthritis.
Instability is determined through physical examination and specialized imaging, such as stress X-rays or a weight-bearing CT scan. Widening of the space between the tibia and fibula beyond a certain threshold confirms the need for surgical stabilization. The presence of an associated fracture, such as a broken fibula, alongside the syndesmotic injury also necessitates an operative repair to stabilize the ankle structure.
The surgical procedure aims to achieve anatomical reduction and fixation. Reduction involves carefully realigning the tibia and fibula to their correct position. Fixation then secures the bones in place to allow the torn syndesmotic ligaments to heal without tension. This is often achieved using techniques such as syndesmotic screws or modern suture-button devices, sometimes called a “tightrope” procedure, which provide dynamic stabilization.
Recovery and Return to Activity
Recovery from a high ankle sprain is generally prolonged, regardless of whether surgery is performed. For stable injuries treated non-surgically, return to activity can take between six to twelve weeks, with athletes typically needing a longer period to regain sport-specific function. This extended timeline reflects the slow healing process of the syndesmotic ligaments, which are subjected to high forces during movement.
In cases requiring surgery, the recovery timeline is significantly longer, often extending to three to six months or more before a full return to high-impact activities. Following fixation, the initial weeks involve strict non-weight-bearing in a cast or boot to protect the repair. Physical therapy is then introduced to focus on regaining strength, balance, and proprioception, which is the body’s sense of joint position.
The final phase of rehabilitation involves progressively loading the ankle with power, agility, and sport-specific movements. A patient is cleared to return when they demonstrate minimal or no pain, full range of motion, and near-equal strength and stability compared to the uninjured ankle.