1. INTRODUCTION
Ankle fractures are among the most common injuries encountered in orthopedic trauma practice, accounting for approximately 9–10% of all fractures. Their incidence continues to rise due to population aging, increased prevalence of osteoporosis, and higher participation in sports activities. This presentation provides a comprehensive and integrated overview of ankle fractures, covering epidemiology, anatomy, injury mechanisms, classification systems, imaging, treatment principles, and advanced surgical techniques.
2. EPIDEMIOLOGY
· Bimodal age distribution:
o Young, active males: high-energy trauma (sports injuries, motor vehicle accidents)
o Elderly females: low-energy rotational injuries associated with osteoporosis
· Major risk factors:
o Osteoporosis
o Obesity
o Diabetes mellitus
o Smoking
o Peripheral vascular disease and neuropathy
· Diabetic patients have a significantly higher risk of complications such as infection, nonunion, and Charcot arthropathy.
3. DEFINITION
An ankle fracture is defined as a disruption of one or more osseous components of the ankle joint complex, including the distal tibia (medial and posterior malleoli) and the distal fibula (lateral malleolus), often accompanied by ligamentous injury and syndesmotic disruption. These injuries range from stable isolated malleolar fractures to complex fracture-dislocations with severe soft tissue compromise.
4. ANATOMY
4.1 Osseous Structures
· Distal tibia (tibial plafond)
· Medial malleolus
· Posterior malleolus
· Distal fibula (lateral malleolus)
· Talus
4.2 Ligamentous Structures
· Lateral ligament complex: anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), posterior talofibular ligament (PTFL)
· Medial ligament complex (deltoid ligament): superficial and deep components
· Syndesmotic complex: anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), interosseous ligament, and interosseous membrane
Ankle stability depends on the congruent bony mortise and intact ligamentous support, particularly the syndesmosis and the deep deltoid ligament.
5. MECHANISM OF INJURY
· Most ankle fractures result from rotational forces applied to a planted foot
· Common mechanisms include:
o Twisting injuries
o Sports-related trauma
o Falls from standing height
o High-energy trauma
These mechanisms form the basis of the Lauge–Hansen classification system.
6. CLASSIFICATION
6.1 Classification by Number of Malleoli
· Unimalleolar fractures
· Bimalleolar fractures
· Trimalleolar fractures
Increasing malleolar involvement correlates with increasing instability.
6.2 Danis–Weber Classification
· Weber A: fracture below the level of the syndesmosis (usually stable)
· Weber B: fracture at the level of the syndesmosis (variable stability)
· Weber C: fracture above the syndesmosis (unstable, syndesmotic injury common)
6.3 Lauge–Hansen Classification (Mechanism-Based)
· Supination–Adduction (SA)
· Supination–External Rotation (SER) – most common
· Pronation–Abduction (PA)
· Pronation–External Rotation (PER)
6.4 Posterior Malleolus Classification (Haraguchi – CT-Based)
· Type I: posterolateral oblique fracture
· Type II: transverse fracture with medial extension
· Type III: small shell-type fragment
Fragment morphology and syndesmotic involvement are more clinically relevant than fragment size alone.
7. IMAGING
· Standard radiographs: anteroposterior (AP), lateral, and mortise views
· Computed tomography (CT): essential for posterior malleolus fractures, intra-articular involvement, and surgical planning
· Magnetic resonance imaging (MRI): rarely required; useful in isolated ligamentous injuries
8. TREATMENT PRINCIPLES
The primary goals of treatment are: - Restoration of joint congruity - Anatomical alignment of the ankle mortise - Stable fixation allowing early mobilization - Prevention of post-traumatic ankle arthritis
Stable fractures may be managed conservatively, whereas unstable fractures typically require surgical intervention.
9. INDICATIONS FOR SURGERY
· Fracture displacement
· Bimalleolar or trimalleolar fractures
· Talar shift or mortise incongruity
· Syndesmotic instability
· Open fractures
· Fracture-dislocations
10. SURGICAL MANAGEMENT AND ADVANCED TECHNIQUES
10.1 ORIF – General Principles
The primary objective of surgical management is anatomical restoration of the ankle mortise. Even minimal talar shift significantly reduces tibiotalar contact area and predisposes to post-traumatic arthritis.
Typical operative sequence: 1. Fixation of the fibula 2. Fixation of the posterior malleolus 3. Fixation of the medial malleolus 4. Assessment and fixation of the syndesmosis if required
10.2 Lateral Malleolus (Fibula) Fixation
Techniques: - Lag screw fixation with neutralization plate - Bridge plating for comminuted fractures - Locking plate fixation in osteoporotic bone - Intramedullary fibular nail (minimally invasive option)
Key technical points: - Accurate restoration of fibular length and rotation is critical - Mortise congruity must be confirmed fluoroscopically
10.3 Medial Malleolus Fixation
· Partially threaded cancellous screws
· Fully threaded screws for small or vertical fragments
· Tension band wiring for avulsion fractures
Vertical shear fractures may require buttress plating.
10.4 Posterior Malleolus Fixation
Indications: - Fragment involving >25–30% of the articular surface - Syndesmotic instability - Posterior talar subluxation
Approaches: - Posterolateral approach - Posteromedial approach
Advantages of direct posterior fixation: - Improved articular reduction - Restoration of PITFL function - Reduced need for syndesmotic screw fixation
10.5 Syndesmotic Fixation
· Syndesmotic screws (3.5 mm or 4.5 mm)
· Suture-button fixation devices
The ankle should be fixed in neutral dorsiflexion, avoiding overcompression.
10.6 External Fixation
Indications include: - Open fractures - Severe soft tissue injury - Fracture-dislocations - Polytrauma patients
External fixation may be used as temporary or definitive stabilization.
10.7 Minimally Invasive Plate Osteosynthesis (MIPO)
Advantages: - Preservation of periosteal blood supply and soft tissues
Limitations: - Limited ability for direct articular reduction - Requires advanced fluoroscopic expertise
11. POSTOPERATIVE CARE AND REHABILITATION
· Initial immobilization with a splint or boot
· Non–weight bearing for 4–6 weeks (depending on fracture pattern)
· Early ankle range-of-motion exercises
· Gradual progression to weight bearing based on radiographic healing
· Structured physiotherapy program
12. COMPLICATIONS
· Wound healing problems and infection
· Malunion and nonunion
· Syndesmotic malreduction
· Post-traumatic ankle arthritis
· Hardware irritation or failure
· Chronic pain and instability