Combined fracture-ligament injuries of the ankle joint

Anatomy and function of the ankle joint

The upper ankle joint (OSG) connects the lower leg (tibia, fibula) with the talus. The external ligament complex (anterior and posterior talofibular ligament, calcaneofibular ligament) stabilizes on the side, while the deltoid ligament stabilizes on the inside; Between the tibia and fibula, the syndesmosis holds the ankle joint fork together. The lower ankle joint (USG) enables compensatory movements and influences gait dynamics.

• Bones: Inner malleolus (medial malleolus), outer malleolus (lateral malleolus), posterior part of the tibial bone (posterior malleolus)
• Ligaments: Outer ligament complex, deltoid ligament (inner ligament), syndesmosis with anterior/posterior syndesmosis ligament
• Function: Stability in stance and gait, guidance of dorsiflexion and plantar flexion

What does “combined fracture-ligament injury” mean?

A combined fracture-ligament injury occurs when, in addition to a bone fracture in the ankle joint, one or more ligament structures are torn or significantly strained. Common patterns are:

• Bimalleolar or trimalleolar fractures (internal, external and possibly posterior malleolus) with ligament involvement
• Weber B or Weber C fractures with injury to the syndesmosis (instability of the ankle joint fork)
• Maisonneuve injury: high fibula fracture with syndesmosis and medial ligament/median malleolus involvement
• Lateral malleolus fracture plus deltoid ligament tear (functionally “bimalleolar”)

What matters is whether joint instability is present. Instabilities increase the risk of misalignment, cartilage damage and later osteoarthritis and influence the treatment decision.

Causes and mechanisms of injury

Injuries usually arise from twisting an ankle, falling while playing sports or on slippery surfaces. Depending on the mechanics, torsion, compression or shear forces act on bones and ligaments.

• Supination/inversion mechanism: frequent fracture of the lateral malleolus with lateral ligament lesions
• Pronation/eversion mechanism: medial ligament/deltoid ligament and medial malleolus affected
• Rotational injuries: syndesmotic lesions up to Weber C or Maisonneuve injuries
• High-speed trauma: multi-fragment fractures, soft tissue damage

Risk factors include previous ligament injuries, misalignments, osteoporosis, unusual stress, inadequate footwear and declining coordination/proprioception.

Symptoms: How do I recognize the injury?

• Acute pain, v. a. on the side or inside of the ankle, reinforcement under load
• Rapid swelling and bruising
• Restriction of movement, inability to bear weight, possibly misalignment/deformity
• Pressure pain over malleoli, syndesmosis (anterior tibial fibula gap), talus
• Sensory disturbances or feeling of cold due to vascular/nerve involvement (rare, clarify immediately)

First aid after the accident

No independent adjustment attempts. Painkillers only after consultation and without delaying the diagnosis.

Diagnostics in practice

The aim is to reliably identify fracture patterns, ligament involvement and instability. The procedure is based on the complaints, mechanism of the accident and clinical findings.

• Clinical examination: swelling, hematoma, pressure points, axial deviation, skin/soft tissue situation, stability test (pain-adapted), blood circulation/sensory/motor function
• X-ray in two planes plus Mortise image; Assessment of joint space, malleoli, posterior malleolus
• If the findings are unclear or joint involvement: CT for fragment analysis (e.g. posterior malleolus), MRI for ligament/cartilage diagnosis
• If necessary, stress recordings/pain provocation tests to assess the syndesmosis (to be considered individually)

Classifications (e.g. Danis-Weber, Lauge-Hansen) help to assess instability and structure therapy paths.

Conservative therapy: when does it make sense?

Stable, slightly displaced fractures without relevant ligament instability can often be treated without surgery. The prerequisite is correct joint position, controllable pain and a good soft tissue situation.

• Immobilization: functional orthosis or walker boots
• Loading: depending on stability, partial loading with forearm crutches; gradual increase after follow-up checks
• Lymphatic drainage, decongestant measures, pain and inflammation management
• Early functional physiotherapy to maintain mobility and proprioception
• Thrombosis prophylaxis after individual risk assessment

Regular X-ray checks ensure the position. If there is a secondary shift or signs of instability, the strategy is reevaluated.

Surgical therapy: indications and procedures

Surgery is considered when instability exists, when fractures are displaced, the joint space is irregular, or relevant fragments (e.g., posterior malleolus) are involved. The aim is to anatomically restore the joint guide, axis and ligament stability.

• Osteosynthesis of the outer/inner ankle (screw/plate osteosynthesis, tension strapping depending on the pattern)
• Reconstruction/fixation of the posterior malleolus in cases of sufficient fragment size or instability
• Syndesmosis stabilization (e.g. adjusting screw or flexible button systems) for syndesmosis lesions
• Accompanying ligament addressing: primarily mostly indirectly via bony stabilization; direct deltoid ligament suture in selected cases

The operation time depends on the soft tissue situation. If the swelling is severe, a short-term wait and immobilization may make sense. We discuss the exact procedure transparently, including benefits, risks and alternatives.

Rehabilitation and healing process

Rehabilitation is based on the injury pattern and stability (conservative vs. surgical). It is controlled individually and checked regularly.

Returning to work and sport depends on healing, stability and symptoms. Rigid timelines do not replace medical follow-up.

Course and prognosis

With a stable recovery and consistent rehabilitation, good functional results are possible. Factors such as extensive soft tissue damage, delays, misalignments, or syndesmosis involvement can prolong recovery.

• Possible residuals: temporary swelling, pain on exertion, restricted movement
• Long-term risks: post-traumatic osteoarthritis, chronic instability - risk increases with remaining misalignment or persistent instability
• Early, guideline-oriented treatment improves the initial situation

Possible complications and warning signs

• Impaired wound healing, infection (post-operative): redness, overheating, weeping
• Thrombosis/embolism: swelling, pain in calf, shortness of breath – emergency
• Nerve/vascular irritation, numbness, circulatory disorders
• Secondary dislocation, lack of bone healing (pseudarthrosis), malunion
• Compartment syndrome in high-speed trauma: severe tension and pain at rest – emergency
• CRPS (rare): burning pain, skin changes, hypersensitivity

Warning signs such as increasing pain despite rest, sensory disturbances, pale/cold feet, fever or severe wound pain should be clarified promptly.

Prevention and recurrence prevention

• Proprioceptive training (balance, one-legged stand, balance board)
• Strength training calf/peroneal muscles, ankle mobility
• Sport-specific warm-up, technique training and adequate footwear
• Taping/orthosis in the early recovery phase after ligament injuries
• Address risk factors: quitting smoking, preventing falls, checking for osteoporosis

Special patient groups

• Athletes: Gradual return-to-play according to functional and stability criteria; Sport-specific tests and prevention are central.
• Older people: Higher risk of osteoporosis and falls; Consider safe mobilization, aid training and environmental adaptation.
• People with diabetes or smokers: increased risk of wound healing problems - careful soft tissue monitoring and adapted aftercare.

Frequently asked questions

Below are answers to frequently asked questions about combined ankle fracture-ligament injuries.