Fracture, Lateral and Medial Malleoli

By admin On Dec 14, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Thomas Sargent

Jeffrey W. R. Dassel

Basics

Description

Any fracture involving the most distal portions of the fibula or tibia, commonly known as the lateral and medial malleoli, respectively
Synonyms: Ankle fracture

Epidemiology

Very common: ∼187 ankle fractures per 100,000 people each year (1)
Fractures to ankle or midfoot occur in <15% of ankle sprains.
Most ankle fractures are malleolar fractures: 60–70% are unimalleolar (lateral being most common), 15–20% are bimalleolar, and 7–12% are trimalleolar (medial, lateral, and posterior malleoli) (2).

Risk Factors

History of prior ankle injury
Inadequate rehabilitation of injury
Skeletal immaturity
Weakness in dynamic (muscles) and/or static (ligamentous) stabilizers of the ankle
Abnormal gait and/or foot biomechanics
Foot and ankle proprioceptive dysfunction (dysfunction in the ability of the foot and ankle to adapt to uneven terrain)
Cigarette smoking
Obesity

Commonly Associated Conditions

Pilon fracture
Maisonneuve fracture

Diagnosis

History

Elicit mechanism: Inversion vs eversion and external vs internal rotation of the ankle and foot
Most frequent injury is inversion
Occasionally caused by direct blow to the affected malleolus
Patient may hear or feel a “pop.”
Immediate, disabling pain and difficulty bearing weight
Acute onset of swelling
Development of ecchymosis
Assess for neurovascular symptoms.

Physical Exam

Swelling and/or deformity about the ankle
Ecchymosis
Limited range of motion of the ankle
Tenderness to palpation over the affected malleolus
Difficulty or inability to bear weight and/or ambulate
May note instability of the ankle joint on examination
Check for signs of neurovascular compromise (pulses/sensation in the foot).

Diagnostic Tests & Interpretation

Imaging

Ottawa Ankle Rules are used to determine whether x-rays are necessary. Obtain x-rays for pain in the malleolar zone associated with any of the following:
- Bony tenderness along distal 6 cm of posterior tibia or fibula, or at medial or lateral malleolar tip.
- Inability to bear weight (4 steps) on ankle immediately after injury and at time of evaluation.
The Ottawa Ankle Rules have a sensitivity for fracture near 100% and a modest specificity (3)[B].
X-rays include anteroposterior (AP), lateral, and mortise (AP with foot in 15 degrees of adduction) views.
Some ankle fractures may not be initially seen. Presence of a large ankle effusion on the lateral radiograph may indicate an occult fracture and the need for further evaluation (4)[C].
On the mortise view, the joint space between the talus and lateral malleolus and the distal tibia and medial malleolus should be equal. Inequality should raise suspicion of an unstable ankle injury.
CT not indicated in most ankle fractures; however, is performed when an occult fracture is suspected or to further evaluate pilon (comminuted distal tibial fracture), triplane (tibial fracture in sagittal, coronal, and axial planes), or suspected talar fractures (5)[C]
When performed, order thin-cut CT in case coronal or sagittal reconstructions are required.

Differential Diagnosis

Contusion
Ankle sprain
Tear of ankle retinacular structures
Syndesmosis injury (“high ankle sprain”)
Foot fracture
Posttraumatic subluxation of peroneal tibialis posterior tendons

Treatment

Acetaminophen at recommended age- or weight-based dosages every 6–8 hr as needed
Consider NSAIDs, although controversy exists as to their effect on bone healing.
Narcotics as needed for severe pain only
Cryotherapy applied 20–30 min every 2–4 hr for the 1st 24–48 hr after injury. Use caution to avoid thermal injury to the skin.
Relative rest and elevation of affected limb for 1st 48–72 hr
Isolated lateral malleolar fractures with 2 mm or less of displacement do not need reduction. Refer to orthopedist for >2 mm displacement (6)[C].
Isolated medial malleolar fractures with any displacement other than small avulsion injuries should be referred to an orthopedist. Do not attempt to reduce.

P.209

Check neurovascular status of foot post reduction.
Post-reduction x-rays are same views as initial films
Non-weight-bearing in stirrup or posterior splint, with ankle in neutral position, for 3–5 days
Isolated, minimally displaced lateral malleolar fracture: Short leg walking cast with ankle in a neutral position or fracture boot with (eg, Cam walker) or without adjustable ankle range of motion for 4–6 wks
Isolated simple avulsion fracture of the medial malleolus: Stirrup splint or Cam walker can be used short-term for comfort, typically 2–4 wks

Additional Treatment

Referral

Any open fracture or fracture associated with neurologic or vascular deficits requires emergent surgical evaluation.
Ankle injuries that are unstable or incongruent should be evaluated by an orthopedic surgeon (1)[C].

Additional Therapies

Patients should seek attention immediately for pain that is increasing, new or worsening numbness, or skin pallor/duskiness distal to the fracture or splint/cast.
Repeat x-rays at 2 wks to ensure maintained alignment and at 6 wks to assess bony healing (1)[C].
Repeat x-rays every 2 wks if not healing.
Total healing time: 6–8 wks. May take months to see complete radiographic healing.
Athletes should cross-train while healing to maintain fitness.
Proper rehabilitation of these injuries with a home instructional program or with formal physical therapy guidance is crucial to successful healing and return to full function.
After period of immobilization is complete, start standard ankle rehabilitation range of motion exercises, strengthening exercises, and proprioceptive training.
The shorter the period of immobilization, the easier it should be for the patient to regain ankle motion and strength.
Follow up every 2–3 wks to assess progress of rehabilitation.

Surgery/Other Procedures

The following injuries are frequently managed with surgical intervention:

Disrupted mortise joint
Fracture-dislocations
Bimalleolar fractures
Trimalleolar fractures
Unimalleolar fracture with contralateral ligament rupture
Lateral malleolar fractures with >2 mm displacement (1)[C]
Lateral malleolar fractures above the tibio-talar joint line (as they are frequently associated with syndesmotic disruption)
Medial malleolar fractures with >2 mm displacement (6)[C]
Posterior malleolus fractures involving >25% of the articular surface or >2 mm displacement (6)[C]

In-Patient Considerations

Admission Criteria

Open fracture
Fracture-dislocations in which adequate reduction is not achieved with manual manipulation
Evidence of/concern for neurovascular compromise (severely comminuted pilon fracture, compartment syndrome)

References

1. Koehler SM, Eiff P. Overview of ankle fractures. UpToDate. 2009. www.uptodate.com

2. Court-Brown CM, McBirnie J, Wilson G. Adult ankle fractures—an increasing problem? Acta Orthop Scand. 1998;69:43–47.

3. Bachmann LM, Kolb E, Koller MT, et al. Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review. BMJ. 2003;326:417.

4. Clark TW, Janzen DL, Ho K, et al. Detection of radiographically occult ankle fractures following acute trauma: positive predictive value of an ankle effusion. AJR Am J Roentgenol. 1995;164:1185–1189.

5. Mulligan ME. Fractures, Ankle. eMedicine. 2009. emedicine.medscape.com/article/398578-imaging

6. Michelson JD. Fractures about the ankle. J Bone Joint Surg Am. 1995;77:142–152.

Additional Reading

Eiff MP, Hatch RL, Calmbach WL. Fracture management for primary care. Philadelphia: WB Saunders, 1998.

Rockwood CA, Green DP, Bucholz RW, eds. Rockwood and Green's fractures in adults. Philadelphia: JB Lippincott, 1996.

Codes

ICD9

824.0 Fracture of medial malleolus, closed
824.1 Fracture of medial malleolus, open
824.2 Fracture of lateral malleolus, closed