Leg injuries

Anatomy

• Four compartments
  • Anterior – Dorsiflexors and deep fibular nerve
  • Lateral – Bordered by anterior crural septum, fibula and posterir crural septum
    • Plantarflexors and eversion with superficial fibular nerve
  • Superficial posterior
  • Deep posterior
• Check nerves by sensation over first web space (deep fibular), lateral heel (sural) and sole of foot (posterior tibial)

Tibial shaft fractures

• Most commonly fractured long bone
• Transverse – direct blow
• Spiral – Rotational
• Comminuted – High energy
• Open tibial fracture classification (Gustilo)

• Grade 1 – Minimal soft tissue and skin lac <1cm
• Grade 2 – Wound with >1cm lac with moderate soft tissue and moderate contamination
• Grade 3 – Segmental injury, vascular injury, highly contaminated or >10cm lac
• It is the soft tissue injury that often determines immediate therapy and outcome

Tibial shaft

• Type A (simple)
  • 1 – Spiral
  • 2 – Oblique angle >30 degrees
  • 3 – Transverse angle <30 degrees
• Type B (multifrag wedge)
  • 1 – Spiral wedge
  • 2 – Bending wedge
  • 3 – Fragmented wedge
• Type C (multifrag complex)
  • 1 – Spiral wedge
  • 2 – Segmental
  • 3 – Irregular

Tibial shaft fractures

• Splint
• Check for compartment syndrome
• Acceptable reduction
  • 50% or more of cortical contact
  • <10-15 degrees of angulation on lateral
  • <10 degrees angulation on AP
  • <5 degrees of rotational deformity
• Significant oedema and spiral # often require ORIF
• Intact fibula can make reduction of tibia far more difficult
• Long leg splint with knee in 5 degrees flexion and slight plantarflexion should be applied
• Key to reduction is ensuring distal foot doesn’t sag down during plaster setting

Tibial shaft fractures

• Can usually achieve weight bearing in 7-14 days but take 4-5 months to heal completely
• Sometimes damage is so severe to either soft tissues or bone that amputation is the best course of action
• Shortening >2cm prior to reduction is a contraindication for casting
• Compartment syndrome in up to 20% and cast immobilisation may increase risk
  • Suggested by increased pain despite reduction and casting, pain on passive stretch and pain over anterior compartment muscles rather than fracture site
  • May not appear for 24 hours
  • Pulse may still be present
  • Anterior compartment syndrome – Weak toe dorsiflexion, pain on passive toe flexion, diminished sensation first web space
  • Posterior compartment syndrome – Weak toe flexion and inversion, pain on passive toe extension, diminished sensation over sole of foot

Tibial shaft fractures

• Indications for operative treatment
  • Ipsilateral femoral shaft fracture
  • Intra-articular
  • Segment fractures
  • Bilateral
  • Open
  • Vascular complications
  • Pathological
  • Inadequate reduction

Pilon fracture

• French word for pestle
• Axial force to talus can drive it into the tibia, causing a tibial plafond fracture
• Obtain a CT as often multiplanar fracture lines
• At risk of compartment syndrome, vertebral body fractures (L1 especially)

Triplane fracture

• Teenagers have relatively weak lateral distal tibial growth plate during fusion
• Starts to fuse between 12-15yo and takes 18 months
• Medial portion fuses first
• External rotational force applied to foot causes lateral growth plate of tibia through growth plate to fusion point and then down through sagittal and coronal planes
• Can look like Salter-Harris III on AP and II on lateral
• Evaluate with CT as often deformity of articular surface can be missed
• Closed reduction often achieves congruent articular surface

Maissoneuve’s fracture

• Proximal fibula fracture
• External rotational force to foot with plane of injury from:

• 1 – medial ankle (either deltoid ligament or medial malleolar injury)
• 2- tearing of IO membrane
• 3- proximal fibula fracture

• Can look like Weber C if middle of fibula
• Need to reduce medial malleolar fracture (if present) and secure fibula to distal tibia to allow IO membrane to heal

Midshaft fibula fractures

• Typically tibial fracture also in which case the tibial fracture takes precedence
• Direct blow can cause isolated fracture
• If tibia is intact, can often weight bear and short get short-leg cast and crutches
• If less intense pain, can get knee immobiliser (proximal fibula) or elastic wrap (distal fibula) and weight bear as tolerated
• Avoid contact sports until healed
• Rule out Maissoneuve

Stress fracture

• Women 2:1
• 50% occur in tibia with tarsals and fibula less common
• In teenagers, proximal third of tibia
• In runners, junction of middle and distal third of tibia
• X-ray often normal initially
• 10-15 days later may see periosteal reaction or demineralisation and fracture line
• Bone scan and MRI more sensitivie
• Rx – Discontinue activity and cast if significant pain persists. Can take up toa  year to resolve

Achilles tendon rupture

• Vascular supply is weakest 2-6 cm above calcaneus
• Typically weekend warrior
• Risk factors include older age, prior quinolone use and prior steroid injection
• Thompson test positive
• US can confirm diagnosis if not clear
• Immobilise in some plantarflexion + crutches and NWB with # clinic f/u
• Rerupture rate <5% with surgery or conservative rx
• Typically immobilised for 2-3 months and return to sport at 3-6 months

Medial gastrocnemius strain

• Originates from medial femoral condyle
• Typically weekend warrior
• Audible pop + sharp stabbing pain
• Asymmetry calf swelling and tenderness of calf with intact Achilles
• Non-urgent MRI or USS can confirm diagnosis
• Treatment in plantarflexion immobilisation, rest, ice immobilisation and # clinic referral

Shin splints

• Exercise-induced pain over medial aspect of tibia
• May be due to repetitive trauma periostitis
• Typically runners, military recruits and those with flat feet
• Uncommon before age 15
• Typically after sudden increase in training on hard surface
• Radiographs are normal and bone scan can rule out stress fracture
• Several weeks of cessation of activity that precipitated pain is usually sufficient

Tillaux fracture

• Most common Salter-Harris III fracture
• Occurs at distal tibia due to partially closed growth plate in adolescence (medial growth plate closed)
• Intra-articular fracture

Last Updated on June 15, 2021 by Andrew Crofton