fractures of the lower limb

Lower limb fractures X-Rays

Abbas A. A. Shawka

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Right v left example - Pelvis and hips

Right v left example - Pelvis and hips• This image of the

pelvis shows subtle irregularity of the cortical outline of the right femoral neck

• Comparison with the other side - which is asymptomatic - increases confidence of a genuine abnormality

• There is also loss of the normal trabecular pattern indicating a fracture (#)

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Clinical information•Right groin pain after a fall•Shortened and externally rotated right leg

Diagnosis•Fractured neck of right femur

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Hip X-ray anatomy - Normal AP

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• Shenton's line is formed by the medial edge of the femoral neck and the inferior edge of the superior pubic ramus

• Loss of contour of Shenton's line is a sign of a fractured neck of femur

• IMPORTANT NOTE: Fractures of the femoral neck do not always cause loss of Shenton's line

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Hip X-ray anatomy - Normal Lateral

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• The cortex of the proximal femur is intact

• The Lateral view is often not so clear because those with hip pain find the positioning required difficult

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Intracapsular vs. extracapsular

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• The capsule envelopes the femoral head and neck

• Subcapital, transcervical and basicervical fractures are intracapsular hip injuries

• Intertrochanteric and subtrochanteric fractures do not involve the neck of femur

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Intracapsular fracture - Subcapital - AP

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• Shenton's line is disrupted

• Increased density of the femoral neck is due to overlapping - impacted bone

• The lesser trochanter is more prominent than usual - due to external rotation of the femur

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Intracapsular fracture -

Subcapital - Lateral

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• Loss of integrity of cortical bone indicates fracture

• Trabecular bone of the femoral neck overlaps

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Garden classification - Simulation

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`• I - Incomplete or

impacted bone injury with valgus angulation of the distal component

• II - Complete (across whole neck) - undisplaced

• III - Complete - partially displaced

• IV - Complete - totally displaced

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Garden IV fracture

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• Loss of Shenton's line

• Complete fracture of the full diameter of the femoral neck

• Total displacement of the 2 fracture components

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Intertrochanteric fracture

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• A fracture line runs between the trochanters

• There is comminution with separation of the lesser trochanter

• Note the fracture does not involve the femoral neck

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Subtrochanteric fracture

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• This fracture passes distal to the trochanters

• The femoral neck remains intact

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Hip dislocation

• (dislocation of the femoral head from the acetabulum) is most frequent following total hip replacement (THR). Dislocation is usually in a posterior direction which clinically leads to leg shortening, with flexion and internal rotation at the hip (note - hip fractures usually cause external rotation).

• may be accompanied by fracture of the acetabulum, or significant soft tissue injuries not visible with X-ray.

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• The femoral head lies superior and lateral to the acetabulum

• No associated fracture is visible in this case but significant soft tissue injury is likely

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Hip dislocation - Dislocated THR

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Patient with Total Hip Replacement (THR)The ball of the femoral component is displaced from the cup of the acetabular component

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Femoral shaft fracture

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• Spiral fracture with posterior angulation, lateral displacement and shortening

• There is rotation of the distal femur so the knee faces laterally

• X-rays of the proximal femur (not shown) did not reveal further injury

• Injury occurred in a road traffic crash

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Pathological femoral shaft fracture

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Transverse fracture with rotational displacement and shorteningPatient with known history of widespread bone metastases - note the abnormal bone textureInjury occurred after a trivial fall

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Knee - Normal AP

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The patella is often not clearly seen on this view

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Knee – Normal AP

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• This x-ray showing the cartilage ( hyaline ) , meniscus and joint soft tissue.

• We can not specific any abnormality for knee components unless we request MRI for the patient.

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MRI – Knee – Normal

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MRI for the Knee joint is used to determine the defects in meniscus, cartilage , cruciate ligaments and other ligaments.

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MRI – Knee – Normal

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MRI – Knee – Normal

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Knee - Normal Lateral (Horizontal Beam)

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• The Horizontal Beam Lateral view is useful for assessing soft tissues as well as bones

• The quadriceps and patellar tendons are visible

• Note the normal suprapatellar pouch between fat pads above the patella (asterisks) - widening of these fat pads or increased density in this area can indicate a knee joint effusion

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Knee - Normal 'Skyline' view

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• Not usually indicated in the context of trauma

• More helpful to assess knee pain due to suspected patellofemoral compartment osteoarthritis

• Normal patellofemoral compartment spacing (arrowheads)

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Tibial plateau fracture - AP

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• Lateral tibial plateau fracture

• The fracture fragment is displaced and depressed from its normal position (dotted line)

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Tibial plateau fracture - Lateral

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• No visible fracture line

• Depressed tibial plateau contour (arrow)

• Lipohaemarthrosis (fat and blood in the joint)

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Patellar fracture - Lateral

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• Increased density separating the fat pads indicates a joint effusion due to leakage of blood (haemarthrosis)

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Patellar dislocation - Skyline view

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• The patella is grossly displaced

• The roll over image shows its normal position

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Knee - Fabella

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A fabella is a normal sesamoid bone of the lateral head of gastrocnemius tendon - not to be mistaken for a fracture or loose body

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Bipartite patella

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• The patella is bipartite (in 2 parts) - a common normal variant

• Note: Injury to the interface of the 2 components is possible which may be symptomati

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Tibial and fibular fracture

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• Comminuted fractures of the tibial and fibular shafts with medial displacement and posterior angulation

• X-rays of the distal end of the bones (not shown) did not reveal further injury

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Tibial stress fracture

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• Periosteal stress reaction are signs of stress injury (often not present on the initial X-ray)

• History of chronic pain worsened by activity

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Toddler's fracture

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• Fine spiral line through the tibial shaft

• This toddler presented with refusal to weight-bear

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Toddler's fracture

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• Fine spiral line through the tibial shaft

• This toddler presented with refusal to weight-bear

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Ankle anatomy - Normal AP 'mortise'

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• The weight-bearing portion is formed by the tibial plafond and the talar dome

• The joint extends into the 'lateral gutter' (1) and the 'medial gutter' (2)

• The joint is evenly spaced throughout

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Ankle anatomy - Normal Lateral

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• Carefully following the bone contour of the tibia and fibula shows the inferior edge of the medial and lateral malleoli

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Ankle bone and ligament anatomy

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The ankle is stabilised by multiple ligaments not visible with X-ray

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Lateral malleolus fracture - AP

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• Soft tissue swelling laterally (asterisks)

• Transverse fracture of fibular tip (Weber A)

• The ankle joint remains aligned normally

• Weber A = Distal to ankle joint (this case)

• Weber B = At level of ankle joint

• Weber C = Proximal to ankle joint

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Bimalleolar fractures - AP

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• Transverse medial malleolus fracture

• Lateral malleolus fracture - at level of ankle joint (WeberB)

• Joint widened medially due to lateral displacement of the talus

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Trimalleolar fracture - AP and Lateral

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1 - Medial malleolus fracture2 - Lateral malleolus fracture - proximal to the ankle and extending up the fibula (Weber C fracture)3 - Posterior malleolus fracture• The joint is unstable and

widened anteriorly (arrowheads) and at the distal tibiofibular syndesmosis (asterisk)

• The talus is displaced posteriorly and laterally along with the medial and lateral malleolus bone fragments

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Maisonneuve fracture - Ankle AP

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• 1 - Disruption of the medial ankle joint with small bone avulsion

• 2 - Disruption of the distal tibio-fibular syndesmosis

• No fibular fracture is visible at the ankle raising the suspicion of a proximal fibular fracture

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Maisonneuve fracture - AP proximal tibia-fibula

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Spiral fracture of the proximal fibula

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Osteochondral fracture

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Loss of the normal talar dome cortex contour due to an osteochondral fracture

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Normal calcaneus - Lateral

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Bohler's angle is normal (39° in this case)

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Normal calcaneus - Axial

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The cortex of the calcaneus is intact

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Calcaneal fracture - Lateral view

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• Flattening of Bohler's angle (18° in this case)

• Depression of the articular surface of the posterior subtalar joint (red line) from its normal position (green line)

• Fracture lines can be seen passing through the calcaneus

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Calcaneal fracture - Axial view

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Loss of smooth cortical edge (orange line)

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Foot X-ray anatomy - DP and Oblique views

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• Hindfoot = Calcaneus + Talus

• Midfoot = Navicular + Cuboid + Cuneiforms

• Forefoot = Metatarsals + Phalanges

• 1 = Hind-midfoot junction

• 2 = Mid-forefoot junction = Tarsometatarsal joints (TMTJs)

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Foot X-ray anatomy - DP and Oblique views

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Metatarsals and phalanges of the toes are numbered 1 to 51 = Big toe5 = Little toeMC = Medial CuneiformIC = Intermediate CuneiformLC = Lateral Cuneiform

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Forefoot X-ray anatomy - Joints

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MTPJ = Metatarsophalangeal JointsIPJ = Interphalangeal Joint (of big toe only)PIPJ = Proximal Interphalangeal JointsDIPJ = Distal Interphalangeal JointsNote the medial side sesamoid is 'bipartite' (in 2 parts) - this is a common normal variant - not a fracture

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Foot ligament anatomy

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• DP - Normal alignment of the 2nd Metatarsal with the Intermediate Cuneiform

• Oblique - Normal alignment of the 3rd Metatarsal with the Lateral Cuneiform

• Position of the Lisfranc Ligament shown

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Lisfranc injury - DP

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• Second metatarsal displaced from the intermediate cuneiform

• No fracture is visible but this is a severe injury which is debilitating if untreated

• Note: Lisfranc ligament injury can be subtle and does not always result in displacement - If there is a clinically suspected ligament injury then clinical and radiological follow-up must be arranged

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Metatarsal shaft fracture

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• Oblique fracture of the 5th Metatarsal shaft

• Fracture more clearly visible on the oblique image

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5th metatarsal base fracture

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• Left image - The fracture line passes transversely across the bone

• Right image - A normal unfused 5th metatarsal base apophysis is aligned more longitudinally along the bone

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Metatarsal stress fracture

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• Subtle periosteal stress reaction of the 2nd metatarsal

• History of chronic pain worsened by activity

• Note: Stress fractures are not always visible on the initial X-ray - if suspected repeat X-ray or MRI may be required

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Thank you