Radiographic evaluation of Lower Limb

Runal Shah1st year - MEM

KDAH, Mumbai

Overview

• ABCs - Systematic Assessment– A : Alignment– B : Bone– C : Cartilage & Joints– S : Soft tissue

• In bone radiology, clinical examination forms the Key tool.

• X-Ray confirms the clinical suspicion.

•Two views – one view is always one view too few

•Two abnormalities – if you see one abnormality, always look for a second

•Two joints – image the joint above

•Two sides – if not sure or difficult X ray, compare with other side

•Two occasions – always compare with old films IF available

•Two visits – bring patient back for repeat examination

•Two opinions Two records – always ask a colleague if not sure & record findings

•Two specialists – always get your ED specialist & a radiologist’s opinion

•Two investigations – always consider whether US, CT or MRI would help in diagnosis

Rule of Two

Pelvis and Hip

• Pelvic fractures in major trauma may be life-threatening (suspect vascular and pelvic organ injuries in these patients)

• If one fracture is detected, always look for a second one.• Hip fractures may occur after minor trauma in elderly.• Mechanism of Injury : (most common)

– Young : RTA– Elderly : Fall / minor Trauma

• The fractures may be subtle on plain radiographs and may be overlooked in particular in obese and elderly osteopenic patients.

Normal Pelvis X-Ray

Normal Pelvis X-Ray

• Three bony rings– Large : pelvic brim– Small : obturator

rings

• Shenton’s line– line along the inner

margin of the femoral neck and extending the superior margin of the obturator foramen

Role of CT scan

• In major trauma, the pelvic CT is covered as part of the whole body CT protocol.

• CT Angio is done for alleged Vascular injuries in clinically suspicious pelvic fractures.

• 3D-CT is essential for major pelvic reconstructions.• CT is also used to exclude and to assess injuries to the

pelvic organs including the bladder, urethra, rectum, uterus, cervix and vagina.

• Pelvic hematomas can be detected and active contrast extravasations at the time of the CT, indicates active ongoing bleeding.

Patterns of Pelvic injuries

• 2 classifications– Tile classification : Integrity of posterior sacro-iliac complex– Young’s classification : Mechanism of injury

• AP Compression• Lateral compression (Most Common)• Vertical Shear• Combination of the above three

Lateral Compression fracture

AP Compression fracture

Vertical Shear fracture

Hip fracture• AP and Lateral views• Shenton’s Line is checked initially• Intracapsular – based on level of

neck femur fracture– Subcapital– Transcervical– Basal

• Avascular Necrosis - Malunion

• Extracapsular – trochanteric fracture– Inter-trochanteric– Sub-trochanteric

• Nonunion

Hip fracture

• Garden Classification (subcapital femur neck)Grade I – incomplete fractureGrade II – complete fracture but no displacementGrade III – some separation of fractureGrade IV – complete separation of fracture

• Delbet classification of femoral neck fractures in ChildrenType 1 – transepiphyseal (avascular necrosis usually follows)Type 2 – transcervical (avascular necrosis common if displaced)Type 3 – cervicotrochantericType 4 – pertrochanteric

Hip fracture

Acetabular fractures• Can occur due to injury to pelvic ring or separately• Fractures of posterior rim occur due to posterior dislocation

of femur head or AP compression of pelvic• Judet–Letournel Classification of the five common

acetabular fractures– Both column– T-shaped fracture– Transverse fracture– Transverse with posterior wall fracture– Isolated posterior wall fracture

Dislocation of the Hip• Anterior / Posterior / Central• Central : femoral head impacts through acetabulum, occurs in

Lateral compression injury due to sideways fall or injury to greater trochanter.

• Femur head is palpable per rectally, leg is shortened.

Dislocation of the Hip• Posterior : a blow to lumbar spine when hip flexed OR

dashboard injury in MVA• Leg is kept in Flexion Adduction & Internal rotation (FADIR),

shortened, femur head goes glutially.

Dislocation of the Hip• Anterior – Flexion, Abduction & External rotation (FABER), leg

is lengthened.

Complications of Hip Dislocation

• Slipped femoral epiphysis (unfused skeleton)• Sciatic nerve palsy• Femoral nerve or artery compression (anterior dislocation)• Failed reduction and recurrent dislocation• Avascular necrosis of the femoral head• Osteoarthritis• Myositis ossificans• Femoral head, neck or shaft fractures in major trauma

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Knee

• AP & Lateral views are standard

• Other views :– Skyline view : Patello-femoral

articulation– Tunnel / notch view :

Intercondylar notch and to identify osteochondral fractures or intra-articular bodies

– Oblique view : Internal/External rotation shows proximal tibio-fibular joint

Knee

Skyline view Lateral view

Ottawa knee rule

Ankle & Foot• Most common to get injured – OTTAWA rules applied clinically

• Ankle x-ray : If Bone tenderness at A / B or Inability to bear weight immediately or in ED.

• Foot x-ray : If Bone tenderness at C / D or Inability to bear weight immediately or in ED.

Ankle Joint• Bony structure of ankle is stabilized by 3 ligament groups

– Medial collateral – Deltoid– Lateral collateral – Anterior talo-fibular, Posterior talo-fibular,

Calcaneo-fibular– Tibio-fibular Syndesmotic complex

• 3 views 1. AP : Both malleoli, distal tib/fib, plafond, talar dome, body

and lateral process of talus, anterior or posterior displacement of the talus, calcaneus.

2. Mortise : Most important- this shows the relationship between the articular surfaces

3. Lateral : anterior and posterior tibial margins, talar neck, posterior talus and lateral calcaneus, ankle effusion

Ankle Joint1 – Tibia2 – Fibula3 – Medial malleolous4 – Lateral malleolus5 – Plafond6 – Dome7 – Talus8 – Calcaneum10 – Anterior colliculus11 – Posterior colliculus

AP view of Ankle Joint

Ankle Joint1 – Tibia2 – Fibula3 – Medial malleolus4 – Lateral malleolus5 – Plafond6 – Dome7 – Talus8 – Calcaneum9 – Posterior malleolus13 – Peroneal groove16 – Navicular 17 – Base of 5th metatarsal18 – Tendo-achilles

Lateral view of Ankle Joint

Ankle Joint

Mortise view of Ankle Joint

Advantages over AP view :• Tibiofibular overlap- 1mm

or less• The normal medial clear

space is less than 4 mm or a difference from medial to lateral of less than 2 mm

• Shows relationship b/w articular surfaces of the Ankle joint

Ankle Joint

• Review areas for #1. Fibula fracture – look

through tibia2. Tibial plafond3. Posterior malleolus4. Flake fractures of navicula

or talus5. Calcaneal fractures6. Anterior process of

calcaneum7. Base of fifth MT

Foot

Other Imaging modality

• Some injuries are poorly visualised on X-rays1) USG – Used to assess soft tissues, muscles, tendons and

ligaments and for intervention; very operator dependent2) CT – Axial slices obtained with multiplanar reconstruction;

good for looking at bones, bone bars and fractures3) MRI – Highly sensitive and specific; shows pathology in

bones, joints, and soft tissues; multiplanar imaging, usually axial, sagittal and coronal

4) Isotopes – Increase of isotope uptake in bones is a non-specific, highly sensitive indicator of disease

Tibial plafond Pilon #Coronal & 3D view

Triplane #Saggital & 3D view

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Which view ? How many fractures?

Thank you…

Ref : 1. ABC of Emergency Radiology 3/e2. www.wikiradiography.com3. Google