General Radiology: Limbs - Knee, Ankle, and Foot - PDF

General Radiology MPA 502 Limbs Part 6 By: Bernadette Evitt, MCMS, PA-C 1  Objectives Identify anatomical structures on radiographs of the knee, lower leg, and foot. Identify various fracture patterns. Based on etiology, history, physical, and radiographic ima...

General Radiology MPA 502 Limbs Part 6 By: Bernadette Evitt, MCMS, PA-C 1  Objectives Identify anatomical structures on radiographs of the knee, lower leg, and foot. Identify various fracture patterns. Based on etiology, history, physical, and radiographic images, identify knee injuries including tibial plateau fracture, knee dislocation, patellar fracture, tibial/fibular fractures. Based on etiology, history, physical, and radiographic images, identify ankle injuries including sprains, fractures, and Maisonneuve fracture. Based on etiology, history, physical, and radiographic images, identify foot injuries including calcaneal fracture, Jone’s fracture, and March fracture. Define and classify Salter Harris fractures, including slipped capital femoral epiphysis. 2  Knee - Anatomy Anteroposterior Normal Knee X-ray Lateral (ML) Normal Knee X- 3  Knee - Anatomy Skyline view of the knee, 4 Knee - Views Merchant view Sunrise view 5 Knee - Dislocation H&P - direct force or activity of the quadriceps. obvious deformity, numbness, decreased pulses. Dx - Knee xray AP, lat, and sometimes oblique views MRI to rule out cartilage damage. Post and Lat Dislocation of Knee. Tibia is displaced laterally and posteriorly relative to the femur (red arrow). The patella is displaced laterally (black and white arrows) and comes to lie over the lateral femoral condyle. Some degree of rotational6 force is usually required to produce  Knee - Patellar fracture: H&P - direct trauma or a forceful contraction of the quadriceps (sudden fall or sports injury). Swelling, bruising, inability to straighten the knee, tenderness, and if also displaced a visible deformity; inability to walk Patellar x-ray Sunrise view Dx – knee xray AP, lat, skyline. Aka skyline axial CT if comminuted. MRI if occult. Patellar Fracture Bipartite Patella Bone scan. Distinguish bipartite from fx. Bipartite: wide gap, round contours, smaller piece. https://insightsimaging.springeropen.com/articles/10.1007/s13244-016-0535-0 7 Knee - Patellar fracture: Fracture skyline view 8  Knee - Patellar fracture: CT reformatted image showing displaced comminuted fracture. (a) Drawing, (b) anteroposterior radiograph, and (c) sagittal computed tomography showing displaced comminuted fracture. Note that the degree of displacement is better appreciated on the 9 reformatted CT image than on conventional radiograph  Knee - Tibial plateau fracture H&P - high energy axial loading and valgus force more common than varus force (fall, MVA, sports). Inability to put wgt on the leg. Dx - knee x-ray AP, lat, oblique, cross table lateral (aka horizontal beam lateral) views. Can be simple, comminuted or depressed. most often fractured. AP Rt Knee X-ray, lateral tibial plateau fx 10  Knee - Tibial plateau Comminuted left fracture tibial plateau fracture (A) AP of left knee - no evidence of fracture. (B) MRI (coronal T2-weighted fast field echo imaging) revealed left tibial plateau fracture. (C) MRI (coronal proton density-weighted fast spin echo imaging) revealed left tibial plateau fracture. 11 Tibial / Fibular Fracture H&P - Falls, MVA, twisting injury (sports). Inability to walk, limp, numbness in foot, tenting. Perform neurovascular exam. Dx – lower leg x-ray PA and lat. MRI for occult stress fracture. Fx line (spiral common), displacement, butterfly fragment (comminuted). Fibular Fx oblique fx tibial shaft (red arrow). Fibula fx (blue arrow). 12 Ankle - Views 13 Ankle Anatomy – AP View 14 Ankle Anatomy – Lateral View 15 Ankle Anatomy – Mortise View Mortise view Oblique 16  Tibial plafond (pilon) fracture H&P - high-impact trauma (falls height, MVA, skiing) or low impact with osteoporosis. Inability to bear weight, considerable bruising, swelling, and skin blistering about the ankle; open fx in 20%. Watch compartment syndrome. Dx - Ankle X-ray AP, lat, mortise. Fx inferior tibia at articular surface. Frontal View 17  Tibial plafond fracture Mortise (A) and lateral (B) plain radiographs of a complete articular injury. the entirety of the articular surface of the tibial plafond is separate from the distal metadiaphysis of the tibia. Significant comminution of the articular surface. 18 Ankle - Maisonneuve fracture H&P - Force on externally rotated foot. P., swelling, inability to put wgt, deformity, tenderness medial and lateral, + squeeze test for ligament injury. Watch peroneal n. injury (weakness on dorsiflexion, eversion); numbness lateral lower leg and dorsum of foot. Dx - Ankle x-ray AP, lateral, and mortise, and Tib-fib X- rays. MRI to assess ligaments. Unstable fx typically involving medial tibial malleolus 19 &/or disruption of distal  Ankle - Maisonneuve fracture Mortise view of ankle AP knee view Medial clear space widening (deep deltoid ligament disruption) with associated proximal fibular fracture. https:// coreem.net/ core/ 20 maisonneuve-  Foot – Anatomy AP View 21 Foot – Anatomy Lateral View 22 Foot – Anatomy Medially rotated oblique view 23 Foot - Calcaneal (lover's) fracture H&P – axial loading (fall from hgt). Tenderness, ecchymosis extending along plantar arch, potential skin tenting in severe cases, esp. w/ "tongue-type" fxs (displacement of bony prominence in posterosuperior direction) Dx - calcaneal series: AP, lat, axial (plantodorsal aka Harris view), oblique. Most commonly fractured tarsal bone. Axial view Lat - measure Boehler's of angle. Angle < 28 degree = calcaneus fx of calcaneus. Obtain views of the thoracolumbar spine if a calcaneal fracture is found. CT is also commonly used. 24  Foot - Calcaneal (lover's) fracture Bilateral calcaneal fxs and fxs of spine. Comminuted fx of left calcaneous (white arrow); comminuted fx of the right calcaneous (red arrow) w/ flattening of Boehler's Angle to 0 degrees. Sagittal reconstructed CT of spine shows compression fxs of superior endplates of T12 and L1 (yellow arrows). 25  : Foot - March fracture H&P - Repeated concentrated trauma to a normal bone, classically 2nd metatarsal. Ballet dancers, athletes and soldiers, Dx – Foot x-ray AP, lat, oblique. MRI AP - Periosteal thickening & elevation of the distal 3rd of the 2nd metatarsal of the R foot, w/ transverse fx line. 26  Foot - Jones' fracture H&P - Plantar flexion and ankle inversion. Athletes. This area has lower blood supply, so it takes longer to heal. Dx – Foot x-ray AP, oblique, lat w/ foot in flexion. Stress fx of the base of the 5th metatarsal, diaphysis. Transverse fx at base of 5th metatarsal 1-2cm from the tuberosity of the 5th metatarsal. 27 Salter Harris Fracture A fx that of the epiphyseal plate or growth plate of a bone. I - S = Same (straight across) II - A = Above (above physis or Away from joint) III - L = Lower (below physis in the epiphysis) IV - T = Through (through metaphysis, physis and epiphysis) V - R = Rammed (physis has been crushed) It is a common injury found in children, occurring in 15% of childhood long bone fractures. 28  Salter Harris Fracture I – Slipped Capital Femoral Epiphysis SCFE H&P - loss of hip flexion & ability to rotate hip inward. Tall heavy (obese) teenager (child) c/o reporting p of groin pain, medial thigh, &/or knee; acute or insidious On plain x-ray, femoral head onset of limp. Immediate tx. is displaced, posteriorly & inferiorly to femoral neck & 6% incidence within confines of Risk factors: Obesity, acetabulum. medications (steroids), thyroid, radiation tx, chemo, bone problems related to kidney dz. Dx - Hip x-rays of hip AP & frog-leg lat. If the SCFE is unstable, a cross-table lateral view is also taken.29  Salter Harris Fracture I – Slipped Capital Femoral Epiphysis SCFE Complication: AVN and Chondrolysis (arthritis where cartilage of the joint is abruptly lost.) Tx - internal fixation. Hospital admission Pediatric Orthopedist. Surgery in 24-48 hr, Crutches, PT, X- ray q 3-4 months, Periodic FU x 2 years. AVN AVN with collapsed head http://www.learningradiology.com/archives2008/COW%20307-Salter%201%20fx/salter1correct.html 30 Salter Harris Fracture Salter Harris Fracture II Salter Harris Fracture III Type II – A fracture through the Type III – A fracture through growth growth plate and the metaphysis plate and epiphysis, sparing , sparing the epiphysis the metaphysis 75% incidence 8% incidence 31  Salter Harris Fracture Salter Harris Fracture IV Salter Harris Fracture V Type IV – fracture through (through Type V – fracture through all three the metaphysis, physis and epiphysis) elements of the bone, the growth plate, metaphysis, and 10% incidence epiphysis complete impaction across the physis (growth plate). 10% incidence 32  References Ouellette H, MD; Tetreault P, MD. Clinical Radiology, made ridiculously simple, 2 nd ed. Miami: MedMaster, 2008 Radiology Masterclass – free tutorials https://www.radiologymasterclass.co.uk/tutorials/tutorials Basics of Radiology, Heřman, Miroslavetal. https://eds.p.ebscohost.com/eds/ebookviewer/ebook/ ZTAwMHhuYV9fMzE3NzAwN19fQU41?sid=6f3abe64-8c91-41ae-8aee- 5a81004c8a33@redis&vid=1&format=EB The End of Part 6 33