Joints: Widened Joint Space


Joints: Widened Joint Space

Table 5.24 Joints: joint effusion




Toxic synovitis

Fig. 5.30a, b

Sterile hip aspiration.

Patients tend to have less painful hip symptoms than those with bacterial synovitis.

Septic arthritis

Fig. 5.31a–d

Pus or bacteria found on hip aspiration.

Other clinical parameters that increase the likelihood of bacterial infection prior to a spiration when US shows an effusion are increases in temperature, leukocyte count, and erythrocyte sedimentation rate.

Renal osteodystrophy (primary and secondary hyperparathyroidism)

Fig. 5.26, p. 512

Widened sacroiliac joints.


Mono- and polyarticular forms. Likely to have more chronic symptoms.

Pigmented villonodular synovitis (PVNS)

Fig. 5.32a–d, p. 516

Synovium is dark on T1 and T2-weighted MRI.

Masses of PVNS may appear similar to hyper-trophied synovium of JIA on MRI and US.

Rheumatic fever

Symptoms change more rapidly in rheumatic fever than JIA.

Hemarthrosis (trauma, hemophilia)

Fig. 5.33a, b, p. 517

Uniform joint space narrowing. Hemosiderin in the synovium (dark on T1- and T2-weighted MRI).

Tends to affect large joints. Patients us ually a lready have a diagnosis of trauma or a b leeding disorder.

Fig. 5.30a, b Toxic synovitis left hip. (a) US of the left hip shows a joint effusion and synovial thickening (arrow) when compared to the unaffected right hip (b). c Cartilage e Epiphysis jf Joint fluid L Labrum m Metaphysis p Physis
Fig. 5.31a–d Septic arthritis in an 8-year-old with hip subluxation from a large joint effusion (a, b) that extends into a pus-filled iliopsoas bursa (arrows in c and d).
Fig. 5.32a–d Pigmented villonodular synovitis. (a) Radiography shows erosions (arrows) with adjacent soft-tissue masses (arrowheads). The PVNS is intermediate to low in signal intensity on T1 (arrow in b) and T2 fat-saturated (arrows in c) imaging. Erosions (arrow in d) adjacent to PVNS are better demonstrated on proton-density imaging.
Fig. 5.33a, b Hemophiliac arthritis. (a) T1-weighted MRI with gadolinium shows regions of enhancement around foci of low signal intensity from chronic deposition of blood products in the elbow joint. (b) Four years later, advanced stages of arthritis have manifested with joint space narrowing and bone remodeling.

Table 5.25 Joints: widened and/or dislocated joint space—traumatic and congenital




Traumatic: transient dislocation of the patella

Fig. 5.34a–c, p. 518

Lateral subluxation of the patella.

May be associated with patellofemoral dysplasia. Secondary findings of impaction fractures at the medial pole of patella and lateral femoral condyle, tears of medial retinaculum and vastus medialis.

Traumatic: radial head dislocation

Fig. 5.35, p. 518

Forearm held in pronation on tangential views of the elbow.

Caused by a sudden pull on the extended pronated forearm.

Brachial plexus palsy

Fig. 5.17, p. 505

Widened joint space in the affected shoulder. ± Flattened epiphysis proximal humerus, ± glenoid dysplasia.

Muscular hypotonia from the brachial plexus paresis causes joint instability and dysplasia as the child grows.

Developmental dysplasia of the hip

Fig. 5.20, p. 507

Pulvinar may produce widening of the hip joint and complicate adequate relocation.

Legg-Calvé-Perthes disease

Fig. 5.36a–d, p. 519

Findings depend on the phase of the disease.

Traumatic epiphyseal separation

Widening of the physis ± subluxation of the epiphysis.

Restricted to unossified epiphyses. Humerus (proximal and distal) is commonly affected.


Fig. 5.37a, b, p. 519

Joint space may be widened from erosions.

Early findings of bone marrow edema on MRI may herald later erosions.

Radial head dislocation

Long axis of the radius does not bisect the capitellum.

Progressive radial head deformity is common.

Potter sequence

Dislocated knees, bell-shaped thorax.

Oligohydramnios due to renal agenesis leads to fetal malposition with dislocation of large joints, club feet, typical facies, and pulmonary hypoplasia.


Joint space may be widened by an osteochondroma.

Typically between the radioulnar or tibiofibular joints (proximal or distal).



Collagen vascular disorders

Joint space widening, subluxations, and dislocations.

DD: Marfan and Ehlers-Danlos syndromes.

Diastrophic dysplasia

Micromelic dysplasia with wide metaphyses, dislocations, subluxated elbows, hips, patellae.

Classic hand radiograph with subluxated thumb joints, oval phalanges, joint contractures, scoliosis.

Larsen syndrome

Dislocation of large joints (knees, hips, and elbows).

Fig. 5.34a–c Transient dislocation of the patella. (a) Lateral subluxation of the patella with an avulsion fraction off the medial pole. Bone contusions in the medial pole of the patella (arrow in b) and on the lateral condyle of the distal femur (arrow in c) from impaction by the patella.
Fig. 5.35 Radial head dislocation. A line drawn through the center of the long axis of the proximal radius does not bisect the center of the capitellum.
Fig. 5.36a–d Legg-Calvé-Perthes disease. Avascular necrosis (AVN) at the proximal epiphysis of the left femur in a patient with Legg-CalvéPerthes disease. Mild increased sclerosis on presentation (a) with decreased T1-weighted signal intensity (b) and increased T2-weighted signal intensity on MRI (c), as well as increased sclerosis 6 months later (d).
Fig. 5.37a, b Juvenile idiopathic arthritis and sacroiliitis. Bone marrow edema on T2-weighted imaging (arrow in a) at the right sacroiliac joint with enhancement on T1-weighted imaging (b).

Table 5.26 Joints: congenital radial head dislocation



Noonan syndrome

Male Turner syndrome. Multisystem involvement. Anterior bowing of the sternum, genu valgum, finger anomalies, scoliosis, vertebral anomalies, Klippel-Feil syndrome.

Holt-Oram syndrome

Radial ray anomalies, hypoplastic clavicle and/or glenoid, Sprengel deformity, pectus deformities, rib anomalies.

Ulnar hypoplasia

Isolated ulnar hypoplasia or associated with other anomalies.

Campomelic dysplasia

(see Table 5.96 )

Osteoonychodysplasia (nail–patella syndrome)

Hypoplastic or absent patella, iliac horn arising offthe central outer surface of the ilium, flared iliac wing, and small iliac angle.

Multiple epiphyseal dysplasia, Fairbank type

Small irregular epiphyses. Flattened and multicentric epiphyses at the femoral head.

Léri-Weill dyschondrosteosis

Most common form of mesomelic dwarfism. Madelung deformity, shortening of both tibias.

Russell-Silver syndrome

Finger anomalies, asymmetric skeletal maturation (left vs. right), urinary system anomalies.

Cornelia de Lange syndrome

(see Table 5.50 )

Acromesomelic dysplasia

Short tubular bones particularly at the forearms, cone-shaped epiphyses of the phalanges and metacarpals, premature epiphyseal fusion of hands and feet, large great toes.


Dysplasia of the radiocapitellar joint, ± radial head dislocation. Characteristic ear shape and short stature.

Larsen syndrome

(see Table 5.34 )

Mesomelic dysplasia, Nievergelt type

(see Table 5.51 )

Otopalatodigital syndrome I (Taybi syndrome)

Hypoplastic clavicle, scoliosis, joint subluxations, long fingers and toes. Dense skull base, under-pneumatization of skull, short thumbs and great toes.

Trichorhinophalangeal dysplasia, types I and II

(see Table 5.33 )

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Jul 12, 2020 | Posted by in PEDIATRIC IMAGING | Comments Off on Joints: Widened Joint Space

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