Ultrasound and bone: a pictorial review

Abstract

The assessment of bone mainly relies on standard radiographs, CT, MRI, and bone scintigraphy depending on the anatomic region complexity and clinical scenario. Ultrasound (US), due to different acoustic impedance between soft tissues and the bone cortex, only allows the evaluation of the bone surfaces. Nevertheless, US can be useful in the evaluation of several bone disorders affecting the limbs as a result of its tomographic capabilities and high definition. This pictorial review article summarises our clinical experience in adults and reviews the literature on US bone examination. We first present the US appearance of normal bone and the main congenital anatomic variations, after which we illustrate the US findings of a variety of bone disorders. Although US has limits in bone assessment, its analysis must be a part of every musculoskeletal US examination.

Keywords: Bone; Congenital conditions; Infections; Trauma; Tumours; Ultrasound.

Conflict of interest statement

All authors has nothing to disclose.

Figures

Fig. 1

US of normal adult bone. a Longitudinal sonogram obtained aver the palmar aspect of the distal radius. The normal periosteum of the radius (white arrowheads) appears as a thin hypoechoic band located on the bone palmar cortex. b, c Axial conventional (b) and colour Doppler (c) sonograms obtained at the middle of the radius. In b note, a focal break in the cortex which corresponds in c to the location where the nutrient artery (curved arrow) enters the bone. d Axial US image obtained over the radial aspect of the distal radius. US shows a small bone ridge at the insertion of the retinaculum (white arrowheads) of the first compartment of the extensor tendons (ETs)

Fig. 2

Non-fusion of ossification centres. Asymptomatic os acromiale. US (a, b) with axial CT (c) correlation in a patient with os acromiale. Sonogram a obtained over the acromioclavicular joint (line A in C) shows the normal joint (white arrowhead). Note smooth borders of bone ends. b US image obtained over the Os acromiale (OA) (line B in C) exhibits a focal interruption (black arrowhead) of the hyperechoic line corresponding to the bone surface due to non-fusion of the os acromiale. In b, c, note the rough borders of the non-fusion

Fig. 3

Non-fusion of ossification centres. Symptomatic patella bipartita. a, b Axial grey scale (a) and colour Doppler b sonograms with c, d sunrise (c) and A–P (d) standard radiographs. In a obtained at the anterior aspect of the patella (Pat), note the break (arrowhead) of the bone cortex related to synchondrosis between the patella and the unfused bone centre (UBC). b Local hyperaemia due to instability of the UBC. c, d Standard radiographs confirms US appearance

Fig. 4

Non-fusion of ossification centres. Symptomatic avulsed accessory navicular. a Axial oblique grey scale and b, c sagittal T1-weighted MR images obtained (b) at the same level and then (a) at the contralateral ankle (c). In a obtained at the medial aspect of the navicular bone (Nav), note the break (arrowheads) of the bone cortex related to avulsion of the unfused bone centre (UBC). The centre is retracted posteriorly (dotted double arrow) due to traction from the tibialis posterior tendon. In b, MR confirms the retraction of the UBC. Note normal appearance of the navicular in c

Fig. 5

Non-fusion of ossification centres. Asymptomatic os hamuli proprium. US (a) with axial T1-weighted MR image (b) correlation in a patient with os hamuli proprium. Sonogram a obtained over the palmar aspect of the wrist shows a focal interruption (black arrowhead) of the hyperechoic line of the ulnar aspect of the hamatum (H) corresponding to non-fusion of the ossification centre. In B, the MR image confirms the US findings. White arrows = ulnar artery

Fig. 6

Bone coalition. Symptomatic avulsed accessory navicular. a, b Coronal oblique US (a) and 3D CT reformatted image (b) in a patient with talocalcaneal osseous collation. c, d Axial oblique sonogram (c) and PD fat Sat sagittal MR image (d) in a patient with calcaneo-navicular fibrous coalition. a US shows a continuous hyperechoic line (black arrowheads) joining the two bones. b CT confirms the complete bone coalition (black arrowheads). ST substentaculum tali. c The fibrous coalition appears as a beak-like pseudo-joint with irregular borders (white arrowhead). In d, MR confirms the coalition (white arrowhead) and images oedema of the bone marrow (small white arrowheads) due to inflammation related to local impingement

Fig. 7

Bone hyperplasia. Symptomatic hyperplastic peroneal tubercle. a, b Coronal oblique US (a) and PD fat Sat coronal MR image b in a patient with symptomatic hyperplastic peroneal tubercle. a US shows a hyperplastic “beak-like” peroneal tubercle (arrow). The tubercle impinges on the peroneus longus tendon that appears irregular (arrowheads). The peroneus brevis tendon (PB) is normal. b MRI confirms the US appearance. Note oedema of the tubercle and longitudinal split of the peroneus longus tendon (arrowheads) associated with tenosynovitis

Fig. 8

Bone hypoplasia. Hypoplasia of the hook. a Axial US and b PD axial MR image in a patient with hypoplasia of the hook of the hamate. US shows a small (black arrowhead) hook of the hamate bone (H). Note the transverse carpal ligament (white arrowheads) inserting on the tip of the hook. CT carpal tunnel. b MRI confirms the US appearance

Fig. 9

Bone hypoplasia. Glenoid hypoplasia. a, b Posterior (a) and anterior (b) axial US of the gleno-humeral joint. c A-P standard radiograph and d 3D reconstructed CT of the shoulder. US shows a posterior displacement (double dotted arrow) of the humeral head (HH) with respect to the glenoid (G). The radiograph images hypoplasia of the inferior glenoid and a small osteophyte of the humeral head. In d, the posterior instability of the humerus is evident

Fig. 10

Bone hypoplasia. Sternal foramen. a, b Axial grey scale (a) and colour Doppler (b) US of the anterior cortex of the sternum. c, d Axial native (c) and d 3D reconstructed CT of the sternum. In a. US shows a sternal foramen as a focal discontinuity (black arrowhead) of the anterior cortex of the sternum (S). Note the regular cortex surrounding the foramen, absence of periosteal reaction, or soft-tissue masses. In b, note visualisation of the heart (H) due to a full-thickness interruption of the sternum. c, d CT confirms the diagnosis of a sternal foramen

Fig. 11

Occult acute fractures. Greater tuberosity fracture. a Coronal oblique US obtained over the supraspinatus tendon (SSt). b A-P standard radiograph and c, d 2D (c) and 3D (d) reconstructed CT of the shoulder. In a, US shows a non-displaced fracture of the greater tuberosity (GT) of the humeral head (HH). Associated thickening of the wall of the subacromial bursa is present (white arrowhead). Standard radiographs were interpreted as normal. A second lecture made after US showed a possible “in situ” fracture (arrow). CT confirmed the US findings

Fig. 12

Occult acute fractures. Rib fracture. a, b Longitudinal (a) and axial b oblique sonograms obtained over the ninth rib. In a, US depicts a focal interruption (black arrow) of the external cortex of the rib compatible with a minimally displaced fracture. Note thickening of the periosteum (callipers) and swelling of the local soft tissues (black arrowheads). In b, early callus formation appears as a small hyperechoic area (white arrowhead)

Fig. 13

Occult acute fractures. Scaphoid tubercle fracture. a, b Conventional (a) and colour Doppler (b) sagittal oblique US obtained over the palmar aspect of the scaphoid (Sc). c, d sagittal 2D (c) and 3D (d) reconstructed CT of the wrist. Previous standard radiographs were normal. In a US shows a non-displaced fracture (arrow) of the scaphoid tubercle which appears as a small fragment (arrowhead). In b, note local hyperaemia at colour Doppler. c, d CT confirmed the US findings

Fig. 14

Occult acute fractures. Trapezium tubercle fracture. a Axial US obtained over the palmar aspect of the trapezium (Tr). c, d Axial native (c) and 3D (d) reconstructed CT of the wrist. Previous standard radiographs were normal. In a, US shows a non-displaced fracture (arrow) of the tubercle of the trapezium which appears as a small fragment (arrowhead). c, d CT confirmed the US findings

Fig. 15

Occult acute fractures. Peroneal malleolus fracture. a, b Conventional (a) and colour Doppler (b) coronal US obtained over the inferior fibula (Fib). c, d Coronal 2D (c) and 3D (d) reconstructed CT of the ankle. Previous standard radiographs were normal. a US shows an non-displaced fracture (arrow) of the fibula and hypoechoic thickening of the periosteum (arrowheads) that shows hypervascular changes at colour Doppler (b). c, d CT confirmed the US findings

Fig. 16

Complications of fractures. Tendons lesions. a, b Axial (a) and sagittal b colour Doppler in a patient with the previous fracture of the distal epiphysis of the radius. Images show irregularity of the dorsal aspect of the radius with a local beak-like appearance (arrows). The adjacent extensor tendons (arrowheads) are irregular and inflamed secondary to impingement of the aggressive bone

Fig. 17

Complications of fractures. Nerves lesions. a, c Sagittal (a) and axial (b, c) sonograms in a patient with the previous fracture of the radius shaft. In a the superficial branch of the radial nerve (black arrowheads) is hypoechoic and thickened. The nerve is displaced by bone callus (asterisks) which is partially calcified. In b, note the swelling (black arrowheads 3.5 mm) of the nerve in the axial plane compared with the nerve (white arrowhead 1.6 mm) imaged at a more distal level (c)

Fig. 18

Complications of fractures. Postsurgical complications. a Axial sonogram in a patient with the previous fracture of the radius shaft treated by an osteosynthesis plate. A screw’s tip (black arrow) can be seen protruding from the surface of the bone cortex. Note swelling, oedema (asterisks), and hypervascular changes in the soft tissues surrounding the screw due to local impingement. b Longitudinal US images obtained over the lateral aspect of the inferior fibula in a patient with local fracture treated by an osteosynthesis plate. US images the surgical plate (black arrow). Note that the superficial branch of the fibular nerve (black arrowheads) is hypoechoic and thickened because of trauma during recent surgery. c Axial sonogram obtained over the proximal metaphysis in a patient with previous arthroscopic surgery for ACL tear. The screw inside the tibial tunnel (arrows) protrudes from the bone cortex and causes local bursitis (white arrowhead) and pain to local pressure. To confirm the origin of the patient’s pain, a US-guided anaesthetic injection was performed. Note the needle (void arrowheads) inserted under real-time scanning the tip of the needle is in contact with the screw

Fig. 19

Intra-articular fractures: haemarthrosis. a, b Longitudinal (a) and axial (b) sonograms on the long head of the biceps tendon obtained over its intra-articular (a) and extra-articular (b) portion. Images were acquired in a patient with post-traumatic shoulder and negative radiographs. c Coronal oblique T2-weighted MR image. US shows a normal biceps tendon (asterisks). The tendon is surrounded by a hyperechoic intra-articular effusion (arrowheads) suggesting a haemarthrosis. Since no fractures were detected by US, MRI was performed (c) and showed a “in situ” fracture of the surgical neck of the humerus and confirmed haemarthrosis (arrowhead)

Fig. 20

Intra-articular fractures. Lipohaemarthrosis. a Sagittal sonogram on the suprapatellar recess obtained in a patient with post-traumatic knee effusion and pain with negative radiographs. b Horizontal bean radiograph. In note a, the presence of an effusion inside the suprapatellar recess presenting a three-layered appearance separated by two fluid–fluid levels (arrowheads). The superior layer is hyperechoic and corresponds to fat (F) and the thin middle hypoechoic layer corresponds to serum (S), while the deep layer is due to sedimentation of cells content (CC). Radiograph (B) confirms the presence of intra-synovial fat (F) floating on blood (B), but cannot visualise the serum content. CT (not shown) showed an occult non-displaced fracture of the tibial plateau

Fig. 21

Intra-articular fractures. Hill–Sachs fracture. a Axial sonogram on the posterior aspect of the humeral head (HH) obtained in a patient with the previous anterior shoulder luxation. b, c Axial T1-weighted (b) and axial CT arthrogram (c). In a, US shows the fracture impaction (arrow) of the head at the level of the superior infraspinatus tendon (ISt). MRI and CT arthrography in the same patient confirm the US findings

Fig. 22

Intra-articular fractures. Freiberg disease. Sagittal conventional (a) and sagittal colour Doppler (b) sonograms on the dorsal aspect of the second metatarsophalangeal joint. c A-P radiograph. Sonograms illustrate a flattened joint surface (black arrowhead) associated with a small dorsal osteophyte of the second metatarsal (MT2). In b, note synovial hypertrophy with hyperaemia (white arrowhead). Radiograph shows a dense head of the metatarsal with a slightly fat articular surface

Fig. 23

Intra-articular fractures. Osteochondral injury and osteochondral fragments. a, b Axial conventional sonograms on the dorsal aspect of the humeral head (HH) obtained (A) at the level of the infraspinatus tendon (ISt) and b in a more inferior position during maximal internal rotation (curved arrow) of the arm. c Axial native CT image, d, e 3D reconstructed CT images. In a, an intra-articular osteochondral fragment (white arrow) is depicted at the posterior joint space. Note the hyaline cartilage (curved arrow) at the surface of the fragment that has a convex shape. In b, the nidus of the fragment depicts a defect in the joint surface (arrowheads). TMm teres minor muscle, Gl glena. C-E CT confirms the US appearance

Fig. 24

Bone avulsion. Gamekeeper’s thumb. a Coronal oblique conventional sonogram obtained on the ulnar aspect of the metacarpophalangeal joint of the thumb in a patient with gamekeeper’s thumb. Image shows a bone avulsion (white arrow) resulting from a retraction (dotted curved arrow) of a fracture avulsion of the base (white arrowheads) of the proximal phalanx (PP). US can appreciate both the size of the avulsed fragment and then the entity of the proximal retraction. MT first metatarsal

Fig. 25

Bone avulsion. Palmar plate. a, b Sagittal conventional sonograms obtained on the palmar aspect of the proximal inter-phalangeal joint of the third finger in a patient with previous joint sprain. In a, the palmar plate (white arrow) is detached (void arrowhead) from the base of the middle phalanx (MP). Note a fluid effusion (asterisk) inside the palmar proximal joint recess. In a slightly more medial image (b), a cortical fragment (white arrowhead) avulsed from the base (black arrowhead) of the proximal phalanx is evident. US can appreciate both the size of the avulsed fragment and then the entity of the proximal retraction. PP proximal phalanx, FTs flexor digitorum tendons

Fig. 26

Bone avulsion. Rectus femoris tendon. a Sagittal sonogram obtained on the anterior inferior iliac spine (AIIS) shows avulsion (dotted arrow) of a bone fragment (white arrow) from the AIIS which shows irregularity of its surface (white arrowhead). The asterisk points to a local hematoma. b, d STIR (b) and T1-weighted post-injection (c) confirm the US findings. d Anterior oblique standard radiographs

Fig. 27

Bone avulsion. Tibialis posterior tendon. a Sagittal sonogram obtained on the distal insertion of the tibialis posterior tendon (TP) shows avulsion (dotted arrow) of a thin bone fragment (white arrow) from the navicular bone (Nav). Note the defect in the surface of the navicular (white arrowheads). b Corresponding “D reconstructed sagittal CT image confirms the US findings

Fig. 28

Bone avulsion. Os peroneum. a, b Axial oblique conventional (a) and coronal oblique colour Doppler (b) sonograms obtained on the Os peroneum in a patient with recent trauma. Images show a fracture of the ossicle with the presence of a proximal large (white arrow) and a small distal (white arrowhead) fragment. Note proximal displacement (dotted arrow) of the proximal fragment due to traction through the peroneus longus tendon. b Colour Doppler shows local hyperaemia (black arrowheads). c, d Internal oblique radiographs of the affected (c) and contralateral (d) foot. In c, note the fracture avulsion of the upper pole of the os peroneum associated with proximal displacement confirming the US appearance. d A normal os peroneum

Fig. 29

Bone avulsion. Anterior talofibular ligament. Axial oblique sonogram obtained on the talofibular ligament (white arrowheads) shows avulsion of the anteroinferior lateral malleolus (LM) with presence of a displaced (dotted arrow) fragment (white arrow)

Fig. 30

Stress fracture. Femur condyle. a US image obtained over the lateral aspect of the knee, b, c MR images, coronal DP fat sat (b), and sagittal DP in a jogger with clinical suspected iliotibial band syndrome. In a, US shows hyperaemia of the thickened periosteum (black arrowheads) as well as intra-osseous extension of the vessels (void arrowhead). The iliotibial tract and the adjacent soft tissues were normal. MRI (b) images of oedema of the periosteum (white arrowheads) associated with cancellous bone oedema (asterisk). In c, MRI detects a stress fracture as a hypointense line (arrow) parallel to the condylar surface

Fig. 31

Stress fracture. Tibial shaft. a, b Axial (a) and coronal oblique (b) sonograms, d Coronal t2-weighted fat sat MR image. Sonograms show a focal irregularity of the bone surface (black arrowheads) associated with periosteal thickening (white arrowheads) and oedema (curved arrows) of the subcutaneous soft tissues. c MR illustrates in a better detail oedema (asterisk) of soft tissues but also bone marrow oedema

Fig. 32

Stress fracture. Calcaneum. a, b Axial oblique conventional (a) and colour Doppler (b) sonograms. c Sagittal T2-weighted fat sat MR image. Sonograms show periosteal thickening (white arrowheads) of the calcaneum (Calc). Note local hyperaemia at colour Doppler and associated oedema (curved arrows) of the subcutaneous soft tissues. c MR illustrates bone marrow oedema (asterisk) and the stress fracture as a hypointense line (black arrowheads)

Fig. 33

Stress fracture. Os peroneum. a, b Axial oblique conventional (a) and colour Doppler (b) sonograms. c Internal oblique radiograph centred at the cuboid region. In a, b US shows discontinuity (black arrowhead) of the cortex of the os peroneum associated with mild periosteal thickening (white arrowhead) and associated oedema (curved arrow) of the adjacent soft tissues. The inflamed periosteum shows important hypervascular changes (void arrowhead) in b. Note associated oedema (curved arrows) of the subcutaneous soft tissues. In c, the ossicle, enlarged and irregular, presents a fracture with mild displacement. MRI (not shown) confirmed the US data showing bone marrow oedema of the ossicle and associated soft-tissue hyperaemia

Fig. 34

Stress fracture. Metatarsal. a, d Axial and sagittal conventional (a, b) and colour Doppler (c, d) sonograms. US shows periosteal thickening (white arrowheads) of the second metatarsal (MT2). The inflamed periosteum shows important hypervascular changes in the colour Doppler images (c, d). Note associated oedema (curved arrows) of the subcutaneous soft tissues

Fig. 35

Stress fracture. MTP sesamoids. a, b Axial (a) and sagittal (b) colour Doppler sonograms. US shows a focal break (black arrowhead) of the medial sesamoid (MS) associated with periosteal thickening (white arrowheads) and hyperaemia. The lateral sesamoid (LS) is normal. MT1 first metatarsal, FHKL flexor hallucis longus tendon

Fig. 36

Infection. Metatarsal. a, b Axial colour Doppler (a) and sagittal conventional (b) sonograms. c, d axial T1-weighted MR images obtained before (c) and after (d) i.v. contrast administration. US shows a focal break (white arrow) of the superior cortex of the first metatarsal (MT1) related to the previous surgery for chronic osteomyelitis. An abscess (white arrowheads) of the adjacent soft tissues appears on US as an irregular area with peripheral hyperaemia and a fluid–fluid level (void arrowheads). MRI confirms the US appearance. A small fluid collection is located at the plantar aspect of the abscess (white asterisk) surrounded by an area of contrast enhancement (black asterisk)

Fig. 37

Tumour. Solitary osteochondroma in an asymptomatic paediatric patient. a Coronal conventional sonogram obtained over the medial aspect of the proximal tibia in a paediatric patient with a suspicion of pes anserinus tendinitis. b, c A-P (b) and L-L (c) standard radiographs obtained after US. US discloses a focal bulging (large white arrow) of the cortical bone contour just distal to the growing cartilage of the proximal tibia (small white arrow). Note regular thick cartilage cap (white arrowheads). The US appearance is that of an osteochondroma. Standard radiographs confirm the US findings

Fig. 38

Tumour. Solitary osteochondroma in a symptomatic adult. a Coronal conventional sonogram obtained over the lateral aspect of the distal femur in an adult with suspicion of iliotibial band syndrome. b A-P radiograph and coronal STIR MR image (c) obtained after US. US discloses an osteochondroma (large white arrow) covered by a thin cartilage cap (white arrowhead). The osteochondroma displaces the iliotibial band (black arrowheads) which appears hypoechoic and slightly irregular. As a result of local frictions during knee movements, a bursitis is detected by US as a fluid collection (asterisk) located proximally to the osteochondroma. The US appearance is that of an osteochondroma. Standard radiographs show the osteochondroma. MRI confirms the bursitis (asterisk) secondary to frictions of the iliotibial band (black arrowheads) against the osteochondroma

Fig. 39

Tumour. Metastasis. a Coronal conventional sonogram obtained over the spine of the scapula in a patient with night shoulder pain. b A-P standard radiographs obtained after US. US discloses a hypoechoic mass (asterisk) located inside the spine of the scapula. The mass is associated to osteolysis (white arrows) of the superficial and deep cortex. Note extension of the mass into the soft tissues (white arrowheads). b Standard radiograph shows an osteolytic lesion (asterisk) associated with a pathologic fracture (black arrowhead)

Fig. 40

Tumour. Glomus tumour. a, b Sagittal conventional (a) and colour Doppler (b) sonograms obtained over distal phalanx (DP) of the third finger. The glomus tumour (asterisk) presents as an ill-defined ovular mass located between the nail (white arrowhead) matrix (void arrowhead) and the superficial bone cortex. Note scalloping of the cortex (black arrowheads) due to chronic local pressure. In b, the tumour shows internal vascular signals