LOOSE (PAINFUL) JOINT REPLACEMENT 289 Fig. 19.12 the right femoral component consistent with infection. AP radiograph of right hip replacement showing patchy cement lysis of SUBASH KC/NMC-15TH/2014 290 CHAPTER 19 Musculoskeletal conditions Primary bone tumors Malignant primary bone tumors are a varied group of neoplasms. They acc ount for only 2/1000 cancers diagnosed and are predominantly seen in children or adults > 5 5 years. They arise from the various elements of bone: osteoid (osteosarcoma), cartilage (c hondrosarcoma), and neural elements (Ewing \200\231s sarcoma). Clinical presentation \200 The age of presentation is the key to the differential diagnos is. \200 Pain is the commonest presentation. \200 Weight loss or malaise. \200 Fever of unknown origin. \200 Swelling at the site of pain. \200 Pathological fractures. Imaging Plain \201 lm (Fig. \200 This is the initial imaging modality of choice. \200 2 \201 lms are taken in perpendicular planes. \200 1 of these views needs to show the whole length of the bone. \200 The following features are important: 19.13 ) Single or multiple. \200 The site of the lesion (epiphyseal, metaphyseal, or diaphyseal). \200 The margins of the lesion (well de \201 ned or ill de \201 ned). \200 Bony expa nsion and breach of cortex. \200 Presence of calci \201 cation in the lesion or surround ing the lesion. \200 Periosteal reaction. A chest radiograph is indicated to exclude metastases. CT \200 This is usually only used to stage the chest. \200 Where necessary CT can be us ed to assess calci \201 cation of the lesion. MRI \200 This is used for local staging to assess the full extent of the lesion, which co mpartments it has breached and whether local neurovascular bundles are involved. Standard protocols include T1, fat saturated T2 sequences, and post-contrast T1 images in orthogonal planes. Scintigraphy A bone scan is indicated to look for bony metastases. Information for the radiologist \200 Age and presenting symptoms. \200 History of malig nancy. \200 Biochemical markers including parathormone levels if suspicion of hyperparathyroidism or renal failure. Tumor markers. SUBASH KC/NMC-15TH/2014 PRIMARY BONE tumors 291 (a) (b) Fig. 19.13 A 67-year-old male presented with knee pain. a) AP and b) lateral radiographs of the proximal tibia show an area of ill-de \201 ned sclerosis with periosteal reaction. Th is proved to be late onset osteosarcoma of the tibia. SUBASH KC/NMC-15TH/2014 292 CHAPTER 19 Musculoskeletal conditions Bone metastases Bony metastases are common. They may be either osteolytic (bone destroying) or osteosclerotic (bone forming). Primary malignancies produce different types of metastas es (see Table ones the most common. 19.3 ) with osteolytic Table 19.3 Common malignancies and type of bone metastases Name Meaning Lung Usually osteolytic Breast Either osteolytic or osteosclerotic Colorectal Osteolytic Prostate Osteosclerotic Renal cell carcinoma Osteolytic with expansion Upper GI cancers Osteolytic Gynecological Usually osteolytic Clinical presentation \200 Non-speci \201 c pain. \200 Pyrexia. \200 Fractures of th e involved bones. Imaging Plain \201 lm (Fig. \200 Radiography is the usual \201 rst-line investigation . \200 Multiple myeloma should always be considered in the differential 19.14 ) diagnosis. Lytic bone lesions may only cause a subtle discontinuity of the trabeculae. Lung is the most common primary. Sclerotic metastases show up as either a generalized bone density increase or as discrete deposits. In men the commonest primary is prostate and in women it is breast. Long-bone fractures with irregular and patchy bone texture should raise the suspicion of a metastasis. Femoral deposits need prompt recognition, as they can be prophylactically \201 xed with an intramedullary nail. CT \200 CT is has a high sensitivity for metastatic deposits. \200 CT shows metastases best bone windows. \200 De \201 nitive diagnosis can be made by a CT-guided biopsy. Bone scan \200 Bone scintigraphy is very good at demonstrating the full extent of bony metastatic spread. SUBASH KC/NMC-15TH/2014 BONE METASTASES 293 It shows areas of high bone turnover. Therefore sclerotic metastases may be poorly demonstrated. MRI MRI is reserved for problem solving, e.g. differentiating between vertebral body collap se secondary to osteoporosis or metastasis. PET-CT \200 PET is both a functional and anatomical imaging method that can identify metastatic deposits by their glucose uptake. PET has a high sensitivity and speci \201 city for identifying bony metastasis and is used after discussion at the MDT. Information for the radiologist \200 Area of the pain. \200 Oncological history. \200 Tumor markers and calcium levels. (a) (b) Fig. 19.14 fall. a) AP and b) lateral radiographs show an ill-de \201 ned lytic/sclerotic lesion in the intertrochanteric region with a break in the superior cortex. The appearances are consistent with a pathological fracture through a metastasis. A 70-year-old patient presented unable to weight bear after a minor SUBASH KC/NMC-15TH/2014 294 CHAPTER 19 Musculoskeletal conditions Myeloma Myeloma is a malignancy characterized by monoclonal proliferation of malignant plas ma cells. It is the most common primary malignant neoplasm in adults and commonly occurs in the 5 th \200\2238 th decades. \200 It occurs in 2 forms: Disseminated (more common). \200 Solitary. This represents the early stages of multiple myeloma and precedes the disease by 1 \200\22320 years. Occurs most commonly in the thoracolumbar spine > pelvis > ribs > sternum. Clinical presentation Bone destruction This can lead to : \200 Vertebral collapse. \200 Hypercalcaemia. Bone marrow in \201 ltration \200 Anemia. \200 Neutropenia. \200 Thrombocytopenia. \200 Renal impairment. Imaging Plain \201 lm Due to the multicentricity of the disease process, a skeletal surve y is required to ensure that no regions of disease have been missed. \200 Diffuse permeat ive lesion (can mimic sarcoma or lymphoma). \200 Widespread osteolytic lesions with a pun ched-out appearance and endosteal scalloping. Expansile osteolytic lesions (ballooning) in ribs, pelvis, long bones. \200 A soft tissue mass may be identi \201 ed adjacent to the area of bone destruction. Bone scintigraphy Myeloma is one of the lesions that is not characteristically \200\230hot \200\231 on a bone scan, therefore plain \201 lms are commonly used for the skeletal sur vey. CT (Fig. \200 Acute myeloma: Swiss-cheese pattern, with multiple \200\230holes \200\231 in the 19.15 ) bone. Chronic myeloma: dense, thick, bony struts. MRI MR imaging allows characterization of the bone lesions and any associated soft tissue c omponents. \200 T1-weighted: multiple focal hypointense area. \200 T2-weighted: corresp onding hyperintense regions. \200 Characteristic \200\230mini-brain \200\231 appearance. SUBASH KC/NMC-15TH/2014 MYELOMA 295 Information for the radiologist \200 Plasma electrophoresis/biochemistry results. \200 Site of patient \200\231s symptoms. \200 History of previous solitary plasmacytoma. Fig. 19.15 Sagittal CT reformat of the cervical spine demonstrating lytic lesions in the po sterior elements of C6 and the body of T1 (arrows) consistent with multiple myeloma. SUBASH KC/NMC-15TH/2014 296 CHAPTER 19 Musculoskeletal conditions Benign bone lesions The most common metaphyseal and epiphyseal benign bone lesions are simp le bone cysts, giant cell tumors, and aneurysmal bone cysts. Clinical presentation \200 Asymptomatic. \200 History of minor trauma that is unrelated to the condition. \200 May present with a pathological fracture. Imaging Plain \201 lm (Fig. Simple bone cyst \200 Skeletally immature patients (epiphys eal fusion has not yet taken place). \200 This is the diagnostic modality of choice. \200 Simple bone cysts are usually well circumscribed with a single cyst and 19.16 ) expansion of the bone. They are commonly seen in the humeral head. Pathological fractures through them are common with the \200\230fallen fragment \200\231 sign, a fragment of bone seen within the cyst that has fractured. Aneurysmal bone cyst (ABC) \200 Skeletally immature patients (epiphyseal fusion has not y et taken place). \200 An expanded lesion in the bone with multiple cystic areas. \200 A BCs do not extend to the joint surface. \200 Pathological fractures occur but they do not show the fallen fragment sign. Giant cell tumor (GCT) \200 GCTs are seen in skeletally mature patients. \200 This tumo r is a multicystic expansile lucent lesion. \200 GCTs extend to the joint surface. CT CT is used to characterize the fractures in the tumors. MRI MRI is used to demonstrate the full extent of these lesions as well as the characterist ics of their contents. Information for the radiologist \200 Clinical presentation. \200 Patient \200\231s age. \200 In \202 ammatory markers. SUBASH KC/NMC-15TH/2014 BENIGN BONE LESIONS 297 (a) (b) Fig. 19.16 pain in their shoulder after a fall. These demonstrate a well-de \201 ned lucen t lesion in the proximal humerus. There is a clear zone of transition. There is a break in the lateral cortex. The appearances are typical of a fracture through a unicameral bone cys t. a) AP and b) axial shoulder radiographs taken after patient complained of SUBASH KC/NMC-15TH/2014 298 CHAPTER 19 Musculoskeletal conditions Diaphyseal benign bone tumors Benign bone lesions are relatively uncommon. There are only 3 benign bone lesions that occur in the diaphysis: the \201 brous cortical defect (of no c linical concern), \201 brous dysplasia (seen in children and resulting in mild deformity of bone), and osteoid osteoma (painful condition affecting children). Clinical presentation \200 Fibrous cortical defects and \201 brous dysplasia are usuall y asymptomatic. \200 Non-speci \201 c pain. In the case of osteoid osteoma, children get night pain relieved by NSAIDs. Fractures of the involved bones. Imaging Plain \201 lm (Fig. \200 Plain radiographs are the modality of choice. \200 A \201 brous cortical defect is a lytic lesion adjacent to the cortex that 19.17 a) disappears after fusion of the growth plate. Fibrous dysplasia is a lytic bone lesion with well-de \201 ned margins and a \200\230ground glass \200\231 matrix. Osteoid osteoma is a bone-forming tumor that presents as a thickened area of cortex in a lo ng bone although vertebral body osteomas are also known. CT \200 CT has a high sensitivity for osteoid osteoma and is the modality of choice to con \201 rm the diagnosis. CT shows a thick cortex with a lucent area in the center. \200 De \201 nitive diagnosis is often made by a CT-guided biopsy and is used to guide therapy. Bone scintigraphy Osteoid osteomas have high bone turnover and will show as a focus of high uptake. MRI (Fig. MRI is reserved for dif \201 cult atypical cases. 19.17 b) Information for the radiologist \200 Area of the pain. \200 Relevant history. \200 Re levant biochemical results including tumor markers and calcium levels. SUBASH KC/NMC-15TH/2014 DIAPHYSEAL BENIGN BONE tumors 299 (a) (b) Fig. 19.17 pain. a) AP radiograph shows mid diaphyseal lesion with chronic perosteal reacti on and medullary lysis. b) T1FS coronal MRI shows extensive in \202 ammation associated wi th this but no soft tissue mass. The appearances are consistent with eosinophic granuloma. An 8-year-old patient presented with a 2-month history of left thigh SUBASH KC/NMC-15TH/2014 300 CHAPTER 19 Musculoskeletal conditions Sclerotic bone lesions The underlying cause for these range from congenital abnormalities t hrough to malignant secondaries. Benign causes \200 Osteoid osteoma. \200 Bone island. \200 Chondroid lesion. \200 P aget \200\231s disease. \200 Infection. \200 Sequestrum. \200 Bone infarct. Clinical presentation This is important as presentation can help to differentiate the under lying cause. Incidental \201 nding In an otherwise well patient this is an essentially reassuring scen ario and would imply that may it well be long-standing in nature. This does not exclude agg ressive lesions. Raised in \202 ammatory markers In this setting an in \202 ammatory process, most likely infection, should be actively investigated as obviously if this is the cause then it is tre atable. Pain The type of pain can be very helpful as ostoid osteomas classically present with night pain that is relieved by NSAIDs. Night pain is, as a rule, a worrying symptom and will war rant a full work-up for an aggressive etiology. Imaging Plain \201 lm These remain the mainstay for initial investigation and usually wil l provide the diagnosis. Key \201 ndings are the transition zone, the age of the patient, and the location of the lesion. Lesions with ill-de \201 ned margins tend to be aggressiv e whereas a well-demarcated margin with a sclerotic edge is reassuring. CT (Fig. This is good for looking at the bony anatomy and the zone of transition. CT will c on \201 rm the diagnosis of osteoid osteoma by con \201 rming its intra- cortical locatio n. In cases of infection it will demonstrate sequestra (dead pieces of bone) that can act a s nutrient reservoirs for bugs. 19.18 ) MRI This is good for demonstrating the soft tissue elements of a lesion as well as involvem ent of joints and local neurovascular bundles. In cases of infection this will show the ful l extent of any osteomyelitis as well as any abscesses. SUBASH KC/NMC-15TH/2014 SCLEROTIC BONE LESIONS 301 Information for the radiologist \200 Does the patient have a known primary tumor? \200 Is the lesion painful and if so when. Fig. 19.18 widespread sclerotic lesions consistent with disseminated prostate metastases. Coronal CT reformation of the pelvis and lumbar spine showing SUBASH KC/NMC-15TH/2014 302 CHAPTER 19 Musculoskeletal conditions Paget \200\231s disease This is a condition where there is a localized increase in size and numbers of osteoclasts leading to an increased rate of osteolysis. This is followed by a c ompensatory increase in osteoblasts causing accelerated bone deposition. This combination o f factors results in the classical Pagetic appearance with a larger, chaotic and sclerotic bone. In early stages areas of ostolysis will be seen, classically in the skull \200\224 o steoporosis circumscripta. Clinical presentation \200 This rarely occurs in patients <40 years of age. The majority of patients are asymptomatic and it is a purely coincidental \201 nding. Symptomatic patients complain of bone pain, headache, hearing-loss, and hip pain. As Pageti c bone loses its \202 exibility pathological fractures are well described. Sarcomatous change in osteosaroma can occur in 1 % of patients as a complication of Paget \200\231s disease. Imaging Plain \201 lm (Fig. These are the mainstay for diagnosis and follow-up of Paget \200\231s disease. This classically demonstrates and enlarged, sclerotic bone with a promin ent trabecular pattern. 19.19 ) Incremental stress fractures are well seen on these and develop on the convex sides of long bones. Bone scintigraphy Paget \200\231s shows a classical whole bone intense activity that is usu ally diag- nostic from the far end of the reporting room. Exceptions to this are when there is sarcomatous change or in osteoporosis circumscripta where there will be areas of lower uptake. CT and MRI These are good at demonstrating the full extent of the bony involvement. They ar e, however, reserved for dif \201 cult cases where the diagnosis is in doubt or where ther e has been sarcomatous change to assess the extent of the tumor. Information for the radiologist What are the patient \200\231s symptoms and has there been any recent change in these? SUBASH KC/NMC-15TH/2014 PAGET \200\231S DISEASE 303 (a) (b) Fig. 19.19 prominent sclerotic trabeculae. b) Image shows the marked bowing of the tibia. a) AP radiograph of tibia showing the classical enlarged bone with SUBASH KC/NMC-15TH/2014 304 CHAPTER 19 Musculoskeletal conditions Avascular necrosis Avascular necrosis (AVN), also known as osteonecrosis, is the cellular d eath of bone secondary to interruption of its blood supply. It affects bones with a single terminal blood supply and is most commonly seen in the epiphyses of long bones, e.g. the fe moral head. Causes of avascular necrosis \200 Idiopathic. \200 Trauma. \200 Steroids. \200 Alco hol. \200 Caisson disease. \200 Haemoglobinopathies. \200 Connective tissue disorders . \200 Hyperlipidaemia. \200 Renal transplant. \200 Gaucher \200\231s disease. \200 Radiotherapy. \200 Bisphosphonates (osteonecrosis of mandible). Clinical presentation AVN may be asymptomatic and an incidental \201 nding. The commonest presenting feature is pain followed by decreased range of movement. Imaging Plain \201 lm (Fig. Plain radiographs are often normal. Early radiographic \201 ndings are subtle changes in bone density. Features of advanced disease include suchondral lucencies, collapse of the articular surface, and deformity. The joint space is preserved until late in the disease. 19.20 ) MRI This is the most sensitive modality for the detection of AVN. The earliest sign is decr eased contrast enhancement in areas of compromised blood supply. Bone marrow oedema best se en on T1-weighted images is an early non-speci \201 c sign. Later, after the onset of osseous repair the classical double line sign may be demonstrated in 80 % of cases on T2-weighted sequences. This sign describes an inner hyp erintense line (hyperaemic granulation tissue) and an outer hypointense line (chemical shif t artifact). This sign is considered pathognomonic of the AVN. Nuclear medicine While MRI is the modality of choice in suspected AVN, bone scintigraphy an d SPECT may be used in the diagnostic work-up of a patient with bone pain. The main feature described is a cold spot representing the area of ischaemia which may have a surrounding a rea of increased signal. Information for the radiologist The site of pain, duration of symptoms, and any risk factor s for AVN. SUBASH KC/NMC-15TH/2014 AVASCULAR NECROSIS 305 Fig. 19.20 Scaphoid radiograph showing a scaphoid non-union. The proximal pole of the scaph oid is more sclerotic than any of the carpal bones consistent with AVN. SUBASH KC/NMC-15TH/2014 306 CHAPTER 19 Musculoskeletal conditions Osteoporosis Reduced bone mass due to equal reduction in both osteoid (matrix) and hydroxya patite (mineral) content. The proportion of mineralization remains the same and is normal. It may be primary (age related) or sec- ondary to another condition. Secondary causes include: \200 Malabsorption (e.g. coeliac/Crohn \200\231s). \200 Renal failure. \200 Hyperparathyroidism. \200 Drugs (e.g. steroids, heparin, anticonvulsants ). \200 Oophorectomy (hypogonadism). \200 Cushing \200\231s syndrome. \200 Acromegaly . \200 Rheumatological disease. \200 Hematological disease. Clinical presentation Presentation is usually with osteoporotic fractures or through screen ing in those with risk factors (listed). Common sites for fracture are the distal radius, f emoral neck, wedge fractures of thoracic and lumbar vertebrae. All these occur with minimal trauma, which should alert the clinician to the underlying cause. Risk factors \200 Increasing age. \200 Female sex. \200 Smoking. \200 Excess alcoho l. Lack of exercise. \200 Early menopause. \200 Low body mass index. \200 Family history . Imaging Plain \201 lm Diffuse osteopenia with cortical thinning may be present, although there has to be signi \201 cant bone loss before the changes become radiographi- cally app arent. This can make early disease detection dif \201 cult. Fractures of the sites listed previously with resulting kyphosis of the thoracic and lumbar spine may be identi \201 ed. Dual energy X-ray absorptiometry (DEXA) This is the most accurate and widely available tech nique. Multiple sites are assessed and a standard deviation from the mean of a young adult (T-score) is obtained. The World Health Organization de \201 nitions are: \200 Normal: T > 1. \200 Osteopenia: T < \210\222 1 to > \210\222 2.5. \200 Osteoporosis: T < \210 \222 2.5. 1 MRI/CT/NM : none of these are routinely used in the diagnosis of oste- oporosis. Information for the radiologist Any relevant risk factors or possible primary causes. Suspi cion due to pre- vious characteristic fractures. SUBASH KC/NMC-15TH/2014 OSTEOPOROSIS 307 (a) (b) Fig. 19.21 a fracture through the sacrum. b) A STIR sagittal MRI con \201 rming the extent of this fracture. This is an unusual injury in such a young person and is consistent with severe osteoporosis secondary to alcohol abuse. A 25-year-old alcoholic who fell down onto his bottom. a) Image shows Reference 1 World Health Organization . Assessment of Fracture Risk and its Application to Screening for Postmenopausal Osteoporosis , 1994 . Organization . WHO Technical Report Series 843 . Geneva : World Health SUBASH KC/NMC-15TH/2014 308 CHAPTER 19 Musculoskeletal conditions Osteomalacia Abnormality of the bones due to reduced bone mineralization that occurs during adulthood. Failure of mineralization in children results in rickets. Histology shows a red uction in hydroxyapatite but normal osteoid matrix content. Clinical presentation Presents with bone pain, non-speci \201 c aches, fractures, and prox imal muscle weakness. A waddling gait and con \201 rmation of proximal muscle weakness is found on examination. Blood tests are not diagnostic and vary during disease stages. They c an include low phosphate, low calcium, low vitamin D, raised alkaline phosphatase, and rais ed parathyroid hormone. Causes Vitamin D de \201 ciency: Renal disease: Reduced sunlight \200 Low oral intake \200 Malabsorption \200 Liver disease exposure Chronic renal failure \200 Dialysis related bone disease \200 Renal tubular acidosis \200 Fanconi \200\231s syndrome Vitamin D-dependent rickets X-linked phosphataemia rickets (hereditary) (hereditary) Multiple myeloma Anticonvulsants Imaging Plain \201 lm (Fig. Looser \200\231s zone (pseudofractures) are radiolucent lines with sclerotic margins that extend from the cortex. These are most commonly found in the m edial femoral neck, axillary border of scapula, ribs, and pubic rami. In more severe diseas e a complete pathological fracture may occur. Patients usually have coarsening of the trabe culae, however some may have gen- eralized osteopenia. 19.22 ) MRI/CT These can be used to identify early radiographically occult fractures. This is usual ly when there is a high index of clinical suspicion but no radio- graphic abnormality prese nt. They also have a role where the radiographic \201 ndings are inconclusive. Nuclear medicine Bone scan shows diffusely increased uptake with no evidence of renal excre tion which is termed a \200\230superscan \200\231 appearance. This can also be used to con \201 rm fractures. Information for the radiologist Clinical history and serological tests may help. Conveying a suspicion of osteomalacia is essential to diagnose the subtle plain \201 lm changes. SUBASH KC/NMC-15TH/2014 OSTEOMALACIA 309 (a) (b) Fig. 19.22 with splaying and fraying of the metaphyses. Images a) and b) demonstrate the pathognomonic appearances of rickets SUBASH KC/NMC-15TH/2014 This page intentionally left blank SUBASH KC/NMC-15TH/2014 311 Chapter 20 Trauma Head trauma 312 Facial trauma 314 Spinal trauma 316 Thoracic trauma 318 Abdominal trauma Pe lvic fractures 322 Shoulder trauma Elbow trauma 326 Hand and wrist trauma 328 Proximal femo ral fractures 332 Knee injuries 334 Ankle trauma 336 Calcaneal fractures 320 324 338 SUBASH KC/NMC-15TH/2014 312 CHAPTER 20 Trauma Head trauma It is now well recognized that the prompt recognition of intracranial injuries and their treatment has a signi \201 cant impact upon these patients \200\231 morbidity an d mortality. This has led to the development of the NICE head injury guidelines. 1 Clinical presentation Patients with any of the following presentations, post head injury, h ave a risk of signi \201 cant head injury: \200 GCS <13. \200 GCS <15 2 hours after th e accident. \200 Suspected open, depressed, or basal skull fracture. \200 Post-traumati c seizure. \200 > 1 episode of vomiting in adults and > 3 in children. \200 Coagulopath y. \200 Focal neurological de \201 cit. Imaging Plain \201 lm These now have very little use in this scenario except where the de mon- stration of a fracture will alter management, e.g. non-accidental injury. CT (Fig. This is indicated for all of the earlier listed scenarios as soon as is possible i n the receiving hospital. The aim of this is to identify treatable intracra- nial bleeds th at will require prompt intervention. These will also act as baseline scans for comparison l ater if the patient deteriorates and has a follow-up scan. 20.1 ) Where there is evidence signi \201 cant head trauma discussion about whether the cervical spine should be imaged at the same time. MRI There are no clear guidelines for the use of MRI in head injuries. It clearly demonstra tes white matter injuries very well and at present is used in dif \201 cult cases after se nior discussion. Information for the radiologist A clear history of the injury, mechanism, and clinical cour se of the patient post injury, listing any of the earlier listed justi \201 cations for im aging. SUBASH KC/NMC-15TH/2014 HEAD TRAUMA 313 Fig. 20.1 An 85-year-old man admitted with reduced level of consciousness after falling ove r. The arrow points to an acute subdural bleed (white area). The \202 uid in the subdural space would indicate previous bleeds making this an acute on chronic subdural hemorrhage. Reference 1 NICE. . London : Head Injury. NICE clinical guideline 5 NICE , 2007 . SUBASH KC/NMC-15TH/2014 314 CHAPTER 20 Trauma Facial trauma Facial trauma used to be a very common problem in emergency depart- ments. Th e mandatory use of seatbelts in combination with the more recent introduction of airbags an d crumple zones has massively reduced these. The facial bones act as the head \200\231s own crumple zone and so it is possible to have massive facial injuries with relatively little injury to the brain. However, the face has a very rich blood supply making immediate treatment of these challeng ing. The long-term cosmetic implications in the modern era where image is so highly valued should not be underestimated. Clinical presentation By de \201 nition these are the result of trauma. This is usually by a blunt mechanism such as a \201 st, although penetrating injuries do occur. The more im aginative of the latter often then \201 nd themselves reported in the gutter press. Imaging This used to be by plain radiography although these are notoriously dif \201 cult to interpret. They can, however, be used as a screening tool as signi \201 cant \202 uid with the sinuses has a good predictive value for fractures in the trauma setting. CT With the introduction of multislice CT technology this is the imaging modality of choice for assessment of facial trauma. A volumetric acquisition is made and then high quality re formations in any plane can be produced as well as 3D models to guide the surgeon (Fig. 20. 2 ). The true extent of facial injuries is only now really being appreciated with the well-estab lished classi \201 cations being revisited and updated. For example, the pterygoid plates could never be visualized by plain radiography but are beautifully seen on CT. For the repo rting radiologist they are key landmarks as fractures of these immediately equate to a LeFo rt type injury. Information for the radiologist \200 Trauma mechanism. \200 Any known previous injuries . SUBASH KC/NMC-15TH/2014 FACIAL TRAUMA 315 Fig. 20.2 with dislocation of the temporomandibular joint. 3D CT reconstruction demonstrating right mandibular condyle fracture SUBASH KC/NMC-15TH/2014 316 CHAPTER 20 Trauma Spinal trauma This is common in polytrauma and there may be multiple injuries. The unconsci ous patient can be particularly challenging to investigate. Early diagnosis reduces the ris k of potentially devastating neurological sequelae. Cervical spine injury can lead to cervi cal cord injury with resultant respiratory arrest. Thoracolumbar injuries can lead to paralysis and are frequently overloo ked. Clinical presentation Pain at the site of injury or neurological disturbance. Look for brui sing, swelling, deformity, and localized spinal tenderness. A full neurological assessment should be documented, including perianal sensation, anal sphincter tone, and evidence of ur inary retention. The Canadian C-spine rules can be applied to \200\230clear \200\231 low-r isk patients of cervical spine injury on clinical grounds whilst the remainder should proce ed to imaging. 1 Imaging Plain \201 lm Standard views are lateral, AP, and an open mouth view of C1/C2 if the C-spine is imaged. C-spine radiographs should include the C7/T1 junction. Indicators of injury include visible fracture lines, bone fragments, soft tissue swelling, reduced vertebral body height, facet joint malalignment, and widened inter spinous distance. Flexion/extension views: not suitable in the acute setting and performed only with extreme caution by an experienced clinician. Can reveal occult ligamentous injuri es. CT This is highly sensitive for bone injury. Indicated if radiographs are inadequate, a fra cture is seen on plain \201 lm, or if clinical \201 ndings are discordant with radio- g raphic \201 ndings. However, a normal CT does not exclude ligamentous injury. MRI This is superior to CT and radiography in demonstrating soft tissue injuries such as li gamentous disruption, cord compression, or epidural hemorrhage. Patients with neurological compromise usually proceed to MRI. Information for the radiologist \200 Timing and mode of injury, site of pain or tendernes s. \200 Neurological \201 ndings including which side and the neurological level. SUBASH KC/NMC-15TH/2014 SPINAL TRAUMA 317 (a) (b) Fig. 20.3 80mph. a) A mid-line sagittal CT reformation of the cervical spine showing an ang ular kyphosis at C4/5 with massive widening of the interlaminar space posteriorly consisten t with a \202 exion injury. b) A parasagittal reformation showing the perched facet at C4 /5. A 45-year-old male who had crashed his motor-cycle into a wall at Reference 1 Stiell IG , Wells trauma patients GA , Vandemheen . JAMA KL , et al. \200\223 8 . The Canadian C-Spine rule study for alert and stable 2001 ; 286 : 1841 SUBASH KC/NMC-15TH/2014 318 CHAPTER 20 Trauma Thoracic trauma Chest trauma can be due to blunt or penetrating injury. The spectrum of pot ential injuries is wide but remember to check: \200 A: airway. \200 A: aorta. \200 B: bones. \200 C: cardiac. \200 D: diaphragm. \200 E: (o)esophagus. Clinical presentation Depend on the location and type of injury, but acute dyspnoea, pallor , shock, cold extremities, tenderness over chest wall are typical in severe cases. Many cas es will be associated with severe injury to other systems. Imaging Plain \201 lm \200 Still has a role in poly trauma but should not delay resusci tation or movement of patient to CT scanner. CXR allows a quick overview of injuries and the position of support tubes such as ET tubes and chest drains, but for an accurate assessment of injuries CT is r equired. Has a high negative predictive value for aortic injury if normal but have high level of suspicion if aortic arch not clearly seen. CT (Fig. \200 CT of the chest should be part of radiological assessment in all cases of 20.4 ) severe polytrauma. Gives accurate assessment of lung, mediastinal, bony, and diaphragmatic injuries. A normal, good quality CT has an almost 100 % negative predictive value for aortic injury. Ultrasound Can be used to look for haemothorax or pneumothorax in experienced hands, but is not as accurate as CT. MRI Little role in acute setting, but can be useful in delayed diagnosis of diaphragm ruptu re. Angiography Largely replaced by multislice CT as a diagnostic tool, but developing an ever- increasing role in the treatment of acute vascular injury, including aortic transection. SUBASH KC/NMC-15TH/2014 THORACIC TRAUMA 319 (a) (b) Fig. 20.4 a road traf \201 c accident. a) The \201 rst CT is viewed on \200\230mediasti nal \200\231 windows, showing \202 uid within the left chest, and active bleeding, seen a s contrast dependently within the lower left chest. b) The second CT is the same image view ed on \200\230lung \200\231 windows, showing an associated pneumothorax. Axial CT images from a patient who sustained multiple injuries following SUBASH KC/NMC-15TH/2014 320 CHAPTER 20 Trauma Abdominal trauma This remains a major cause of morbidity and mortality in the Western world . Perhaps not surprisingly road traf \201 c accidents (RTAs) remain the major cause even w ith modern safety developments. Traditional ATLS (Advanced Trauma Life Support) management relied upon good clinical history taking, examination and basic bedside tests. The exponential imp rovement in CT technology means that, where available, CT really should be the C in the ABC approach. Clinical presentation The presentation can be variable although high-energy mechanisms shou ld raise concern that for an intra-abdominal injury. Obviously direct trauma to the abdomen or lower rib cage carries a very high risk and there should be a very low threshold for im aging these patients. Imaging Ultrasound FAST (focused assessment with sonography for trauma) scans remain popula r in emergency departments as the demonstration of free \202 uid con \201 rms that there is an intra-abdominal injury. Unfortunately ultrasound remains very poor at delineating th e injuries themselves and is of little value in assessing bowel trauma. Ultrasound does, however, retain a role in following-up known injuries, particularly in children where dose is an issue. CT (Fig. It is now well recognized that anyone with presenting with injuries to 2 or more m ajor body parts should have a Pan-Scan (vertex to symphysis). This is because these patient s often have multiple injuries some of which can be very dif \201 cult to locate surgicall y. 20.5 ) Traditional teaching is that no haemodynamically unstable patient should go for a CT scan. Once again the speed of modern scanners means that patients spend very little time in the s can room. Indeed the rapid and accurate identi \201 cation of life-threatening injuries is unsurpassed by any other approach. Once the scan is done and all the injuries identi \201 ed then a management plan for the p atient for the remainder of his hospital stay can be drawn up. Information for the radiologist \200 Mechanism of injury. \200 Known injuries. \200 H aemodynamic status. SUBASH KC/NMC-15TH/2014 ABDOMINAL TRAUMA 321 Fig. 20.5 showing active bleeding from the spleen (arrow) and intra-abdominal free blood (a rrowheads). Trauma. A 35-year-old female who had fallen off her horse. Axial CT SUBASH KC/NMC-15TH/2014 322 CHAPTER 20 Trauma Pelvic fractures Pelvic fractures are associated with high-energy injuries (in the UK eithe r RTAs or falls from a height). The incidence of pelvic fractures in patients with blunt tr auma is approximately 10 skeletal structure whose integrity is maintained by extremely stro ng ligaments and powerful muscles. % . The pelvis is an extremely resilient Hence, any trauma to the pelvis has a high risk of injury to the soft tissues, abdominal or gans, and spine. The most important association is with active bleeding. Clinical presentation The main mechanisms of injury occur through 3 vectors: \200 AP comp ression: this is the commonest type of injury characterized by pubic diastasis sacroiliac (SI) joint disruption. AP compression can result in an increa se in the volume of the pelvis putting the patient at risk of exsanguination. Lateral compression: the hallmark of lateral compression fractures is the fracture of the p ubic rami with sacral buckle fractures. This is associated with intra-abdominal and intra-p elvic injuries but is less likely to have major pelvic hemorrhage. Vertical shear injuries occur due to a vertical force, often from the femur. There are vert ical fractures of the pubic rami and SI joints with ligamentous disruption and hemi-pelvic displacement. Imaging Plain \201 lm The AP pelvis \201 lm allows the initial assessment of the pelvic bones and their alignment (Fig. 20.6 ). CT \200 CT is the modality of choice for assessment of pelvic injuries, as not only does it give detailed analysis of the fractures but it demonstrates the associated soft tissue i njuries. The most important \201 nding is of active bleeding. MRI MRI can help in identifying occult fractures of the pelvis and hips. Information for the radiologist \200 Mechanism of injury. \200 The haemodynamic status of the patient. SUBASH KC/NMC-15TH/2014 PELVIC FRACTURES 323 A 65-year-old male admitted after frontal impact in an RTA. AP pelvic Fig. 20.6 radiograph which demonstrates disruption to the pubic symphysis and external rotation of the left hemi -pelvis. This is consistent with an AP compression injury (open book). SUBASH KC/NMC-15TH/2014 324 CHAPTER 20 Trauma Shoulder trauma Shoulder trauma presents with a variety of fracture/dislocation patterns. U sually it is the result of a fall onto an awkwardly held arm. Clinical presentation Patients with a fracture can usually get the arm into a semi-comforta ble position compared to a dislocation, which is exceptionally painful no matter what they do. Imaging Plain \201 lm Most shoulder injuries can be diagnosed with conventional radiograp hy. Clavicular fracture These commonly occur at the junction between the middle and outer third s. There may be displacement and fragment overlap. Acromio-clavicular (AC) joint subluxation/dislocation (Fig. Seen as widening and vertical s eparation of the AC joint space. Comparison or weight-bearing views of both shoulders can b e helpful. 20.7 ) Anterior dislocation (commonest) This is characterized by subcoracoid position of the humer al head on the AP view. The dislocation is often more obvious in a scapular \200\230Y \200 \231 view, where the humeral head lies anterior to the \200\230Y. \200\231 In the axillary view, the \200\230golf ball \200\231 (i.e. humeral head) falls anterior to the \200\230t ee \200\231 (i.e. glenoid). Posterior dislocation (2 The AP view may show medial rotation of the humeral head, resembli ng a light bulb. The scapular \200\230Y \200\231 view reveals the humeral head behind the glenoid (the center of the \200\230Y \200\231). In an axillary view, the \200\230golf bal l \200\231 falls poste- riorly off the \200\230tee \200\231. % ) Inferior dislocation (rare) The patient presents with arm held abducted above the head. The AP view may show the arm raised over the head with the humeral head infe- rior to the glen oid. Humeral neck/head fracture These are often impacted or oblique fractures. They are classi \201 ed according to separation of the head, shaft, greater and lesser tuberosities (Neer c lassi \201 cation).