112 J Can Chiropr Assoc 2007; 51(2)

Radiology Review

Figure 1 Anterior-posterior lumbar spine. Figure 2 Lateral lumbar spine.

Case 1

Clinical historyA 59-year-old male with a history of prostate cancer

complains of 3 weeks of left hip and lower back pain.What’s your diagnosis?

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Clinical historyA 30-year-old male presents with right wrist pain. Hesprained his wrist 12 months ago after falling while iceskating. Since then, he notices worsening pain and limit-ed range of motion. What’s the important x-ray finding?

Case 2

Figure 1 Right posterior-anterior wrist.

Radiology Review was submitted by Dr. Kelly E Donkers Ainsworth, BSc, DC, MD

McMaster University, Faculty of Health Sciences, Department of Radiology, Room 25, Radiology1200 Main St. West, Hamilton, Ontario

Radiology Review

114 J Can Chiropr Assoc 2007; 51(2)

DiagnosisBlastic metastasis secondary to prostate cancer.

Clinical featuresPatients with bony metastatic disease typically complainof constant, dull, and nocturnal pain.1 Their past medicalhistory may or may not be significant for malignancy.With severe bone destruction, patients may experiencefracture, instability, and deformity.2 Signs and symptomsof neurological deficits resulting from spinal cord com-pression may also be present.

PathophysiologySixty percent of spinal metastasis in adults arise frombreast, lung, or prostate cancer.1 Metastatic tumours tothe spine are generally spread hematogenously and thevertebral body is affected 80% of the time. Cellular inva-sion of the bone causes increased interosseous pressuresleading to bone pain.1 Signs and symptoms of spinal cordcompression result from encroachment of tumour or bone(secondary to pathological fracture) into the spinal ca-nal.2 Involvement of the lumbar spine causes symptomsof stenosis and cauda equina syndrome.2 The most com-monly accepted theories on how compression leads tonerve dysfunction include pressure-induced impedanceof nerve firing and ischemia.2

In blastic metastasis, the bone attempts to repair thedamage made by tumour infiltration by laying down newbone. This is what gives blastic metastasis its characteris-tic radiopaque appearance.3

Imaging findingsOsteoblastic metastases are characterized by increased ra-diopacity on x-ray.3 Figures 1–3 show multiple ill-efined

sclerotic lesions in the lower lumbar spine, pelvic bonesand proximal femurs bilaterally. There are no pathologicalfractures. There is normal alignment of the hip joints. Softtissues are unremarkable. X-ray findings are consistentwith multiple foci of sclerotic metastatic disease.

Figure 3 Anterior-posterior pelvis.

AcknowledgementsRadiographs courtesy of Dr Ian Dayes, Juravinski CancerCentre, Hamilton, Ontario.

References1 Aebi M. Spinal metastasis in the elderly. Eur Spine J 2005;

12:S202–S213.2 Heary RF, Bono CM. Metastatic spinal tumors. Neurosurg

Focus 2001; 11:1–9.3 Yochum TR, Rowe LJ. Essentials of skeletal radiology.

2nd ed. Baltimore: Williams & Wilkins, 1996: 978.

Case 1 answer

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J Can Chiropr Assoc 2007; 51(2) 115

DiagnosisAvascular osteonecrosis of the lunate (AVNL). Alsoknown as Kienböck’s disease or lunatomalacia.

Clinical featuresAVNL affects males more commonly than females (9:1)and is most commonly seen in the 20–40 year age cate-gory.1 A classic patient history includes acute trauma orchronic/repetitive occupational trauma, although manyhistories may be noncontributory.1,2 Patients most com-monly present with unilateral, localizing wrist pain,swelling, and gradual worsening function.1 Long-termcomplications include severe pain, entrapment neuropa-thy, separation of the scaphoid and lunate, and degenera-tive arthritis.1

PathophysiologyAVNL appears to progress through 4 stages: resorption,deposition, fragmentation, and collapse. The etiology ofAVNL remains unclear.2 Several theories suggest initiat-ing, and predisposing factors.2 Although the evidence isinconclusive, trauma to the lunate blood supply appearsto be the most prominent initiating factor.2 Predisposingfactors include negative ulnar variance and normal lunateblood supply anatomy.1,2 In one study, AVNL was associ-ated with negative ulnar variance (ulna > 2 mm shorterthan radius) 78% of the time.2 A short ulna alters normalforce transmission, causing an increased axial load in theradiolunate articular compartment, which theoreticallycompromises blood supply to the lunate.1,2 The normal

lunate blood supply anatomy is also regarded as a predis-posing factor because the proximal pole of the lunate issupplied by terminal arteries.2

Imaging findingsAVNL may not manifest radiographically for severalmonths.1,2 In early stages, the entire lunate will have in-creased radiopacity but be normal in shape (see figure1).1,2 Later, fragmentation, fracture, and collapse of thelunate will result in loss of normal lunate shape and size,with mixed lucent and sclerotic bony lesions.1 Irregulararticular surfaces (most commonly at the radiolunatecompartment) occur as a result of lunate flattening, andcollapse.1 Long-term complications of AVNL are radio-logically manifest by scapho-lunate joint space widening(secondary to separation) and typical features of degener-ative arthritis (joint space narrowing, subchondral sclero-sis, subchondral cysts, and osteophytes).

AcknowledgmentsRadiograph courtesy of Dr Ghida Chouraiki, LebaneseUniversity in Beirut, Lebanon.

References1 Yochum TR, Rowe LJ. Essentials of skeletal radiology. 2nd

ed. Baltimore: Williams & Wilkins, 1996: 978.2 Schmitt R, Heinze A, Fellner F, et al. Imaging and staging of

avascular osteonecroses at the wrist and hand. Eur J Radiol 1997; 25:92–103.

Case 2 answer