Radiology Review. Figure 1 ... Radiology Review was submitted by Dr. Kelly E Donkers Ainsworth, BSc, DC, MD ... Essentials of skeletal radiology. 2nd ed.
Radiology Review Case 1 Clinical history A 59-year-old male with a history of prostate cancer
Figure 1 112
Anterior-posterior lumbar spine.
complains of 3 weeks of left hip and lower back pain. What’s your diagnosis?
Figure 2
Lateral lumbar spine. J Can Chiropr Assoc 2007; 51(2)
Radiology Review
Case 2
Clinical history A 30-year-old male presents with right wrist pain. He sprained his wrist 12 months ago after falling while ice skating. Since then, he notices worsening pain and limited range of motion. What’s the important x-ray finding?
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, Radiology 1200 Main St. West, Hamilton, Ontario
J Can Chiropr Assoc 2007; 51(2)
113
Radiology Review
Case 1 answer
Diagnosis Blastic metastasis secondary to prostate cancer. Clinical features Patients with bony metastatic disease typically complain of constant, dull, and nocturnal pain.1 Their past medical history may or may not be significant for malignancy. With severe bone destruction, patients may experience fracture, instability, and deformity.2 Signs and symptoms of neurological deficits resulting from spinal cord compression may also be present. Pathophysiology Sixty percent of spinal metastasis in adults arise from breast, lung, or prostate cancer.1 Metastatic tumours to the spine are generally spread hematogenously and the vertebral body is affected 80% of the time. Cellular invasion of the bone causes increased interosseous pressures leading to bone pain.1 Signs and symptoms of spinal cord compression result from encroachment of tumour or bone (secondary to pathological fracture) into the spinal canal.2 Involvement of the lumbar spine causes symptoms of stenosis and cauda equina syndrome.2 The most commonly accepted theories on how compression leads to nerve dysfunction include pressure-induced impedance of nerve firing and ischemia.2 In blastic metastasis, the bone attempts to repair the damage made by tumour infiltration by laying down new bone. This is what gives blastic metastasis its characteristic radiopaque appearance.3 Imaging findings Osteoblastic metastases are characterized by increased radiopacity on x-ray.3 Figures 1–3 show multiple ill-efined
114
sclerotic lesions in the lower lumbar spine, pelvic bones and proximal femurs bilaterally. There are no pathological fractures. There is normal alignment of the hip joints. Soft tissues are unremarkable. X-ray findings are consistent with multiple foci of sclerotic metastatic disease.
Figure 3
Anterior-posterior pelvis.
Acknowledgements Radiographs courtesy of Dr Ian Dayes, Juravinski Cancer Centre, Hamilton, Ontario. References 1 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.
J Can Chiropr Assoc 2007; 51(2)
Radiology Review
Case 2 answer
Diagnosis Avascular osteonecrosis of the lunate (AVNL). Also known as Kienböck’s disease or lunatomalacia.
lunate blood supply anatomy is also regarded as a predisposing factor because the proximal pole of the lunate is supplied by terminal arteries.2
Clinical features AVNL affects males more commonly than females (9:1) and is most commonly seen in the 20–40 year age category.1 A classic patient history includes acute trauma or chronic/repetitive occupational trauma, although many histories may be noncontributory.1,2 Patients most commonly present with unilateral, localizing wrist pain, swelling, and gradual worsening function.1 Long-term complications include severe pain, entrapment neuropathy, separation of the scaphoid and lunate, and degenerative arthritis.1
Imaging findings AVNL may not manifest radiographically for several months.1,2 In early stages, the entire lunate will have increased radiopacity but be normal in shape (see figure 1).1,2 Later, fragmentation, fracture, and collapse of the lunate will result in loss of normal lunate shape and size, with mixed lucent and sclerotic bony lesions.1 Irregular articular surfaces (most commonly at the radiolunate compartment) occur as a result of lunate flattening, and collapse.1 Long-term complications of AVNL are radiologically manifest by scapho-lunate joint space widening (secondary to separation) and typical features of degenerative arthritis (joint space narrowing, subchondral sclerosis, subchondral cysts, and osteophytes).
Pathophysiology AVNL appears to progress through 4 stages: resorption, deposition, fragmentation, and collapse. The etiology of AVNL remains unclear.2 Several theories suggest initiating, and predisposing factors.2 Although the evidence is inconclusive, trauma to the lunate blood supply appears to be the most prominent initiating factor.2 Predisposing factors include negative ulnar variance and normal lunate blood supply anatomy.1,2 In one study, AVNL was associated with negative ulnar variance (ulna > 2 mm shorter than radius) 78% of the time.2 A short ulna alters normal force transmission, causing an increased axial load in the radiolunate articular compartment, which theoretically compromises blood supply to the lunate.1,2 The normal
J Can Chiropr Assoc 2007; 51(2)
Acknowledgments Radiograph courtesy of Dr Ghida Chouraiki, Lebanese University in Beirut, Lebanon. References 1 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.
115
