Benign Bone Disease & Sports Injury
Snapshot
Bone scintigraphy (with SPECT/CT) characterises many non-malignant conditions: Paget’s disease (intense expansile uptake), avascular necrosis, complex regional pain syndrome, and stress/overuse injuries — often detecting stress fractures before radiographs change and helping date and localise the injury.
Increased osteoblastic activity accompanies healing, remodelling and reactive change, so the bone scan is sensitive to injury and benign turnover — with SPECT/CT giving the anatomical diagnosis.
PagetExpansile uptake
Stress injuryEarly detection
AVN / CRPSCharacteristic patterns
When to image
- Suspected stress/overuse injury with normal radiographs.
- Characterising Paget’s disease and its extent/activity.
- Suspected avascular necrosis or complex regional pain syndrome.
- Unexplained bone pain.
How to read it
- Stress injury: focal cortical uptake, increasing with severity grade.
- Paget’s: intense uptake with bony expansion and deformity.
- AVN: photopenia early, then reactive uptake; CRPS: periarticular uptake in a limb.
Protocol
- Delayed (± three-phase) imaging with SPECT/CT of the symptomatic region.
- Correlate with activity history and radiographs.
Pitfalls
- Degenerative change is a common confounder.
- Timing affects AVN appearances.
- Correlate to avoid over-calling benign uptake as malignancy.
Evidence & guidelines
- Bone scintigraphy is sensitive for stress injury and metabolic bone disease.
- SPECT/CT adds the specific anatomical diagnosis.
In depth
- In osteoporosis the bone scan is usually normal apart from fractures; it does not show a metabolic bone disease pattern, and radiographs or densitometry are preferred for diagnosis.
- An acute vertebral compression fracture shows intense horizontal linear uptake, with increased blood-pool activity in the acute phase; uptake usually fades over months, so fractures older than about a year are often not visible.
- Osteomalacia/rickets: generalised increased axial uptake, prominent sternum, and rib-end beading (rachitic rosary); pseudofractures (Looser zones) are symmetric, perpendicular to the cortex, in ribs/scapula/pubic rami/femora.
- In primary hyperparathyroidism the bone scan is often normal (only about half showed metabolic features in an early series); when abnormal it may show calvarial, mandibular and sternal uptake, brown tumours and, with marked hypercalcaemia, extraskeletal uptake in lung, stomach or kidney.
- Renal osteodystrophy typically shows a metabolic superscan and may show extraskeletal uptake (for example lung metastatic calcification); aluminium toxicity instead gives a poor-quality scan with low skeletal and high soft-tissue uptake.
- Paget’s disease shows markedly increased uptake (sometimes less intense in burnt-out sclerotic lesions), most commonly in the pelvis, spine, femur and skull.
- Bone scintigraphy is the most sensitive way to map the extent of Paget’s disease, showing more sites than radiographs; characteristic patterns include the ‘Mickey Mouse’ vertebra and the ‘black beard’ sign of mandibular involvement.
Sources: Fogelman & Carr, Clin Radiol 1980 (PMID 7428273) · Ryan & Fogelman, Semin Nucl Med 1997 (PMID 9224668) · Meunier et al. Clin Orthop 1987 (PMID 3103964) · Khan et al. Clin Nucl Med 2022 (PMID 35025786)
Practise with a case
- Buttock pain in a 78-year-old woman · Beginner