Serial Ultrasonography for Early Detection and Follow-up of Heterotopic Ossification in Stroke

Abstract

KEY WORDSheterotopic ossification, stroke, ultrasonography Heterotopic ossification (HO) is a common complication in patients with neurologic deficits. Once developed, limited range of motion may occur and interfere with rehabilitation programs. Early diagnosis is crucial but difficult because radiographs may be negative, and similar clinical symptoms could appear in deep venous thrombosis, cellulitis, and osteomyelitis. A three-phase bone scan can detect the disease early, but it has high radiation and low specificity. Magnetic resonance imaging (MRI) may also assist in diagnosis, but is costly and has some contraindications. Ultrasonography has been used in HO detection and is safe, economical, easily accessible, and involves no radiation exposure. However, a few studies have described its use in HO, especially in serial follow-ups. We report a case with HO clinical symptoms, but the MRI results created a necrotizing fasciitis suspicion. Serial ultrasonography images implied the formation of HO rather than necrotizing fasciitis. Ultrasonography images serve as a good initial screening tool for HO and are useful for following up such dynamic disease processes. ª

The development and impact of heterotopic ossification in burns: a review of four decades of research

“…31 The case report indicated that serial ultrasonography (US) provided earlier and more specific diagnosis of a hip muscle HO lesion than did X-ray or MRI, the latter indicated necrotising fasciitis initially. 31 Ultrasonography depicted clear disease progression, with calcification visible on day 15 after onset of first symptoms. 31 Similarly, in the orthopaedic patients, US has high sensitivity and specificity for early HO diagnosis one week after total hip arthroplasty.…”

“…Widely used diagnostic techniques have low sensitivity or specificity to incremental progression of mineralisation at early time points in HO development. 30 Yeh et al 31 reported that ectopic bone formation generally does not show on plain film until four to eight weeks after the initial symptoms. Without accurate and reliable early diagnosis, there is little chance of early intervention, and late detection fails to limit unabated progression of HO which often results in joint contractures, nerve entrapment and marked pain.…”

“…30 As proposed by Chen et al, 11 a solution to provide early differential diagnosis of HO was documented in a stroke patient. 31 The case report indicated that serial ultrasonography (US) provided earlier and more specific diagnosis of a hip muscle HO lesion than did X-ray or MRI, the latter indicated necrotising fasciitis initially. 31 Ultrasonography depicted clear disease progression, with calcification visible on day 15 after onset of first symptoms.…”

“…11 Three-phase bone scintigraphy (SPECT) has been proposed as a method for early detection and may serve as an index for following up on HO maturity. 31 However, the presence of inflammation in burn wound healing may generate false positives when HO is not present. 30 As proposed by Chen et al, 11 a solution to provide early differential diagnosis of HO was documented in a stroke patient.…”

“…All told, due to accessibility, low relative cost and lack of radiation, US is a feasible and safe screening tool for early diagnosis of HO in the burn population. 11,31 Lastly, it is worth noting emergent technology, suggested in a study of non-invasive near infra-red (NIR) imaging to diagnose and monitor the progression of HO in vivo in a mouse model. 30 NIR detected HO from the first assessment on day 5 and revealed a temporal response in HO formation and heterotopic bone turnover when using NIR contrast agents.…”