The rheumatic manifestations of traumatic spinal cord injury

Neurogenic heterotopic ossification in spinal cord injury

“…Although the precise pathophysiology of NHO is still unknown, humoral, 26,79 ± 85 neural, 1,3,6,36,46,48,73,86 ± 89 and local factors 12,27,90 ± 92 probably all play a role in the formation of ectopic bone. Apart from the completeness of SCI 1,13,14,19,21,22,24,88 and the possible role of (micro) trauma, 6,9,17,46,51,107 ± 112 reports of possible risk factors like DVT, pressure ulceration, infection, and spasticity 6,7,10,14,21,22,24,30,47,89 and their presumed causal relationship with NHO are inconclusive. Studies on experimental bone induction have emphasized the role of neuro-immunological and humoral factors.…”

“…Whether a disruption of the neuro-immunological pathways could result in an abnormal balance between osteoblast and osteoclasts and the subsequent induction of NHO is also still hypothetical. 89 Yet the presence of interstitial oedema by itself, whether due to autonomic dysregulation, 1 hypersensitivity, or hypoproteinemia 6 may add to a permissive environment by facilitating pathological calci®cation of the osteoid.…”

“…11 An infected urinary tract could serve as a source of antigenic material precipitating an immune response that triggers subsequent NHO. 89 On the other hand, it may be that demineralization of bone accompanied by a loss of calcium and a subsequent loss of collagen as is seen in the acute phase of SCI 102,103 is associated with an increased risk of developing both urinary tract stones, osteoporosis and NHO. 3,4,17,100 As yet, the conclusion seems justi®ed that the relatively high incidence of urinary tract infection and stone formation in SCI patients with NHO is not well understood from a pathophysiological perspective.…”

Traumatic Spinal Cord Injury

“…The exact cause of neurogenic heterotopic ossification is not known but it might involve a combination of local, humoral and neuro-immunological factors. Management can include physical therapy, pharmacological 32 therapy (such as bisphosphonates and/or non-steroidal anti-inflammatories), radiation therapy, or surgical resection of the ossification 144 .…”

False-Negative Triple-Phase Bone Scans in Spinal Cord Injury to Detect Clinically Suspect Heterotopic Ossification: A Case Series

“…It begins in an area of inflammation, where first an exudative cellular infiltration is seen, followed by fibrosis and osteoid formation, and subsequent deposition of bony matrix (6). The mineralization of the soft tissues involves the replacement of calcium phosphate by hydroxyapatite crystals, and the process of bone maturation is normally completed within…”