Spinal Stenosis Caused by Calcinosis in a Patient With Systemic Sclerosis

Bone but not Bone: Systemic Calcinosis Presenting as Lumbar Facet Pseudohypertrophy with Neurogenic Claudication

Systemic sclerosis affects 14-21 per million persons annually and can present with calcinosis-deposition in the skin and subcutaneous tissues. In rare circumstances, paraspinal depositions are also seen, which can cause neural element compression requiring surgical intervention. Here we present the case of a 61-year-old woman with systemic sclerosis on goal-directed therapy who presented with neurogenic pseudoclaudication and imaging suggesting severe joint hypertrophy. The case illustrates that calcinosis in scleroderma can cause facet joint pseudohypertrophy that is difficult to distinguish from true hypertrophy on imaging. Such pseudohypertrophy is often refractory to medical therapy, necessitating surgical intervention. Last, owing to the fluid nature of the calcinotic fluid, decompression is often easier than would be expected based on preoperative imaging alone.

Calcinosis in systemic sclerosis

PURPOSE OF REVIEW

To provide updated information on the prevalence, pathogenesis, diagnostics, and therapeutics of calcinosis cutis associated with systemic sclerosis (SSc).

RECENT FINDINGS

Observational studies show ethnic and geographical differences in the prevalence of calcinosis. In addition to clinical and serological associations, biochemical studies and in-vivo models have attempted to explain theories behind its pathogenesis, including prolonged state of inflammation, mechanical stress, hypoxia, and dysregulation in bone and phosphate metabolism. Long-term use of proton pump inhibitors may increase the risk for calcinosis in SSc. Few single center observational studies have shown mild benefit with minocycline and topical sodium thiosulfate.

SUMMARY

Calcinosis cutis is the deposition of insoluble calcium in the skin and subcutaneous tissues. It affects up to 40% of SSc patients and causes significant morbidity. Long disease duration, features of vascular dysfunction, and osteoporosis have been associated with calcinosis. Altered levels of inorganic pyrophosphate and fibroblast growth factor-23 have been implicated in dysregulated phosphate metabolism that may lead to calcinosis in SSc. Plain radiography can help with diagnosis and quantifying the calcinosis burden. Surgical treatment remains the most effective therapy when feasible. At present, no medical therapies have proven efficacy in large randomized controlled trials.

Calcinosis in systemic sclerosis

PURPOSE OF REVIEW

The aim of this study was to provide updated information on the prevalence, pathogenesis, diagnostics and therapeutics of calcinosis cutis associated with systemic sclerosis (SSc).

RECENT FINDINGS

Observational studies show ethnic and geographical differences in the prevalence of calcinosis. In addition to clinical and serological associations, biochemical studies and in-vivo models have attempted to explain theories behind its pathogenesis, including prolonged state of inflammation, mechanical stress, hypoxia and dysregulation in bone and phosphate metabolism. Long-term use of proton pump inhibitors may increase the risk for calcinosis in SSc. Few single-centre observational studies have shown mild benefit with minocycline and topical sodium thiosulfate.

SUMMARY

Calcinosis cutis is the deposition of insoluble calcium in the skin and subcutaneous tissues. It affects up to 40% of SSc patients and causes significant morbidity. Long disease duration, features of vascular dysfunction and osteoporosis have been associated with calcinosis. Altered levels of inorganic pyrophosphate and fibroblast growth factor-23 have been implicated in dysregulated phosphate metabolism that may lead to calcinosis in SSc. Plain radiography can help with diagnosis and quantifying the calcinosis burden. Surgical treatment remains the most effective therapy when feasible. At present, no medical therapies have proven efficacy in large randomized controlled trials.