Management of Acquired Compressive Myelopathy due to Spinal Fluorosis

Fluorosis is an endemic disease of India which causes compressive cervical and/or dorsal myelopathy. This study aims to evaluate the role of surgical management in the crippling fluorosis along with evaluation of radiological imaging as screening/diagnosing tool for the disease.

This is a prospective cohort study of 33 patients operated at tertiary care center having nontraumatic involvement of spinal cord affecting neurology with history, clinical and radiological features (Ossified Posterior Longitudinal Ligament-, Ossified Ligamentum flavum) suggesting fluorosis as the cause of compression. Outcomes were measured in terms of improvement in Nurick grading, Rankins scale, spasticity, Oswestry Disability Index, modified Japanese Orthopaedic Association scores.

Spinal fluorosis is a male predominant disease affecting the elderly after years of fluorine intake. Cervical and/or dorsal spine are predominantly involved at multiple levels (>=2). Diagnosis of the disease poses difficulty due to lack of established laboratory parameters with high sensitivity, availability, and lack of awareness among surgeons. Skeletal survey alone has >90% sensitivity for diagnosing the disease. Once evaluated properly, decompression at correctly identified levels invariably improves the spasticity and quality of life immediately post-surgery. At final followup, there was on average improvement of 2 scales in nurick grade, rankins scale and ashworth grading whereas average improvement in ODI, mJOA and dorsal specific mJOA were 52%, 3.17 points and 2.7 points respectively. However, preoperative counselling for "apparent neurological deterioration" in immediate postoperative period is very important. Complications like infection and dural tear have to be prevented with special surgical tactics.

Skeletal survey along with computed tomography and magnetic resonance imaging is cost-effective modality for the screening/diagnosis for fluorosis. Once developed, surgery, either curative or palliative, is the best treatment at crippling stage of the disease.