STUDY DESIGN: Two cases of ossification of the transverse atlantal ligament (OTAL) are reported, and the literature is reviewed. OBJECTIVE: To report two cases of OTAL, which share fluorosis as a possible etiologic link. SUMMARY OF BACKGROUND DATA: OTAL, a rare phenomenon, may cause upper cervical canal stenosis and spastic quadriparesis. However, the incidence, etiology, and the best therapeutic options are currently unclear. METHODS: Two cases are reported. Included are pertinent history, physical examination, radiographic evaluation, nonsurgical interventions, and outcomes. The available literature is also reviewed. RESULTS: On systemic examination, these two cases were found to have ossification of many ligaments and interosseous membranes, i.e., the atlantal transverse ligament, posterior longitudinal ligament, and interosseous membranes of ribs, forearm, and leg. These findings were coupled with a history of high fluoride intake and dental fluorosis; the diagnosis of fluorosis was made. After 2 weeks of treatment with halo ring traction, and protection and stabilization with a hard cervical collar, the clinical symptoms significantly improved. CONCLUSION: The incidence of OTAL may be not as rare as has been thought. Although the complete etiology of OTAL is not known, fluorosis may be one of the etiologic factors related to OTAL, as well as the ossification of other ligaments and interosseous membranes. Nonsurgical treatment may be safe and effective.
STUDY DESIGN: Two cases of ossification of the transverse atlantal ligament (OTAL) are reported, and the literature is reviewed. OBJECTIVE: To report two cases of OTAL, which share fluorosis as a possible etiologic link. SUMMARY OF BACKGROUND DATA: OTAL, a rare phenomenon, may cause upper cervical canal stenosis and spastic quadriparesis. However, the incidence, etiology, and the best therapeutic options are currently unclear. METHODS: Two cases are reported. Included are pertinent history, physical examination, radiographic evaluation, nonsurgical interventions, and outcomes. The available literature is also reviewed. RESULTS: On systemic examination, these two cases were found to have ossification of many ligaments and interosseous membranes, i.e., the atlantal transverse ligament, posterior longitudinal ligament, and interosseous membranes of ribs, forearm, and leg. These findings were coupled with a history of high fluoride intake and dental fluorosis; the diagnosis of fluorosis was made. After 2 weeks of treatment with halo ring traction, and protection and stabilization with a hard cervical collar, the clinical symptoms significantly improved. CONCLUSION: The incidence of OTAL may be not as rare as has been thought. Although the complete etiology of OTAL is not known, fluorosis may be one of the etiologic factors related to OTAL, as well as the ossification of other ligaments and interosseous membranes. Nonsurgical treatment may be safe and effective.