ABSTRACT
PURPOSE: To analyze the significance of ossification index of cervical posterior longitudinal ligament as a risk factor for thoracic OPLL (ossification of the posterior longitudinal ligament) in patients with cervical OPLL. METHODS: We retrospectively analyzed the clinical data of cervical OPLL patients in Changzheng hospital, who received chest CT scans for screening of COVID-19, and included 87 patients into this study. According to the radiographic evidence, 87 patients were divided into CT group(cervical OPLL combined with thoracic OPLLï¼and C group(cervical OPLL group). We measured the cervical OS index (ossification index), and analyzed the relationship between thoracic OPLL and cervical OS index. RESULTS: There was no difference of ageãsexãduration of symptomsãcomorbidity between the 2 groups(Pï¼0.05). The mean cervical OS index was higher in the CT group than in the C group (8 ± 2 VS 3 ± 2ï¼Pï¼0.001). CONCLUSIONS: Patients with cervical OS index ï¼8 was considered as "high risk" of tandem OPLL, while with value ≤ 4 was considered as "low risk". Index between 5 and 8 were considered as "middle risk". This study demonstrated that the cervical OS index may be used as an indicator of thoracic OPLL in patients with cervical OPLL, with a high diagnostic accuracy.