Ossification of Ligamentum Flavum Related to Thoracic Kyphosis After Tuberculosis Case Report and Review of the Literature

Study Design. Case report and review of the literature. Objective. To report 2 patients, with a history of thoracic tuberculosis, in whom ossification of ligamentum flavum (OLF) was found adjacent to progressive kyphosis and resulted in incomplete paralysis. The relevant literature was also to be reviewed. Summary of Background Data. Progressive kyphosis is the most common cause of late onset paralysis after spinal tuberculosis. However, OLF related to tuberculous kyphosis is rarely observed and this makes surgical treatment become very difficult. Methods. Clinical history, laboratory examination, and radiographic findings of the 2 patients were described. Posterior laminectomy and instrumented fusion were performed for both 2 patients, but additional osteoectomy was performed through posterolateral zygapophysial approach in only 1 patient in whom the kyphotic deformity was partially corrected. A review of the relevant literature was also done. Results. Two patients were observed up for 2 and 6 years, respectively. Neurologic status was significantly improved after operation and no further kyphosis developed. To our knowledge, only 1 article had reported 2 similar cases of spinal stenosis above a healed tuberculous kyphosis. Conclusion. OLF related to tuberculous kyphosis was rarely observed. The local instability and repetitive stimulus of excessive stress could lead to development of OLF. Our experience suggested that decompression of OLF was more important than correction of kyphotic deformity to improve the neurologic status in these patients.