RESUMO
To investigate the frequency of ossification of the ligamentum flavum [OLF] in the spine among the Arab population in Kuwait using magnetic resonance imaging [MRI] surveillance of the whole spine. A consecutive series of 102 patients with low back pain were recruited from the outpatient clinic of Mubarak Al-Kabeer Hospital, Kuwait. MRI of the whole spine in the sagittal plane was obtained in at least two sequences [T[1] and T[2]]. The OLF was defined as low signal intensity thickening of the ligament in both T[1] and T[2] sequences on the posterior margin of the spinal canal, causing indentation of the theca with or without cord compression. Of the 102 cases, 19 [18.6%] patients had OLF. Of the 19 positive cases, 12 [63.2%] were present at a single level, and 7 [36.8%] at multiple levels. A total of 26 OLF segments were identified in the following anatomical distribution: cervical: 15 [57.7%]; upper thoracic [T1-T4]: 1 [3.8%]; mid thoracic [T5-T8]: 4 [15.4%]; lower thoracic [T9-T12]: 4 [15.4%], and lumbar region: 2 [7.7%]. Of the 19 OLF patients, 2 [10.5%] had tandem ossification of the posterior longitudinal ligament in the cervical spine and were symptomatic. The frequency of OLF appears to be high among this hospital-based cohort of the Arab population. OLF should be kept in mind if a patient presents with radiculopathy, particularly in the cervical region, for which surgical intervention is contemplated