OBJECTIVE: The aim of this study is to describe the surgical outcome and determine prognostic factors of thoracic ossified ligamentum flavum(OLF). METHODS: From April 1998 to November 2001, 32 consecutive patients with symptomatic thoracic OLF were treated surgically in our institution. Among them, the authors conducted a retrospective analysis of 28 patients in whom preoperative magnetic resonance imaging and computed tomogram were available. Decompressive laminectomy including removal of OLF mass was performed in each case. Mean follow-up period was 25.2 months, ranged from 3 to 46 months. RESULTS: Twenty-two patients(79%) showed functional improvement, in whom average Nurick Grade changed from 3.6 to 2.5 after surgery. Fifteen of eighteen patients presented with motor weakness, six of seven with leg or back pain and one of three with leg numbness or paresthesia improved respectively. No patient had deteriorated postoperatively. Clinical presentation and preoperative Nurick Grade were significant predictive factors for surgical outcome(p=0.004 and p<0.001, respectively). In addition, combined facet joint hypertrophy and/or compressive anterior element indicated poor prognosis(p=0.008). CONCLUSION: Appropriate evaluation and sufficient surgical decompression for combined compressive elements on imaging study could improve the functional prognosis in thoracic OLF.
Back Pain ; Decompression, Surgical ; Follow-Up Studies ; Humans ; Hypertrophy ; Hypesthesia ; Laminectomy ; Leg ; Ligamentum Flavum* ; Magnetic Resonance Imaging ; Paresthesia ; Prognosis ; Retrospective Studies ; Spine* ; Zygapophyseal Joint