title: Ossification of the posterior longitudinal ligament of the lumbar spine: a case series.
abstract: BACKGROUND
  Reports on ossification of the posterior longitudinal ligament (OPLL) of the lumbar spine have so far been limited.
  
  
  OBJECTIVE
  To evaluate surgically documented cases of lumbar OPLL at our facility to clarify its characteristics and analyze clinical outcomes.
  
  
  METHODS
  During the past 27 years, 6192 patients underwent operations for degenerative lumbar spine diseases. Of these, we selected surgically treated lumbar OPLL patients from our database to analyze the clinical and radiological disease characteristics. Surgical results were classified according to the Japanese Orthopaedic Association scale.
  
  
  RESULTS
  Only 10 patients underwent surgery for lumbar OPLL: 6 men and 4 women (mean age 44.1 years). Among these, OPLL developed in 4 patients at multiple vertebral body levels and in 6 at a single level. Coexisting lumbar disc herniation was observed in 4 patients. Although the rate of maximum canal stenosis brought about by OPLL was relatively high (mean 45.1%), unilateral radicular symptoms were the most frequently observed, and only 2 patients exhibited typical lumbar claudication caused by the canal stenosis. Two patients underwent surgery via an anterior approach and 8 via a posterior approach. The mean preoperative Japanese Orthopaedic Association scale score was 7.9, which improved to 17.8 postoperatively. No neurological deterioration caused by surgery was observed in any case.
  
  
  CONCLUSIONS
  Although the frequency of lumbar OPLL requiring surgical treatment was remarkably low, its clinical condition varies greatly among patients depending on the localization and degree of ossification. To achieve a better surgical outcome, precise diagnosis with computed tomography and an appropriate surgical approach are important.
authors.affiliation: Department of Orthopaedic Surgery, Kyushu University Hospital, Fukuoka, Japan. seokada@ortho.med.kyushu-u.ac.jp
authors.forename: Seiji
authors.initials: S
authors.lastname: Okada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Maeda
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Saiwai
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ohkawa
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Shiba
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D017846:Longitudinal Ligaments / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000453:epidemiology* / Q000601:surgery*; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult