title: The influence of sagittal instability factors on clinical lumbar spinal symptoms.
abstract: METHODS
  Cross-sectional and prospective study.
  
  
  OBJECTIVE
  To find the critical order of 3 radiographic factors observed in standing flexion-extension films and to discover their combined effect on lumbar symptoms.
  
  
  BACKGROUND
  Many previous reports have described relationships between degenerative change in the lumbar disc and segmental instability; however, few reports have attempted to show any relationship between instability and symptoms. Little is known about which type of instability is the most critical in the sagittal plane of the lumbar spine.
  
  
  METHODS
  Excessive segmental motion (factors): >3 mm slip, >3 mm translation, and >10 degrees angulation, at the L4/5 segment in 880 patients (389 men and 491 women; mean age, 49.4 y) with low back and/or leg pain were investigated at initial visit. Symptoms of low back and leg pain, and walking ability were evaluated at initial visit and 4.6-year follow-up using Japanese Orthopaedic Association's scoring system. Severity and continuity of symptoms were evaluated and compared among the groups according to various combinations of excessive motion.
  
  
  RESULTS
  Of the 3 factors, patients with >3 mm slip had the lowest scores, and patients with >10 degrees angulation had the highest, both at initial visit and follow-up (P<0.001). In the comparative study of various factors, the groups with >3 mm slip had significantly lower scores than the group with no factors, and these groups had significantly lower scores in leg pain and walking ability than the nonfactor group (P<0.05).
  
  
  CONCLUSIONS
  Of the 3 factors, >3 mm slip had the strongest effect on symptoms followed by >3 mm translation and then >10 degrees angulation. Therefore, patients with low back and/or leg pain at initial visit and >3 mm slip, may expect symptoms of a duration exceeding 4 years. More than 10 degrees angulation had the least effect on symptoms as shown by the similarity in scores with the nonfactor group.
authors.affiliation: Department of Orthopaedic Surgery, Kobe Rosai Hospital, Japan.
authors.forename: Aritetsu
authors.initials: A
authors.lastname: Kanemura
authors.forename: Minoru
authors.initials: M
authors.lastname: Doita
authors.forename: Koichi
authors.initials: K
authors.lastname: Kasahara
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Sumi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Iguchi
mesh_terms: D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D017116:Low Back Pain / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D012585:Sciatica / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D012720:Severity of Illness Index