title: Passive reduction of spondylolisthesis on the operating room table: a prospective study.
abstract: Translational motion of low-grade spondylolisthesis is traditionally assessed with lateral flexion and extension radiographs. Maximum motion in an unanesthetized patient may be limited by patient cooperation, pain, or muscle spasm. Twenty-four patients with degenerative or isthmic spondylolisthesis were assessed with preoperative lateral flexion and extension radiographs. A lateral radiograph was obtained on the operating room table after administering an anesthetic, exposing the spine, and performing a laminectomy. The percentage slip decreased from 24 to 15 to 6% on flexion, extension, and intraoperative lateral radiographs, respectively (p < 0.001). The amount of reduction did not correlate with disc height, slip angle, slip level, or type of spondylolisthesis. Many low-grade spondylolisthesis deformities reduce almost completely on the operating table. Translational motion of spondylolisthesis is greater than preoperative flexion and extension radiographs indicate.
authors.affiliation: Department of Orthopaedic Surgery, William Beaumont Hospital, Royal Oak, Michigan.
authors.forename: D M
authors.initials: DM
authors.lastname: Montgomery
authors.forename: J S
authors.initials: JS
authors.lastname: Fischgrund
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007796:Laminectomy; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D011859:Radiography; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000601:surgery*