title: "Spring-back" closure associated with open-door cervical laminoplasty.
abstract: BACKGROUND
  Spring-back complication after open-door laminoplasty as described by Hirabayashi is a well-known risk, but its definition, incidence, and associated neurologic outcome remain unclear.
  
  
  OBJECTIVE
  To investigate the incidence and the neurologic consequence of spring-back closure after open-door laminoplasty.
  
  
  METHODS
  A retrospective radiographic and clinical review.
  
  
  METHODS
  Lateral cervical spine X-rays were evaluated. Anteroposterior diameters (APD) of the vertebral canal of C3-C7 were measured. Spring-back was defined as loss of APD on follow-up in comparison to immediate postoperative canal expansion. The loss of the end-on lamina silhouette with consequent reappearance of the lateral profile of the spinous processes was also assessed to verify the presence of spring-back. Spring-back closure was classified based on whether the collapse was total or partial, and whether all the operated levels or only a subset had collapsed (ie, complete vs. partial closure, segmental closure vs. total-construct closure). Neurologic status was documented using the Japanese Orthopaedic Association (JOA) score.
  
  
  METHODS
  Thirty consecutive patients who underwent open-door laminoplasty from 1995 to 2005 at a single institution with a minimum follow-up of 2 years were assessed. They were all operated on using the classic Hirabayashi technique. Radiographic outcomes were assessed independently by two individuals.
  
  
  RESULTS
  Sixteen men and 14 women with an average follow-up of 5 years (range, 2-12 years) were included. Of these patients, 24 had cervical spondylotic myelopathy and six had ossification of the posterior longitudinal ligament. Spring-back closure was found in three patients (10%) and 7 of 117 laminae (6%) within 6 months of the operation, which was further confirmed by computed tomography and magnetic resonance imaging. All spring-back closures were partial segmental closures. Gender and age were not significant factors related to spring back (p>.05). The mean JOA score on follow-up was 12.5, with a recovery rate of 40%. All patients with spring back and available JOA data exhibited postoperative neurologic deterioration. Of the three patients with spring back, two patients underwent revision surgery, whereas one declined.
  
  
  CONCLUSIONS
  Spring-back closure occurred in 10% of our patients at or before 6 months after surgery. The incidence of spring-back by level (ie, 117 laminae) was 6%, mainly occurring at the lower cervical spine. All spring-back closures were partial segmental closures, most commonly involving C5 and C6. Postoperative neurologic deficit was associated with spring-back closure; therefore, surgeons should adopt preemptive surgical measures to prevent the occurrence of such a complication.
authors: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, 15 Changle Western Rd, Xi'an, Shaanxi Province, China 710032.
authors: Hai-Qiang
authors: HQ
authors: Wang
authors: Kin-Cheung
authors: KC
authors: Mak
authors: Dino
authors: D
authors: Samartzis
authors: Tarek
authors: T
authors: El-Fiky
authors: Yat W
authors: YW
authors: Wong
authors: Zhuo-Jing
authors: ZJ
authors: Luo
authors: Xin
authors: X
authors: Kang
authors: Wai Y
authors: WY
authors: Cheung
authors: Keith D K
authors: KD
authors: Luk
authors: Kenneth M C
authors: KM
authors: Cheung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects; D017887:Ossification of Posterior Longitudinal Ligament / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D011859:Radiography; D012189:Retrospective Studies; D055009:Spondylosis / Q000000981:diagnostic imaging / Q000601:surgery*; D055815:Young Adult