title: Development of degenerative spondylosis of the lumbar spine after partial discectomy. Comparison of laminotomy, discectomy, and posterolateral discectomy.
abstract: METHODS
  The development of degenerative spondylosis after successful operative decompression of the affected nerve root was prospectively evaluated in a comparative case series of 100 patients with a herniated lumbar nucleus pulposus.
  
  
  OBJECTIVE
  The objective of this study was to compare the relative incidence of degenerative spondyloarthrosis after successful posterior laminotomy and discectomy and posterolateral extradural discectomy for decompression of a compromised lumbar nerve root.
  
  
  BACKGROUND
  The relationship between the radiographic appearance of degenerative spondylosis and prior operative procedures has been controversial and at times contradictory. The posterior operative approach with a partial discectomy has been associated with a significant incidence of postoperative degenerative spondylosis and intraneural and perineural fibrosis, complications that may be minimized, or perhaps even eliminated, with the posterolateral evacuation of the offending intervertebral disc fragment.
  
  
  METHODS
  Each patient had: 1) not responded favorably to nonoperative treatment, 2) a persistent radiculopathy, 3) correlative imaging studies with no preoperative spondyloarthrosis and 4) minimum 2-year follow-up. Fifty patients were treated by posterior laminotomy and discectomy and fifty were treated by a posterolateral extradural discectomy. Postoperative spondylosis was graded based on the radiographic presence or absence of osteophytes, the intervertebral disc height, the vertebral body alignment and the facet joint changes.
  
  
  RESULTS
  At an average postoperative follow-up of 65 months, the incidence of a one grade increase in degenerative spondylosis was 80% of the laminotomy and discectomy patients as compared to 39% of the posterolateral discectomy patients.
  
  
  CONCLUSIONS
  The increased incidence of spondyloarthrosis with the posterior approach suggests that minimally invasive posterolateral extradural procedures should be considered for the decompression of a compromised lumbar nerve root.
authors.affiliation: Graduate Hospital Disc Treatment and Research Center, Department of Orthopaedic Surgery, Pennsylvania, USA.
authors.forename: P
authors.initials: P
authors.lastname: Kambin
authors.forename: L F
authors.initials: LF
authors.lastname: Cohen
authors.forename: M
authors.initials: M
authors.lastname: Brooks
authors.forename: J L
authors.initials: JL
authors.lastname: Schaffer
mesh_terms: D017586:Diskectomy; D006801:Humans; D017116:Low Back Pain / Q000209:etiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D009408:Nerve Compression Syndromes / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D013126:Spinal Nerve Roots; D013128:Spinal Osteophytosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D014057:Tomography, X-Ray Computed