title: Paraspinal Muscle Sparing Versus Percutaneous Screw Fixation: A Comparative Enzyme Study of Tissue Injury during the Treatment of L4-L5 Spondylolisthesis.
abstract: OBJECTIVE
  Screw fixation via the paraspinal muscle sparing approach and by percutaneous screw fixation are known to diminish the risk of complications, such as, iatrogenic muscle injury as compared with the conventional midline approach. The purpose of this study was to evaluate tissue injury markers after these less traumatic screw fixation techniques for the treatment of L4-L5 spondylolisthesis.
  
  
  METHODS
  Twenty-two patients scheduled for posterior lumbar interbody fusion (PLIF) at the L4-L5 segment for spondylolisthesis were prospectively studied. Patients were divided into two groups by screw fixation technique (Group I: paraspinal muscle sparing approach and Group II: percutaneous screw fixation). Levels of serum enzymes representing muscle injury (CK-MM and Troponin C type 2 fast), pro-inflammatory cytokine (IL-8), and anti-inflammatory cytokine (IL-1ra) were analyzed using ELISA techniques on the day of the surgery and 1, 3, and 7 days after the surgery.
  
  
  RESULTS
  Serum CK-MM, Troponic C type 2 fast (TNNC2), and IL-1ra levels were significantly elevated in Group I on postoperative day 1 and 3, and returned to preoperative levels on postoperative day 7. No significant intergroup difference was found between IL-8 levels despite higher concentrations in Group I on postoperative day 1 and 3.
  
  
  CONCLUSIONS
  This study shows that percutaneous screw fixation procedure is the preferable minimally invasive technique in terms of minimizing muscle injury associated with L4-L5 spondylolisthesis.
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Republic of Korea.
authors.forename: Dong Am
authors.initials: DA
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Republic of Korea.
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Republic of Korea.
authors.forename: Sung Myung
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Republic of Korea.
authors.forename: Chang Il
authors.initials: CI
authors.lastname: Ju
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Republic of Korea.
authors.forename: Chong Gue
authors.initials: CG
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Republic of Korea.
authors.forename: Suk Jung
authors.initials: SJ
authors.lastname: Jang
keywords: Paraspinal muscle sparing approach; Percutaneous screw fixation; Tissue injury