Biomechanical Effects of Facet Capsule Injuries in Posterior Lumbar Fusion Operations

후방경유 요추 융합수술시 척추후관절낭 손상의 운동역학적 영향

  • Park, Seung Won (Department of Neurosurgery, College of Medicine, Chung-Ang University) ;
  • Kim, Young Baeg (Department of Neurosurgery, College of Medicine, Chung-Ang University) ;
  • Hwang, Sung Nam (Department of Neurosurgery, College of Medicine, Chung-Ang University) ;
  • Choi, Duck Young (Department of Neurosurgery, College of Medicine, Chung-Ang University) ;
  • Kwon, Jeong Taik (Department of Neurosurgery, College of Medicine, Chung-Ang University) ;
  • Min, Byung Kook (Department of Neurosurgery, College of Medicine, Chung-Ang University) ;
  • Suk, Jong Sik (Department of Neurosurgery, College of Medicine, Chung-Ang University)
  • 박승원 (중앙대학교 의과대학 신경외과학교실) ;
  • 김영백 (중앙대학교 의과대학 신경외과학교실) ;
  • 황성남 (중앙대학교 의과대학 신경외과학교실) ;
  • 최덕영 (중앙대학교 의과대학 신경외과학교실) ;
  • 권정택 (중앙대학교 의과대학 신경외과학교실) ;
  • 민병국 (중앙대학교 의과대학 신경외과학교실) ;
  • 석종식 (중앙대학교 의과대학 신경외과학교실)
  • Received : 2000.01.08
  • Accepted : 2001.03.30
  • Published : 2001.03.28

Abstract

Objectives : Although posterior lumbar fusion operations had been reported to accelerate spinal degeneration, there have been only a few studies for their biomechanical effects. We have studied the change of motion range at the vertebral joint one level above the fusion(UVJ) in pedicle screw fixation group(PSF)(n=13) where facet capsule was destroyed and in posterior lumbar interbody fusion group(PLIF)(n=8) where it was spared. Patients and Methods : The patients were divided into early(3 to 6 months) and late(over 12 months) according to postoperative follow-up period. The flexion, extension and flexion-extension angles(FA, EA, FEA) were measured at the UVJ with pre-operative, early and late post-operative films. Results : Mean age and male to female ratio were $52.7{\pm}9.3$ and 1 : 3.2. Mean follow-up periods were $144.1{\pm}30.0$ and $528.8{\pm}160.3$ days in early and late groups, respectively. The FEA and FA in the late PSF($11.8{\pm}3.1$, $8.5{\pm}2.9$) were significantly greater than pre-operative angles($7.8{\pm}3.9$, $5.1{\pm}3.7$)(p<0.01, p<0.05). All angles in the PLIF showed no significant changes with time. The FEA and FA in the late PSF($11.8{\pm}3.1$, $8.5{\pm}2.9$) were significantly greater than those of the late PLIF($7.6{\pm}2.3$, $3.4{\pm}2.0$)(p<0.01, p<0.001). All angles at early follow-up period were similar between PSF and PLIF. The EA showed no significant change in relation with follow-up period or fusion method. Conclusion : As a result, the facet capsule injury in pedicle screw fixation seems to be related with increased flexion angle or degeneration of the adjacent joint above the fused vertebra in the late phase.

Keywords