title: Is Degenerative Spondylolisthesis a Contraindication for Total Disc Replacement? Kineflex Lumbar Disc Replacement in 7 Patients With 24-Month Follow-up.
abstract: BACKGROUND
  Degenerative spondylolisthesis is associated with a significant segmental kyphosis at the level of the listhesis. We treated 7 disc spaces with Grade 2 listhesis and/or kyphosis of the slipped disc level with Kineflex disc replacement.
  
  
  METHODS
  Out of a single-center prospective registry, involving 310 lumbar disc replacement patients, 7 patients underwent a single-level Kineflex disc replacement at the level of a degenerative spondylolisthesis with either segmental kyphosis or a Grade 2 slip. Preoperative and follow-up radiological parameters studied were: pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis L1-S1, degree of segmental listhesis, segmental lordosis, and range of motion (ROM). Clinical outcome measures were Visual Analog Scale pain score (VAS), Oswestry Disability Index (ODI), and patient satisfaction.
  
  
  RESULTS
  Five replacements were performed at the L4-L5 level, and 2 were performed at a L3-4 level, above a pre-existing L4-S1 posterolateral fusion. Mean age was 50 (32-62) years. Average follow-up was 23.8 ± 13.1 months. Six of 7 patients considered their outcome as good or excellent. The mean VAS score decreased from 8.4 ± 1.9 to 2.7 ± 2.2 (P < .01). The ODI decreased from 45.2 ± 9.9 preoperatively to 19.7 ± 12.8 (P < .01). There were increases in lumbar lordosis (from 47.4o ± 10.6 to 61.3o ± 8.0 (P < .03)), in segmental lordosis (from 0.17° ± 7.0° to 16.4° ± 2.0° (P < .03)), and in sacral slope (from 34.5° ± 4.8° to 40.7° ± 4.5° (P < .03)). There were decreases in pelvic tilt (from 22.6° ± 6.3° to 15.5° ± 5.9° (P < .05)), and degree of segmental listhesis (from 24.4% ± 7.7 to 3.7% ± 3.4 (P < .03)). Pelvic incidence and ROM did not change.
  
  
  CONCLUSIONS
  Disc replacement resulted in significant improvement in clinical outcome and excellent sagittal balance and slip correction. However, the influence of improved sagittal spinal alignment on clinical outcomes needs to be investigated in larger studies including a control group.
  
  
  CONCLUSIONS
  This study is the first focused on disc replacement in degenerative spondylolisthesis.
authors: University of the Witwatersrand, Johannesburg, South Africa ; Linkfield Park Clinic, Johannesburg, South Africa.
authors: Ulrich R
authors: UR
authors: Hähnle
authors: University of the Witwatersrand, Johannesburg, South Africa.
authors: Karen
authors: K
authors: Sliwa
authors: University of Potchefstroom, South Africa.
authors: Malan
authors: M
authors: de Villiers
authors: Linkfield Park Clinic, Johannesburg, South Africa.
authors: Ian R
authors: IR
authors: Weinberg
authors: University of the Witwatersrand, Johannesburg, South Africa.
authors: Barry M B E
authors: BM
authors: Sweet
authors: University of the Witwatersrand, Johannesburg, South Africa.
authors: Geoffrey P
authors: GP
authors: Candy
keywords: Spondylolisthesis; clinical outcome; radiological outcome; total disc replacement