Subsidence after total lumbar disc replacement is predictable and related to clinical outcome

J. Kitzen*, V. Verbiest, I. Buil, M.G.M. Schotanus, B. van Rietbergen, S.M.J. van Kuijk, L.W. van Rhijn, P.C.P.H. Willems

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Purpose As yet, there are no studies describing a relationship between radiographic subsidence after lumbar total disc replacement (TDR) and patient symptoms. To investigate if subsidence, in terms of penetrated bone volume or angular rotation over time (Delta PBV and Delta AR), is related to clinical outcome. To assess if subsidence can be predicted by position implant asymmetry (IA) or relative size of the TDR, areal undersizing index (AUI) on direct post-operative radiographs. Methods Retrospective cohort study consists of 209 consecutive patients with lumbar TDR for degenerative disc disease. A three-dimensional graphical representation of the implant in relation to the bony endplates was created on conventional radiographs. Consequently, the PBV, AR, IA and AUI were calculated, direct post-operative (DPO) and at last follow-up (LFU). For clinical evaluation, patients with substantial pain (VAS >= 50) and malfunction (ODI >= 40) were considered failures. Results At a mean follow-up of 16.7 years, 152 patients (73%) were available for analysis. In 32 patients, revision by spinal fusion had been performed. Both Delta AR (4.33 degrees vs. 1.83 degrees, p = 0.019) and Delta PBV (1448.4 mm(3) vs. 747.3 mm(3), p = 0.003) were significantly higher in the failure-compared to the success-group. Using ROC curves, thresholds for symptomatic subsidence were defined as Delta PBV >= 829 mm(3) or PBV-LFU >= 1223 mm(3) [area under the curve (AUC) 0.723, p = 0.003 and 0.724, p = 0.005, respectively]. Associations between symptomatic subsidence and AUI-DPO >= 0.50 (AUC 0.750, p = 0.002) and AR-DPO >= 3.95 degrees (AUC 0.690, p = 0.022) were found. Conclusion Subsidence of a TDR is associated with a worse clinical outcome. The occurrence of subsidence is higher in case of incorrect placement or shape mismatch.
Original languageEnglish
Pages (from-to)1544-1552
Number of pages9
JournalEuropean Spine Journal
Issue number7
Publication statusPublished - 1 Jul 2020


  • adjacent
  • chronic low back pain
  • degeneration
  • degenerative disc disease
  • diagnosis
  • facet joint
  • flexion-extension
  • fusion
  • instrumented lumbar
  • lumbar spine
  • malposition
  • migration or subsidence
  • sacroiliac joint
  • spine
  • surgery
  • total disc replacement
  • Lumbar spine
  • Total disc replacement
  • Malposition
  • Degenerative disc disease
  • Chronic low back pain

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