The Fate of Facet Joint and Adjacent Level Disc Degeneration Following Total Lumbar Disc Replacement

Abstract

TDR proved to have a beneficial effect with respect to adjacent level disc preservation. The degenerative changes were mild, occurred late after surgery and did not reveal a negative effect on postoperative clinical outcome. There was no significant correlation between index-level ROM and the occurrence of ALD (P > 0.05).TDR was, however, associated with a progression of index-level FJD in a considerable number of patients, particularly at the lumbosacral junction. Lower segmental mobility and less favorable clinical results point to the fact that a particular cohort of patients may predominantly be affected in which TDR shows inferior compatibility with the index-segment's biomechanics.

Parameters influencing the outcome after total disc replacement at the lumbosacral junction. Part 2: distraction and posterior translation lead to clinical failure after a mean follow-up of 5 years

“…Similar to the results of Siepe et al [22,23], the patients with clinical failure reported pain during the early postoperative stage without apparent FJD at this time. The early and final clinical scores correlated with each other.…”

“…Our probabilistic FEM study identified that sagittal misalignment can cause both, increased facet joint capsule tensile forces in the case of iatrogenic posterior translation and increased compressive forces when iatrogenically shifting the superior vertebra anteriorly [27]. Although both situations would theoretically explain the development of FJD in patients with TDR [19][20][21][22][23], we have proven that especially a posterior translation of the superior vertebra leads to clinical failure. As discussed, posterior translation leads to higher capsule tensile or shear forces.…”

“…A preoperatively existent high-grade facet joint degeneration (FJD) can especially lead to inferior clinical results; therefore, FJD was suggested as a contraindication for this procedure [18]. However, facet joint forces may increase after TDR followed by a de novo development or the progression of preoperatively existing initial FJD in a relevant percentage of patients (20-36 %) with a resulting inferior clinical outcome [19][20][21][22][23]. In a prospective study, Siepe et al [23] found that FJD appeared more frequently at the index level compared with the adjacent levels and significantly more frequently at the lumbosacral junction compared with the levels above it.…”

“…However, facet joint forces may increase after TDR followed by a de novo development or the progression of preoperatively existing initial FJD in a relevant percentage of patients (20-36 %) with a resulting inferior clinical outcome [19][20][21][22][23]. In a prospective study, Siepe et al [23] found that FJD appeared more frequently at the index level compared with the adjacent levels and significantly more frequently at the lumbosacral junction compared with the levels above it. The latter may be caused by the unique facet joint configuration of L5/S1 or specific sagittal profile parameters [24] that theoretically result in higher facet joint shear stresses or contact forces [25].…”

“…The latter may be caused by the unique facet joint configuration of L5/S1 or specific sagittal profile parameters [24] that theoretically result in higher facet joint shear stresses or contact forces [25]. Interestingly, patients with FJD progression after TDR present with inferior clinical results a few month postoperatively [23], which suggests that FJD itself may not be the only cause of pain or functional impairment. Several factors, such as malposition in the frontal plane, the grade of restoration of the disc height by segmental distraction, or the consecutive changes of the local sagittal curve with increased segmental lordosis, may affect facet joint forces after TDR [20,25,26].…”