Total Lumbar Facet Replacement: Indication, Technique, and 3- and 4-Year Results

Abstract

Facet degeneration and subsequent spinal stenosis or instability may be accountable for a wide variety of pathologies that cause pain, motion restriction, or neurogenic dysfunction. Surgical treatment aiming predominantly at decompression of neural structures usually has little effect on facet-generated pain. Decompression and segmental immobilization by fusion are able to reduce or eliminate facet pain but represent a major alteration of spinal mechanics. Adjacent levels – especially when already affected by degeneration – may respond to increased and unaccustomed loads with accelerated degeneration and pain. Therefore, replacements of severely damaged facets by functional implants have long been an objective for spine surgeons and implant designers. Between 2008 and 2010, at the Neurosurgical Department HSK Wiesbaden, Germany, 10 patients had been implanted with a new anatomical facet replacement (ACADIA™). Indications were severe motion-dependent lumbar facet pain not responding to conservative treatment, symptomatic lumbar spinal canal, or foraminal stenosis with or without degenerative slip. Follow-up for 3 patients was 36 and for 7 patients 24 months. Mean improvement of Oswestry Disability Index (ODI) was 51 %. Mean visual analog scale (VAS, range 0–100) improvement for back pain was 53 and for leg pain on the affected side, 77 points. There have been no implant-related or other complications, in particular, no implant loosening or delayed fusion. After 3 and 4 years of the implantation, patient satisfaction was 98 %.