The aim of this study was to pilot a randomized clinical study to evaluate whether instrumented anterior lumbar interbody fusion (ALIF) with a new nanocrystalline hydroxyapatite embedded in a silica gel matrix (NH-SiO2) leads to superior radiologic and clinical outcomes at 12-month follow-up compared with instrumented ALIF with homologous bone. ALIF completed with interbody cages is an established technique for performing arthrodesis of the lumbar spine. There is ongoing discussion about which cage-filling material is most appropriate. This is the first study to assess the efficacy of NH-SiO2 in ALIF surgery. This randomized, clinical, pilot trial included 2 groups of 20 patients with monosegmental or multisegmental degenerative disease of the lumbar spine who were suitable to undergo monosegmental or bisegmental ALIF fusion at the level L4/L5 and L5/S1 with a carbon fiber reinforced polymer ALIF cage filled with either NH-SiO2 or homogenous bone. Clinical evaluations using Oswestry Disability Index (ODI), fusion rates, back and leg pain and quality of life were assessed post operatively at 3,6 and 12 months. Successful and complete fusion was observed in both groups by 12 months, with slightly higher fusion rates observed in the Nanobone group (96%) compared to the HB group (88%). At the 3-month follow-up, Bridwell grade I was seen in 40% of the patients in both groups, whereas complete fusion (Bridwell grade 1 or 2) was seen in 92% in the Nanobone group and 80.0% in the HB group but this difference was not statistically significant. Clinical outcomes, quality of life, and pain scores did not significantly differ between the Nanobone and HB groups. No intraoperative complications related to the cage-filling material were recorded in either group. Nanobone is a synthetic hydroxyapatite with a porous silica gel matrix that facilitates neovascularization. This study demonstrated non-inferiority of Nanobone packed polymer cages compared to allograft packed polymer cages for ALIF.
The abstract can be read, and the full paper can be obtained
here.