Comparison of Stand-alone Cage versus Intervertebral Cage with Pedicle Screw and Rod Fixation in Dogs with Degenerative Lumbosacral Stenosis

Abstract

Objective The aim of this study was to assess the clinical outcome of treatment of degenerative lumbosacral stenosis in dogs with a stand-alone intervertebral spacer (S group) and combined with a pedicle screw and rod fixation (S + PSRF group) in the lumbosacral junction. Study Design Retrospective study. Medical records (2014-2023) were reviewed for dogs treated with a stand-alone intervertebral spacer (S group) or a spacer combined with PSRF (S + PSRF group). Data collected included clinical signs at the time of presentation, surgical technique, implant type, perioperative bacterial culture, complications, outcomes and subsidence. Results Minor complications occurred in 10/11 dogs in the S group and 6/17 dogs in the S + PSRF group. Major complications occurred in 3/11 dogs in the S group and 5/17 dogs in the S + PSRF group. Long-term outcome was excellent in 63.6% dogs in the S group and 64.7% dogs in the S + PSRF group. Subsidence was noted in 75% of the cases in the S group compared with 33% of cases in the S + PSRF group. Bacterial cultures were positive in 6/28 cases. Conclusion Both treatment options were associated with full return of function in 64 to 65% of cases. Complications were more frequent in the S group. The S + PSRF group showed less subsidence of the cage. There was more frequent evidence of bone ingrowth in the intervertebral spacer in the S + PSRF group. Based on the observations in this study, both treatment options are viable for the treatment of degenerative lumbosacral stenosis with similar long-term outcomes; however, S + PSRF may result in less subsidence and better fusion and may therefore be preferable.