Postoperative outcomes of combined surgery comprising dorsal laminectomy, transarticular screws, pedicle screws and polymethylmethacrylate for dorsal fixation in 21 dogs with degenerative lumbosacral stenosis

Abstract

OBJECTIVE To retrospectively review the efficacy of combined surgery comprising dorsal laminectomy and dorsal fixation using screws and polymethylmethacrylate as treatment for dogs with degenerative lumbosacral stenosis (DLSS). ANIMALS 21 client owned dogs diagnosed with DLSS and treated surgically. PROCEDURES Based on clinical records, signalments, clinical signs, findings from orthopedic and neurological examinations, imaging findings, and postoperative complications were evaluated at the following time points: preoperatively, postoperatively, and 3, 6, 12, 24, and 36 months after surgery. RESULTS In all 21 cases, clinical signs were alleviated, proprioceptive deficits were improved from 3 months after surgery, and no recurrence of clinical signs was observed during the observation period. Minor complications were observed in 6 cases (28.6%), including implant failure in 2 (9.5%), delayed healing of surgical wounds in 2 (9.5%), seroma in 1 (4.8%), and swelling of the affected area in 1 (4.8%). There was no case with major complications. CLINICAL RELEVANCE Combined surgery comprising dorsal laminectomy and dorsal fixation using screws and polymethylmethacrylate is a useful treatment that can improve long-term clinical signs in dogs with DLSS.

Stabilization with a String-of-Pearls Plate as Treatment for Degenerative Lumbosacral Disease in a Young German Shepherd Dog

“…9 10 In this case, MRI was deemed unnecessary, the diagnosis being clear on CT only. The ventral displacement of the sacrum relative to the vertebral body of L7 occasionally present in dogs with degenerative LS stenosis (DLSS) has been proposed as evidence of instability of the LSJ 11 12 13 which matches our conclusions in this case. However, dynamic imaging could help confirm the instability.…”

“…11 The changes in dimensions of the IVF with positioning may be clinically relevant because the narrowing of the IVF with certain movements that extend the spine such as jumping may result in mechanical compression of L7 nerve roots, inducing pain, lameness, and/or neurological dysfunction. 11,13,14 Surgical treatment for DLSS is the standard choice of treatment in the presence of severe caudal lumbar pain or neurologic deficits that do not respond to conservative therapies like in our case. 6,12,13,15 The techniques described consist of a dorsal laminectomy associated with the removal of the osteochondral fragment if possible, plus distractionfusion of the LS space 6,9 as decompressive surgery alone could further aggravate instability of the LSJ.…”

“…12 Distraction-fusion consists of expanding the L7-S1 IVF and spinal canal, alleviating pressure on the nerve roots, and permanently stabilizing L7-S1 vertebrae in "normal alignment." 6,12,13,16 The success of this distraction-fusion technique is related to elimination of nerve root irritation by expanding the IVF, stretching the dorsal annulus of L7-S1, and halting degenerative changes. 6,12,16 To make the construct stiffer and stronger and avoid implant failure, multiple pins or screws can be placed within L7 and S1, and then bonded into a dorsal construct with bone cement (polymethyl methacrylate [PMMA]) while maintaining the LSJ at a neutral angle.…”

“…11 The changes in dimensions of the IVF with positioning may be clinically relevant because the narrowing of the IVF with certain movements that extend the spine such as jumping may result in mechanical compression of L7 nerve roots, inducing pain, lameness, and/or neurological dysfunction. 11 13 14…”

“…Surgical treatment for DLSS is the standard choice of treatment in the presence of severe caudal lumbar pain or neurologic deficits that do not respond to conservative therapies like in our case. 6 12 13 15 The techniques described consist of a dorsal laminectomy associated with the removal of the osteochondral fragment if possible, plus distraction-fusion of the LS space 6 9 as decompressive surgery alone could further aggravate instability of the LSJ. 13 15 Fenestration of the LS disc space has also been described.…”