Stress fracture of the pedicle after extensive decompression and contralateral posterior fusion for lumbar stenosis. Report of three cases.

Lumbar spinal stenosis can be effectively treated by performing an extensive ipsilateral spinal decompression, including a partial pediculotomy, and contralateral posterior bone fusion. Infrequently, complications can arise following radical decompression to alleviate symptoms of stenosis, and one such complication is a pedicle fracture. Three reports of pedicle fractures following extensive spinal decompression and contralateral posterior fusion are detailed. This complication is emphasized, and interventions are discussed. Three patients presented with symptoms attributable to lumbar stenosis; they were initially treated with an ipsilateral decompression, achieved in part, through a partial pediculotomy followed by contralateral autologous bone fusion. Initially, all three patients improved postoperatively; however, they later developed neurological symptoms ipsilateral to the side of spinal decompression. Computerized tomography scanning demonstrated pedicle fractures on the decompressed side. This complication has not yet been reported in association with decompression and fusion for lumbar stenosis. Two of the patients developed leg pain necessitating reoperation whereas the third experienced only mild transient symptoms. The fractured pedicle was removed in one patient; laminar and spinous process fusion was performed again. Another patient underwent a total laminectomy, removal of the fractured pedicle, and bilateral transverse process fusion. Reoperation yielded satisfactory outcomes. The third patient's symptoms resolved without intervention. Pedicle fractures are a potential complication of extensive lumbar decompression and contralateral posterior fusion. Loading forces from the facets or transverse processes are possibly the cause of such fractures. Removal of the fractured pedicle, additional decompression, and enhanced bone fusion are recommended when the symptoms warrant surgical intervention.