Symptomatic
spondylolysis is always challenging to treat because the pars defect causing the instability needs to be stabilized while segmental fusion needs to be avoided. Direct repair of the pars defect is ideal in cases of
spondylolysis in which posterior
decompression is not necessary. We report clinical results using segmental
pedicle-screw-rod fixation with
bone grafting in patients with symptomatic
spondylolysis, a modification of a technique first reported by Tokuhashi and Matsuzaki in 1996. We also describe the surgical technique, assess the fusion and analyze the outcomes of patients.
CASE PRESENTATION: At Cairo University Hospital, eight out of twelve Egyptian patients' acute pars fractures healed after
conservative management. Of those, two young male patients underwent an operative procedure for chronic
low back pain secondary to pars defect. Case one was a 25-year-old Egyptian man who presented with a one-year history of axial
low back pain, not radiating to the lower limbs, after falling from height. Case two was a 29-year-old Egyptian man who presented with a one-year history of axial
low back pain and a one-year history of mild claudication and infrequent radiation to the leg, never below the knee. Utilizing a standardized mini-access fluoroscopically-guided surgical protocol, fixation was established with two
titanium pedicle screws place into both pedicles, at the same level as the pars defect, without violating the facet joint. The cleaned pars defect was grafted; a curved
titanium rod was then passed under the base of the spinous process of the affected vertebra, bridging the loose fragment, and attached to the
pedicle screw heads, to uplift the spinal process, followed by compression of the defect. The patients were discharged three days after the procedure, with successful fusion at one-year follow-up. No rod breakage or implant-related complications were reported.
CONCLUSIONS: Where there is no evidence of frank
spondylolisthesis or displacement and
pain does not radiate below the knee, we recommend direct repair of the pars interarticularis fracture, especially in young active adults. We describe a modified form of the Buck screw procedure with a minimally invasive, image-guided method of pars interarticularis fixation. The use of image guidance simplifies the otherwise difficult visualization required for pars interarticularis screw placement and allows minimal skin and muscle dissection, which may translate into a more rapid postoperative recovery.