Spondylolysis/Spondylolistheses



Spondylolysis/Spondylolistheses


M. Timothy Hresko



Pars Repair


Operative Indications



  • Failed nonoperative treatment of documented pars intra-articularis defect


  • MRI—absence of intervertebral disk degeneration


  • Less than 5 mm of translation of superior vertebral body


  • Pain relief on pars injection



Positioning



  • Prone on radiolucent table (Figure 7.1A)


  • Flex hips to reduce anterior pelvis tilt and lumbar lordosis (Figure 7.1B)


Procedure-Specific Checklist



  • Implant for your specific procedure


  • Intraoperative fluoroscopy to confirm surgical site at correct location


  • Compare to preop imaging—be cognizant of transitional LS vertebrae


Surgical Approach



  • Surface landmark of dimple of Venus (posterior iliac spine) at level of S1 spinous process


  • Midline approach 8 cm cephalad from S1


  • Raise skin flap to iliac crest


  • Elevate muscle from L5 lamina to L4-L5 facet, lateral to base of transverse process (if using Scott wire technique elevate to tip of TP and ventral on the specific vertebrae)


  • Maintain ligament of posterior process to L4, L5, S1








Techniques in Steps


Common to All Technique



  • Obtain bone graft from iliac crest—cancellous


  • Use Rongeur, curette, or burrs to clean out pars defect


  • Buck screw technique (Figure 7.2A-C)



    • Preoperative CT to confirm lamina intact—absence of bifid lamina


    • Use fluoroscopy and K-wire to plan path for cannulated drill AP and lateral fluoroscopy


    • Burr starting point at inferior aspect of ipsilateral lamina


    • Percutaneous insertion of threaded guide pin for cannulated drill inserted midline and distal to incision, angled lateral and ventral under fluoroscopy


    • Advance guide pin to pars defect


    • Place bone graft


    • Advance guide pin to anterior superior cortex


    • Drill over wire and far cortex


    • Remove wire and place solid 4.5 mm screw—bicortical


    • Repeat on contralateral side


    • Decorticate base of TP and lamina


    • Place additional bone graft on lamina


    • Close wound


  • Scott wire technique (Figures 7.3 and 7.4)



    • Pass loop wire over lateral aspect of TP to base of TP



      • Alternative is place pedicle screw or bone screw and washer in pedicle and loop wire under the washer


    • Decorticate base of TP and lamina


    • Pass free end of wire through posterior ligament in “figure of 8” fashion and secure on contralateral side of spinous process



















    • Insert bone graft in pars defect and lamina ventral to wire


    • Place contralateral wire in a similar fashion


    • Tighten both wires


    • Close wound


  • Pedicle screw



    • Place bilateral polyaxial pedicle screws avoiding facet joint


    • Decorticate base of TP and lamina


    • Insert bone graft into pars defect, base of TP, and lamina


    • Implant secured to posterior process. Implant options:



      • Contour 4.5 mm rod in “U” shape passed rod inferior to L5 spinous process


      • Polyethylene cord instead of rod (physician directed use, not FDA approved)


      • Wire


    • Insert rod into pedicle screw head and compress


Postoperative Care



  • Optional use of lumbosacral orthosis


  • Out of bed to chair and ambulate as tolerated


  • Short course of oral opioid; avoid nonsteroid anti-inflammatory drugs


  • Restricted lumbar hyperextension/flexion activity 4 to 6 weeks


  • CT scan at 3 months to assess healing and return to conditioning for sport


Jun 9, 2022 | Posted by in Reconstructive surgery | Comments Off on Spondylolysis/Spondylolistheses
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