Pearls & Pitfalls Orthobullets Technique Guides cover information that is "not testable" on ABOS Part I Preparation radiolucent flat Jackson spine table placed into slight Trendelenburg to get abdominal fat out of the way Positioning supine with IV bag under sacrum to accentuate lordosis arms crossed over chest and taped down c-arm from right side of table along with arm attachment for abdominal retractor drape in lateral position then move to head of bed out of operative field Approach paramedian anterior approach to spine determined by disc level localization 3-4cm lateral of midline on left side Annulotomy remove disc using knife, pituitary, curettes, microcurettes, and ring curettes define endplates using Cobb elevator Implants sequentially distract endplates continue posterior discectomy until posterior annulus visualized microcurette laterally to clear foramen and confirm level of distraction on xray size implant trials and degree of lordosis fill with bone graft and insert finals under xray place vertebral body screws Postoperative serial neurovascular exams advance diet when return of flatus and remove Foley when ambulating Planning & Preparation Neurologic Exam need to carefully document neurological status of bilateral lower extremities strength, sensation, reflexes, and primary symptoms need to document failure of nonoperative measures such as physical therapy and epidural streoid injections Imaging review advanced imaging such as MRI look for specific findings such as spondylolisthesis, central/lateral recess/foraminal stenosis, and levels of involvement Equipment & Positioning Equipment ALIF Cage System ALIF may increase chance of union by more complete discectomy and endplate preparation allows improved restoration of disc height decompression of nerve roots are done indirectly by foraminal distraction via restoration of disc height grafts for cage autologous iliac crest, structural allograft, bone marrow augments abdominal retractors (with attchments to table) c-arm fluoroscopy Position patient supine slight Trendelenburg if obese to move pannus out of way IV bag under sacrum to accentuate lordosis arms crossed over chest and Foley in place prep and drape entire abdomen including iliac crest OR Setup and C-arm radiolucent Jackson spine flat top table c-arm from right side of table drape in lateral position take initial Lat fluoro of lumbar spine to localize disc level omni retractor and flexiarm attachment on right side of table Approaches Paramedian Anterior Approach to the Spine paramedian anterior approach determined by disc level localization 3-4cm lateral of midline on left side through rectus fascia and transversalis fascia into retroperitoneal space blunt dissection to psoas identify iliac artery and vein, iliolumbar artery (L4-5), midsacral arteries (L5-S1) localize with needle in disc space Surgical Technique Localization and Abdominal Frame Setup localize disc level under lateral fluoro for L5-S1: especially in Grade 1-2 or higher spondylolisthesis need distal incision cheat slightly past midline extending left across midline to ~3-4cm left of midline for men: usually go medially to rectus for L5-S1 disc set up abdominal retractor system on right side of table move as far towards head as possible watch out for C-arm laterally attach frame and bring in and drape C-arm in lateral position move C-arm to head of bed away from operative field Superficial Approach incision with 10blade in left paramedian space determined by localization 3-4 cm lateral from midline towards left side (~4-5cm in length) blunt dissection through subcutaneous fat to anterior rectus fascia divide anterior rectus fascia with cautery blunt dissection around rectus retract medially until posterior sheath identified divide transversalis fascia to get into retroperitoneal space blunt dissection with hands until retroperitoneal fat visualized in left retroperitoneal space blunt dissection down to psoas retract medially along with left ureter move medial and over psoas to anterior spine L5-S1 disc spacc iliac artery will be anterior and typically lateral to iliac vein move superior and left lateral to the iliac vessels to get to L4-5 disc space cauterize and ligate iliolumbar artery during L4-5 approach cauterize and ligate left iliolumbar vein during L4-5 approach measures 2cm long x 1cm wide single vessel (70%) joins common iliac vein 4cm distal to IVC may be double vessels (30%) at 3 and 6cm distal to IVC usually the proximal of 2 vessels will tear during mobilization lumbosacral trunk and lumbar plexus lie deep to ILV obturator nerve lies superficial to ILV (3cm lateral to where ILV joins CIV) cauterize and ligate midsacral vessels during L5-S1 approach Deep Approach carefully dissect off ascending lumbar vessels and tie off as needed with 2-0 silk suture stick tie of 5-0 Prolene proximal end doubly clipped and divided deep retractors x2 to bluntly dissect to spine first place deep retractor medially over edge of anterior body/disc place second retractor laterally over edge of body/disc take care to retract and preserve iliac vein self-retainer first replaces medial deep abdominal retractor attach to frame with arm in-line with direction of pull second self-retainer replaces lateral deep abdominal retractor superior blade is attached last bluntly clear off disc space divide hypogastric plexus confirm level with lateral fluoro use spinal needle into disc Annulotomy 15 blade or bovie to perform annulotomy remove disc fragments with pituitary use Cobb to define endplates clearly large curette at anterior part of disc microcurettes as disc space collapses down pituitary to remove fragments burr/kerrasen to remove anterior osteophytes and to level endplate ring curette to finish endplate preparation Implants sequentially distract endplate with distractors start with 6mm and move up primary tether is posterolateral annulus keep working on discectomy posteriorly until posterior annulus visualized microcurette laterally to clear foramen hook curette behind endplate above and below final distractor is ~14mm feel it “pop” open and place size 12 trial confirm adequate distraction on lateral with trial but not overdistraction size implant and degree of lordosis (i.e. 12x30x38mm, 12° lordosis at L5-S1, 8° lordosis at L4-L5) fill implant with autologous or allograft bone can also use BMP or bone marrow augment use Jamshidi needle to puncture vertebral body and remove bone marrow for biologic implant place 2 inferior to superior vertebral body screws first then 1 screw from superior to inferior vertebral body (i.e. two 4.5x25mm screws into L4, one 4.5x25 screw into L5) Confirm Implant Position take final AP/Lat of cage and screws to confirm position and lordosis Closure Irrigation & Hemostasis flush out retroperitoneal space with saline bulb irrigation carefully remove abdominal retractors while protecting iliac vessels Close Fascia close fascia with 0-PDS subcutaneous with 2-0 vicryl skin closure with buried 3-0 monocryl Dressing soft incision dressings over abdomen Postoperative Care Immediate Post-op weight-bearing as tolerated, physical and occupational therapy no heavy lifting and limited flexion/extension serial neurovascular exams foley catheter out when ambulating advance diet when return of flatus 2 Weeks wound check 3 Months repeat xrays of lumbar spine look for evidence of fusion in cage advance spine restrictions and activity levels Complications Exanguination from injury to iliolumbar vein (tear, slipped suture/vascular clip) Damage to superior hypogastric sympathetic plexus retrograde ejaculation and sexual dysfunction Persistent radiculopathy due to inadequate foraminal decompression Superficial, deep wound infection Iatrogenic injury to segmental lumbar arteries and veins, aorta, ureter Persistent low back pain by nociceptive pain fibers in pars