Multi level lumbosacral spinal fusion including lumbo-Sacral (L5-S1) junction fixation in adult deformity surgery; is postero-lateral fusion at (L5-S1) alone adequate?

Background/aims: To assess the revision rate at L5-S1 when only posterior fixation with pedicle screws is done with multi-level spinal fixation. Patients and Methods: The Retrospective quasi experimental study was conducted at the Combined Military Hospital, Rawalpinidi and comprised data from 2009 to 2014 of patients in whom multi-level posterior decompression including lumbosacral junction (L5-S1) with laminectomy and posterior fixation with pedicle screws was done till L3 and higher. Those with known cause of implant failure like osteoporosis, osteomalacia and infection were excluded. Patients were followed up and need for revision at L5-S1 level was assessed. Result: Of the 22 cases, 5(23%) were males and 17(77%) were females with an overall mean age of 64 +/- 10.38 years (range 48-84 years). Mean number of levels fixed was 5.22 +/- 1.15 the highest level of fixation being T11. Mean followup was 08 +/- 3.22 months and focused only at the failure of fixation at L5-S1. Two (9%) cases showed implant loosening and required revision at L5-S1 because of screw cut out. Conclusion: Properly placed pedicle screws were adequate with fusion for multilevel spinal fixations.