Posterior Lumbar Interbody Fusion (PLIF) - CC Tai 7/1/2002

History   

Hibbs & Albee were the first to introduce stabilisation of the spine in1911, with the use of an interlaminar fusion technique for Pott’s disease. In 1929, Hibbs and Swift published the first paper dealing with lumbosacral fusion for degenerative disease. First posterior lumbar interbody fusion (PLIF) was reported by Jaslow in 1946 when he utilized a bone peg that was placed within the lumbar interspace after discectomy. The first instrumentation systems developed for scoliosis by Harrington (but did not use fusion) thus initially high failure rate. Initial pedicle screw systems were developed by Raymond Roy Camille, who used a semirigid system of placing a screw within an open-holed plate, and by Steffee used a rigidly locked plate/screw system.   This was followed by development of threaded, cylindrical titanium cages because of the theoretical advantages of interbody fusion and axial load resistance compared with pedicle screw fixation.

What do the Papers say

According to Gibson 2001 who reviewed 16 published trials of all forms of surgical treatment for degenerative lumbar spondylosis – no scientific evidence about the effectiveness of any form of surgical decompression or fusion for degenerative lumbar spondylosis compared with natural history, placebo, or conservative treatment. Ten trials randomly compared instrumented and non-instrumented fusion – instrumented produced a higher fusion rate but did not improve clinical outcomes and may associate with higher complication rates.

Turner 1992 meta-analysis: on average 64% patients obtained satisfactory results from surgery (but ranging from 16-95%); Mardjetko 1994 meta-analysis: decompression with and without fusion gave 90% and 69% satisfactory outcome respectively, fusion with pedicle screws produced a higher fusion rate (93% vs 86%) than without instrumentation but no difference in clinical outcomes (86% vs 90%)

There is weak evidence that adjunct fusion to supplement decompression for degenerative spondylolisthesis produce less progressive slip and better clinical outcome than decompression alone. There is preliminary evidence that in general, instrumentation makes no difference to clinical outcomes.

Implant Design

PLIF – iliac crest bone graft, allograft bone, dowel shaped graft, keystone graft, tricortical graft, bone chips; implants used – stainless steel basket, titanium mesh, threaded titanium fusion cage

Spinal implants that are currently available and that use pedicle screw fixation:

a) rigid - rigid longitudinal member linked rigidly to the pedicle screw eg VSP device, TSRH

b) semirigid – rigid longitudinal member linked in a non-rigid fashion to the pedicle screw; any simple bone plate/screw device would into semirigid category. depends on the plate-spine contact for fixation ad with bony absorption would allow toggling bet screw and plate

c) flexible – flexible longitudinal member (Wiltse)

Indication

severe degenerative lumbar spondylosis inc. degenerative disc disease, isthmic spondylolisthesis or other spndylolisthesis (less than grade III), degenerative scoliosis with spinal stenosis etc

idiopathic scoliosis

spinal instability or mal-alignment

recurrent lumbar disc herniations

postsurgical instability or pseudoarthrosis after attempted posterior fusions

Contraindication

multilevel disc disease with a nondiagnostic discogram; single level disease, with radicular pain only (little or no mechanical back pain), and patients with severe osteoporosis

(Relative contraindication – active smoker, multilevel disease with more than one level positive on discogram, significant co-morbid illness)

Complication

nerve root injuries

cerebrospinal fluid leaks / dural tear

failure of fusion or stabilisation

failed implants

bone graft collapse, slippage, displacement, or extrusion

pseudoarthrosis

Other Ref: