Comparative Study of Three Pedicle Screw Devices

Abstract

There are a wide variety of indications for lumbar fusion in orthopedic and traumatic surgery. Lehmann et al. reported that the incidence of lower lumbar fusions for orthopedic diseases in the United States doubled between 1979 and 1983 [1]. In the field of trauma surgery of the spine, various authors have described the advantages of operative treatmet of compression and burst fractures over conservative non-operative treatment [2–4]. Considerations as to whether internal fixation devices are necessary differ depending on the trauma or orthopedic indications. Operative treatment of thoracolumbar fractures requires internal stabilization to maintain position and reduce the load on the anterior and middle column of the spine until the fracture has healed, irrespective of the necessity of simultaneous posterolateral fusion [4]. Lower lumbar or lumbosacral fusions in orthopedic cases are generally performed as in situ fusions except in cases of spondylolisthesis where some authors recommend reposition so only stability is required to support the bone fusion. The main problem of lumbar fusion is the considerably high rate of pseudarthrosis, that ranges between 18% and 49% depending on the number of fused segments and the kind of fusion (posterolateral or interbody) [5].