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• Subperiosteal wedge-shaped sleds of various materials have been used in treating the enophthalmic anophthalmic socket and in correcting the enophthalmic seeing eye. Posterior fixation of the sled may be difficult, as the sled tends to migrate anteriorly. Tissue adhesives were studied as a fixation method for silicone sleds in rabbit orbits. Gross examination revealed that the sleds were secured in position until well encapsulated. Butyl 2-cyanoacrylate (Histoacryl Blue) induced minimal inflammation, while ethyl cyanoacrylate (Crazy Glue) caused a giant-cell response.

Background Anterior bone grafts are used as struts to reconstruct the anterior column of the spine in kyphosis or following injury. An incomplete fusion can lead to later correction losses and compromise further healing. Despite the different stabilizing techniques that have evolved, from posterior or anterior fixating implants to combined anterior/posterior instrumentation, graft pseudarthrosis rates remain an important concern. Furthermore, the need for additional anterior implant fixation is still controversial. In this bench-top study, we focused on the graft-bone interface under various conditions, using two simulated spinal injury models and common surgical fixation techniques to investigate the effect of implant-mediated compression and contact on the anterior graft. Methods Calf spines were stabilised with posterior internal fixators. The wooden blocks as substitutes for strut grafts were impacted using a “pressfit” technique and pressure-sensitive films placed at the interface between the vertebral bone and the graft to record the compression force and the contact area with various stabilization techniques. Compression was achieved either with posterior internal fixator alone or with an additional anterior implant. The importance of concomitant ligament damage was also considered using two simulated injury models: pure compression Magerl/AO fracture type A or rotation/translation fracture type C models. Results In type A injury models, 1 mm-oversized grafts for impaction grafting provided good compression and fair contact areas that were both markedly increased by the use of additional compressing anterior rods or by shortening the posterior fixator construct. Anterior instrumentation by itself had similar effects. For type C injuries, dramatic differences were observed between the techniques, as there was a net decrease in compression and an inadequate contact on the graft occurred in this model. Under these circumstances, both compression and the contact area on graft could only be maintained at high levels with the use of additional anterior rods. Conclusions Under experimental conditions, we observed that ligamentous injury following type C fracture has a negative influence on the compression and contact area of anterior interbody bone grafts when only an internal fixator is used for stabilization. Because of the loss of tension banding effects in type C injuries, an additional anterior compressing implant can be beneficial to restore both compression to and contact on the strut graft.

Spondylolysis is a defect in the bony portion of the posterior neural arch of a vertebra [1]. It occurs in the pars intenarticulanis between the superior and inferior articulan facets and, if bilateral, separates the vertebral body from its posterior fixation. Such breaks may cause a spondyioiisthesis, a forward slipping of the affected vertebral body oven the one below. Some investigators believe that spondylolysis is a congenital defect, citing a higher incidence in Eskimos [2] and other ethnic groups. However, most now believe the defect to be a traumatic fracture [3]. The occurrence of spondylolysis with acute and other types of trauma [4], and as a result of a stress fracture [5] advancing to complete fracture, has been documented in numerous articles [3]. It has been theorized that a genetic predisposition to fracture exists in some persons [6]. Although healing of the pans intenarticulanis defect (fracture spondyiolysis) has occasionally been reported [7, 8], it appears to be quite uncommon, perhaps because immobilization of the spine and/on surgical fixation is difficult and, in most cases, not warranted. Despite the plethora of reports on spondyiolysis, few details of the soft tissues surrounding the bony defects are known. In our patient a capsule continuous with that of the apophyseal joint may be present.

Lumbar pain is one of the most common problems of population. Far too often it is caused by ageing and degeneration of intervertebral discs. Fusion techniques, as arthrodesis which used screw fixation, were the first surgeries used to avoid lumbar pathologies. However, arthrodesis reduced dramatically the spine movement.Stand-alone cage is a minimally invasive surgery alternative to lumbar fusion with posterior fixation. Despite their previous reported successful results (Ahmadian et al., 2014) some physicians continue questioning their effectiveness because of the risk of spine destabilization and cage migration (Oxland et al., 2000).The purpose of this research was to demonstrate that stand-alone cages introduced in a minimally invasive way are a good surgical solution for the IVD diseases.This main goal has been divided into three different partial goals: prove spinal stability, show the decompression on the neural region and compare the effects over the adjacent discs with and without posterior fixation. It is also of the interest of this work to compare between cage designs based on the above mentioned criteria.

In Reply. —Dr Simonsz' assertion that posterior fixation surgery reduces the angle of strabismic deviation measured at distance fixation led me to reexamine data from 39 of my patients with partly accommodative esotropia with a high accommodative convergence-accommodation ratio, whom I had treated with posterior fixation combined with bilateral medial rectus recessions. For each case I calculated the expected correction from a previously published dose-response curve. 1 This dose-response curve was almost identical to the basic formula for bilateral medial rectus recessions cited by Kushner et al. The average additional correction measured at distance fixation obtained for these patients varied from −4 prism diopters (PD) for posterior fixation sutures placed 12 mm posterior to the original insertion of the medial recti to 7 PD for posterior fixation sutures placed 15 mm posterior to the original insertion of the medial recti. These averages are somewhat smaller than those suggested by Dr

• A curved ruler for measurement along the surface of the globe has been designed to measure the arc instead of the cord measurement. The ruler is especially helpful when one is doing large recessions and posterior fixation of the recti muscles (Faden operation).