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spine
StenoFix Stenofix is an interspinous implant used after decompressive surgery. The device is intended for use as a space holder between the spinous processes for one or two lumbar levels L1–S1. The resulting effects on the posterior elements are preservation of the foraminal height, reduction of stress on the facet joints and reduction of pressure on the posterior annulus. The W-shaped spring allows for dampening of high axial loads. The implant is designed with divergent wings to ensure implant insertion. For an optimized anatomical fit the shape of the cranial radius of the implant fits into the natural concavity of the superior spinous process. Further, the wings facilitate double-level implantation. Fig 1 Staggered wings facilitate double-level implantation.
a
The stenofix implants are available in sizes 8–16 mm in 2 mm increments. Construction material is titanium alloy and supplied sterile. Each implant is color coded along with trial implants of the same size and shape.
A 56 year-old-man had low-back pain for 10 years, with 2 years of sciatica radiating into the left leg. He had no sensory or motor deficiency. Nonoperative treatment failed completely. Surgery included decompression of level L4/5 and implantation of an interspinous stenofix L4/5 device size 12. He had a normal postoperative course with rapid decrease of pain. Case provided by Andreas Korge, München, Germany
b
Fig 2a–b A 66-year-old man with L3/L4, implant size 10.
Fig 1 X-ray shows dynamic extension 3 months postoperatively.
Fig 2 Intraoperative view with original stenofix implant in place.