Percutaneous pedicle screw and rod fixation with TLIF in a series of 14 patients with recurrent lumbar disc herniation.

PURPOSE: To determine if minimally invasive transforaminal lumbar interbody fusion (TLIF) using the Medtronic Sextant system is a reliable surgical treatment option in patients with recurrent lumbar disc herniation, compared with the traditional open procedure. PATIENTS AND METHODS: Clinical and radiographic data were retrospectively collected from a total of 33 patients who underwent single level lumbar fusion between 2007 and 2010. 14 underwent minimally invasive TLIF using the Sextant system, and the other 19 patients underwent the open procedure. All patients suffered from at least first recurrent lumbar disc herniation, and additionally from disc degeneration associated with erosive chondrosis Modic grade I-II due to previous surgical, non-instrumental interventions. RESULTS: Median operation time in the minimally invasive group was 140 min (95-190); average X-ray exposure time: 2.35 min (1.5-3.5); median postoperative resting time in hospital: 5 days (3-7). Postoperative pain relief and mobility improvement were documented with the visual analogue scale (6.9-3.0) and the Oswestry Disability Index (6.8-2.4). All patients benefited from surgery at follow up. These data were on many terms significantly superior compared with data of patients in the open surgery group. CONCLUSION: Percutaneous minimally invasive TLIF technique with the Medtronic Sextant system is a gentle, tissue protecting and safe alternative procedure for lumbar fusion in patients with recurrent lumbar disc herniation and erosive chondrosis.

3D reconstitution of the patterned neural tube from embryonic stem cells.

Inducing organogenesis in 3D culture is an important aspect of stem cell research. Anterior neural structures have been produced from large embryonic stem cell (ESC) aggregates, but the steps involved in patterning such complex structures have been ill defined, as embryoid bodies typically contained many cell types. Here we show that single mouse ESCs directly embedded in Matrigel or defined synthetic matrices under neural induction conditions can clonally form neuroepithelial cysts containing a single lumen in 3D. Untreated cysts were uniformly dorsal and could be ventralized to floor plate (FP). Retinoic acid posteriorized cysts to cervical levels and induced localize FP formation yielding full patterning along the dorsal/ventral (DV) axis. Correct spatial organization of motor neurons, interneurons, and dorsal interneurons along the DV axis was observed. This system serves as a valuable tool for studying morphogen action in 3D and as a source of patterned spinal cord tissue.