Unilateral dynamic stabilization for unilateral lumbar spinal pathologies; a new surgical concept

Simple facet joint repair with dynamic pedicular system: Technical note and case series

Purpose:

Facet joints are important anatomical structures for the stability of spine. Surgical or degenerative damage to a facet joint may lead to spinal instability and causes clinical problems. This article explains the importance of facet joints, reviews facet replacement systems, and describes a simple and effective method for facet replacement after surgical removal of facet joints.

Materials and Methods:

Ten patients were operated with the diagnosis of unilateral nerve root compression secondary to facet degeneration. The hypertrophic facet joints were removed with microsurgical techniques and the roots were decompressed. Then, a unilateral artificial facet joint was created using two hinged screws and a dynamic rod.

Results:

The clinical outcome of all the patients was determined good or excellent at second and last follow-up (mean 13.3 months) controls using visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. Radiological evaluations also demonstrated no implant-related complications.

Conclusions:

The authors suggest that, if removal of a facet joint is necessary to decompress the nerve roots, the joint can be replaced by a construct composed of two hinged screws connected by a dynamic rod. This simple system mimics the function of a normal facet joint and is an effective technique for unilateral facet joint replacement.

Evaluation of hemilaminectomy use in microsurgical resection of intradural extramedullary tumors

The aim of this study was to investigate the microsurgical techniques of hemilaminectomy, used in the excision of intradural extramedullary (IDEM) tumors, and to illustrate its clinical effects. Clinical data obtained from 16 patients (seven males, nine females) with IDEM tumors, which were treated at the China-Japan Union Hospital between January 2009 and December 2011, were retrospectively analyzed. The mean age of patients was 49 years, ranging from 34-72 years. The IDEM tumors were located cervically in three patients, thoracically in four patients and at the thoracico-lumbar level in nine patients. Fourteen patients underwent hemilaminectomy, while two patients were treated with laminectomy during surgery. The clinical effect of hemilaminectomy was evaluated based on Frankel grade. The mean bleeding volume was 300 ml (range, 150-500 ml) and the mean duration of surgery was 140 min (range, 90-200 min). The maximum and minimum tumor volumes were 4×1.5×1.5 cm and 1.5×1.0×1.0 cm, respectively. Neurinoma was evident in 11 patients, meningioma in four cases and neurofibroma in one case. Three cases improved from Frankel grade B to C, five cases improved from grade C to D and seven cases improved from grade D to grade E. All patients were followed up for a period of 6-40 months, with a mean follow-up time of 23.7 months. None of the patients exhibited tumor recurrence or spinal instability. The mean bleeding volume of patients that underwent hemilaminectomy and laminectomy was 275 and 475 ml, respectively. The advantages of hemilaminectomy are minor invasion, less bleeding and retention of spinal stability. In general, hemilaminectomy for the excision of IDEM tumors has a satisfactory outcome.