We are developing a new spinal implant system (SIS) without fusion (bone graft). This SIS is made from two materials, metal and polyetheretherketone (PEEK) polymer. The Food and Drug Administration recommended testing in vivo, in an animal model, whether the PEEK polymer could be used in a SIS without any harm of wear debris to the nervous tissue (spinal cord and nerve roots). The objective was to evaluate the biological response of the spinal cord and nerve roots (dura mater) to PEEK polymer particles. Twenty-four female New Zealand white rabbits were used. The rabbits were divided into three groups: test (n = 12), control (n = 9), and sham (n = 3). During the surgery, the test group received the PEEK particle injections (5 x 10(7) particles per site, lumbar and thoracic), while the control group received only the vehicle (0.9% saline solution). The sham group had the same surgical approach without injection. In each group, the rabbits were euthanized at 1, 4, and 12 weeks postsurgery. The macroscopic and semiquantitative histologic analyses of the spinal cords (dura mater) showed normal vascularization and particle adherence to the connective tissue especially at the injection sites. Neither necrosis nor swelling of the dura mater and nerve roots was observed. The PEEK polymer is harmless to the spinal cord; thus it might be used as component in the spinal implant system.

Porous titanium-nickel (PTN) implants represent an alternative to traditional intervertebral fusion cages. Indeed, PTN materials possess interconnecting pores with cell capillarity properties that may promote bone ingrowth and intervertebral fusion without the need for bone grafting. In this study, a PTN intervertebral fusion device was compared to a conventional TiAlV cage packed with autologous bone in a sheep model. The two devices were implanted at two noncontiguous intervertebral lumbar sites for 3, 6, and 12 months. PTN osseointegration showed a time-dependent trend increasing from 21.4% to 37.6% (3-12 months), whereas TiAlV cages remained at the same level of bone ingrowth (22.7%-25.4%; 3-12 months). Furthermore, PTN bone apposition (10.9%-24.2%; 3-12 months) was significantly higher than that of TiAlV implants (1.1%-5.1%; 3-12 months; p < 0.001, ANOVA). Radiological fusion scores increased with postsurgery time regardless of material type, but were consistently superior for PTN (12.5-18.5; 3-12 months) than for TiAlV cages (2.0-15.0; 3-12 months; p < 0.001, ANOVA). Implant materials were not significantly different according to the radiological interbody index based on preoperative disc height: Interbody index began at 132.6% (PTN) and 123.5% (TiAlV) immediately after surgery, then declined to 80.8% (PTN) and 91.0% (TiAlV) after 12 months. Nevertheless, ungrafted PTN constituted an excellent substrate for osteogenic cell integration and represents a new osteoconductive biomaterial with improved fusion characteristics in comparison to conventional TiAlV cages.

The proposed technique appears to give more representative results than those presented in the literature. It has the advantage of being part of a global noninvasive postural evaluation. Using this approach in a systematic manner could help reduce radiograph exposure while keeping track of the spine sagittal curvatures.

The purpose of this prospective observational study was to evaluate the effectiveness of the Dynamic SpineCor brace for adolescent idiopathic scoliosis in accordance with the standardized criteria proposed by the Scoliosis Research Society Committee on Bracing and Nonoperative Management. They proposed these guidelines to make the comparison among studies more valid and reliable. From 1993 to 2006, 493 patients were treated using the SpineCor brace. Two hundred forty-nine patients met the criteria for inclusion, and 79 patients were still actively being treated. Overall, 170 patients have a definitive outcome. All girls were premenarchal or less than 1 year postmenarchal. Assessment of brace effectiveness included (1) percentage of patients who have 5 degrees or less curve progression, and percentage of patients who have 6 degrees or more progression; (2) percentage of patients who have been recommended/undergone surgery before skeletal maturity; (3) percentage of patients with curves exceeding 45 degrees at maturity (end of treatment); and (4) Two-year follow-up beyond maturity to determine the percentage of patients who subsequently underwent surgery. Successful treatment (correction, >5 degrees, or stabilization, +/-5 degrees) was achieved in 101 (59.4%) of the 170 patients from the time of the fitting of the SpineCor brace to the point in which it was discontinued. Thirty-nine immature patients (22.9%) required surgical fusion while receiving treatment. Two (1.2%) of 170 patients had curves exceeding 45 degrees at maturity. One mature patient (2.1%) required surgery within 2 years of follow-up beyond skeletal maturity. The conclusion drawn from these findings is that the SpineCor brace is effective for the treatment of adolescent idiopathic scoliosis. Moreover, positive outcomes are maintained after 2 years because 45 (95.7%) of 47 patients stabilized or corrected their end of bracing Cobb angle up to 2 years after bracing. Therapeutic study-investigating the results of treatment: level II.

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The objective of this study was to identify acute spinal and three-dimensional postural adaptations induced by a shoe lift in a population of idiopathic scoliosis (IS) patients. Forty-six IS patients (mean age: 12 +/- 2 years) were evaluated radiologically and with a stereovideographic system for pelvic obliquity. Based on the initial postural and radiological evaluation, a pertinent shoe lift height was chosen for each with the result that 12 patients were tested with 5-mm (S5) lifts, 20 patients were tested with 10-mm (S10) lifts, and 14 patients with 15-mm (S15) lifts. The posture for all 46 patients was then re-evaluated and a spinal radiograph obtained for 14 patients. The implementation of a shoe lift independent of the type of curve and amplitude significantly decreased the Cobb angle. As expected there was a change in the vertical height of the left tibial plateau and greater trochanter that induced a change in pelvic tilt. There was also a significant increase in the vertical height of S1 and T1. There was a significant change in the left and right iliac bone version, as well as a decrease in the difference in version between these two bones. The implementation of the shoe lifts also changed the lateral shift of the pelvis. A relative change between the shoulders and pelvis for tilt and anteroposterior shift was also found to be significant. In conclusion, using a shoe lift resulted in acute postural adaptations which specifically affected the spine and the three-dimensional position and orientation of the pelvis and shoulder girdle.

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