Introduction: The purpose of this clinical assessment is the evaluation of the capability of the interspinous system (Coflex-F) to create a single level fusion in combination of bone substitute. The clinical experience would support the in vitro results reported above showing that the system is an effective means of synthesis.

Methods: This clinical assessment enrolled 25 patients with lumbar stenosis (L1-L5) with or without low-grade spondylolisthesis. The patients have already undergone conservative treatment for six months without achieving significant success or improvements in their clinical picture. Patients were enrolled in three months from 1 June 2011 to 01 December 2011 and subject to the following analyzes and questionnaires: • The personal data and identification of the clinical picture of the patient • Descriptive data of the surgical procedure • VAS - pre-operative, post-operatively, six months and twelve months • ODI - preoperative, postoperative, six months and twelve months • CT scan - preoperative, postoperative, six months and twelve months The subjective evaluation of pain by the VAS and ODI questionnaires and evaluating radiological arthrodesis obtained determine the reliability and effectiveness of the device.

Results: This clinical assessment involves subjective evaluation of pain by the VAS and SF-36 questionnaires with analysis of the indices: - Pre-operatory - Six months post-operatory - Twelve months post-operatory The study is complemented by radiological assessment of patients to determine the degree of arthrodesis reached in the treated level. The early results are promising and initial radiological signs of fusion are demonstrated on x-ray and CT studies.

Conclusions: The result obtained shows how the interspinous system is capable of inducing spinal stability with arthrodesis, comparable to that obtainable with of pedicle screw and rod systems, but with clearly many clinical advantages such as: • Reduced skin incision. • Reduced muscle trauma due to minimally invasive procedure. • Reduced operating risk of pedicle screw and their related problems. • Reduction in time of surgery.

Patient Care: lesser traumatic surgical technique with reduced operative risks. Patient outcome must be the same as pedicle fixation. Lower cost.

Learning Objectives: Evaluation of interspinous procedure for single level arthrodesis.

References: Kabir SM, Gupta SR, Casey AT. Lumbar interspinous spacers: A systematic review of clinical and biomechanical evidence. Spine 2010;35:E1499-506. Lo CC, Tsai KJ, Zhong ZC, Hung C. Biomechanical Differences of Coflex-F and Pedicle Screw Fixation in Stabilization of TLIF or ALIF Condition - A Finite Element Study. 6th World Congress of Biomechanics (WCB 2010). August 1-6, 2010 Singapore,IFMBE Proceedings, 2010, Volume 31, Part 2, 565-568. Jutte P, Castelein R. Complications of pedicle screws in lumbar and lumbosacral fusions in 105 consecutive primary operations European Spine Journal Volume 11, Number 6, 594-598.