Purpose of study. Unstable pelvic ring injuries usually occur in polytrauma patients and are associated with high mortality and morbidity. Percutaneous screw fixation of sacro-iliac joint dislocations, fracture-dislocations and sacral fractures is a well-recognised technique first described by Routt and is increasingly gaining popularity. This method is biomechanically comparable to open reduction and internal fixation with plates and screws but offers the advantages of minimally invasive surgical techniques. It is however a technically demanding procedure with reported complications including hardware failure, misplacement of screws, nerve injury and poor posterior reduction. The purpose of the study is to report clinical results of patients treated with closed reduction and percutaneous ilio-sacral screw fixation for unstable pelvic ring fractures by a single surgeon. Methods. A review of prospectively collected data was performed on all patients who had percutaneous sacro-iliac fixation between 2009 and 2012. Thirty five percutaneus sacro-iliac screws were inserted in 30 patients with a mean age of 25.6 years (range 17–62). Fracture types included 10 AO type B, and 20 AO type C. The mean follow-up period was 11.6 months (range 3–38). The complications assessed were screw misplacement, neurovascular complications, hardware breakage and loss of reduction. Results. All patients had a satisfactory initial reduction. One patient (2.8%) had misplacement of a screw with resultant temporary neurological fallout. One patient (2.8%) had screw misplacement without neurological fallout. Both of these patients initially had two screws inserted and the misplaced screws were removed and not reinserted. One patient (2.8%) had screw cut-out with loss of reduction. This screw was removed, open reduction peformed and the screw was re-inserted. Conclusion. The use of percutaneous sacro-iliac screws provides a safe and effective technique for the management of unstable posterior pelvic ring injuries. Our combined complication rate is comparable to published literature. NO DISCLOSURES

The progressive kyphosis and pain in patients with acute thoracolumbar burst fractures treated conservatively so as the recurrent kyphosis after posterior reduction and fixation were associated to disc collapse rather than vertebral body compression. It depends on redistribution of the disc tissue in the changed morphology of the space after fractures of the endplate. The aim of this study is to evaluate the safety and the efficacy of balloon kyphoplasty with calcium phosphate, alone or associated to short posterior instrumentation, in the treatment of acute thoracolumbar burst fractures. Eleven fractures in ten consecutive patients with an average age of 48 years who sustained acute thoracolumbar traumatic burst fractures without neurological deficits were included in this study. The fractures were A1.2 (3), A3.1 (4) and A3.2 (4), according to AO classification. In 7 fractures (A1.2 and A3.1) the kyphopasty was performed alone in order to make the most of efficacy in fracture reduction, anterior and medium column stabilization and, as much as possible, segmental kyphosis correction. In the A3.2 fractures (4), that are unstable, the kyphoplasty was associated to a short posterior instrumentation. To avoid the PMMA long run complications in younger patients, we used a calcium phosphate cement. VAS, SF-36, Roland-Morris questionnaire (RMQ) and Oswestry low back pain disability questionnaire (ODQ) were used to evaluate pain, state of health, functional outcomes and spine disability. To the average follow-up time of 15.5 months (range 8–31) we did not observe statistically significant differences in 7 of 8 SF-36 domains in comparison to general healthy population of same sex and age. At the same follow-up, the spine disability questionnaire showed a functional restriction of 18% (ODQ) and 29,6% (RMQ) being 100% the maximum of disability. No bone cement leakage, no implant failure and no height correction loss were observed in any case. Our data confirm the safety and the efficacy of ballon kyphoplasty with calcium phosphate in the treatment of acute thoracolumbar burst fractures. In this way we can reduce the possible complications resulted from discal space collapse and obtain an early functional restoration. When performed alone, this mini invasive surgical technique offer the advantage of almost immediate return to daily activities. When associated to posterior instrumentation, it decreases the long run complications and allows to reduce the number of stabilized levels, maintaining, in part, the thoracolumbar junction movement