present images of normal and grade 1 to grade 3 PTT pa-thology and discuss the technique for PTT assessment onsonography.

Poster 115Final Needle Position on Lateral FluoroscopicImage During Confirmed Intra-articularSacroiliac Joint Injections: A RetrospectiveReview.Kevin Berry, MD (University of Colorado Schoolof Medicine, Aurora, CO); Venu Akuthota, MD;Peter G. Gonzalez, MD; Jeri E. Harwood, PhD;Brian H. Keogh; William J. Sullivan, MD.

Disclosures: K. Berry, None.Objective: To assess the needle position on lateral fluoro-scopic images in unequivocal intra-articular sacroiliac joint(SIJ) injections.Design: Retrospective review.Setting: An academic spine center.Participants: 29 patients undergoing diagnostic SIJinjections.Interventions: Intra-articular SIJ injections.Main Outcome Measures: Final needle tip position onlateral imaging of confirmed intra-articular injections, asdetermined by a panel of trained spine interventionists. Finalneedle tip position was defined as posterior to the sacrum, inthe posterior 50% of the sacrum, in the anterior 50% of thesacrum, or anterior to the sacrum.Results: None of the SIJ injections were posterior to thesacrum and only 3 of the 29 images were in the posterior 50%of the sacrum. The majority of the injections were in anteriorportion of the sacrum, with 18 in the anterior 50% and 8anterior to the sacrum. Calculated confidence intervals re-vealed a statistical significance between the anterior 50%group and the posterior 50% group.Conclusions: Varying depths may be required to accessthe synovial portion of the SIJ. We would postulate that morecephalad targeted injections may cannulate the mid portionof the SIJ and allow for more anterior or ventral placement ofthe needle within the SIJ and therefore a greater likelihoodof an intra-articular contrast pattern on SIJ injection. Routinelateral views during fluoroscopically guided SIJ injectionswill help determine depth of final needle position and possi-bly increase rate of intra-articular contrast patterns.

Poster 116Finite Element Modeling of the SacroiliacJoint.Dennis E. Enix, DC, MBA (Logan University, Ches-terfield, MO); Douglas Smith, PhD, PE.

Disclosures: D. E. Enix, HRSA Grant R18HP15125-01-00,Research grants.Objective: To better understand the forces acting on the

sacroiliac (SI) joint, the surface topography of the auricular SIjoint was modeled with a finite element model analysis.Design: Biomechanical and anatomical studySetting: University anatomy laboratory and mechanicaland aerospace engineering department.Participants: Ten human formalin embalmed cadavericspecimens aged 64.2�14.7 (7 men aged 65.5�14.8 and 3women aged 57.2�14.0).Interventions: Finite element modeling of human SI jointsto create a topographical map of the joint articular surface.Main Outcome Measures: Finite element models al-low the stress distribution on the articular surfaces of the SIjoint to be examined. The compressive and vertical shearingforces on the sacroiliac joint creating by unequal loads andtensions across ligaments are studied.Results: Increases the shear across that joint and placingmore stress on the ligament system. If ligaments are stretchedbeyond their elastic barrier they lose some of their rebound-ing properties. Loss of ligament elasticity alters the transfer ofreaction forces, which may alter the shearing forces across theSI joint.Conclusions: This computer model may aid to un-derstanding of ligament tension forces in LBP and LBP inpregnancy, especially lumbosacral and posterior pelvic painsyndromes.

Poster 117Functional Movement Disorders: SuccessfulTreatment Using an Intensive One-Week MotorReprogramming Protocol.Jeff Thompson, MD (Mayo Clinic, Rochester, MN);J Eric Ahlskog, MD; Kathrin Czarnecki, MD.

Disclosures: J. Thompson, None.Objective: Assess the effectiveness of a 1 week intensivetherapy program for the treatment of functional movementdisorder patients.Design: Retrospective series.Setting: Tertiary academic medical center.Participants: 60 consecutive participants in the Func-tional Movement Treatment Protocol.Interventions: Participation in the 1-week protocol con-sisting of twice a day physical and occupational therapy (andspeech therapy as indicated) utilizing progressive motor re-training principles. A key component is the referring neurol-ogist and the consulting physiatrist “selling” of the concept of“reprogramming” of the patient’s motor system.Main Outcome Measures: Provider rating of improve-ment on a 5-step scale from “not improved” to “in remission”at the end of the 1-week treatment.Results: Between January 2005 and December 2008, 60consecutive patients underwent the protocol (46 women/14 men); mean age: 45.3 years (17-79). This included func-tional gait disorders (40%), hyperkinetic movements (15%),tremor (13.3%), dystonia (11.7%), paresis (10%), paroxys-

S56 PRESENTATIONS