Total Shoulder Replacement Amal Alam David Babayev Rakshya Bista Shreenath Varma Wahaj Patel S
Glenohumeral joint Articular cartilage: prevents bone-on-bone friction. Labrum: offers the joint more stability Rotator cuffs: group of muscles, stabilize the jointhttp://www.eorthopod.com/sites/default/files/images/shoulder_anatomy_ligaments01.jpg1. American Academy of Orthopedic Surgeons, http://orthoinfo.aaos.org/topic.cfm?topic=A00094, reviewed December 20112. Huguet D, DeClercq G, Rio B, Teissier J. (2010) Results of a new stemless shoulder prosthesis: Radiologic proof of maintained fixation and stability after a minimum of three years follow-up. Journal of Shoulder and Elbow Surgery, 19:847-852.
Normal Range of Motion http://www.crossfitskopje.com/wp-content/uploads/2012/12/bigliani_flatlow_shoulder3.jpegS Forward flexion is the movement of the shoulder forward. Normal range of motion is 180 degreeS pushing a doorS lifting an object from the ground.
Normal Range of Motion S External Rotation: elbow bent to 90 degrees S Opening the front door S Normal range of Motion is 70 to 90 degreeshttp://t0.gstatic.com/images?q=tbn:ANd9GcRWzNgo0gKHQhaPWS9-boRsjQ0-Zguy7zQIR-PwY-iGx3ItGGct
Instability: ball of the humerus becomes larger than the shoulder socket that holds it. The muscles, tendons and ligaments, must anchor the shoulder in order to maintain the normal stability. The main causes for a total shoulder replacement revolve around arthritis.1. American Academy of Orthopedic Surgeons, http://orthoinfo.aaos.org/topic.cfm?topic=A00094, reviewed December 20112. Hospital For Special Surgery, www.hss.edu, assessed October 2012
S Osteoarthritis: “wear and tear” arthritis, most people are familiar with it, where the cartilage in the joint wears away over time.http://www.eorthopod.com/images/ContentImages/shoulder/shoulder_reverse_replacement/shoulder_reverse_oa_rationale01.jpg1. American Academy of Orthopedic Surgeons, http://orthoinfo.aaos.org/topic.cfm?topic=A00094, reviewed December 2011
Rheumatoid arthritis S an inflammation and thickening of the tissues around the jointhttp://www.fulllifeusa.com/images/fulllife_enfermedades_01.jpg 1. Hospital For Special Surgery, www.hss.edu, assessed October 2012
S Post-traumatic arthritis: follow a serious shoulder injury and cause fractures. S Fractures: common reason people have shoulder replacements, bones of the shoulder matter completely shatter, difficult to put the pieces back together. S Avascular necrosis, where the blood supply is severely hampered, causing bone death.http://www.eorthopod.com/images/ContentImages/Fractures/adult_fractures1. American Academy of Orthopedic Surgeons, http://orthoinfo.aaos.org/topic.cfm?topic=A00094, reviewed December 20112. Hospital For Special Surgery, www.hss.edu, assessed October 2012
Total Shoulder Replacement S Glenoid is replaced with a plastic socket S Humeral head is metal S Metal portion is inserted into humeral bone www.lima.it
Procedure Part I S Glenoid is removed and cleaned S Three to four holes are drilled for the pegs of the implant S Cement or porous material is used for implantationhttp://www.zimmer.com
Procedure Part II S Humerus is sliced off and cleaned S The soft bone inside the humerus is drilled out S Cement might be injected into the humerus S Metal humeral stem is inserted and then the ball of the humerus is screwed and cemented to the tophttp://www.zimmer.com
Current Devices S Uses various porous material to allow bone ingrowth S Promotes natural fixation of implants S The glenoid can become loose regardless http://www.biomet.comhttp://www.zimmer.com
Reverse Shoulder Replacement S The glenoid and humeral pieces are switched S Uses different muscles to function S Generally for people with irreparable rotator cuff injuries, not used very oftenhttp://shoulderreplacement-hobgood.org
Experimental Set UpS In Vivo human clinical trialS Anterior Active Elevation and Exterior Active Rotation will be measured in subjects at intervals of six months every two yearsS IRB Approved Clinical Trial
Working HypothesisS The new device should increase both the external active rotation and anterior active elevation
Control GroupS We will receive control group data from Biomet via collaboration on their Comprehensive ® Total Shoulder Replacement Model, which was tailored to patients with osteoarthritis.
Experimental Group People with Osteoarthritis People of all ages 18+ Patient ScreeningReference: Shttp://img.webmd.com/dtmcms/live/webmd/consumer_assets/site_images/rich_media_quiz/topic/rmq_coping_with_acne/getty_rf_photo_of_diverse_group_of_people_of_all_ages.jpg
Power AnalysisIMAGE and reference of tool used to calculate poweranalysis
Power AnalysisDependent Variable 1: Anterior Active ElevationExpected average value: ___ degreesTest value of CTSS: ___ degrees (reference: Biomet client profile)Allowed Standard Deviation: 10 degrees (reference: TESS)α level: 5%ϐ level: 10%Calculated Sample Size: ___
Power AnalysisDependent Variable 2: External Active RotationExpected average value: ___ degreesTest value of CTSS: ___ degrees (reference: Biomet client profile)Allowed Standard Deviation: 10 degrees (reference: TESS)α level: 5%ϐ level: 10%Calculated Sample Size: ___How many sample will we use: _____
Minimizing Sample LossS Substantial Discount for deviceS Sample size needed for dependent variable 2 is much smaller okay for some subject to leave mid-study Reference: http://modernpivotdoors.com/pivot-doors/security-door- locks/defendius-security-door-lock.jpg
Normal DistributionS Percentile ChecksS Normality PlotS Chi-squared goodness of fit Mathworks.com
Parametric TestsS Multivariate Analysis of Variance S Two dependent variables S Anterior Active Elevation S External Active RotationS Alternatively, we can conduct two repeated measures ANOVA S One for each dependent variable.