Summary The Skeletal Dynamics Distal Elbow Plating System consists of the following systems Proximal Ulna Plate with FREEFIX® ALIGN® Radial Head System (this page) IJS® Elbow Stabilization System The Skeletal Dynamics Align Radial Head System features precision-engineered titanium alloy implants designed to restore radial head anatomy and optimize elbow stability Included in the system are cobalt-chrome modular components, cannulated instrumentation, and specialized tools for precise radial head reconstruction Indications Indications replacement of the radial head for degenerative or post-traumatic disabilities pain, crepitation, and decreased motion radio-humeral proximal radio-ulnar joint Anatomy Osteology biconcave and slightly elliptical capitellum Muscles extensor digitorum supinator anconeus posterior triceps Ligaments LCL complex RCL LUCL annular ligament Nerves radial nerve posterior interosseous nerve superficial radial nerve lateral antebrachial cutaneous nerve Blood supply radial artery recurrent radial interosseous vessels ular recurrent Preoperative Planning Imaging x-ray standard AP lateral oblique elbow CT three-dimensional reconstructions Surgical Approach Kaplan aproach lateral epicondyle Implant Technique Elbow Landmarks with the elbow flexed 90 degrees, palpate and mark the lateral epicondyle make an 8 -10cm line through the marked point Distal Ulna Landmarks to identify the axis of forearm rotation, pronate the hand and flex the wrist palpate and mark the ulnar styloid, ulnar head and the direction of the shaft note: use fluoroscopic imaging to verify proper landmark placement Superficial Exposure make your incision make a longitudinal facial incision over the center of the capitellum for the Kaplan approach Deep Exposure open the join and gain access to the radial head limit distal dissection to protect the radial nerve Head Sizing remove the radial head fragments assemble and measure them using the Radial Head Sizing Tray note: if between radial head sizes, select the smaller Trial Head Selection select the Trial Head that corresponds to the native head Provisional Neck Sizing with the forearm pronated, select the radial neck length using the Neck Sizing Gauges neck sizing options: 0 offset - 15 mm 2 offset - 17 mm 4 offset - 19 mm 6 offset - 21 mm 8 offset - 23 mm note: if between two lengths, always select the shortest sizing option Initial Neck Sizing use the Neck Sizing Gauge to select the level of the desired radial cut mark the radial neck just distal to the Neck Sizing Gauge Attaching Bone Forcepts secure the Bone Holding Forceps just distal to the marked radial neck Resection lift the radius with the Bone Holding Forceps, then make the radial neck cut caution: protect the radial nerve note: the maximum defect that can be corrected is 23mm Opening Radial Canal starting with the smallest Rasp, position the hand in pronation and insert the Rasp past the tuberosity in the direction of the radial styloid note: this will establish the trajectory for all subsequent Rasps Canal Preparation fully insert each of the rasps up to the proximal depth mark using an oscillating motion continue sequential rasping until cortical bone is encountered note the size of the final rasp used while final rasp is still fully inserted, maintain positive pressure and perform counter clockwise rotation prior to removing note: do not use rasps under power Identifying Planing Line if the radial cut is not coplanar with the proximal depth mark of the rasp, planing may be required for proper seating of the prosthesis with the final rasp fully seated, mark the highest point on the radius to identify the area to be planed Neck planing prepare the respected end of the radius using the planer Final Neck Sizing with the forearm pronated, confirm the final radial neck length using the Neck Sizing Gauges note: if between two lengths, always select the shortest sizing option. Trial Stem Selection select the Trial Stem that corresponds to the final Rasp/Planer used and insert it into the prepared canal Trial Head & Neck Assembly assemble the Trial Head and Neck by threading the two components together thread the handle of the Neck Sizing Gauge into the Trial Head to facilitate loading onto the Trial Stem Trial Validation assemble the Trial Head and Neck into the Trial Stem reduce the joint and assess the sizing of the trial components by manipulating the elbow through its full range of motion note: ensure that the joint has not been over-stuffed Fluoroscopic Confirmation confirm a proper fit using fluoroscopy, then remove the trial components A in a true A/P view of the proximal forearm in supination, confirm that the height of the radial head trial is at or distal to the corner formed by the lesser and greater sigmoid notches B also, confirm proper radial head diameter by assuring that the apex of the capitellum is centered over the radial head Prosthetic Stem Insertion with the forearm in pronation, use the Bone Holding Forceps to lift the radius out of the wound, then insert the Radial Stem implant into the canal if the Radial Stem cannot be inserted by hand to a depth covering more than half of the TPS coated area, remove the stem and see optional next step Prosthetic Stem Insertion (optional) use the next larger sized Rasp and insert it up to the distal depth mark (A) to slightly enlarge the proximal portion of the intramedullary canal in a counter clockwise motion reinsert the stem to confirm adequate insertion depth (at least half of the TPS coated section) Prosthetic Stem Impactor insert the Stem Impactor laterally, then lower the handle until in-line with the stem impact the stem until the collar seats flush against the radius note: the notch on the Stem Impactor facilitates loading Prosthetic Stem Loading side load the Radial Head implant onto the stem, then rotate it until the threads are positioned laterally note: each Radial Head implant is packaged with its respective Lock Screw Head Alignment Tool Engagement remove the Bone Holding Forceps and secure the Head Alignment Tool to the Radial Head the two tines of the Head Alignment Tool should engage the grooves of the Radial Head note: the Head Alignment Tool is used to control the position of the Radial Head Lock Screw Insertion loosely thread the Lock Screw into the Radial Head Forearm Guide Assembly keeping the Head Alignment Tool connected to the Radial Head, slide the rail of the Forearm Axis Jig into the handle until it snaps securely with the elbow flexed and the forearm in neutral, adjust and lock the distal end of the Forearm Axis Jig to the marked fovea of the ulna Initial Implant Locking pronate the Head Alignment Tool ~20 - 30 degrees from the neutral forearm position, then tighten the Lock Screw while providing counter-torque warning: the Head Alignment Tool must be used when tightening the Lock Screw to provide the necessary counter-torque note: positioning the Head Alignment Tool in 20 - 30 degrees of pronation ensures the Lock Screw is at the center of the “safe zone” Final Implant Locking use the torque indicating T-Handle Driver to ensure the minimal torque has been achieved if desired, additional torque can be gained using the Universal Driver Handle warning: the Head Alignment Tool must be used when tightening the Lock Screw to provide the necessary counter-torque Implant Validation remove the Forearm Axis Guide assembly manipulate the elbow through its full range of motion to confirm final implant alignment Fluoroscopic Confirmation confirm final implant alignment using fluoroscopic imaging Wound Closure repair soft tissues as needed, then close the incision Technical specifications Cobalt–chromium heads 18 mm 20 mm 22 mm 24 mm 26 mm Provisional neck sizing 0 offset - 15 mm 2 offset - 17 mm 4 offset - 19 mm 6 offset - 21 mm 8 offset - 23 mm