Summary The T2 Alpha Humerus Nailing System is indicated for humeral shaft and proximal humerus fractures. The system maximizes rotational and axial stability across varying bone qualities through versatile locking configurations and a minimally invasive insertion technique. It streamlines surgical efficiency and OR logistics by utilizing a standardized single core tray that is compatible across the entire Gamma4® and T2 Alpha® platforms. Design Stryker Orthopedic Modeling and Analytics (SOMA) designed straight nail design allows for alignment of the epiphyseal fragment with the diaphysis and gives structural support to the humeral head fragment proximal screw trajectories are designed to aim for dense bone to reduce the potential of displacement of the humeral head diameters defined through the SOMA database cover a wide range of intramedullary canal diameters in the analyzed population Active intraoperative compression up to 6mm of controlled compression for long nails designed to allow for a more controlled reduction of the fragments when compared to the traditional backslapping/backstroke method Guided targeters targeters available for every hole except the distal lateral to medial Unique instrumentation nail height stop: facilitates precise nail depth placement, while reducing the risk of nail protrusion through the proximal humerus Advanced locking screws designed to provide increased axial fracture stability in any 4mm round locking hole when the surgeon chooses Hybrid locking configuration designed for fixation of varying fracture patterns Anatomy Osteology greater tuberosity landmark humeral shaft diaphysis distal humerus flare Muscles anterolateral split supraspinatus entry interval proximal landmark anterior humerus Ligaments coracoacromial ligament coracohumeral ligament superior glenohumeral ligament middle glenohumeral ligament Nerves axillary nerve radial nerve musculocutaneous nerve median nerve ulnar nerve Blood supply anterior circumflex humeral artery posterior circumflex humeral artery profunda brachii artery periosteal branches of the brachial artery Approach Incision an anterolateral incision splits the deltoid, exposing the bursa and supraspinatus tendon percutaneous approach using an incision on the upper arm, the deltoid muscle is bluntly split to expose the rotator cuff superior transdeltoid approach the anterior deltoid is detached from the anterior acromion to expose the rotator cuff Entry point central entry point located at the very top of the humeral head, in the articular surface, in line with humeral axis Technique Reaming & nail selection guide wire insert 2.5mm ball-tip wire to desired depth reaming (long nails) reamin 0.5mm incredments use a pusher on the guide wire during reamer extraction to maintain position sizing select nail 1.0–1.5mm smaller than the last reamer used measure remaining guide wire length with the ruler seated on bone if between sizes, round down to the shorter nail measurement measure remaining guide wire length with the ruler seated on bone if between sizes, round down to the shorter nail Assembly & insertion assembly hand-tighten nail to adapter; secure with ball-tip screwdriver remove targeting devices before insetion insertion advance nail over smooth-tip wire depth countersink the nail below the articular surface use fluoroscopy to ensure a depth of ≥6mm if compression is planned completion remove guide wire once positioned Targeting device setup attachment slide targeting device onto adapter (unlocked) until it hits the stop and turn knob to lock validation insert tissue protection sleeve/drill sleeve and 3.5mm drill to confirm alignment repeat for the anterior device Proximal locking alignment rotate nail for tuberosity access align k-wire (AP plane) with the forearm for 30° retroversion drilling incise skin at the sleeve tip drill the first cortex, then advance (no rotation) to the subchondral bone leave a second drill bit in an adjacent hole to stabilize the arm during screw insertion screw placement measure length via the sleeve use the gray friction lock to hold the sleeve and press to release use imaging to confirm the screw head is seated on bone Distal locking short nails (guided) static two round holes dynamic oblong hole long nails (guided/distal device) align c-arm 30° oblique to the sleeve axis adjust the device knob until the sleeve and nail are collinear always start with a standard bicortical screw to prevent "skiving" freehand (long nails) use the "perfect circle" technique under x-ray drill perpendicular to the nail and measure via scale or depth gauge Apposition (long nails) setup insert two distal screws and one proximal screw in the oblong hole execution insert the compression screwdriver through the nail holding screw apply up to 6mm of compression finalize insert a second proximal shaft screw to lock the compression Advanced screws & end cap advanced screws open the near cortex with a counterbore drill push the screw until it engages the nail and rotate counter-clockwise until it "clicks" to ensure alignment, then tighten end cap remove adapter select appropriate length to prevent impingement fully seat the cap to prevent loosening and adjust nail height if necessary Nail Sizes Short nail diameter: Ø8mm length: 150mm Long nail diameter: Ø7mm–Ø10mm in 1mm increments length: 180-315mm in 15mm increments Technical Specifications Driving end diameter driving end diameter of the 7–9mm is Ø10mm nail size 10mm has a constant diameter Drills 3.5mm – orange 4.5mm – orange (counterbore drill) PEEK insert designed to reduce potential for screw backout with locking screw or advanced locking screw in proximal holes Washers designed to increase surface area while reducing screw head prominence designed to improve bone fragment compression through increased surface area includes suture holes End caps available in three sizes 0mm 2mm 4mm Screws Locking Screw Ø4mm, 20–60mm length in 2.5mm increments Advanced Locking Screw Ø4mm, 20–60mm length in 2.5mm increments Compression Screw Humerus