Summary Implant Summary in simple sentence Implant indications in simple sentence Key features of implant in simple sentence Related Implants IJS-elbow elbow stabilization system Proximal Ulna Plate System Indications Indications Contraindications Anatomy Osteology capitellum: spherical surface accepting the radial head; fluoroscopic checks aim to center the capitellar apex over the head . radial head/neck: cylindrical-concave head with tapered neck; final head height target at or distal to the corner formed by the lesser and greater sigmoid notches on AP in supination (Technique Guide, p. 13, item 19A). sigmoid notches (ulna): landmarks for height check and restoration of radioulnar articulation . general clinical context; manufacturer materials do not specify: restoration of native head diameter/height avoids over- or under-stuffing that alters contact pressures and forearm kinematics. Muscles kaplan interval through the extensor-supinator mass centered over the capitellum provides exposure. general clinical context; manufacturer materials do not specify: preserve the common extensor origin when feasible to maintain lateral stability. Ligaments general clinical context; manufacturer materials do not specify: the lateral collateral ligament complex is critical to posterolateral stability; protect/reconstruct as needed during exposure and trialing. Nerves limit distal dissection to protect the radial nerve. Blood supply general clinical context; manufacturer materials do not specify: radial head/neck vascularity is segmental; avoid circumferential stripping during preparation. Preoperative Planning Imaging x-ray standard AP and lateral views of elbow/forearm to assess comminution, displacement, and estimate head diameter/height for planning (general clinical context; manufacturer materials do not specify). CT obtain CT for unclear morphology, articular impaction, associated coronoid/ulnar injury, or for revision planning (general clinical context; manufacturer materials do not specify). Surgical Approach Identify Landmarks mark the lateral epicondyle with the elbow at 90° flexion and draw an 8–10 cm line through the mark. identify distal ulna landmarks—ulnar styloid, ulnar head, and shaft direction—to establish the forearm rotation axis for the Forearm Axis Jig. Skin incision Superficial dissection perform a kaplan approach with a longitudinal fascial incision centered over the capitellum; open the joint and limit distal dissection to protect the radial nerve . Deep Dissection muscular plane identify bony landmarks Implant Technique 1) head sizing and trial head selection: assemble native fragments in the sizing tray; if between sizes, choose the smaller; select the corresponding trial head. 2) provisional and initial neck sizing: with the forearm pronated, select neck length using neck sizing gauges; if between two lengths, choose the shortest; mark the neck just distal to the gauge (Technique Guide, p. 7–8). 3) resection: apply bone forceps distal to the mark, elevate the radius, and make the neck cut. caution: protect the radial nerve. note: the maximum defect that can be corrected is 23 mm. 4) canal preparation: open the canal in pronation toward the radial styloid to set trajectory; sequentially rasp by hand to the proximal depth mark, maintaining pressure and counter-clockwise rotation to remove the final rasp. note: do not use rasps under power. 5) neck planing: if the cut is not co-planar with the rasp’s proximal depth mark, mark the high point and plane the neck (Technique Guide, p. 10). 6) final neck sizing and trial stem: confirm neck length; if between, choose the shortest; insert the trial stem that matches the last rasp/planer (Technique Guide, p. 11). 7) trial head/neck assembly and validation: thread trial head and neck, load onto the trial stem, reduce, and take the elbow through full ROM; ensure the joint has not been over-stuffed. 8) fluoroscopic confirmation: AP in supination—confirm head height at or distal to the lesser/greater sigmoid notch corner and confirm capitellar apex centering . 9) stem insertion (press-fit): insert the definitive stem by hand to cover at least half of the TPS-coated area; if tight, optionally enlarge the proximal canal using the next rasp to the distal depth mark; impact until the collar seats flush with the stem impactor (Technique Guide, p. 13–14). 10) head loading and alignment: side-load the head, rotate until threads are lateral, and loosely insert the lock screw; keep the Head Alignment Tool engaged in the head grooves; assemble the Forearm Axis Jig and align to the ulnar fovea with the elbow flexed and forearm neutral. 11) locking in the safe zone: pronate the Head Alignment Tool 20–30° from neutral to center the lock screw in the safe zone, then tighten with counter-torque and verify minimum torque using the torque-indicating T-handle. warning: the Head Alignment Tool must be used when tightening the lock screw to provide counter-torque. 12) final validation and imaging: remove the jig; assess full ROM; confirm alignment fluoroscopically in pronation/supination; perform layered closure callout: protect the radial nerve . callout: do not use rasps under power. callout: ensure the joint has not been over-stuffed. Fixation Strategy the lock screw is packaged with each radial head and secures the head to the stem. after head loading, loosely thread the lock screw, use the Head Alignment Tool to provide counter-torque, and align with the Forearm Axis Jig; lock in 20–30° pronation using the torque-indicating T-handle while maintaining counter-torque. Technical specifications Design features side-loading head titanium plasma spray (TPS) stem surface long stem engineered for three-point fixation to achieve a solid press-fit distal stem flutes for rotational stability atraumatic dish intended to minimize capitellar wear press-fit intended use Sizes and catalog numbers heads (CoCr) ALN-RHI-180 — Ø 18 mm ALN-RHI-200 — Ø 20 mm ALN-RHI-220 — Ø 22 mm ALN-RHI-240 — Ø 24 mm ALN-RHI-260 — Ø 26 mm stems (Ti): A (diameter), B (offset), C (stem length), D (neck height) ALN-RST-0700 — A 7 mm; B 0 mm; C 29 mm; D 15 mm ALN-RST-0702 — A 7 mm; B 2 mm; C 29 mm; D 17 mm ALN-RST-0704 — A 7 mm; B 4 mm; C 29 mm; D 19 mm ALN-RST-0706 — A 7 mm; B 6 mm; C 29 mm; D 21 mm ALN-RST-0708 — A 7 mm; B 8 mm; C 29 mm; D 23 mm ALN-RST-0800 — A 8 mm; B 0 mm; C 30 mm; D 15 mm ALN-RST-0802 — A 8 mm; B 2 mm; C 30 mm; D 17 mm ALN-RST-0804 — A 8 mm; B 4 mm; C 30 mm; D 19 mm ALN-RST-0806 — A 8 mm; B 6 mm; C 30 mm; D 21 mm ALN-RST-0808 — A 8 mm; B 8 mm; C 30 mm; D 23 mm ALN-RST-0900 — A 9 mm; B 0 mm; C 33 mm; D 15 mm ALN-RST-0902 — A 9 mm; B 2 mm; C 33 mm; D 17 mm ALN-RST-0904 — A 9 mm; B 4 mm; C 33 mm; D 19 mm ALN-RST-0906 — A 9 mm; B 6 mm; C 33 mm; D 21 mm ALN-RST-0908 — A 9 mm; B 8 mm; C 33 mm; D 23 mm ALN-RST-1000 — A 10 mm; B 0 mm; C 35 mm; D 15 mm ALN-RST-1002 — A 10 mm; B 2 mm; C 35 mm; D 17 mm ALN-RST-1004 — A 10 mm; B 4 mm; C 35 mm; D 19 mm ALN-RST-1006 — A 10 mm; B 6 mm; C 35 mm; D 21 mm ALN-RST-1008 — A 10 mm; B 8 mm; C 35 mm; D 23 mm ALN-RST-1100 — A 11 mm; B 0 mm; C 37 mm; D 15 mm ALN-RST-1102 — A 11 mm; B 2 mm; C 37 mm; D 17 mm ALN-RST-1104 — A 11 mm; B 4 mm; C 37 mm; D 19 mm ALN-RST-1106 — A 11 mm; B 6 mm; C 37 mm; D 21 mm ALN-RST-1108 — A 11 mm; B 8 mm; C 37 mm; D 23 mm system pack ALN-RHA-SYS Complications Complication A Pearls & Pitfalls Pearls if between head sizes, choose the smaller head. if between neck lengths, choose the shortest neck. set rasp trajectory toward the radial styloid. confirm height at the lesser/greater sigmoid notch corner and capitellar centering on AP in supination. use the Forearm Axis Jig to standardize rotational alignment before final locking. Pitfalls over-stuffing the radiocapitellar joint during trialing. under-preparation that prevents press-fit seating; address with optional proximal enlargement using the next rasp to the distal depth mark. locking outside the safe zone or without counter-torque. excessive distal dissection with risk to the radial nerve .