Radial Head Replacement (Arthroplasty)

Indications

• Comminuted radial head fractures (Mason III/IV) associated with elbow dislocation - the lateral ulnar collateral ligament (LUCL) is typically injured, making prosthetic replacement necessary to stabilize the joint and allow early mobilization
• Terrible Triad injuries (elbow dislocation + radial head fracture + coronoid fracture) - a metal replacement is performed after coronoid fracture fixation, since radial head removal provides excellent coronoid exposure
• Essex-Lopresti lesion (radial head fracture + distal radioulnar joint dislocation) - a prosthesis prevents proximal radial migration that would otherwise occur after simple excision
• Fractures with concomitant medial collateral ligament rupture or coronoid fracture adding to elbow instability
• Situations with significant instability of the elbow, radial forearm axis, or DRUJ from injury or disease

Short-term outcomes of radial head arthroplasty for comminuted fractures have been reported as superior to ORIF at short-term follow-up. - Campbell's Operative Orthopaedics 15th Ed 2026, p.808

Prosthesis Design

Surgical Technique (Campbell's Technique 15.4)

• Incision begins superior to the lateral epicondyle, extends ~6 cm distally
• Extensor digitorum communis (EDC) split or Kaplan approach - when the LUCL is intact
• Kocher approach (between ECU and anconeus) - when the LUCL is disrupted

1. Develop the lateral capsule and expose the radial neck
2. If a coronoid fracture is present, repair it first (radial head resection improves coronoid access)
3. Incise the annular ligament transversely to expose the radial canal end-on
4. Cut the radial neck just proximal to the fracture site
5. Prepare the medullary canal with burrs or rasps
6. Cut the proximal radial surface flat for full contact with the prosthesis collar
7. Achieve a tight press-fit; use trial prosthesis to confirm radiocapitellar contact under fluoroscopy
8. Check range of motion (flexion-extension, pronation-supination) and implant tracking
9. Insert the final prosthesis
10. Repair the LUCL to its isometric point at the capitellar rotation center (suture anchor or drill holes); the ulnohumeral joint must be held reduced during this step

• Reassemble excised fragments on the back table to estimate native diameter and thickness
• The native radial head is elliptical and offset; most implants are axisymmetric
• Optimal diameter = minor axis of the ellipse (typically ~2 mm smaller than maximum diameter)
• The proximal edge of the prosthesis should be level with the lateral coronoid edge (native position is 0.9 mm distal to it)
• Avoid overstuffing - more than 2 mm of lengthening increases radiocapitellar contact pressures
• When between sizes, choose the smaller diameter and smaller thickness

"Overlengthening of the radial head is the commonest technical cause of failed radial head arthroplasty." - Rockwood and Green's Fractures in Adults 10th Ed 2025

Sizing Pitfalls

• The reassembled excised radial head fragments
• The relationship of the prosthesis to the proximal ulna (lateral coronoid edge)
• Intraoperative fluoroscopy assessing ulnohumeral joint gapping (lateral ulnohumeral gapping = overstuffing)
• Ipsilateral ulnar variance can drop if the head is oversized

• Increases tension on the interosseous membrane
• Causes stiffness and pain
• Produces capitellar wear and erosion of the lateral trochlea
• May prevent proper annular ligament closure

Outcomes

• Good to excellent results in ~80% of patients
• 10-20% reduction in grip/elbow strength
• Pain relief is typically excellent
• Elbow flexion-extension and forearm rotation arcs are within 10-20 degrees of normal
• Ulnohumeral joint stability is generally maintained
• Return to high-demand activities (sports, military) has a more guarded prognosis

• Stem loosening - reported in one-third or more of press-fit designs; causes significant proximal radial osteolysis and typically necessitates removal
• Rigid fixation (porous ingrowth, cemented) is linked to higher complication and revision rates
• Smooth-stemmed implants show lower osteolysis rates than porous ingrowth designs
• Mid-term follow-up (>8 years) with smooth-stemmed modular implants shows preserved good outcomes

Postoperative Management

• A hinged external fixator or internal joint stabilizing system (internal joint stabilizer, e.g., Orbay et al.) can augment stability
• Tape suture augmentation of the ligament repair is a described reliable technique

• Campbell's Operative Orthopaedics 15th Ed 2026, pp. 808-810 (Technique 15.4)
• Rockwood and Green's Fractures in Adults 10th Ed 2025, pp. 1669+ (Key Surgical Steps, Pitfalls)

• Monir & Wagner, Hand Clin 2025 - "Updates on Radial Head Arthroplasty in Trauma" [PMID: 41106923]
• Celli et al., Arch Orthop Trauma Surg 2024 - Long-term outcomes with bipolar prosthesis [PMID: 38568386]
• Heifner et al., Hand (NY) 2024 - Revision of failed RHA [PMID: 36752100]