CORR Insights®: High Risk of Further Surgery After Radial Head Replacement for Unstable Fractures: Longer-term Outcomes at a Minimum Follow-up of 8 Years.

Radial head replacement is more akin to silicone arthroplasty of the metacarpophalangeal joint than it is to total hip or knee replacement. A prosthetic radial head is a spacer that keeps the elbow aligned while the ligaments scar. A prosthetic radial head is helpful for stabilizing the elbow during the 3 or 4 weeks after dislocation, particularly when there is an associated fracture of the tip of the coronoid (the so-called “terrible triad fracture-dislocation”). It’s unclear whether a prosthetic radial head improves the health of the elbow more than 4 weeks after dislocation. A prosthetic radial head might limit the development of ulnotrochlear arthritis by helping to support the elbow, but it might cause arthritis by contributing to subluxation if not appropriately sized or an abnormal articular milieu to the degree that a metal articulation with cartilage is unhealthy. Intentionally loose radial heads are associated with radiographic lucencies in the radial neck [3, 7]. Prostheses intended to bond with the bone of the radial neck may create substantial lucencywhen they don’t [8] or loss of bone at the collar of the prosthesis when they do [4]. Bipolar arthroplasties canhave osteolysis and this inflammation can harm the ulnohumeral cartilage [9]. Prostheses that are too long may be associated with capitellar wear, capitellar lucency, and ulnohumeral subluxation [1]. But none of these factors seem to correlate well or consistently with symptom intensity, magnitude of limitations, or even elbow motion. Cristofaro and colleagues [2] describe a second operation to revise (three patients) or remove (27 patients) a radial head prosthesis among 119 total prostheses (25%). Seventy percent had re-operation within a year (median time from initial to second surgery, 7 months). If we consider synovitis, subluxation, and ulnar neuritis as types of pain (otherwise it’s unclear why the prosthesis would be removed), then 29 out of the 30 operationswere for pain (with one operation due to deep infection). It’s possible that the subluxations were technical issues with the prosthesis, but we don’t know how many people had similar issues and did not have subsequent surgery.More than half the silastic implants (nine out of 17) were removed [2].