Radial head fractures

Abstract

The shape and size of the radial head is highly variable but correlates to the contralateral side. The radial head is a secondary stabilizer to valgus stress and provides lateral stability. The modified Mason-Hotchkiss classification is the most commonly used and describes three types, depending on the number of fragments and their displacement. Type 1 fractures are typically treated conservatively. Surgical reduction and fixation are recommended for type 2 fractures, if there is a mechanical block to motion. This can be done arthroscopically or open. Controversy exists for two-part fractures with >2 mm and <5 mm displacement, without a mechanical bloc as good results have been published with conservative treatment. Type 3 fractures are often treated with radial head replacement. Although radial head resection is also an option as long-term results have been shown to be favourable. Radial head arthroplasty is recommended in type 3 fractures with ligamentous injury or proximal ulna fractures. Failure of primary radial head replacement may be due to several factors. Identification of the cause of failure is essential. Failed radial head arthroplasty can be treated by implant removal alone, interposition arthroplasty, revision radial head replacement either as a single stage or two-stage procedure.

Keywords: arthroscopy; elbow; fracture; instability; prosthesis; radial head; radius.

Figure 1.

Anteroposterior plain radiograph showing a non-displaced radial head fracture, classified as a Mason–Hotchkiss type I radial head fracture. (Courtesy of MoRe Foundation.)

Figure 2.

Axial CT image of a Mason-Hotchkiss type II radial head fracture. From this image it is clear that one of the displaced fragments is responsible for a block to forearm rotation. (Courtesy of MoRe Foundation.)

Figure 3.

Intraoperative photograph showing radial head headless screw fixation through a minimally invasive EDC split. (Courtesy of MoRe Foundation.)

Figure 4.

(a) Preoperative radiograph showing an elbow dislocation and displaced radial head fracture. (Courtesy of MoRe Foundation.) (b) AP and (c) lateral radiographs showing low-profile screw fixation. (Courtesy of MoRe Foundation.)

Figure 5.

Arthroscopic view of a radial head fracture. (Courtesy of MoRe Foundation.)

Figure 6.

Arthroscopic view showing a complete lateral collateral ligament avulsion. An anchor is placed in the lateral epicondyle to reinsert the lateral collateral ligament. (Courtesy of MoRe Foundation.)

Figure 7.

Anteroposterior postoperative radiograph showing overstuffing of a radial head prosthesis with clear asymmetry of the ulnohumeral joint and loosening of a poorly fixed cemented radial head prosthesis. (Courtesy of MoRe Foundation.)

Figure 8.

CT scan showing proximal radio-ulnar impingement causing scalloping of the ulna. (Courtesy of Adam C Watts, elbowdoc.co.uk)

Figure 9.

Anteroposterior postoperative radiograph showing a long stem-cemented bipolar radial head. (Courtesy of Adam C Watts, elbowdoc.co.uk)

Figure 10.

Achilles allograft interposition. (Courtesy of Adam C Watts, elbowdoc.co.uk)