Madelung Deformity Workup

Updated: Jul 22, 2020
  • Author: Paul M Lamberti, MD; Chief Editor: Jeffrey D Thomson, MD  more...
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Workup

Plain Radiography

The diagnosis of Madelung deformity (MD) is confirmed radiographically with posteroanterior (PA) and lateral views of the forearm and wrist. (See the images below.)

Preoperative wrist posteroanterior radiograph of a Preoperative wrist posteroanterior radiograph of a 13-year-old girl (patient A) with dyschondrosteosis and Madelung deformity of the wrist.
Preoperative lateral wrist radiograph of patient A Preoperative lateral wrist radiograph of patient A.
Lateral radiograph of elbow of patient A, depictin Lateral radiograph of elbow of patient A, depicting a dysplastic proximal radius. This is characteristic of dyschondrosteosis.
Preoperative anteroposterior radiograph of wrist o Preoperative anteroposterior radiograph of wrist of patient B. This patient has primary Madelung deformity (no sign of dyschondrosteosis).
Preoperative lateral radiograph of wrist of patien Preoperative lateral radiograph of wrist of patient B. The flame-shaped radiolucency in the metaphysis of the radius is occupied by the fibrocartilaginous Vickers ligament.
Preoperative posteroanterior radiograph of wrist f Preoperative posteroanterior radiograph of wrist from patient C.
Preoperative lateral radiograph of wrist from pati Preoperative lateral radiograph of wrist from patient C.

Carter and Ezaki standardized a method of obtaining the PA forearm radiographs in patients with MD. [21]  Both right and left forearm images are placed on the same radiographic plate for comparison. The true PA radiograph is obtained with the forearm in neutral rotation, the elbow at 90° of flexion, and the shoulder abducted to 90°. These authors have found this method of analysis useful in preoperative planning, and it is highly reproducible by radiology staff.

A lateral radiograph is obtained by rotating the shoulder to the side of the patient and laying the ulnar border of the forearm on the plate.

Several distinct radiographic features of MD exist. Dannenberg et al described elements of radiographic diagnosis after their review of 172 cases. [24]  Criteria include the following:

  • Lateral and dorsal curvature of the radius
  • Widened interosseous space
  • True shortening of the total length of the radius
  • Premature fusion of the ulnar half of the distal radial physis
  • Focal osteopenia in the area of the ulnar portion of the distal radius
  • Exostosis at the distal ulnar border of the radius
  • Triangularization of the distal radial epiphysis
  • Ulnar- and palmar-facing distal radial articular surface
  • Relative dorsal subluxation of the ulna
  • Increased radiodensity of the ulnar head
  • Carpal wedging with the lunate at the apex of the wedge
  • An arched curvature of the carpal bones in direct continuation of the dorsal bowing of the radius on the lateral radiograph

Carter and Ezaki added the observations that there is an increased radial tilt on the PA radiograph and that the radial epiphysis becomes teardrop-shaped. [21]  On the lateral view, the radius tilts volarward until the ulna appears dislocated from its normal articulation with the radius. The ulna lies dorsal to the proximal carpal row. The distal ulna is not actually subluxated dorsally. Rather, the hand and radius are translated palmarward, resulting in incongruence of the distal radioulnar joint (DRUJ). The unaffected ulna continues to grow, ultimately becoming longer than the ulnar aspect of the radius.

Vickers and Nielsen described a physeal measurement for preoperative and postoperative assessment of severity and correction, respectively. [25]  PA radiographs are used for measurement; lateral views have too much variation to be of value. The longitudinal and transverse axes of the radius are difficult to determine because of the considerable bowing of the radius. The ulna usually is straight, which provides a reliable longitudinal axis. Therefore, a perpendicular line to the long axis of the ulna can be passed through the most radial extent of the radial physis.

A line joining the most radial and ulnar extents of the physis is drawn. The angle subtended by the transverse line and the physeal line is termed the physeal angle. With increasing severity, the lunate follows the ulnar-volar corner and eventually becomes interposed between the radius and ulna. The relative position of the proximal aspect of the lunate can be measured from the transverse line.

McCarroll et al described the following threshold values for four radiographic measurements as leading to a diagnosis of MD [26] :

  • Ulnar tilt ≥33º
  • Lunate subsidence ≥4 mm
  • Lunar fossa angle ≥40º
  • Palmar carpal displacement ≥20 mm
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Tomography and CT

Because the deformity is three-dimensional (3D), a better understanding may be obtained with tomography or computed tomography (CT). These studies may be helpful in precisely visualizing physeal and articular morphology. A CT-derived three-dimensional (3D) reconstruction may assist in clarifying the articular orientation. [27] However, Carter and Ezaki stated that after the complexity of this lesion is appreciated, CT and 3D imaging are not necessary for routine treatment. [21]

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