Madelung deformity is an abnormality of the wrist caused by a growth disturbance volar-ulnar distal radial physis that retards the development of the ulnar and volar portions of the distal radial physis. Due to growth abnormality, the distal radius gets tilted volarward and ulnarward. There is a palmar translation of the hand and wrist and a dorsally prominent distal ulna.
The eponym gives credit to Otto W. Madelung, who described this entity. Carpus curvus, radius curvus, and progressive subluxation of the wrist, manus valgus, and manus furca are other terms used for this condition.
Madelung deformity results in tilting of the radius and its relationship with the ulna.
An idea of normal articular surface and relationship can be evaluated if one knows the normal values.
Therefore the following measurements are important.
This is the angle formed by a line from the distal radioulnar joint (DRUJ) to the radial styloid and a line perpendicular to the shaft of the radius through the lunate fossa; it is normally 21-23°
This is the difference in longitudinal level between the lunate fossa and the radial styloid, which should be 12-15 mm
This value is measured on a lateral view x-ray of the wrist. The angle formed between a line perpendicular to the radial shaft and a line through the dorsal and volar rims of the radial joint surface is called volar tilt. It is normally 10-15 degrees.
Ulnar variance refers to the difference between the levels of radial and ulnar articular surfaces. Normally, the articular surface lies slightly in distal position than the ulnar articular surface.
Pathophysiology of Madelung Deformity
Madelung deformity is the deformity in the wrist due to a growth disturbance in the volar-ulnar distal radial physis. Due to growth abnormality, the distal radius gets tilted volarward and ulnarward, there is a volar translation of the hand and wrist and a dorsally prominent distal ulna.
The primary deformity is bowing of the distal end of the radius, which is the most typical form curves in a volar direction while the ulna continues to grow in a straight line.
The distal ends of the radius and ulna are at different levels in the lateral plane. This is because the ulna has maintained its original normal position, while that of the radius has curved down to a volar level.
It is the distal end of the radius that is displaced. Because of its curvature and growth disturbance, the radius has become short while the ulna has continued to grow normally and has become relatively longer thus leading to negative ulnar variance.
Causes of Madelung Deformity
There are four types of Madelung deformity
Following trauma that disrupts the growth of the distal radial ulnar-volar physis.
Associated with bone dysplasias like multiple hereditary osteochondromatosis, Ollier disease, achondroplasia, multiple epiphyseal dysplasias, and the mucopolysaccharidoses. This type can also be seen secondary to sickle-cell disease, infection, tumors, and rickets.
The most important dysplasia associated with Madelung deformity, however, is Leri-Weill dyschondrosteosis.
About 30% of cases of Madelung deformity are transmitted in an autosomal dominant fashion though there is a variable expression and 50% penetrance.
Madelung deformity is bilateral in about 50% of the cases.
The most common chromosomal association is with Turner syndrome where the mutation has been found in short stature homeobox-containing gene, SHOX, present on X chromosome.
But families with this mutation and individuals with Turner syndrome and families with a history of MD have been shown to exhibit a variable expression of MD and dyschondrosteosis. This raises a possibility of a modifier gene on another area of the X chromosome or on an autosomal gene may be involved.
Where no cause or association can be found.
The exact nature of the pathologic process that causes the disturbance in the growth of the distal radial physis is unknown.
When Madelung deformity is a hereditary disorder, it is transmitted as an autosomal dominant trait with incomplete penetrance.
Sporadic forms do occur.
It is more common in the females and involvement is frequently bilateral.
Normally, the distal articular surface of the radius is tilted 5 degrees toward its volar surface and 25 degrees toward the ulna, with its dorsal surface and radial margin convex and its volar surface and ulnar border concave.
There are two types of Madelung’s deformity.
- Typical, or regular
- Atypical, or reverse.
In the typical form, the distal articular surface of the radius may tilt toward its palmar surface as much as 80 degrees and ulnarward as much as 90 degrees. In the normal wrist, the proximal row of the carpal bones is arranged in an arc, with its proximal surface forming a convex dome.
In Madelung deformity, this dome becomes peaked, its apex resting on the lunate bone. The radius and ulna are separated, with the peak of the carpal bones wedged into the interosseous space. The entire carpus is shifted toward the ulnar and volar side of the wrist. A coalition of carpal bones may be present.
In reverse Madelung deformity (it is rarer form), the distal end of the radius is tilted dorsally, reversing the plane of the distal end of the articular surface with a shift of the carpus toward the dorsal side. The distal end of the ulna then appears to be displaced volarly instead of dorsally.
- Leri-Weill syndrome
- Turner syndrome
- Gonadal dysgenesis
- Nail-patella syndrome
- Hereditary multiple exostosis
- Hurler mucopolysaccharidosis
- Ollier disease
Deformity of the wrist is the initial presenting complaint. It usually becomes obvious in late childhood or early adolescence, between the ages of 8 and 12 years.
In typical Madelung’s deformity, the distal end of the ulna remains in its normal anatomic position and grows distally, causing a visible prominence on the dorsal and ulnar aspects of the wrist.
Normally, the radial styloid process is long and is located 1 cm distal to the ulnar styloid. In Madelung’s deformity, the radius is shortened at the wrist; the radial styloid process may be on the same horizontal line as the ulnar styloid or may reach a point proximal to it.
The range of motion of the wrist is limited, especially in dorsal extension and ulnar deviation. Pronation and supination of the forearm are also limited.
As a rule, supination is definitely decreased, and pronation is impaired to a slight degree.
In reverse Madelung’s deformity, palmar flexion of the wrist is decreased, while dorsiflexion is increased. The range of rotation of the forearm, especially pronation, is decreased. When it is minimal, Madelung’s deformity may be asymptomatic. In moderate or severe deformity, however, pain develops insidiously at the wrist.
Initially, it is minimal, disappearing on rest. With the progression of the deformity and impingement of the displaced carpus on the distal ulna, the pain increases. Volar displacement of the carpus may cause discomfort in the region of the median nerve and flexor tendons. The weakness of the wrist may result from progressive instability of the joint.
The deformity is characterized by
- Dorsal and radial bowing of the radius
- Exaggerated palmar (up to 35°) and ulnar tilt (up to 60°) of the radiocarpal articulation
- Failure of ossification of the ulnar side of the distal radial epiphysis
- Exaggerated radial inclination
- Decreased carpal angle below 118°; normal from 118° to 139°.
- Carpal subluxation in a palmar and ulnar direction
- Lunate is gradually forced to the apex of the V-shaped radioulnarcarpal joint
- V-shaped proximal carpal row [pyramiding of carpal bones]
- Dorsal subluxation of the distal radio-ulnar joint
- Positive ulnar variance
- Wedging of the carpus between the radius and ulna
CT scan provides better details of three-dimensional deformity though CT scans and 3-dimensional imaging are not necessary for routine treatment.
Trauma (dislocation of the distal radioulnar joint), rickets, inflammatory conditions of the wrist such as rheumatoid arthritis, and infection involving the ulnar half of the distal radial physis.
Treatment of Madelung Deformity
Surgery is indicated for the relief of pain and cosmetic improvement. The function is usually only minimally improved.
Nonoperative management may be helpful in skeletally mature individuals with mild-to-moderate short-term wrist pain due to distal radioulnar joint or radiocarpal joint.
The treatment involves splintage and decrease in activity levels.
The pain that is caused by the tension within the Vickers ligament does not improve with these measures and may need Release of the ligament alone or in combination with an osteotomy
When a patient has attained skeletal maturity, the treatments to be considered are osteotomy and radioscaphocapitate arthrodesis if joint congruency can be achieved.
Darrach or Sauve-Kapandji procedure if distal radioulnar joint congruency cannot be achieved.
No specific contraindications to surgery exist other than those associated with any elective surgical procedure.
The decision of surgery is guided by patients age and remaining growth potential, the severity of deformity and symptoms along with radiographic findings
Surgical procedures either correct the primary deformity of the radius or make a compensatory change in the ulna or both. The goal of ulnar procedures is to change the relationship of the relatively long ulna to the radius.
When the deformity is noticed early and significant growth remains, changing the growth pattern of the distal radial physis to correct the deformity is possible.
The Vickers ligament originates on the radius in a fossa, is 5-7 mm thick and inserts into the anterior surface of the lunate and the anterior radioulnar ligament portion of the triangular fibrocartilage complex. This ligament could be a cause of pain in Madelung deformity.
It is said that the lesion is both bony and ligamentous and physiolysis [resecting the bony and ligamentous lesion] allows for a normal and compensatory growth to correct the deformity.
Osteotomy of radius
This is considered in the older child when remaining growth is insufficient. The osteotomy can correct the position of the distal radiocarpal joint surface and brings the radius and ulna into a more proper position. It could be closing or opening wedge osteotomy. An ulna-shortening procedure can be performed along where required.
Because the radius is volar, the ulna appears to be subluxated dorsally and the incongruence at the distal radioulnar joint and impingement of the radius on the ulna in supination could lead to pain and stiffness.
Following ulnar procedures have been described to allow rotation
This is considered in the skeletally mature patient who presents with pain and in whom physical examination demonstrates the limitation of motion and severe radiocarpal joint incongruity
Radiocarpal arthrodesis and distal ulna resection are indicated.
Prognosis of Madelung Deformity
Pain relief and correction of the cosmetic deformity are the main goals of treatment and most of the patients attain both of them. The range of motion usually is only moderately improved at best.