MADELUNG DEFORMITY

MADELUNG DEFORMITY

Madelung deformity is an abnormality of the palmar ulnar part of the distal radial physis in which progressive ulnar and volar tilt develops at the distal radial articular surface, with dorsal subluxation of the distal ulna.

First described by Malgaigne in 1855 and later by Madelung in 1878.
It is believed to be a congenital disorder, although it seldom is obvious until late childhood or adolescence.
It is a rare anomaly, accounting for only 1.7% of hand anomalies in Flatt's series.
The cause of Madelung deformity is uncertain;
it has been shown to be transmitted in an autosomal dominant pattern.
Other Madelung-like deformities have occurred after trauma, as reported by Vender and Watson in a gymnast, and after infection or neoplasm.
There is no definitive method of distinguishing these from idiopathic Madelung deformity.

Vender and Watson classified Madelung and Madelung-like deformities into four groups:
1. posttraumatic,
2. dysplastic (dyschondrosteosis or diaphyseal aclasis),
3. genetic (e.g., Turner syndrome), and
4. idiopathic.


They believe that acquired deformities usually can be distinguished by a lack of appropriate physical findings, unilaterality, less severe carpal deformities, and the appropriate history of repetitive injury or stress.

A deformity of the wrist similar to Madelung deformity frequently is associated with dyschondrosteosis, the most common form of mesomelic dwarfism.
This disorder consists of mild shortness of stature, shortness of the middle segment of the upper and lower extremities, and Madelung deformity.

Other associated conditions include mucopolysaccharidosis, Turner syndrome, achondroplasia, multiple exostoses, multiple epiphyseal dysplasia, and dyschondroplasia (Ollier disease).
Madelung deformity typically consists of volar subluxation of the hand, with prominence of the distal ulna and volar and ulnar angulation of the distal radius. It is more commonly bilateral and affects girls more frequently than boys. A family history of the deformity often is present. The deformity usually manifests in late childhood or early adolescence, with decreased motion and minimal pain. As growth occurs, the deformity worsens in appearance. 

X-ray abnormalities are seen in the radius, ulna, and carpal bones. The radius is curved, with its convexity dorsal and radial, and there is a similar angulation of the distal radial articular surface.

The forearm is relatively short. The distal radial epiphysis is triangular because of the failure of growth in the ulnar and volar aspects of the physis; early closure of these aspects of the physis also is frequent. Osteophyte formation may be visible at the volar ulnar border of the radius.

The ulna is subluxated dorsally, the ulnar head is enlarged, and the overall length of the ulna is decreased. The carpus appears to have subluxated ulnarward and palmarward into the distal radioulnar joint, which usually is spread apart. The carpus appears wedge shaped, with its apex proximal within the lunate.

Treatment Because children with Madelung deformity usually have minimal pain and excellent function, a conservative approach is warranted initially.

Surgery should be considered for severe deformity or persistent pain, usually from ulnocarpal impingement of the carpus.
Vickers and Nielson reported some success with resection of the abnormal portion of the radial physis and insertion of fat as a form of surgical prophylaxis. In their series all 17 patients had pain relief and no progression of the deformity after surgery. Distal radial osteotomy with ulnar shortening (Milch recession) is a preferred treatment in skeletally immature patients. The radial osteotomy may be a closing or opening wedge as needed for alignment.

Osteotomy combined with a judicious Darrach excision of the distal ulnar head may be used in skeletally mature patients.
Watson, Pitts, and Herber performed balanced radial osteotomies combined with a matched ulnar resection in 10 patients. They reported that radial length was preserved better using this technique; experience with this technique is relatively less.
Resection of Dyschondrosteosis Lesion TECHNIQUE (Vickers and Nielsen)

Under tourniquet control, make a volar transverse incision 1.5 cm proximal to the most proximal wrist crease, passing either on the ulnar side to the flexor carpi radialis and palmaris longus or on the radial side.

Protect the median nerve and radial artery. Continue the approach radial to the mass of the digital flexor tendons to the distal edge of the pronator quadratus muscle, some of which can be mobilized at the radial end.
Using an osteotome, make the initial longitudinal osteotomy in the radius, parallel to the long axis of the forearm, about 5 mm from the radioulnar joint.
In patients with extreme volar subluxation of the carpus, take care not to mistake the lunate for the underlying radius. Reflect the small fragment of the distal radius ulnarward with the osteotome to preserve what exists of the flimsy connections between it and the ulna and to leave some support for the lunate. A sagittal section of the distal radius should now be visible. Magnification is recommended. If the initial osteotomy is too shallow, a white sheet of fibrous tissue and cartilage is seen. Make successive osteotomy cuts 1 mm thick until the physis is clearly identified. When first seen the physis is thin and wavy and significantly narrowed. When the physeal cartilage is clearly defined, carefully remove bone from the metaphyseal side with a gouge or burr so that the profile of the cartilage is above the bone and is intact from the dorsal periosteum to the volar periosteum to prevent a new bar of bone from forming. Identify and excise the abnormal volar ligament tethering the lunate to the radius. Deflate the tourniquet and obtain hemostasis, using bone wax if necessary. Reinflate the tourniquet and flush with normal saline to remove all bone chips and blood. Obtain a generous quantity of fat from the proximal forearm medially and insert to fill the surgical cavity completely. This fat must make intimate contact with the entire length of the physeal cartilage, isolating the bony epiphysis from the bony metaphysis. Soft tissues fall together to hold the fat in place. Suture the skin and apply a short arm volar slab or a crepe bandage. 


AFTERTREATMENT. The bandage should be worn for 2 weeks depending on the degree of the deformity.

 Closing Wedge Osteotomy Combined with Darrach Excision of Distal Ulnar Head TECHNIQUE (Ranawat, DeFiore, and Straub)

Make a dorsal longitudinal incision over the distal forearm, detach the extensor retinaculum from the radius over the extensor digitorum communis tendons, and reflect the retinaculum and the tendon of the extensor digiti minimi ulnarward. If the patient is skeletally mature, expose the distal radioulnar joint and excise about 1 cm of the distal ulna. If the patient is skeletally immature, expose the ulnar shaft and perform an appropriate cuff recession as described by Milch. Next perform an osteotomy parallel with the distal articular surface of the radius. Resect an appropriate wedge of bone based radially and dorsally from the distal end of the proximal fragment of the radius and appose the raw surfaces. Stabilize the osteotomy with Kirschner wires so that the distal articular surface of the radius is facing volarward 0 to 15 degrees to the long axis of the radius and ulnarward 60 to 70 degrees. Close the incision in routine fashion and apply a long arm cast.

AFTERTREATMENT.
The cast and pins are removed 4 weeks after surgery, and active exercises of the wrist are begun. The osteotomy incision is protected with a cast or splint until there are sufficient radiographic and clinical signs of bone healing. Normal activities are progressively resumed.
After the final cast is removed, protective splinting may be necessary for 8 to 10 weeks after surgery.