MADELUNG’S DEFORMITY

CONGENITAL SUBLUXATION OF THE WRIST (MADELUNG’S DEFORMITY)

Pathogenesis (Brailsford):

• Stunted development of inner third of the growth cartilage at the lower end of the radius, due to still unknown cause.
• Growth of the outer two-thirds continues and, as a result, the radial shaft is bowed backwards, the interosseous space is increased, there is overgrowth of lower end of ulna and is subluxated backwards.

Soft tissue changes:

• Abnormal tethering of soft tissues from the distal radius to the carpus and ulna.

• These have included aberrant ligaments and pronator quadratus muscle insertions

• Hypertrophy of the palmar ligaments, including the radiotriquetral and the short radiolunate ligaments and an anomalous volar ligament(Vicker’s ligament)

Clinical Features:

• Often bilateral, hence disability may not be identified early and hence late presentation is common
• Often seen for the first time in adolescence.
• Females>males.
• Early cases: mild symptoms of ulnocarpal impaction with power grip activities, and distal radioulnar joint incongruity with forearm rotation
• Wrist appears enlarged; dorsiflexion of the hand is impaired. Flexion may be increased;
• In severe cases pronation and supination are limited.
• May be associated with Dyschondrosteosis (Leri Weil syndrome), Turner’s syndrome, Achondroplasia, Ollier’s disease

Vender and Watson Classification:

a) Post traumatic b) Dysplastic c) Genetic d) Idiopathic

X-ray:

• Steep ulnar slope and deficient ulnar margin of radius
• Lunate uncovered.
• The carpus subluxates ulnar and palmarward and appears wedge shaped (lunate lies at the apex of the wedge)
• Increased width between the distal radius and ulna.
• Relatively long ulna compared to radius (positive ulnar variance).
• Decreased carpal angle.
• Triangularization of the distal radial epiphysis.
• Carpus migrates more proximal into the increasing diastasis between the radius and the ulna

Treatment

• In recent or acute cases, dorsiflexion of the wrist-maintained by a full arm plaster for 4 weeks.

• Indications for surgery: Acute pain and deformity.

Early presentation:

• In early-detected cases distal radial epiphysiolysis is done (Vickers and Nielsen et al.)

• Epiphysiolysis involves resection of the abnormal volar, ulnar physeal region of the radius and fat interposition. At the same time, any aberrant, tethering anatomic structures are excised

• Early presentation with marked deformity and complete lack of a lunate fossa for carpal support, needs combined radial and ulnar osteotomies. Alternatively ulnar and radial epiphysiodesis maybe done

Late presentation:

– Osteotomy of the lower end of the radius may be done.

– Options include dome osteotomy, dorsal radial closing-wedge osteotomy, or volar opening-wedge radial osteotomy and bone grafting

– Ulnar shortening procedure like the Suave-kapandji maybe useful, though there may already be deterioration of the articular cartilage, wrist ligaments, or triangular fibrocartilage, resulting in continued pain and limitation of motion postoperatively..

Ref:

1. Vickers D, Nielsen G. Madelung’s deformity: treatment by osteotomy of the radius and Lauenstein procedure. J Hand Surg [Am] 1987;12(2):202-204

2. Ranawat CS, DeFiore J, Straub LR. Madelung’s deformity. An end-result study of surgical treatment. J Bone Joint Surg Am 1975;57(6):772-775