Madelung Deformity

 

 

 

Clinical History: A 13-year-old girl presents with a progressive wrist deformity beginning a year ago. She has mild ulnar-sided wrist pain with activities. On exam, both wrists demonstrate dorsal prominence of the ulnar heads. Coronal T1-weighted (1a) and fat-suppressed proton density-weighted (1b) images and axial T1-weighted images (1c and 1d) are shown. What are the findings? What is your diagnosis?

 

Findings

Diagnosis

Madelung deformity with an anomalous volar radiotriquetral ligament.

 

Introduction

Madelung deformity is a relatively rare abnormality of the wrist, first described in 1834 by Guillaume Dupuytren (better known for the finger contracture named after him), and more fully by Otto Madelung in 1878.¹ It is characterized primarily by a developmental growth deficiency of the ulnar and volar aspect of the distal radius resulting in secondary changes in the morphology of the carpus. Classically, the condition has been associated with an abnormal volar short radiolunate ligament (Vickers ligament). However, recent investigations have identified a second anomalous radiotriquetral ligament in many cases.  

Pathophysiology

Madelung deformity is caused by premature closure of the ulnovolar portion of the distal radial physis, leading to increased radial inclination and volar tilt of the distal radius. In approximately 83% of cases, an abnormally thick volar short radiolunate ligament, known as Vickers ligament, can be identified.^2,3 Unlike the normal short radiolunate ligament that originates from the distal radial epiphysis, Vickers ligament originates in the metaphysis proximal to the physis so that is crosses the ulnar aspect of the distal radial growth plate, potentially tethering it and restricting growth.^{2, 4,5,6} However, Vickers ligament is not typically visible at surgery until approximately 7 years of age, leading some authors to posit that it may be a result of the deformity and not its primary cause.³ Recently, a second anomalous ligament has been identified in some patients with Madelung deformity – a volar radiotriquetral ligament – that can occur in isolation or together with Vickers ligament.^7,8,9,10 This ligament also has an origin in the distal radial metaphysis, proximal to the physis. Based on MR appearances, both ligaments tend to insert along the ulnar margins of either the lunate or triquetrum (Figure 3).

 

Clinical Features

The overall incidence of Madelung deformity is unknown because mild cases may be asymptomatic and go unrecognized. Girls are affected more frequently than boys, in a ratio of approximately 4:1.^11,12The condition can occur spontaneously or have a familial occurrence, related to mutations in the short stature homeobox (SHOX) gene located on the X and Y sex chromosomes, which are inherited with a pseudoautosomal dominant pattern.¹³ Madelung deformity is also seen in association with Leri-Weill dyschondrosteosis, a skeletal dysplasia characterized by histologic abnormalities in the growth zone of the physis. These patients present with mesomelia (short forearms), dwarfism, and bilateral symmetric Madelung deformity.¹³ Like patients with the congenital form of Madelung deformity, individuals with Leri-Weill syndrome have a mutation in the SHOX gene.¹⁴ Additionally, Madelung deformity can develop in some patients with Turner’s syndrome (Figure 4); these patients have only one X chromosome meaning that one copy of the SHOX gene will be absent.^{13, 15}

  The deformity is bilateral in approximately 73% of cases.¹¹ Some patients are identified in early childhood before symptoms develop when radiographs performed for wrist trauma identify an incidental deformity. However, most patients present between ages 8 and 14 years with a progressive cosmetic deformity, due to the continued growth of the ulna, with the ulnar head becoming progressively prominent dorsally.^{5, 6} The resultant deformity is sometimes referred to as “bayonet-like,” describing the appearance of the wrist when viewed from the side. While some patients experience no additional symptoms, others will develop pain related to ulnocarpal impaction or carpal tunnel syndrome. Decreased grip strength and loss of wrist extension or forearm rotation may occur.¹⁶ A more severe “entire radius” variant results in pronounced shortening and bowing of the radial shaft,¹⁷ often in association with Leri-Weill dyschondrosteosis (Figure 5).   Left untreated, the deformity typically progresses until skeletal maturity. Adults with Madelung deformity may be asymptomatic, or may present with symptoms related to arthritis or instability at the distal radioulnar or radiocarpal joints.¹¹ Spontaneous attritional rupture of the ulnar-sided extensor tendons has been reported as a complication of long-standing disease, due to friction of the tendons against the dorsally subluxed distal ulna.^18,19 Severe positive ulnar variance can produce symptoms of ulnocarpal impaction, including tears of the triangular fibrocartilage.^{11, 14}

 

Imaging Findings

The diagnosis of Madelung deformity is typically made radiographically.^{12, 15} The findings are characteristic: Prior to skeletal maturity the ulnar side of the distal radial epiphysis will be deficient and a physeal bar may be visible crossing the adjacent growth plate, with the PA radiograph showing excessive inclination of the distal radius towards the ulna, which results in the lunate displaced proximally into a deep concavity in the distal radius (Figure 6). In older patients, the lunate and proximal carpal row can acquire a pyramidal or V-shape. A flame-shaped notch may be visible in the distal radial metaphysis (Figure 7), corresponding the origin site of an anomalous volar ligament,^{5, 14} although in one large series 4 out of 54 patients with a radiographic notch did not have a Vickers ligament at surgical exploration, while 12 of 62 patients with a surgically proved Vickers ligament did not show a notch.³ Positive ulnar variance can be severe, with incongruity or subluxation at the distal radioulnar joint.⁵ In the whole-radius variant severe bowing of the radial shaft and widening of the radiocapitellar joint is characteristic (Figure 5). On the lateral view of the wrist, the distal radius shows excessive volar tilt, with volar subluxation of the carpus and dorsal displacement of the ulnar head.²⁰

    Multiple measurements have been devised to help identify suspected cases with subtle findings.²¹ However, many of the proposed measurements demonstrate overlap between patients with mild Madelung deformity and normal subjects.^{4, 22} Inter-observer agreement is relatively poor, especially in mild cases.²³ The most useful measurement for early diagnosis may be the lunate fossa angle (Figure 8a), defined as the complement of the angle between the long axis of the ulna and the lunate fossa of the radius; an angle ≥ 35° is strongly associated with Madelung deformity.²⁰ A lunate that extends at least 4 mm proximal to the distal articular surface of the ulnar head (Figure 8b) seems to be a specific, but relatively late-occurring finding in Madelung deformity.²⁰   MRI can show many of the same findings as radiographs, including the abnormal morphology of the distal radius and carpus (Figure 9).⁸ The triangular fibrocartilage disc will take on an oblique orientation with respect to the distal radius articular surface.¹⁴ A physical bar may be present in the ulnovolar aspect of the distal radial physis in skeletally immature patients, which can be identified with either CT or MRI.^{7, 8, 14} In long-standing cases, MRI may be indicated to identify late complications of the condition, including ulnocarpal impaction and tears of the triangular fibrocartilage (Figure 10), secondary osteoarthritis, and extensor tendon ruptures.^{11, 14} The main role of MRI in Madelung deformity is to identify a Vickers ligament and/or radiotriquetral ligament to assist in surgical planning.⁸ Before skeletal maturity, Vickers ligament is seen along the volar aspect of the carpus, originating from the ulnar-sided metaphysis of the distal radial physis.^{2, 14} Distally, it inserts on the ulnovolar surface of the lunate. The sensitivity of MRI sensitivity for demonstrating a Vickers ligament is 95% in patients who undergo surgery.³ Some authors advocate using MRI to screen for the presence of a Vicker’s ligament in young children with a strong family history of Madelung deformity to facilitate prophylactic surgery before a severe deformity develops.² After growth plate closure, Vickers ligament will appear to originate close to the articular surface of the distal radius due to undergrowth of the ulnar side of the epiphysis (Figure 11). An anomalous radiotriquetral ligament (Figure 12) is often more conspicuous than a classic Vickers ligament. The radiotriquetral ligament originates from the distal radius just ulnar and dorsal to the location of Vickers ligament.^{8, 9} Distally the radiotriquetral ligament attaches to the volar aspect of the triquetrum and the triangular fibrocartilage disc; there may be additional fibers extending to the interosseous lunotriquetral, volar distal radioulnar, and volar extrinsic ulnotriquetral ligaments.⁹ Both anomalous ligaments can coexist in the same wrist (Figure 13). MRI may also be useful in cases of suspected acquired (post-traumatic) Madelung-type deformity where an anomalous ligament should not be present,^{9, 14} but where marrow edema around the injured physis or prematurely closed growth plate may be seen (see Differential Diagnosis, below).   CT with 3-D reconstructions may be useful for skeletally mature patients with severe deformities, where a multiplanar corrective osteotomy is being planned.¹⁶ CT can also be used to confirm and characterize the presence of a physeal bar in both Madelung deformity and post-traumatic Madelung-type deformities (Figure 14).⁷

 

Treatment Options

Conservative therapy with non-steroidal anti-inflammatory drugs, activity modification, and splinting will often suffice in patients with mild symptoms,²⁴ with sequential radiographs acquired until skeletal maturity to monitor progression of the deformity.¹¹ For more symptomatic patients, surgery is usually recommended. The choice of operation depends on the age of the patient and the anatomic abnormalities present. In patients who are still growing, resection of Vickers ligament and/or an anomalous radiotriquetral ligament is typically performed to relieve pain and prevent progression of the deformity;²⁵ when combined with a radial physiolysis (resection of a physeal bar and fat interposition) this is known as a Langenskiöld procedure.^{2, 6, 26}  Alternatively or in addition, epiphysiodesis of the distal ulnar and radial aspect of the distal radial growth plates can be performed to arrest growth and maintain a more normal relationship between the distal radius and ulna.²⁶ After skeletal maturity, deformity progression is no longer an issue so surgical treatment is indicated for severe chronic pain or decreased motion, with the goal of addressing the deformity that has already occurred.^{16, 25} This may be accomplished through a distal radius dome osteotomy allowing for multiplanar correction, ulnar head resection, Suavé-Kapandji procedure (distal radioulnar joint arthrodesis with an ulnar osteotomy proximal to the fusion site), ulnar shortening osteotomy, or distal radioulnar arthroplasty.^{12, 16, 27}

 

Differential Diagnosis

Other conditions may result in a wrist appearance that appears similar to classic Madelung deformity, sometimes referred to as a Madelung-type or pseudo-Madelung deformity. These include prior childhood trauma that damages the distal radial growth plate (Figure 14), either a Salter-Harris fracture or chronic, repetitive injury as might occur with gymnast’s wrist.^{11, 15, 28}Prior infection or juvenile chronic arthritis can also arrest growth in a portion of the distal physis, causing a Madelung-type deformity.^{14, 29} When detected before skeletal maturity, cases of premature segmental growth plate closure can be managed surgically by resection of a physeal bar and/or epiphysiodesis and osteotomies. Madelung-type deformities have also been reported in association with multiple epiphyseal dysplasia (Figure 15), Ollier disease (multiple enchondromas), and multiple hereditary exostosis.^{5, 14} While their deformities may morphologically resemble classic Madelung deformity, wrists in patients with Madelung-type deformities should not harbor a Vickers or anomalous radiotriquetral ligament.¹⁵

 

Conclusion

Madelung deformity of the wrist results from a growth disturbance primarily involving the ulnar aspect of the distal radius, and is frequently associated with an anomalous volar short radial ligament (Vickers ligament) and/or radiotriquetral ligament. Diagnosis is made radiographically by identification of several characteristic features. MRI is useful to identify associated anomalous ligament(s), which affects treatment, especially before skeletal maturity. In longstanding cases, MRI is used to identify complications secondary to the deformity. Several other conditions can produce similar findings called Madelung-like deformities, but in these wrists, anomalous ligaments are not present.    

References