Clinodactyly



Clinodactyly


Robert Carrigan





ANATOMY



  • The finger consists of three phalanges (proximal, middle, and distal).


  • The normal phalangeal physis is located at the proximal portion of each phalanx.


PATHOGENESIS



  • The angulation is result of abnormal development of one of the phalanges (most often the middle phalanx [p2]).


  • Abnormal development of the phalanx may be due to an irregular physis (longitudinal bracket epiphysis). This may also be referred to as a delta phalanx.


  • The tethering effect of the bracket epiphysis on the radial side of the finger causes abnormal growth of the phalanx resulting in a triangular or trapezoidal shape.


  • Extra bones may be encountered.


NATURAL HISTORY



  • The natural history of clinodactyly is variable and poorly documented, owing to the great number of cases that are asymptomatic and do not require treatment.


  • Angulation may be stable or rapidly progressive at times of growth, depending on the extent of the involvement of the physis and/or presence of extra phalanges.


PATIENT HISTORY AND PHYSICAL EXAM FINDINGS



  • Clinodactyly may be present at birth or develop during a period of growth (FIG 1).


  • Clinodactyly is often bilateral in the small finger.


  • Clinodactyly is an autosomal dominant condition with variable penetration.


  • Involvement of the thumb is rare and is associated with varying syndromes.


IMAGING AND OTHER DIAGNOSTIC STUDIES



  • Standard radiographs (three views: anteroposterior[AP], lateral [LAT], and oblique [OBL]) of the hand and affected digit are sufficient to determine the area of involvement.


  • Contralateral images are useful for comparison.


  • Advanced imaging such as computed tomography (CT) is rarely needed. Magnetic resonance imaging (MRI) may be useful to delineate the shape of a bracket diaphysis.




NONOPERATIVE MANAGEMENT



  • Observation may be considered for angulated digits that do not impair function. Splinting is not effective.


  • Most cases can be treated nonoperatively; surgery should be considered for significant angular deformity that compromises hand function.


SURGICAL MANAGEMENT


Preoperative Planning



  • Timing of surgery is variable, depending on the degree of angulation and how much growth potential remains.


  • Small amounts of angulation with little remaining growth potential may be addressed when the child is older.


  • Larger amounts of angulation or children with the potential for worsening angulation may consider earlier intervention.


Positioning