Radioulnar Synostosis Derotation Osteotomy



Radioulnar Synostosis Derotation Osteotomy


Peter M. Waters



Operative Indications



  • Complete radioulnar congenital synostosis (Figure 13.1)


  • Pronation contracture >60° to >90°, especially if bilateral (Figure 13.2)


  • Functional limitations in activities of daily living


Alternative Treatments



  • Natural history adaptations



    • Adaptable shoulder internal rotation to supinate by back-handing (Figure 13.3)


    • Palm to ceiling to hold objects


    • Compensatory increased rotation through radiocarpal joint (Figure 13.4)


  • Surgical synostosis excision



    • Synostosis takedown and interposition arthroplasty (silastic, fat, aconeus, vascularized fascia)


    • High rate of recurrent synostosis


    • Even with successful takedown, without recurrence, true forearm rotation only mildly improved




Positioning



  • Supine with operative arm on radiolucent table


Surgical Approach




  • Use lateral fluoroscopy to identify the synostosis, proximal and distal extent of radioulnar synostosis (RUS), ulnotrochlear joint



    • Mark skin to aid percutaneous technique


  • Use fluoroscopy to identify medullary canal ulna



    • Choose wire diameter that will fill 50%-75% of the ulna medullary canal


  • Identify entry site olecranon apophysis (Figure 13.6)


  • Medullary canal usually thinner than expected



    • Choose smaller diameter smooth wire to fit full-length ulna