Post-Traumatic Radio-ulnar Synostosis Managed by the Excision of the Bone Bridge and Palmaris Longus Encircling Loop over the Ulna: A Case Report.

Introduction: Radioulnar synostosis is an uncommon complication of forearm fractures and presents with varying degrees of restricted forearm movement. The diaphysial distal third synostosis is less common and excision of the synostosis is fraught with risk of re-ossification. Use of inert or biological interposing material has thus been accompanied with the synostosis excision and various methods have been described. There is still no consensus on the ideal treatment method.

Case Report: We, hereby, report a case of a long-standing radioulnar synostosis with rotational restriction of movement. Despite the movement restriction, the patient could perform basic activities of daily living and wanted to improve the movements. The presence of diaphyseal radioulnar synostosis was conformed on the radiographs and computerized tomography scan. A volar forearm approach was used and the bony bridge was excised. The ipsilateral native palmaris longus (PL) tendon was extracted from distal wrist crease and with its proximal attachment intact, circumferentially wrapped around the ulnar raw surface as an interposing material. Apart from this, free fat was also placed at the synostosis site. In the long-term follow-up of 10 years, there was no radiological evidence of re-ossification noted. The clinical improvement was not much but the patient was performing activities of daily living with no discomfort.

Conclusion: The use of an encircling loop of the native PL tendon, over the raw surface of one of the forearm bones, may be another useful method to decrease the chances of recurrence following the excision of the synostosis.