Atraumatic Painful Pseudotendon of Flexor Carpi Radialis: A Literature Review and Case Report.

Introduction: Rupture of the flexor carpi radialis (FCR) tendon is a rare phenomenon that is often described in the setting of rheumatoid arthritis or following trauma. Pseudotendon formation is seen commonly among extensor tendons of the antebrachium, typically as a sequelae of traumatic injury, spontaneous rupture in rheumatism, or postoperatively. Less frequent is the presence of pseudotendon in flexor tendons of the forearm. The development of a pseudotendon tends to result from the preservation of the tendon sheath with subsequent fibroblast proliferation. This results in a functionally deficient structure, often incapable of effective tension resistance. Case Report: We present a case of painful pseudotendon of the FCR in a patient with no identifiable common risk factors. A partial tear was identified on magnetic resonance imaging at the level of radiocarpal articulation and the patient was treated with debridement of tenosynovium and excision of the FCR tendon. The patient subsequently achieved 100% pain relief at 3 months follow-up with complete preservation of sensory and motor function and strength, and no functional complaints. We discuss the etiology of painful pseudotendon of the FCR and discuss relevant literature. Conclusion: The significance of this report stems from the evidence that pseudotendon may form through non-classical pathways idiopathically. Our case demonstrated successful removal of tenosynovium, the pseudotendon sheath and FCR tenotomy is safe, effective, and demonstrates minimal clinical deficits.