Distal Plantaris Tendon Rupture and Reconstitution in a Young Semi-Professional Soccer Player: A Case Report

Background: Plantaris tendon (PT) is an accessory muscle with a negligible functional role. Isolated ruptures of the muscletendon complex in athletes usually occur in the proximal myo-tendinous junction in the upper part of the calf. The distal ruptures are not frequent and no more than ten cases have been reported in literature. In this paper we are going to describe a new case of distal PT rupture in a young soccer player. Methods: An 18 years old semi-professional football player, after kicking the ball with his right foot, reported pain and functional limitation in the distal third of the left leg, at the medial edge of the Achilles tendon. Clinical examination showed tenderness on palpation associated with mild swelling. Walking was associated with pain at the phase of plantar flexion of the left foot. Thompson test and neurological/vascular examinations were negative. The radiological evaluations (ultrasound and magnetic resonance imaging), performed a few days after the event, showed a distal sub-total tear of the left PT. Between the tendon ends, connected by a thin tendinous filament, a fluid collection was present. Results: A structured rehabilitation protocol was implemented, allowing the player to come back to his full athletic activity after 9 weeks. Radiological examination after 6 weeks demonstrated scar reconstitution with no residual tear or fibre discontinuity. The tendon demonstrated fusiform thickening reflecting incompletely remodeled scarring. Conclusions: At our best knowledge, this is the first case where the spontaneous reconstitution of PT has been demonstrated by imaging techniques.