Direct reconstruction of chronic extensor digitorum longus tendon rupture using interposed scar tissue in the foot: A case report.

Rationale: Primary repair of acute ligament injury is possible due to the proximity of the ends. In the case of chronic injury, however, primary repair is difficult because the ends of ruptured ligament will have receded, and tendon graft, transfer, or reconstruction is needed. Satisfactory clinical results have been reported after reconstruction with newly formed interposed scar tissue between the ends of the ruptured tendon in chronic Achilles tendon injury and chronic extensor halluces longus (EHL) tendon injury. Here, we report a patient treated with reconstructive surgery using well-formed scar tissue between the ends in a case of chronic EDL tendon rupture.

Patient Concerns: A 34-year-old woman visited the clinic with pain in the dorsum aspect of the right foot associated with weakness and loss of extension of the second toe. She had sustained an injury to the dorsal aspect of her foot by falling on broken glass 3 months before coming to our clinic. The patient reported pain and limitation of the extension of the second toe for 2 months. Her pain continued to worsen, and 1 month later she was transferred to our hospital because a different local clinician suspected she had ruptured her second EDL tendon.

Diagnosis: Magnetic resonance imaging (MRI) revealed complete rupture of the second EDL tendon at the metatarsal neck junction, with displacement of the distal end to the proximal phalanx shaft area and of the proximal end to the metatarsal shaft area.

Interventions: Chronic rupture of the EDL tendon was treated with direct reconstruction using interposed scar tissue.

Outcomes: At the 3-month follow-up, the patient was almost asymptomatic and had nearly full range of motion in dorsiflexion of the second toe. She has no discomfort in her daily life and has returned to almost her preoperative level of functional activities.

Lessons: Here, we presented an extremely rare case of reconstruction using interposed scar tissue in a patient with neglected EDL tendon rupture. Direct reconstruction using interposed scar tissues located between the ends of the ruptured tendon is considered a reliable method with satisfactory clinical results in carefully selected patients.