Spontaneous Bilateral Patellar Tendon Rupture in Patient with Ehlers-Danlos Syndrome: A Case Report

Bilateral spontaneous patellar tendon ruptures are rare, though it is hypothesized to be more common in patients with risk factors such as connective tissue disorders such as Ehlers-Danlos syndrome (EDS), systemic disorders weakening collagen structures, chronic stress around the patellar tendon, medications, and obesity or sedentary lifestyles. Clinicians should maintain a high degree of clinical suspicion for concerning features on clinical examination and radiological investigations to facilitate prompt diagnosis and operative management. This case report describes the first documented case of an adult patient with EDS who sustained bilateral spontaneous patellar tendon ruptures. There is one previously reported acute bilateral patellar tendon rupture occurring in a pediatric patient with EDS. Within the adult literature, two case reports have reported patients with EDS: One acute unilateral patellar tendon rupture who underwent operative management and one chronic patellar tendon tear requiring reconstruction 2.5 years following initial end-to-end repair.

A 45-year-old male sustained bilateral patellar tendon ruptures after falling onto his knees while pushing a heavy cart. The patient reported a giving-way sensation and was unable to mobilize independently. On presentation to the emergency department, the patient was noted to have an absent straight-leg raise and a palpable gap between the distal pole of the patella and patellar tendon. Plain radiograph and ultrasound investigations confirmed bilateral complete patellar tendon ruptures. The patient underwent operative management 5 days following injury through bilateral direct patellar tendon repair utilizing the Krackow technique with transosseous fixation. Twelve months post-operatively, the patient had returned to pre-injuries activities of daily living, a full active range of motion without extensor lag, and recorded "fair knee function" on the Lysholm Knee Scoring Scale.

This case report described the first reported bilateral spontaneous patellar tendon rupture in an adult patient with EDS, who underwent operative management and achieved a return to pre-injury function. Furthermore, this case report summarizes the pre-existing literature on spontaneous bilateral patellar tendon ruptures and patellar tendon ruptures in patients with EDS.