Atraumatic Bilateral Quadriceps Tendon Rupture in a Patient with Hypothyroidism.

A 66-year-old male with hypothyroidism sustained atraumatic bilateral quadriceps tendon rupture in the absence of obvious trauma or formerly recognized risk factors. The patient's past medical history is significant for hypothyroidism. Tendon repair was managed with suture anchors. Re-rupture of the left following a fall was managed with trans-osseous suture tunnels. At one-year postoperatively, full motion and a 5 deg loss of extension were observed in the left and right knees, respectively. Tegner Lysholm Knee score demonstrated a "good" outcome (86/100). Bilateral quadriceps tendon rupture may occur in patients without obvious trauma or common predisposing medical comorbidities reported in the literature. Tendinopathy from hypothyroidism may be a risk factor for atraumatic quadriceps rupture.