Quadriceps Tendon Ruptures
A 38-year-old man with end-stage renal disease who was undergoing hemodialysis presented to the hospital with several years of progressive difficulty in walking. Four years before presentation, acute pain and swelling in both knees had developed after he had stepped off an auto rickshaw. At that time, he had opted for conservative management of his injuries. On physical examination at the current presentation, there was a soft-tissue depression proximal to the patella on both sides (Panel A). A palpable suprapatellar gap was also present on both sides at the site of the expected quadriceps tendon insertion (Panel B). The patient was unable to extend his knees and walked with flexed knees. Laboratory studies indicated secondary hyperparathyroidism. Radiographs of the knees showed inferior displacement of the patellae. The patient declined magnetic resonance imaging of the knees owing to cost. A diagnosis of quadriceps tendon rupture in both knees was made. Quadriceps tendon rupture is a rare condition, but it may occur spontaneously or with minimal trauma in patients with chronic kidney disease and secondary hyperparathyroidism. The underlying pathophysiological mechanisms of rupture are not well understood. Calcitriol was initiated to treat the secondary hyperparathyroidism. The patient declined surgical repair and was lost to follow-up.