A 59-year-old hemodialysis patient was hospitalized for bilateral painful knee swelling after a fall and mild contusion injury. He refused parathyroidectomy despite an intact parathyroid hormone level of 193 pmol/l (normal range: 1.5–7.6 pmol/l). Complete tear of bilateral quadriceps tendons was diagnosed (Figure 1) and confirmed during open repair. The relatively uncommon occurrence of bilateral quadriceps rupture has been largely described in association with secondary hyperparathyroidism. Elevated parathyroid levels and thus high bone turnover have been thought to be responsible for subtendinous bone resorption at the site of tendon insertion, weakening the osseotendinous junction. The tendon is further weakened by dystrophic calcifications of soft tissue (Figure 2) in patients with secondary hyperparathyroidism.

• Figure 1 Figure 1
• Figure 2 Figure 2
•  

REFERENCE:

Kidney International (2009) 75, 568; doi:10.1038/ki.2008.289

CORRESPONDANCE

Kai Ming Chow, Department of Medicine & Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Ngan Shing Street, Shatin, New Territories, Hong Kong 852-26375396, China. Mailto Kai Ming Chow