Spontaneous quadriceps femoris tendon rupture in an chronic kidney disease patient with secondary hyperparathyroidism

Abstract

Background: Spontaneous tendon rupture is a recognised but uncommon complication of chronic kidney disease (CKD) and secondary hyperparathyroidism (SHPT). The vast majority of reported cases involve patients already receiving haemodialysis; reports in predialysis patients with advanced CKD remain exceedingly rare.

Case Presentation: A 57-year-old Japanese man presented to the Emergency Department with sudden-onset right lower-limb weakness. He had a background of advanced CKD (serum creatinine 8.97 mg/dL; estimated glomerular filtration rate [eGFR] 5.51 mL/min/1.73 m2) secondary to diabetic nephropathy, and had not yet commenced renal replacement therapy. Clinical examination demonstrated anterior distal-thigh swelling and a suprapatellar sulcus consistent with quadriceps tendon disruption. Preoperative magnetic resonance imaging (MRI) confirmed complete rupture of the right quadriceps tendon at the osteotendinous junction.

Results: Laboratory investigations revealed markedly elevated serum intact parathyroid hormone (PTH) at 675.5 pg/mL (reference range 10.3–65.9 pg/mL), hypocalcaemia (corrected calcium 8.2 mg/dL; reference 8.8–10.1 mg/dL), and hyperphosphataemia (5.3 mg/dL; reference 2.7–4.6 mg/dL). Ultrasonography identified enlargement of all four parathyroid glands. Computed tomography (CT) demonstrated extensive vascular calcification and a characteristic “rugger-jersey spine.†Surgical repair was performed and postoperative MRI confirmed satisfactory tendon continuity prior to discharge.

Conclusion: This case highlights the importance of considering SHPT-related tendinopathy in predialysis patients with advanced CKD presenting with unexplained tendon rupture. Proactive management of hyperparathyroidism in this population is essential to prevent spontaneous quadriceps tendon rupture (QTR) and its recurrence.