Abstract
INTRODUCTION: Bilateral quadriceps tendon rupture (BQTR) is rare and typically occurs in older adults or in the presence of systemic disease. CASE REPORT: A 30-year-old previously healthy male presented with acute inability to extend both knees after missing a step while descending stairs. Clinical examination and ultrasound confirmed complete BQTRs. Initial blood tests revealed hypercalcemia (value: 3.96 mmol/L; ref: 2.15-2.55) with normal renal function. Parathyroid hormone was elevated (1908 pg/mL; ref: 15-65). Neck magnet resonance imaging demonstrated a solitary hypoechoic nodule consistent with a parathyroid adenoma. The patient underwent bilateral tendon repair and parathyroidectomy during the same admission. Biochemical parameters normalized postoperatively, and the patient reported resolution of longstanding musculoskeletal aches. CONCLUSION: In young patients with tendon rupture after minimal trauma, clinicians should consider metabolic and endocrine causes. Early identification and treatment of primary hyperparathyroidism can prevent further musculoskeletal injury and improve quality of life.