613 - Right Quad Tendon Rupture in a Patient with Bilateral Lower Extremity Brown Tumors Secondary to Hyperparathyroidism: A Case Report

Case Diagnosis: 24 year-old male with PMH ESRD admitted following complete avulsion of right quadriceps tendon, with tendon repair. Course complicated by secondary hyperparathyroidism, L tibial and R fibular brown tumors.

Case Description:

Patient presented to the ED following R knee pain after stepping back with right leg. Physical exam revealed palpable masses at lateral R fibula and anterior L tibia. MRI revealing avulsion of R quad tendon and lytic lesions consistent with brown tumors. Right quad tendon repaired, and subsequent thyroid US revealed parathyroid hyperplasia. He underwent parathyroidectomy and L tibial ORIF for tibial plateau fracture. Patient has no documented history of tendon rupture, hypermobility, or connective tissue disorder. He discharged home successfully requiring rolling walker for ambulation.



Discussions: There are other documented cases of spontaneous tendon rupture, some with and without LT dialysis use. It is thought that chronic hyperparathyroidism and/or uremia may cause abnormal osteoclast activity and/or osteolytic bone resorption at tendonous insertions, leading to degenerative changes in osteotendinous junctions. However, to our knowledge, there is only one other case describing spontaneous quad tendon rupture also with brown tumor lesions.

Conclusions: Given the diagnostic and therapeutic impact to prevent further tendon rupture, any patient presenting to rehab following spontaneous tendon rupture requiring hemodialysis should be evaluated for hyperparathyroidism.