Abstract: FR-PO634
Normohormonal Primary Hyperparathyroidism Presenting as Fracture Non-Union
Session Information
- Trainee Case Reports - IV
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 402 Bone and Mineral Metabolism: Clinical
Authors
- Maibam, Amita, University of Kentucky, Lexington, Kentucky, United States
- Rao, Madhumathi, University of Kentucky, Lexington, Kentucky, United States
Introduction
Primary hyperparathyroidism (PHPT) is a rare cause of poor fracture healing. We present a patient with osteopenia and fracture non-union with mild hypercalcemia in the setting of hydrochlorthiazide (HCTZ) treatment and normal intact parathyroid hormone (iPTH) level.
Case Description
A 54-year-old Caucasian female with history of hypertension, hypothyroidism and depression presented with progressive pain and deformity of the left forearm, 8 months after open reduction and internal fixation of fractures of left radius and ulna. X-ray showed fracture non-union (Figure:1, left); laboratory evaluation revealed mild hypercalcemia (10.5 mg/dl), non-suppressed iPTH (41 pg/ml), and elevated serum creatinine (1.3 mg/dl). Repeat serum calcium after stopping HCTZ, remained 10.5 mg/dl though iPTH increased to 64 pg/ml (range 14-66) Urine calcium was 851 mg/d and bone densitometry showed osteopenia of lumbar spine. A right inferior parathyroid adenoma was demonstrated on nuclear scan establishing a diagnosis of PHPT. The remainder of the work up for hypercalcemia was also significant for a diagnosis of monoclonal gammopathy of undetermined significance (MGUS) confirmed by bone marrow aspiration. Patient underwent parathyroidectomy with prompt reversal of biochemical abnormalities. At 4 weeks after surgery, repeat calcium was 9.6 mg/dl and iPTH level 27 pg/ml; bone pain was improved, and forearm X-ray showed evidence of healing with new bone formation and reversal of cystic changes (Figure:1, right).
Discussion
Normohormonal PHPT accounts for about 5 % of parathyroid explorations and should be considered in patients with fracture non-union and should be corrected before any further orthopedic intervention is undertaken. Mild hypercalcemia in the setting of thiazide treatment and normal iPTH levels may confound the diagnosis and require a high degree of suspicion. The reported association between PHPT and MGUS was also notable in this patient.
Left Forearm XRAY showing fracture site before (left) and after (right) parathyroidectomy.