Parathyroid adenoma in total knee replacement: A case report of missed diagnosis and treatment challenge

Abstract

Background: Primary parathyroid adenoma is a diagnostic challenge especially in asymp- tomatic patients. We report a late diagnosed case of primary parathyroid adenoma in a patient who underwent bilateral total knee replacement. Case Presentation: A 65 year old female patient underwent bilateral Total Knee Arthroplasty (TKA) for tri-compartmental osteoarthritis. Since intra-operatively the bone was extremely soft, a metabolic workup was done. Serum calcium and parathyroid hormone was extremely high and phosphorus was low immediate post-total knee replacement. The DEXA scan of hip, spine, distal radius showed density less than -2.5 SD. Ultrasound scan and nuclear imaging was suggestive of parathyroid adenoma. Patient underwent focused parathyroidectomy of right inferior parathyroid after 1 month. Post parathyroidectomy, PTH, serum calcium and phosphorus levels reverted back to normal. At six months follow up after bilateral TKA, patient is walking without any symptoms. Conclusion: Delayed diagnosis of parathyroid adenoma, especially in arthroplasty surgeries, leads to intra-operative complications, but it can be avoided. Proper metabolic workup of all the arthroplasty cases and a multi-disciplinary approach is necessary.