Hypercalcemia and Postoperative Joint Symptoms Following Joint Replacement for Osteoarthritis

Introduction: Calcium metabolism dysregulation in the setting of primary hyperparathyroidism (PHPT) mediated chondrocalcinosis is implicated in joint pain, a key element in the decision regarding arthroplasty for osteoarthritis. The relationship between hypercalcemia and joint pain, before and after arthroplasty, is unknown. This study investigates the association between preoperative hypercalcemia and postoperative outcomes following total knee (TKA) and total hip arthroplasty (THA). Methods: A retrospective chart review was conducted on patients who underwent initial elective THA or TKA. Patients with a preoperative serum calcium >10.2 mg/dL were matched (1:2-1:4) with nearest neighbor to patients with normal serum calcium. THA and TKA functional outcomes were measured at baseline and 1-y postoperatively using patient-reported Hip Disability and Osteoarthritis Outcome Scores and Knee Injury and Osteoarthritis Outcome Scores surveys. Postoperative complications, readmissions, length of stay, and functional outcome scores were compared. Results: Four hundred ninety-five patients (106 hypercalcemic cases, 389 matched controls) were included. Of these, 223 patients underwent THA (46 cases; 177 controls) and 272 patients underwent TKA (61 cases; 211 controls). There were no differences in Hip Disability and Osteoarthritis Outcome Scores and Knee Injury and Osteoarthritis Outcome Scores scores, postoperative complications, readmissions, or length of stay between cases and controls. Only 19/106 (18%) hypercalcemic patients had a parathyroid hormone (PTH); of these, 9 (47%) had possible PHPT (PTH > 40). Conclusions: Patients with hypercalcemia undergoing arthroplasty have similar functional and postoperative outcomes as normocalcemic patients. As PTH was obtained in <20% of hypercalcemic cases and 50% had possible PHPT, we recommend that hypercalcemic patients undergo PHPT workup. Additional investigation is needed to determine the effect of PHPT on arthroplasty outcomes.