Hemoglobin Drop and Blood Transfusion Requirement After Primary Knee Arthroplasty with or Without Drain Insertion: A Comparative Study

Abstract

Background: Postoperative blood loss after primary total knee arthroplasty (TKA) remains a concern, and the value of routine closed suction drainage is uncertain. Objectives: This study aimed to compare hemoglobin drop and need for blood transfusion among patients undergoing PKA with or without drain insertion. Methods:  A randomized, open-label trial was performed at the Department of Trauma and Orthopaedic Surgery, Shifa International Hospital, Islamabad, from September 2025 to April 2026 (NCT07494708). 92 adults undergoing unilateral primary TKA were divided into two groups using random sequencing generated through computer (46 per group). Standard perioperative care, including tranexamic acid, was provided. Hemoglobin was measured before surgery and at 24 and 48 hours; transfusions and hospital stay were recorded. Results: All 92 randomized patients were analyzed. Preoperative hemoglobin was 12.74 ± 1.15 g/dL in the drain group versus 12.95 ± 1.13 g/dL in the no-drain group (p = 0.367). At 24 hours, values were 10.39 ± 1.04 versus 11.52 ± 0.97 g/dL, and at 48 hours, 9.65 ± 1.01 versus 10.79 ± 0.99 g/dL (both p < 0.001). Reported hemoglobin drop was 2.47 ± 0.79 versus 1.46 ± 0.65 g/dL (mean difference 1.01 g/dL, 95% CI 0.71–1.30; p < 0.001). Transfusion was required in 9 (19.6%) versus 3 (6.5%) patients (p = 0.063). Transfused units did not differ significantly (p = 0.058), whereas hospital stay was longer with drainage (median 6 versus 5 days; p = 0.003). Conclusion: Drain insertion was associated with greater reported hemoglobin decline and longer hospital stay. Differences in transfusion frequency and units transfused were not statistically significant. Routine drainage should be assessed individually rather than avoided categorically.