Vascular calcifications on the preoperative radiograph: harbinger of tourniquet failure in patients undergoing total knee arthroplasty?

OBJECTIVE: Vascular calcifications on the preoperative radiograph of patients scheduled for total knee arthroplasty (TKA) often give rise to concern, as their clinical relevance remains uncertain. The aim of this study was to investigate whether these vascular calcifications-especially medial artery calcifications (MACs), which increase arterial stiffness-were associated with tourniquet failure and thus with increased intraoperative blood loss. MATERIALS AND METHODS: A total of 765 patients who underwent primary TKA with a tourniquet (cuff pressure 350 mmHg) between 2009 and 2011 were screened for vascular calcifications on the preoperative radiograph. Vascular calcifications were classified into intimal and medial artery calcifications. Intraoperative blood loss of patients with and without MAC was compared, and a mixed linear regression model was used to adjust for the presence of several confounding factors (e.g., obesity, operating time). RESULTS: None of the 50 (6.5%) patients with MAC showed signs of tourniquet failure. Intraoperative blood loss of patients with MAC was not significantly elevated compared to the overall study group (p = 0.592) even when corrected for the presence of several confounding factors. CONCLUSION: We found no evidence that vascular calcifications seen on the preoperative radiograph might be associated with tourniquet failure. However, surgeons should be aware of this possibility as tourniquet failure might become more common considering the ongoing trend toward minimizing cuff pressures.

Vascular Calcifications on the Preoperative Radiograph: Predictor of Ischemic Complications in Total Knee Arthroplasty?

BACKGROUND: Vascular calcifications seen on the preoperative radiograph of patients scheduled for total knee arthroplasty (TKA) are intuitively seen as a risk factor for ischemic complications though there is no empiric evidence to support this assumption. The aim of this study was the correlation of perioperative ischemic complications and vascular calcifications of patients undergoing TKA. METHODS: In this retrospective analysis, all 825 patients who had undergone primary TKA in the period 2009-2011 with intraoperative use of a tourniquet were included. Patients with pathologic pulse status and history of vascular intervention were excluded. Vascular calcifications seen on the preoperative radiograph were classified as intimal-type and medial-type calcifications and were correlated to perioperative ischemic complications. RESULTS: Vascular calcifications were seen in 268 patients (medial type: n = 54, intimal type: n = 214). Major ischemic complications such as arterial thrombosis were seen in 2 patients, one of them with intimal-type calcifications and one without (complication rate 0.5% vs 0.2%, P = .715). The rate of minor ischemic complications such as protracted wound healing was significantly elevated in patients with intimal-type calcifications (6.1%) when compared to patients with medial-type calcifications (1.9%) and those without (1.6%, P = .003) even when multiple regression analysis was performed taking into account 2 potential influencing factors "age" and "diabetes mellitus" (P = .008). CONCLUSION: Owing to the significantly increased risk of ischemic complications in patients with intimal-type calcifications undergoing TKA, we recommend high alertness to the presence of calcifications on preoperative radiographs, careful intraoperative soft tissue management, and postoperative monitoring of the vascular status.