Efficacy of the “Popliteal Compression Test” in detecting intraoperative popliteal artery transection injury during knee arthroplasty in a Tier 2 hospital in India: A rapid intra op clinical test to initiate treatment algorithm

Vascular injury during knee replacement surgery is a rare but a catastrophic complication. Its incidence is higher in complex primary and revision knee arthroplasties. Identification of such events at the earliest is of utmost importance to prevent long term morbidity and mortality. A simple clinical test is proposed and evaluated, while the limb is still under tourniquet; to be performed immediately before implantation; that can provide a reasonably accurate indication of such vascular transection injury. We hypothesise that the Popliteal Compression Test (PCT) accurately predicts the occurrence of any intraoperative transection vascular injury also confirmed with post operative CT angiogram thereby conferring an advantage in planning the vascular input in a tier 2 peripheral hospital within the critical revascularisation window. The test was performed on 200 consecutive knee arthroplasty patients (143- primary, 38- complex primary, 19- revision). Three patients showed a positive test of which two patients needed open vascular surgical input. The test has 100% sensitivity, 99.5% specificity, 66.7% Positive Predictive Value and 100% Negative Predictive Value. The greater proportion of high-risk patients in our cohort, a low sample size and a meticulous intaraoperative procedure to detect vascular injury prevented direct comparison with literature reported incidence; even though a χ2 test was performed. Our limitation was the sample size in this study of only 3 predicted positive patients. The PCT represents a simple procedure that can provide an incalculable advantage in planning at a tier 2 surgical centre, where mobilising a vascular surgical team can take considerable time (up to 4 hrs). This test should be incorporated into the surgical routine of every knee arthroplasty surgeon to prevent physical morbidity to the patient and psychological burden to the surgical team.