The effect of a tourniquet on intraoperative patellofemoral tracking during total knee arthroplasty.

A prospective investigation was performed on the effect of the tourniquet on intraoperative patellofemoral tracking during primary total knee arthroplasty (TKA). A total of 75 TKAs in 67 patients were performed by 1 surgeon in a consecutive series using the same technique. Using strict criteria, patellar tracking was assessed both before and after tourniquet release. Patients were placed into 1 of 3 groups: Group I were knees that tracked properly both before and after tourniquet release. Group II were knees that maltracked with the tourniquet inflated and subsequently corrected with the tourniquet released. Group III were knees that maltracked both before and after tourniquet release, therefore requiring a lateral release. Knees were categorized as group I, 34 of 75 (45.3%); group II, 36 of 75 (48.0%); and group III, 5 of 75 (6.7%). Using this criterion, lateral release was avoided in all group II knees. Tourniquet application alters intraoperative patellofemoral tracking during TKA. When contemplating lateral release, tourniquet deflation and reevaluation of patellofemoral tracking should be considered.