Tourniquet and/or Adductor Canal Block Use Confer No Additional Early Quadriceps Weakness Following Total Knee Arthroplasty: An Analysis of 203 Patients.

Background: Quadriceps weakness following total knee arthroplasty (TKA) delays rehabilitation and increases fall risk. The combined impact of tourniquets and adductor canal blocks (ACBs) on postoperative quadriceps strength has not been defined. This study evaluated the early effects of tourniquet and/or ACB usage on quadriceps strength following TKA.

Methods: Primary, elective TKA patients were assigned to one of four groups based on whether they received an ACB and/or tourniquet. We prospectively measured bilateral, isometric knee extension strength preoperatively and within 36 hours postoperatively. Pre/post-change (Δ) and percent strength change were calculated and standardized to the contralateral leg. Strength, postoperative pain, mobility, knee buckling incidence, and falls were compared across groups. Measurements were collected for 203 patients: 68, 45, 45, and 45 in the tourniquet/ACB, tourniquet/ no ACB, ACB/no tourniquet, and no tourniquet/ no ACB groups, respectively.

Results: Tourniquet use was associated with shorter operative time (p=0.004), while ACB use was associated with longer lengths of stay (p=0.005). Average preoperative (p=0.53), postoperative (p=0.12), pre/post-Δ (p=0.60), percent change (p=0.14), and standardized percent change (p=0.85) in strength measures were comparable across groups. Postoperative pain (p=0.67) and knee buckling events (p=0.18) were also comparable across groups. The no tourniquet/no ACB group had decreased postoperative mobility (p=0.004), though it was not clinically significant. No patients sustained inpatient falls.

Conclusion: Combined tourniquet and ACB use during TKA does not lead to additional weakness in postoperative knee extension or buckling events. Concern for impaired early postoperative functionality should not influence arthroplasty surgeons' decision to use a tourniquet or ACB. Level of Evidence: II.