Question: In patients having knee arthroscopy, what is the effect of tourniquet use on postoperative pain and functional outcomes?
Design: Randomized (allocation concealed), double-blind, controlled trial with 3-month follow-up.
Setting: University hospital in London, Ontario, Canada.
Patients: Patients older than 16 years of age who were scheduled for 1-hour knee arthroscopy. Exclusion criteria were anterior cruciate or posterior cruciate ligament reconstructive surgery, total synovectomy or meniscal suturing, evidence of neuromuscular disease or systemic illness, or in- ability to read or write in English. Of 145 patients enrolled, 120 (83%) (mean age, 43 years; 72% men) met the inclusion criteria and completed the study.
Intervention: All patients had a pneumatic tourniquet applied to the thigh of the operative leg and were allocated to the tourniquet being inflated to 300 mm Hg (n = 61) or not inflated (n = 59). General anesthesia was used for all operations.
Main outcome measures: Oral narcotic use and pain (measured by a 100-mm visual analog scale) for the first 5 postoperative days; self-reported health status using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); objective functional outcome measured by the 6-minute walk test, 30-second stair climb, and 1-leg standing vertical leap; iso- kinetic strength testing; and time to return to work or sport. Health status and functional outcomes were assessed at 2 and 6 weeks and at 3 months.
Results: The study had 80% power to de- tect a 25% mean difference in WOMAC pain score. Mean WOMAC scores did not differ between the groups (2 wk, P = 0.88; 6wk,P=0.93;3mo,P=0.62).Theaver- age oral narcotic use was 48.9 mg in the inflated tourniquet group and 49.1 mg in the uninflated group. The groups did not differ for assessment of postoperative pain (P = 0.24), except in patients whose surgery lasted >30 minutes (n = 51) (greater pain was reported by the inflated tourniquet group [P = 0.019]). The groups did not differ at any time point in objec- tive functional outcome measures or iso- kinetic strength testing, time to return to work (18.2 d vs. 15.4 d, P = 0.61), or return to sport (28.2 d vs. 20.9 d, P = 0.58). The surgeons, who were blinded to tourniquet status, reported improved visibility and less technical difficulty with the inflated tourniquet, but mean operative time did not differ between the groups.
Conclusion: In patients having knee arthroscopy, tourniquet use during the procedure did not affect postoperative pain or functional outcomes.