[Effect of continuous and single shot adductor canal blocks for postoperative analgesia and early rehabilitation after total knee arthroplasty].

OBJECTIVE

To compare the analgesia effect and clinical rehabilitation between continuous adductor canal block (ACB) and single shot ACB in total knee arthroplasty (TKA)．.

METHODS

Between October 2016 and February 2017, 60 patients with severe knee osteoarthritis undergoing primary unilateral TKA were prospectively recruited in the study. All the patients were randomly allocated into 2 groups and received ultrasound-guided continuous ACB (group A, =30) or single shot ACB (group B, =30), respectively. There was no significant difference in gender, age, body mass index, nationality, American Society of Anesthesiology (ASA) grading, and preoperative knee range of motion and quadriceps strength between 2 groups ( >0.05). After operation, the tourniquet time, postoperative drainage volume, hospitalization time, and adverse events in 2 groups were recorded. Visual analogue scale (VAS) scores at rest and during activity, the quadriceps strength, the knee range of motion, and the time of 90° knee flexion in 2 groups were also recorded and compared.

RESULTS

There was no significant difference in tourniquet time, postoperative drainage volume, and incidence of adverse events between 2 groups ( >0.05). But the hospitalization time was significant shorter in group A than in group B ( <0.05). VAS scores at rest and during activity were lower in group A than in group B, with significant differences in VAS score at rest after 12 hours and in VAS score during activity after 8 hours between 2 groups ( <0.05). The quadriceps strength was higher in group A than in group B, with significant difference at 24, 48, and 72 hours ( <0.05). The knee range of motion was significantly better in group A than in group B at 24, 48, 72 hours and on discharge ( <0.05). The time of 90° knee flexion was significantly shorter in group A than in group B ( =-2.951, =0.016). There were 4 patients in group A and 7 patients in group B requiring meperidine hydrochloride (50 mg/time) within 24 hours, and 3 patients in group A and 7 patients in group B at 24 to 48 hours, and 1 patient in group A and 3 patients in group B at 48 to 72 hours. Effusion in the catheter site occurred in 2 cases of group A, but no catheter extrusion occurred.

CONCLUSION

Continuous ACB is superior in analgesia both at rest and during activity and opioid consumption compared with single shot ACB after TKA. And the quadriceps strength could be reserved better in continuous ACB group, which can perform benefits in early rehabilitation.