The Effect of Adductor-Canal-Blockade on Outcome after Medial Unicondylar Knee Arthroplasty: A Preliminary Study.

INTRODUCTION

Unicondylar knee arthroplasty (UKA) offers decreased morbidity, faster recovery, better functional outcomes, and equivalent survivorship compared to TKA for certain patients. To fully capture these benefits, regional anesthesia techniques must facilitate rather than compromise patients ability for early postoperative mobilization and safe discharge following UKA. The purpose of this study was to determine whether the predominantly sensory adductor canal blockade (ACB) shortens hospital stay after medial UKA (mUKA). Secondary endpoints were narcotic consumption, steps walked during PT sessions, and total PT sessions required prior to discharge.

METHODS

Twelve patients scheduled for elective mUKA received spinal anesthesia and single-shot ACB. ACB patients were matched by age, gender, body mass index (BMI), and Charlson Comorbidity Index in a 1:2 ratio to 24 lumbar plexus block (LPB) patients. Time to hospital discharge, number of physical therapy (PT) sessions required for safe discharge, and steps taken during PT sessions were retrospectively abstracted from each patient's medical record.

RESULTS

Patients who received ACB had a significantly shorter hospital stay (27.8 ± 3.9 hours) compared with patients who received LPB (39.7 ±18.5 hours, p = 0.025). Patients treated with ACB required significantly fewer PT sessions (1.3 ± 0.6 sessions) compared to patients who received LPB (2.4 ± 1.5 sessions, p = 0.007). Patients treated with ACB walked significantly more steps during their first PT session (225.0 ± 156.6 steps) compared with patients treated with LPB (107.4 ± 170.0, p = 0.045). There was a trend towards decreased narcotic requirements in the ACB group.

DISCUSSION AND CONCLUSIONS

Data from our study suggests that ACB may permit earlier hospital discharge and better participation in PT without compromising the quality of perioperative analgesia. Thus, ACB may represent a promising option for patients undergoing mUKA in terms of improved clinical outcomes, decreased postoperative morbidity, and cost-effectiveness.