BACKGROUND: Both neuraxial and peripheral regional analgesic techniques offer postoperative analgesia for total hip arthroplasty (THA) patients. While no single technique is preferred, quadriceps muscle weakness from peripheral nerve blocks may impede rehabilitation. We designed this study to compare postoperative ambulation outcome in THA patients who were treated with a new ultrasound-guided fascia iliaca catheter (FIC) technique or intrathecal morphine (ITM). METHODS: We reviewed the electronic health records of a sequential series of primary unilateral THA patients who were part of a standardized clinical pathway; apart from differences in regional analgesic technique, all other aspects of the pathway were the same. Our primary outcome was total ambulation distance (meters) combined for postoperative days 1 and 2. Secondary outcomes included daily opioid consumption (morphine milligram equivalents) and analgesic-related side effects. We examined the association between the primary outcome and analgesic technique by performing crude and adjusted ordinary least-squares linear regression. A P value < 0.05 was considered statistically-significant. RESULTS: The study analyzed the records of 179 patients (fascia iliaca, n = 106; intrathecal, n = 73). The primary outcome (total ambulation distance) did not differ between the groups (P = 0.08). Body mass index (BMI) was the only factor (β = -1.7 [95% CI -0.5 to -2.9], P < 0.01) associated with ambulation distance. Opioid consumption did not differ, while increased pruritus was seen in the intrathecal group (P < 0.01). CONCLUSIONS: BMI affects postoperative ambulation outcome after hip arthroplasty, whereas the type of regional analgesic technique used does not. An ultrasound-guided FIC technique offers similar analgesia with fewer side effects when compared with ITM.
Analgesia ; Anesthesia, Conduction ; Anesthesia, Spinal ; Arthroplasty ; Arthroplasty, Replacement, Hip* ; Body Mass Index ; Catheters* ; Critical Pathways* ; Electronic Health Records ; Fascia* ; Hip ; Humans ; Linear Models ; Morphine ; Nerve Block ; Peripheral Nerves ; Pruritus ; Quadriceps Muscle ; Rehabilitation ; Ultrasonography ; Walking

BACKGROUND: Adductor canal catheters offer advantages over femoral nerve catheters for knee replacement patients because they produce less quadriceps muscle weakness; however, applying adductor canal catheters in bedside clinical practice remains challenging. There is currently no patient-reported outcome that accurately predicts patients' physical function after knee replacement. The present study evaluates the validity of a relatively new patient-reported outcome, i.e., a numbness score obtained using a numeric rating scale, and assesses its predictive value on postoperative ambulation. METHODS: We conducted a retrospective cohort study pooling data from two previously-published clinical trials using identical research methodologies. Both studies recruited patients undergoing knee replacement; one studied adductor canal catheters while the other studied femoral nerve catheters. Our primary outcome was patient-reported numbness scores on postoperative day 1. We also examined postoperative day 1 ambulation distance and its association with postoperative numbness using linear regression, adjusting for age, body mass index, and physical status. RESULTS: Data from 94 subjects were included (femoral subjects, n = 46; adductor canal subjects, n = 48). Adductor canal patients reported decreased numbness (median [10th-90th percentiles]) compared to femoral patients (0 [0-5] vs. 4 [0-10], P = 0.001). Adductor canal patients also ambulated seven times further on postoperative day 1 relative to femoral patients. There was a significant association between postoperative day 1 total ambulation distance and numbness (Beta = -2.6; 95% CI: -4.5, -0.8, P = 0.01) with R2 = 0.1. CONCLUSIONS: Adductor canal catheters facilitate improved early ambulation and produce less patient-reported numbness after knee replacement, but the correlation between these two variables is weak.
Arthroplasty* ; Body Mass Index ; Catheters* ; Cohort Studies ; Early Ambulation ; Femoral Nerve ; Humans ; Hypesthesia* ; Knee* ; Linear Models ; Nerve Block* ; Quadriceps Muscle ; Retrospective Studies ; Walking*