Assessment of liposome bupivacaine infiltration versus continuous femoral nerve block for postsurgical analgesia following total knee arthroplasty: a retrospective cohort study

Figures & data

Table 1. Patient profile.

Item	Control^a (n = 105)		Group A^a (n = 98)		Group B^a (n = 34)		p Value
	No.	%	No.	%	No.	%
Gender (female)	63	60.0	52	53.1	14	41.2	0.150
Insurance
Medicare	73	69.5	71	72.4	22	64.7	0.513
Medicaid	2	1.9	0	0.0	0	0.0
Private	30	28.6	27	27.6	12	35.3
Body mass index
<25	11	10.5	13	13.3	3	8.8	0.620
25–29.9	35	33.3	25	25.5	8	23.5
≥30	59	56.2	60	61.2	23	67.6
Complications
Yes	4	3.8	10	10.2	1	2.9	0.119
Discharge disposition
Assisted/nursing/religious home	44	41.9	37	37.8	10	29.4	0.225
Home	1	1.0	4	4.1	2	5.9
Home OPPT	55	52.4	49	50.0	22	64.7
Home with HH	5	4.8	8	8.2	0	0.0
Comorbidity (yes)
Cancer	25	23.8	30	30.6	9	26.5	0.550
Cardiovascular	18	17.1	23	23.5	9	26.5	0.385
Cerebrovascular disease	5	4.8	4	4.1	3	8.8	0.544
Chronic pulmonary disease	17	16.2	11	11.2	6	17.6	0.504
Circulatory	12	11.4	8	8.2	2	5.9	0.552
Connective tissue disease	3	2.9	0	0.0	1	2.9	0.238
Dementia	1	1.0	1	1.0	0	0.0	0.843
Diabetes	25	23.8	21	21.4	3	8.8	0.167
Hepatitis	1	1.0	1	1.0	0	0.0	0.843
Hypertension	72	68.6	65	66.3	24	70.6	Q
Hypothyroid	0	0.0	1	1.0	0	0.0	0.491
Kidney	6	5.7	2	2.0	0	0.0	0.175
Liver	2	1.9	0	0.0	0	0.0	0.281
Mental health	20	19.0	14	14.3	2	5.9	0.169
Myocardial infarction	6	5.7	9	9.2	1	2.9	0.390
Nervous system disorder	0	0.0	1	1.0	0	0.0	0.491
Obesity	3	2.9	1	1.0	1	2.9	0.618
Peripheral vascular disease	1	1.0	2	2.0	0	0.0	0.610
Sleep apnea	25	23.8	22	22.4	11	32.4	0.500
Age, mean (SD), y	70.0 (8.6)		70.1 (8.4)		69.6 (8.2)		0.967

Abbreviations. FNB, femoral nerve block; HH, home health services; OPPT, outpatient physical therapy; SD, standard deviation.

^a Study Group A: adductor canal infiltration (ACI) with bupivacaine HCl and knee infiltration with liposome bupivacaine (KI/LB); Study Group B: ACI with LB and KI/LB; control group: a continuous FNB with an elastomeric pump with ropivacaine HCl.

Table 2. Comparisons of NPRS among the three groups^a.

NPRS	N	Mean (SD)	Median	Minimum	Maximum	Group comparisons
POD0
Control	63	2.3 (2.4)	2.0	0.0	9.7
Group A	96	1.8 (1.7)	1.6	0.0	8.3
Group B	34	2.7 (1.8)	2.4	0.0	7.3	†
POD1
Control	92	3.9 (2.2)	3.8	0.0	10.0
Group A	98	3.5 (1.7)	3.3	0.0	8.4
Group B	34	3.1 (1.6)	2.9	0.7	6.4
POD2
Control	101	4.4 (1.7)	4.3	0.8	8.1
Group A	92	3.8 (1.5)	3.8	0.7	8.0	*
Group B	19	3.4 (1.2)	3.3	1.3	5.6	*
POD3
Control	94	4.0 (1.9)	3.8	0.0	9.0
Group A	66	3.3 (1.7)	3.3	0.0	9.0
Group B	16	3.4 (1.9)	3.0	0.0	6.0
Discharge Day
Control	104	4.0 (1.9)	3.8	0.0	9.0
Group A	98	3.2 (1.6)	3.3	0.0	9.0	*
Group B	34	2.9 (1.7)	2.6	0.0	6.0	*

Abbreviations. FNB, femoral nerve block; NPRS, numeric pain rating score; POD, postoperative day; SD, standard deviation.

^a Study Group A: adductor canal infiltration (ACI) with bupivacaine HCl and knee infiltration with liposome bupivacaine (KI/LB); Study Group B: ACI with LB and KI/LB; control group: a continuous FNB with an elastomeric pump with ropivacaine HCl.

* Compared with the control group, the difference was statistically significant (p < 0.05) based on analysis of variance.

† The difference between study Group A and Group B was statistically significant (p < 0.05) based on analysis of variance.

Table 3. Comparison of distance walked among the three groups^a.

Distance walked (feet)	N	Mean (SD)	Median	Minimum	Maximum	Group Comparisons
POD0
Control	0	NA	NA	NA	NA
Group A	57	33.4 (42.3)	12	0	160
Group B	15	42.4 (81.5)	6	0	300
POD1
Control	104	46.3 (72.6)	26	0	504
Group A	98	193.0 (202.9)	129	0	1000	*
Group B	33	210.8 (143.7)	200	5	500	*
POD2
Control	103	153.8 (124.0)	130	0	700
Group A	91	228.4 (183.3)	197	0	1300	*
Group B	19	211.3 (126.4)	200	0	420
POD3
Control	54	133.0 (102.3)	108	0	550
Group A	64	177.0 (122.4)	160	5	600
Group B	13	174.2 (89.2)	200	8	300
Discharge Day
Control	105	154.5 (126.4)	120	0	700
Group A	97	213.7 (155.2)	200	5	1000	*
Group B	33	241.9 (123.1)	210	10	500	*

Abbreviations. FNB, femoral nerve block; NA, not applicable; POD, postoperative day; SD, standard deviation.

^a Study Group A: adductor canal infiltration (ACI) with bupivacaine HCl and knee infiltration with liposome bupivacaine (KI/LB); Study Group B: ACI with LB and KI/LB; control group: a continuous FNB with an elastomeric pump with ropivacaine HCl.

* Compared with the control group, the difference was statistically significant (p < 0.05) based on generalized linear model with a gamma distribution and a log link.

Figure 1. Comparison of narcotic medication use in the first 72 hours among the three groups. Study Group A: adductor canal infiltration (ACI) with bupivacaine HCl and knee infiltration with liposome bupivacaine (KI/LB); Study Group B: ACI with LB and KI/LB; control group: a continuous femoral nerve block with an elastomeric pump with ropivacaine HCl. Study Group A: adductor canal infiltration (ACI) with bupivacaine and knee infiltration with liposome bupivacaine (KI/LB); Study Group B: ACI with LB and KI/LB; control group: a continuous femoral nerve; with an elastomeric pump and ropivacaine.^aThe dose difference between Group A and the control group was statistically significant (p < 0.05) based on generalized linear model with a gamma distribution and a log link. The dose for Group A was also significantly greater than for Group B.