Local anesthetic wound infiltration for pain management after periacetabular osteotomy

Figures & data

Figure 1. Flow chart of patients

Table 1. Criteria for inclusion and exclusion

Inclusion criteria
Periacetabular osteotomy due to dysplasia or retroverted acetabulum
Exclusion criteria
Younger than 18 years.
Comorbidities supposed to affect interpretation of pain, e.g. chronic back pain.
Drug or medical abuse. Substantial opioid intake preoperatively.
Mental retardation or active psychiatric disorder, e.g. depression.
Spinal anesthesia.
Second intervention carried out simultaneously, e.g. femur osteotomy.

Table 2. Characteristics of 53 patients randomized to receive postoperative wound infiltration of either ropivacaine or placebo (saline). Values are median (range) or number

	Intervention group(ropivacaine)(n = 26)	Placebo group(saline)(n = 27)
Sex (M/F)	9/17	3/24
Age (y)	35 (18–54)	31 (18–55)
Weight (kg)	79 (50–127)	70 (48–105)
Height (cm)	173 (162–193)	171 (154–193)
Surgeon 1/Surgeon 2	9/17	13/14
Duration of surgery (min)	83 (65–110)	77 (63–123)

Table 3. Postoperative pain and timed up-and-go (TUG) results. Values are mean (SD) or number of registrations in the 2 groups. Self-reporting of pain at rest was scheduled 4 times every day. Pain during activity was assessed once a day, immediately after the TUG test

	Intervention(ropivacaine)	GroupPlacebo(saline)	Intervention/placebo, n ^a	p-value
VAS 6 h postoperatively	29 (18)	38 (17)	18/19	0.1
VAS on POD 1	31 (23)	35 (21)	97/95	0.2
VAS on POD 2	24 (20)	31 (20)	100/100	0.009 ^b
VAS on POD 3	19 (16)	31 (22)	91/92	< 0.001 ^b
VAS on POD 4	18 (17)	28 (23)	81/85	< 0.001 ^b
TUG, POD 1	44 (11)	63 (40)	11/9	0.2
TUG, POD 2	41 (18)	39 (17)	17/13	0.8
TUG, POD 3	38 (17)	42 (32)	20/16	0.7
TUG, POD 4	33 (16)	42 (21)	13/11	0.2
VAS after TUG, POD 1	43 (14)	47 (25)	11/10	0.8
VAS after TUG, POD 2	30 (14)	38 (22)	17/14	0.2
VAS after TUG, POD 3	29 (19)	31 (20)	19/16	0.8
VAS after TUG, POD 4	32 (22)	33 (28)	13/11	0.9

VAS: visual analog scale; POD: postoperative day; TUG: timed up-and-go test.

^a Number of registrations in the two groups. Self reported pain was scheduled four times each day.

^b Using the Bonferroni-Holm correction, the level of significance should be 0.004 (0.05/13)

Figure 2. Boxplot showing median oxycodone consumption postoperative day (POD) 1–4. POD 1: p = 0.66, POD 2: p = 0.86, POD 3: p = 0.57, and POD 4: p = 0.85. Boxes indicate median with 25th and 75th percentilrs and whisker caps indicate 10th and 90th percentiles. Dots show each observation outside whiskers.