A stiff and straight back preoperatively is associated with a good outcome 2 years after lumbar disc surgery

Figures & data

Table 1.  Numbers of patients with severe pain measured as pain right now (VAS-N > 54) and results from generalized estimating equation (GEE) models expressed with odds ratios (ORs) supplemented with 95% confidence intervals (CIs). An odds ratio of > 1 indicates more pain

	Preop.	2 weeks	6 weeks	3 months	6 months	1 year	2 years	OR ^a (95% CI)	p-value
All (n = 79)	34	2	4	4 ^c	2 ^c	5 ^c	5 ^c
Hypoflexion (n = 40)	20	1	2	2	1 ^c	2 ^c	2 ^c	reference
Hyperflexion (n = 39)	14	1	2	2 ^c	1	3	3	1.25 (0.27–5.7)	0.8
Hyperlordosis (n = 41)	21	2	2	4 ^c	1	4 ^c	4	reference
Hypolordosis (n = 38)	13	0	2	0	1 ^c	1	1 ^c	0.60 (0.15–2.4)	0.5
Only patients with hypoflexion
Hyperlordosis (n = 16)	16	1	2	2	1	2 ^c	2	reference
Hypolordosis (n = 24)	21	0	0	0	0 ^c	0	0 ^c	Not possible to estimate ^b
Only patients with hyperflexion
Hyperlordosis (n = 25)	21	1	0	2 ^c	0	2	2	reference
Hypolordosis (n = 14)	13	0	2	0	1	1	1	2.90 (0.85–9.9)	0.2

^a Adjusted for corticosteroid treatment, preoperative pain, time, sex, and age.

^b Not possible to estimate because none of the patients with hypolordosis had severe pain postoperatively.

^c 1 patient is missing.

Table 2.  Numbers of patients with severe pain measured as worst pain last week (VAS-W > 54) and results from generalized estimating equation (GEE) models expressed with odds ratios (ORs) supplemented with 95% confidence intervals (CIs). An odds ratio of > 1 indicates more pain

	Preop.	2 weeks	6 weeks	3 months	6 months	1 year	2 years	OR ^a (95% CI)	p-value
All (n = 79)	71	14 ^c	8	10 ^c	11 ^c	13 ^c	12 ^c
Hypoflexion (n = 40)	37	6	5	5	5 ^c	5 ^c	5 ^c	reference
Hyperflexion (n = 39)	34	8 ^c	3	5 ^c	6	8	7	1.1 (0.45–2.9)	0.8
Hyperlordosis (n = 41)	37	10 ^c	4	8 ^c	9	8 ^c	9	reference
Hypolordosis (n = 38)	34	4	4	2	2 ^c	5	3 ^c	0.42 (0.16–1.1)	0.07
Only patients with hypoflexion
Hyperlordosis (n = 16)	16	5	3	5	5	4 ^c	5 ^b	reference
Hypolordosis (n = 24)	21	1	2	0	0 ^c	1	0 ^c	0.06 (0.01–0.27)	0.003
Only patients with hyperflexion
Hyperlordosis (n = 25)	21	5 ^c	1	3 ^c	4	4	4	reference
Hypolordosis (n = 14)	13	3	2	2	2	4	3	1.2 (0.37–4.2)	0.8

^a Adjusted for corticosteroid treatment, preoperative pain, time, sex, and age.

^b Adjusted for corticosteroid treatment, time, sex, and age but not for preoperative pain because of concordance, all patients had severe pain preoperatively.

^c 1 patient is missing.

Table 3.  Numbers of patients with DRI > 40 and results from generalized estimating equation (GEE) models expressed with odds ratios (ORs) supplemented with 95% confidence intervals (CIs). An odds ratio of > 1 indicates more perceived disability

	Preop.	2 weeks	6 weeks	3 months	6 months	1 year	2 years	OR ^a (95% CI)	p-value
All (n = 79)	74	66	37	19 ^c	11 ^c	9 ^c	10 ^c
Hypoflexion (n = 40)	40	33	19	10	4 ^c	4 ^c	4 ^c	reference
Hyperflexion (n = 39)	34	33	18	9 ^c	7	5	6	1.3 (0.57–3.0)	0.5
Hyperlordosis (n = 41)	37	36	23	13 ^c	8	7 ^c	8	reference
Hypolordosis (n = 38)	37	30	14	6	3 ^c	2	2 ^c	0.37 (0.16–0.86)	0.02
Only patients with hypoflexion
Hyperlordosis (n = 16)	16	15	13	7	4	3 ^c	4	reference
Hypolordosis (n = 24)	24	18	6	3	0 ^c	1	0 ^c	0.11 (0.04–0.35) ^c	< 0.001
Only patients with hyperflexion
Hyperlordosis (n = 25)	21	21	10	6 ^c	4	4	4	reference
Hypolordosis (n = 14)	13	12	8	3	3	1	2	1.3 (0.38–4.1)	0.7

^a Adjusted for corticosteroid treatment, preoperative pain, time, sex and age.

^b Adjusted for corticosteroid treatment and time but not preoperative disability because of concordance, all patients had DRI > 40 preoperatively.

^c 1 patient is missing.

Figure 1. The distribution of lumbar lordosis in all patients (n = 79), measured preoperatively to 2 years postoperatively.

Figure 2. The distribution of lumbar flexion in all patients (n = 79), measured preoperatively to 2 years postoperatively.