Instrumentation in lumbar fusion improves back pain but not quality of life 2 years after surgery

Figures & data

Figure 1. Flow diagram for the inclusion of patients in this study.

Figure 2. Distribution of the use of the 3 surgical methods over time.

Table 1. Baseline characteristics of the study group, by surgical method

	UIF n = 115	IPF n = 620	IIF n = 575
Females	62	57	53
Previous spine surgery	31	31	24
Smokers	23	22	17
Age ^a	47 (10)	48 (11)	45 (10)
Follow-up, years ^a	2.2 (0.4)	2.1 (0.3)	2.1 (0.2)
EQ-5D ^a	0.35 (0.32)	0.31 (0.32)	0.33 (0.33)
Oswestry disability index ^a	42 (14)	46 (14)	45 (14)
Back pain, VAS ^a	65 (19)	64 (21)	62 (20)
Leg pain, VAS ^a	45 (28)	45 (29)	46 (28)

^a Mean (SD)

UIF: uninstrumented fusion;

IPF: instrumented posterolateral fusion;

IIF: instrumented interbody fusion.

Table 2. Outcome 2 years postoperatively related to surgical method. Values are adjusted means (95% CI) a

	UIF ^b	IPF ^b	IIF ^b
EQ-5D	0.61 (0.54–0.69)  Ref	0.62 (0.57–0.67) p = 0.54	0.64 (0.59–0.69) p = 0.4
Oswestry disability index	28 (23–34)  Ref	28 (24–33) p = 0.96	27 (23–32) p = 0.6
Back pain, VAS	40 (33–47)  Ref	34 (30–39) p = 0.06	33 (28–38) p = 0.02
Leg pain, VAS	32 (24–39)  Ref	29 (24–34) p = 0.37	29 (23–35) p = 0.5

^a The estimated mean values have been adjusted for differences in age, sex, smoking, previous spine surgery, duration of symptoms, year of surgery, hospital, and differences at baseline for the variable studied.

^b For abbreviations, see Table 1