First clinical experience with posterior lumbar interbody fusion using a thermal-sprayed silver-containing hydroxyapatite-coated cage

Table 2 Summary of clinical improvement and fusion status

	n = 48
	Preoperative	6 months	12 months
Clinical improvement
NRS for low back/lower limb pain	7 (5–8)	2 (1–3)*	1.5 (0.0–3.25)
Improvement over MCID (1.6)		37 (82)*	39 (81)
Oswestry Disability Index	44 (12)	12 (6–26)**	11 (3.5–29)
Improvement over MCID (12.8)		39 (83)**	39 (81)
Fusion status^†
Intervertebral bone fusion		42 (88)	44 (91)
Visible gap around the pedicle screws		2 (3.9)	4 (7.8)
Cage subsidence (> 2 mm)		3 (5.9)	3 (5.9)
Vertebral endplate cyst formation		15 (29)	11 (22)

Normally and non-normally distributed continuous variables are presented as the mean (standard deviation) and median (interquartile range (IQR)), respectively, while categorical variables are presented as the frequency (percentage)
NRS numerical rating scale, MCID minimum clinically important difference
^*n = 45 because of three missing measurements
^**n = 47 because of one missing measurement
^†The number of intervertebral spaces fixed, not the number of participants; thus, n = 51

ISSN: 1749-799X