Table 1. Demographic Characteristics.

Number of patients	35
Sex (male/female)	17/18
Age, mean (range), yrs	67±6.5 (34-81)
Symptom duration, mean (range), yrs	2.0 (1-10)
Follow-up after surgery, mean (range), months	7 (2-15)
BMD (young adult mean), mean (range), %	85±5 (65-100)
Diagnosis
Spondylolisthesis	20
Discogenic low back pain	4
Kyphoscoliosis	11
Complication before surgery
Diabetes mellitus	6
Parkinson disease	3
Revision surgery	6
Hemodialysis	1
Number of fusion levels (OLIF)	1 level: 26 patients
	2 levels: 4 patients
	3 levels: 3 patients
	4 levels: 2 patients
Posterior fixation (open pedicle screws, open cortical bone trajectory, or percutaneous pedicle screws)	Open PS: 8 patients
	Open CBT: 5 patients
	PPS: 22 patients
Posterior decompression	Performed, 18 patients
	Not performed, 17 patients

BMD, bone mineral density; OLIF, oblique lateral interbody fusion; PS, pedicle screws; CBT, cortical bone trajectory; PPS, percutaneous pedicle screws.