Supplementary pedicle screw fixation in spinal fusion for degenerative spondylolisthesis in patients aged 65 and over: Outcome after a minimum of 2 years follow-up in 82 patients

Figures & data

Figure 1. A 67-year-old man. Preoperatively, anteroposterior (A) and lateral (B) views showing degenerative spondylo-listhesis at L4/L5.Two years postoperatively, anteroposterior (C), lateral (D), flexion (E) and extension (F) views showed stable implants, solid fusion, and no motion in flexion and extension on stress radiographs.

Figure 2. A 72-year-old woman with degenerative spondylolisthesis at L3/ L4 and L4/L5. Two years postoperatively, anteroposterior (A) and lateral (B) views showed stable implants and solid fusion.

Table 1.  Factors that may be predictive of a “dissatisfied” result

	Satisfied	Dissatisfied	P-value
	(n = 65)	(n = 17)
Mean age	69	70	0.8 ^a
Sex (female)	46	15	0.2^b
Mean BMD (T-score)	-1.87	-1.82	0.6 ^a
Grade of spondylolisthesis (grade 2)	20	4	0.8^b
Fused segment (two segments)	31	7	0.8^b
Mean preoperative ODI scores	55	60	0.08 ^a
Co-morbidity	32	10	0.6^b
Fusion to the sacrum	13	6	0.2^b
Not solid fusion	17	3	0.5^b

^a Independent t-test.

^b Fisher's exact test.

Table 2.  Factors that may be predictive of a “not solid fusion” result

	Solid	Not solid	P-value
	(n = 62)	(n = 20)
Mean age	69	71	0.005 ^a
Sex (female)	48	13	0.4^b
Mean BMD (T-score)	-1.78	-2.11	< 0. 001 ^a
Grade of spondylolisthesis (grade 2)	17	7	0.6^b
Fused segment (two segments)	30	8	0.6^b
Mean preoperative ODI scores	56	55	0.6 ^a
Co-morbidity	36	8	0.2^b
Fusion to the sacrum	15	4	1.0^b

^a Independent t-test.

Fisher's exact test.