Long-Term Effectiveness of Polymerized-Type I Collagen Intra-Articular Injections in Patients with Symptomatic Knee Osteoarthritis: Clinical and Radiographic Evaluation in a Cohort Study

Table 1

Demographic and disease history at baseline and during follow-up of the study.

Demographics	Baseline	6–11 Mo	12–35 Mo	36–48 Mo	49–60 Mo
	(n = 309)	(n = 309)	(n = 255)	(n = 206)	(n = 48)
Gender
Female; n (%)	208 (67)
Male; n (%)	101 (33)
Age (years); mean ± SD	64.0 ± 8.7
(Range)	(45–82)
Body mass index (kg/m^2);  mean ± SD;	23.9 ± 3.2
(Range)	(18.2–34.6)
Kellgren-Lawrence grade
II; n (%)	160 (52)
III; n (%)	149 (48)
Deformity
Valgus; n (%)	7 (2)
Varus; n (%)	302 (98)
Clinical variables
WOMAC pain subscale; mean ± SD	6.1 ± 3.4	4.4 ± 3.1	3.4 ± 2.4	4.3 ± 2.2	3.6 ± 2.1
(Range)	(2–16)	(0–14)	(0–14)	(2–10)	(2–12)
Δ (%)		−27.8	−44.2	−29.5	−41.0
WOMAC stiffness subscale; mean ± SD	4.2 ± 2.0	3.2 ± 1.7	2.5 ± 1.5	2.8 ± 1.5	2.4 ± 1.1
(Range)	(2–10)	(1–10)	(0–12)	(2–8)	(0–6)
Δ (%)		−23.8	−40.47	−33.3	−42.9
WOMAC disability; mean ± SD	21.0 ± 4.9	19.1 ± 4.8	16.3 ± 4.9	17.2 ± 5.4	15.9 ± 5.5
(Range)	(2–36)	(10–32)	(2–30)	(6–32)	(4–32)
Δ (%)		−9.0	−22.4	−18.1	−24.3
Patient pain (mm); mean ± SD	56.2 ± 13.5	32.1 ± 15	35.5 ± 13.6	29.4 ± 11.7	20.4 ± 10.6
(Range)	(30–100)	(0–80)	(20–70)	(0–70)	(0–60)
Δ (%)		−42.9	−36.8	−47.7	−63.7
Physician pain (mm); mean ± SD	54.0 ± 12.6	29.7 ± 13.2	30.4 ± 13.9	25.1 ± 12.1	20.1 ± 10.6
(Range)	(30–100)	(0–80)	(20–70)	(0–70)	(0–60)
Δ (%)		−45.0	−43.7	−53.5	−62.8
Patient Likert score (cm); mean ± SD	1.8 ± 0.9	2.1 ± 1.0	2.3 ± 0.9	2.5 ± 0.8	2.9 ± 0.7
(Range)	(0–3)	(0–8)	(0–6)	(0–6)	(1–6)
Δ (%)		18.3	27.8	38.9	61.1
Physician Likert score (cm); mean ± SD	1.8 ± 1.0	2.2 ± 1.0	2.3 ± 0.9	2.6 ± 0.9	3.0 ± 0.7
(Range)	(0–6)	(0–6)	(0–6)	(0–6)	(1–6)
Δ (%)		22.0	27.8	44.4	66.7
Patient drug evaluation (cm); mean ± SD		2.4 ± 0.9	2.0 ± 0.9	2.2 ±0.7	3.1 ± 0.5
(Range)		(0–4)	(0–4)	(1–4)	(2–4)
Δ (%)			6.0	9.1	29.2
Physician drug evaluation (cm); mean ± SD		2.1 ± 1.0	1.9 ± 0.9	2.1 ± 0.9	2.8 ± 0.7
(Range)		(0–4)	(0–3)	(0–4)	(1–4)
Δ (%)			8.0	0.0	33.3

Bold numbers depict clinically significant improvement.