Predictors of use of pain medications for persistent knee pain after primary Total Knee Arthroplasty: a cohort study using an institutional joint registry

Table 1 Characteristics of patients with primary total knee arthroplasty

	Two-year follow-up(n= 7,139)	Five-year follow-up(n= 4,234)
Mean age, yrs (± SD)	68 ± 10	68 ± 10
Men/women (%)	44/56	45/55
Bilateral (%)	20	23
Age groups (%)
≤ 60 yrs	18	18
> 60 to 70 yrs	35	37
> 70 to 80 yrs	38	38
> 80 yrs	8	7
Body mass index, kg/m² (%)
< 25.0	13	13
25.0 to 29.9	35	36
30.0 to 34.9	29	43
35.0 to 39.9	14	7
≥ 40.0	9	7
ASA score (%)
Class I to II	58	58
Class III to IV	42	41
Cemented (%)
Yes	98.0	99.5
Hybrid	2.0	0.5
Underlying diagnoses (%)
Rheumatoid arthritis/ other^a Inflammatory arthritis conditions	4	4
Osteoarthritis	94	93
Other	2	3

ASA, American Society of Anesthesiologists. ^aOther includes avascular necrosis, fracture, neoplasms, Paget's disease, septic arthritis, etcetera.

ISSN: 1478-6362