Determinants of pain, functional limitations and health-related quality of life six months after total knee arthroplasty: results from a prospective cohort study

Table 1 Selected characteristics of the study participants who underwent primary unilateral total knee arthroplasty (n = 138)

Variables	n (%)	Mean (SD)	Variables	n (%)	Mean (SD)
Demographics			Clinical characteristics
Age (years)		67 (9.3)	Diagnosis
			Osteoarthritis	133 (96)
Gender			Rheumatoid arthritis	5 (4)
Female	91 (66)		BMI ^‡ (kg/m²)		31.2 (6.2)
Marital status			Comorbidities ( /56)		6.5 (2.2)
Single, separated, divorced or widowed	51 (37)		Duration of knee symptoms before enrolment (years) ^§ (years)		8.2 (8.3)
Married or common law	87 (63)		Contralateral knee pain ^∣∣	100 (72)
			Use of a walking aid before surgery	52 (38)
Living alone	33 (24)		Surgical characteristics
			Implant type
Socioeconomic characteristics			Postero-stabilized	108 (78)
Educational level (part or complete)			Cruciate retaining	30 (22)
High school or less	77 (56)		Implant fixation
College or university	61 (44)		Cementless	4 (3)
Employment status			Hybrid	2 (1)
Unemployed or retired	108 (78)		Cemented	132 (96)
Employed	30 (22)		Implant bearing type
Household income ^*			Mobile	4 (3)
< $30 000 / year	48 (35)		Fixed	134 (97)
$30 000 - $59 999/ year	42 (30)		Patella resurfacing	129 (93)
≥ $60 000/ year	32 (23)		Number of in-hospital complications ^¶
			0	103 (77)
Psychosocial characteristics			1	34 (24)
Psychological distress (/42)		7.1 (6.3)	≥2	9 (7)
Social support ^†			Health services utilization
Low	66 (48)		Hospital length of stay (days)		7.1 (2.9)
High	72 (52)		Discharged directly home	120 (87)
			Post-surgery community physiotherapy(hours)		14.7 (18.3)

^*n = 125 – CND $.
^† Social support was dichotomized around the median score: Low (≤ 80) and High (>80).
^‡ Body mass index.
^§ n = 132.
^∣∣WOMAC pain score at enrolment on pre-surgery wait list dichotomized into presence or absence of contralateral knee pain.
^¶In-hospital complications: wound infection (n = 5), implant infection (n = 4), fracture or dislocation (n = 3), knee ankylosis and manipulation (n = 4), cardiovascular/pulmonary/ circulatory complications (n = 12), peripheral/central nervous system involvement (n = 9), urinary infection (n = 3), acute confusion (n = 1), tendon and ligament rupture (n = 1) or blood transfusion (n = 14).

ISSN: 2052-1847