Mid-term clinical outcomes of the uncemented Robert Mathys pressfit cup

Table 1 Baseline demographic and clinical characteristics of the study population, n (%)

	N = 1324 THA’s
Demographic characteristics
Age at surgery, yr, mean (SD)	64.9 ± 11.6
Female gender	835 (63.1)
Right side	724 (54.7)
BMI, kg/m2, mean (SD)	26.4 ± 4.1
Clinical characteristics
Diagnoses
Osteoarthritis	948 (71.6)
Dysplasia	55 (4.2)
Fracture	28 (2.1)
Osteonecrosis	37 (2.8)
Rheumatoid arthritis	21 (1.6)
Posttraumatic	26 (2.0)
Other	19 (1.4)
Surgical approaches
Anterior	254 (19.2)
Anterolateral	219 (16.5)
Posterolateral	50 (3.8)
Straight lateral	613 (46.3)
Unknown	188 (14.2)

BMI: Body mass index; THA: Total hip arthroplasty.

Table 2 Yearly change of the PROMs (ß) during the first postoperative year

HOOS	First year
	ßcrude (95%CI)1	P value	ßadjusted (95%CI)1	P value
Symptoms	40.3 (29.6-51.0)	< 0.001	39.6 (27.2-52.0)	< 0.001
Pain	41.9 (39.8-43.9)	< 0.001	40.7 (38.6-42.9)	< 0.001
ADL	39.9 (37.9-41.9)	< 0.001	38.9 (36.8-41.0)	< 0.001
Sport/Rec	46.7 (44.2-49.2)	< 0.001	45.5 (42.9-48.2)	< 0.001
QoL	45.9 (43.6-48.2)	< 0.001	45.2 (42.8-47.6)	< 0.001

¹Mixed model analysis, ß = yearly change (crude and adjusted for age, gender and BMI). HOOS: Hip disability and osteoarthritis outcome score; ADL: Activities in daily living; Sport/Rec: Sport and recreation; QoL: Quality of life.

Table 3 Yearly change of the PROMs (ß) during the second postoperative year

HOOS	Second year
	ßcrude (95%CI)1	P value	ßadjusted (95%CI)1	P value
Symptoms	0.95 (-0.40-1.30)	0.169	1.63 (0.20-3.05)	0.025
Pain	0.04 (-1.22-1.31)	0.948	0.44 (-0.93-1.80)	0.529
ADL	0.39 (-1.06-1.83)	0.597	0.81 (-0.70-2.32)	0.294
Sport/Rec	-0.03 (-2.19-2.13)	0.977	0.98 (-1.34-3.29)	0.407
QoL	2.20 (0.32-4.09)	0.022	2.41 (0.40-4.41)	0.019

¹Mixed model analysis, ß = yearly change (crude and adjusted for age, gender and BMI). HOOS: Hip disability and osteoarthritis outcome score; ADL: Activities in daily living; Sport/Rec: Sport and recreation; QoL: Quality of life.