Key factors in determining surgical timing of total knee arthroplasty in osteoarthritic patients: age, radiographic severity, and symptomatic severity

Journal of Orthopaedics and Traumatology

Official Journal of the Italian Society of Orthopaedics and Traumatology

Table 3 Comparisons between the group of typical patients with all selection criteria satisfied and the groups of patients who did not satisfy one of the selection criteria

Parameters	Typical candidates^a [N = 190 (49.6%)]	Patients not satisfying the age criterion [N = 20 (5.2%)]		Patients not satisfying the radiographic criterion [N = 53 (13.8%)]		Patients not satisfying the symptomatic criterion [N = 77 (20.1%)]
Parameters	Mean (SD)	Mean (SD)	Significance^b (P-value)	Mean (SD)	Significance^b (P-value)	Mean (SD)	Significance^b (P-value)
Age	70.3 (4.8)	56.9 (1.5)	<0.001	69.6 (4.9)	0.419	69.5 (5.7)	0.365
Radiographic OA score	6.1 (1.5)	5.7 (1.1)	0.609	3.5 (0.5)	<0.001	6.0 (1.3)	0.598
Preoperative WOMAC
Pain (20)	13.3 (3.2)	12.7 (3.4)	0.385	13.8 (3.3)	0.364	7.2 (2.7)	<0.001
Function (68)	48.3 (8.5)	41.1 (6.8)	0.002	46.6 (10.4)	0.352	27.4 (5.5)	<0.001
Postoperative WOMAC
Pain (20)	2.6 (3.1)	1.4 (2.6)	0.101	2.4 (2.7)	0.803	1.6 (2.2)	0.023
Function (68)	17.3 (10.0)	10.8 (10.1)	0.015	18.2 (11.5)	0.634	13.3 (9.3)	0.016
Proportion dissatisfied^c	8.7% (14/161)	0% (0/16)	NA	8.9% (4/45)	0.968	3.0% (2/66)	0.130

SD Standard deviation, OA osteoarthritis, WOMAC Western Ontario and McMaster Universities Osteoarthritis Index, NA not applicable
^aTypical patients satisfied all three selection criteria: (1) age ≥61 years, (2) radiographic OA score ≥4.5, (3) preoperative WOMAC total score ≤50% of full mark
^bComparisons were made to the group of typical candidates
^cNot all patients responded to this question. Therefore, calculation of the proportions and comparisons between the groups were done with the numbers of patients who responded to the question