Retrospective Cohort Study
Copyright ©The Author(s) 2024.
World J Orthop. Jul 18, 2024; 15(7): 608-617
Published online Jul 18, 2024. doi: 10.5312/wjo.v15.i7.608
Table 1 Patient characteristics, surgical characteristics, and preoperative patient-reported outcomes, n (%)
Characteristics
Respondents, n = 2063
Nonrespondents, n = 367
P value
Patient characteristics
Age in year, median (IQR)65.80 (7.19)65.13 (8.39)0.222
BMI in kg/m2, median (IQR)27.77 (3.44)27.84 (3.31)0.516
Sex, male973 (47.2)190 (51.8)0.112
ASA, I799 (38.7)143 (39.0)0.954
Smoking status, yes156 (7.6)42 (11.4)0.017a
Alcohol consumption, yes1499 (72.7)244 (66.5)0.020a
Previous knee surgery, yes986 (47.8)173 (47.1)0.821
Charnley classification0.113
A Unilateral knee arthritis972 (47.1)160 (43.6)
B1 Unilateral knee TKA482 (23.4)78 (21.3)
B2 Bilateral TKA412 (20.0)94 (25.6)
C more joints affected197 (9.5)34 (9.3)
Surgical characteristics
Diagnosis, osteoarthritis2021 (98.0)355 (96.7)0.175
Anesthesia technique, spinal2043 (99.0)362 (98.6)0.763
Operative duration in min, median (IQR)40.77 (9.51)41.04 (9.83)0.551
Complication, yes62 (3.0)18 (4.9)0.078
Preoperative PROs
NRS pain score at rest, median (IQR)4.92 (2.38)5.23 (2.43)0.021a
NRS pain score during activity, median (IQR)7.18 (1.88)7.18 (2.00)0.558
KOOS-PS score, median (IQR)47.23 (12.74)48.98 (14.19)0.084
EQVAS score, median (IQR)72.91 (18.65)72.96 (19.03)0.906
EQ-5D descriptive system score, median (IQR)0.590 (0.250)0.551 (0.273)0.013a
OKS, median (IQR)24.92 (7.16)23.83 (7.64)0.042a
Table 2 Return to daily activities, work, and sports within 6 mo after total knee arthroplasty
Activity3 mo
6 mo
Within 6 mo
Return to activity, n (%)1
Time to return in days, median (IQR)
Return to activity, n (%)1
Time to return in days, median (IQR)
Return to activity, n (%)1
Time to return in days, median (IQR)
Daily activities
Night rest1435 (72.6)26.0 (36.0)--1435 (72.6)26.0 (36.0)
Walking without aids1859 (94.0)32.0 (23.5)--1859 (94.0)32.0 (23.5)
Stair climbing1655 (83.7)42.0 (26.0)--1655 (83.7)42.0 (26.0)
Grocery shopping1867 (94.4)37.0 (23.0)--1867 (94.4)37.0 (23.0)
Domestic work1700 (86.0)42.0 (25.0)--1700 (86.0)42.0 (25.0)
Putting on shoes/socks1940 (98.1)20.0 (27.0)--1940 (98.1)20.0 (27.0)
Kneeling403 (20.4)57.0 (25.0)439 (30.0)96.0 (50.3)551 (27.7)74.0 (56.5)
Driving a car1725 (91.7)42.0 (20.0)--1725 (91.7)42.0 (20.0)
Outdoor cycling1518 (80.8)43.0 (24.0)--1518 (80.8)43.0 (24.0)
Work
Low-impact work691 (86.6)33.0 (29.0)--691 (86.6)33.0 (29.0)
Medium-impact work238 (34.9)57.0 (24.0)342 (72.3)97.0 (54.0)422 (62.1)78.0 (55.0)
Sports
Low-impact sports1588 (89.5)43.0 (24.0)--1588 (89.5)43.0 (24.0)
Medium-impact sports185 (21.7)57.0 (26.0)327 (63.0)98.0 (52.0)381 (48.4)89.5 (60.0)
Swimming231 (34.9)51.0 (28.5)385 (81.6)90.8 (36.0)468 (68.6)80.0 (61.0)
Table 3 Factors predicting return to daily activities, work, and sports within 6 mo after total knee arthroplasty
ActivitynR2Predictive factorsOR (95%CI)P value
Daily activities
Night rest19010.029Sex0.734 (0.589-0.913)0.006b
ASA1.217 (0.989-1.498)0.064
Previous surgery0.829 (0.670-1.025)0.083
Operative duration0.989 (0.978-1.000)0.047a
NRS pain at rest0.912 (0.863-0.964)0.001b
NRS pain during activity1.080 (1.003-1.163)0.042a
OKS1.020 (1.002-1.038)0.030a
Walking without aids19010.033Sex0.681 (0.456-1.016)0.06
Anesthesia technique4.456 (1.232-16.120)0.023a
OKS1.054 (1.024-1.084)< 0.001b
Stair climbing19010.05BMI0.941 (0.908-0.975)< 0.001b
Sex0.499 (0.381-0.653)< 0.001b
Operative duration0.987 (0.974-1.000)0.053
OKS1.024 (1.006-1.043)0.010a
Grocery shopping19010.051Age0.960 (0.933-0.989)0.007b
BMI0.939 (0.886-0.996)0.037a
EQ-5D descriptive system0.299 (0.106-0.846)0.023a
OKS1.094 (1.052-1.137)< 0.001b
Domestic work19010.05Age0.958 (0.940-0.977)< 0.001b
BMI0.924 (0.889-0.961)< 0.001b
NRS pain during activity1.082 (0.995-1.178)0.067
OKS1.054 (1.031-1.078)< 0.001b
Putting on shoes/socks19010.067Sex2.794 (1.366-5.712)0.005b
OKS1.106 (1.052-1.163)< 0.001b
Kneeling19100.1BMI0.946 (0.917-0.976)< 0.001b
Sex0.433 (0.349-0.538)< 0.001b
Alcohol consumption1.305 (1.015-1.681)0.039a
KOOS-PS0.989 (0.978-1.001)0.083
OKS1.022 (1.000-1.044)0.048a
Driving a car18110.127Age0.966 (0.941-0.990)0.007b
Sex0.217 (0.140-0.337)< 0.001b
ASA0.678 (0.461-0.998)0.049a
Anesthesia technique3.815 (0.970-14.998)0.055
Charnley classification1.173 (0.988-1.391)0.068
OKS1.055 (1.028-1.083)< 0.001b
Outdoor cycling18060.123Age0.949 (0.931-0.967)< 0.001b
BMI0.937 (0.903-0.972)< 0.001b
Sex0.347 (0.266-0.452)< 0.001b
ASA0.763 (0.580-1.004)0.053
Charnley classification1.175 (1.041-1.326)0.009b
OKS1.032 (1.013-1.051)< 0.001b
Work
Low-impact work7650.026Age1.032 (0.999-1.065)0.054
EQ-5D descriptive system2.540 (1.150-5.612)0.021a
Medium-impact work4480.069Alcohol consumption1.497 (0.932-2.406)0.095
EQ VAS1.015 (1.004-1.027)0.007b
OKS1.030 (0.997-1.065)0.075
Sports
Low-impact sports17050.022Age1.038 (1.015-1.062)0.001b
ASA0.728 (0.519-1.021)0.066
EQ VAS1.009 (1.001-1.017)0.032a
Medium-impact sports7580.028Operative duration0.985 (0.971-1.000)0.044a
EQ VAS1.007 (0.999-1.016)0.071
OKS1.026 (1.004-1.048)0.018a
Swimming6580.013EQ-5D descriptive system0.398 (0.164-0.961)0.041a
OKS1.039 (1.007-1.071)0.016a