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. 2023 Dec 18;14(12):853–867. doi: 10.5312/wjo.v14.i12.853

Table 7.

Pre-operative and post-operative impact of body mass index category on patient reported outcome measure scores: Total knee replacements



Normal (n = 8), median (IQR)
Overweight (n = 24), median (IQR)
Obese (n = 31), median (IQR)
P value1
H value
KOOS pain Pre-operative 41 (22-51) 38 (26-49) 33 (22-42) 0.230 2.936
Post-operative 97 (95-100) 92 (73-97) 88 (72-98) 0.046a 6.160
KOOS symptoms Pre-operative 32 (23-62) 38 (21-56) 32 (22-43) 0.701 0.712
Post-operative 91 (86-95) 89 (86-93) 86 (79-93) 0.129 4.098
KOOS ADL Pre-operative 40 (25-53) 38 (34-45) 40 (26-43) 0.466 1.527
Post-operative 96 (89-99) 91 (78-97) 87 (76-96) 0.214 3.079
KOOS Sport/Rec Pre-operative 5 (0-63) 8 (0-25) 5 (0-20) 0.621 0.952
Post-operative 75 (60-100) 73 (51-84) 65 (45-88) 0.582 1.083
KOOS QoL Pre-operative 19 (0-44) 19 (6-31) 6 (6-19) 0.302 2.394
Post-operative 91 (75-99) 75 (63-100) 63 (47-81) 0.032a 6.881
Overall KOOS Pre-operative 36.5 (12.1-51.1) 32.2 (20.8-43.8) 26.6 (16.7-33.7) 0.354 2.075
Post-operative 87 (80-97) 81.3 (67.2-92.0) 79.9 (64.1-84.8) 0.208 3.139
WOMAC pain Pre-operative 45 (25-54) 40 (30-50) 35 (25-50) 0.332 2.206
Post-operative 100 (95-100) 90 (75-99) 90 (79-100) 0.045a 6.186
WOMAC stiffness Pre-operative 38 (6-59) 25 (25-47) 25 (25-38) 0.704 0.702
Post-operative 100 (75-100) 75 (63-100) 75 (63-88) 0.084 4.960
WOMAC function Pre-operative 39.7 (25.0-53.3) 38.2 (34.1-45.2) 39.7 (26.5-44.1) 0.521 1.302
Post-operative 97.1 (93.0-100) 91.2 (78.3-97.1) 86.0 (75.7-97.1) 0.125 4.154
Oxford knee score Pre-operative 17 (11-23) 15 (11-19) 14 (11-19) 0.566 1.137
Post-operative 39 (38-40) 42 (33-45) 39 (33-43) 0.559 1.165
EQ-5D index Pre-operative 0.502 (0.107-0.630) 0.304 (0.215-0.479) 0.356 (0.206-0.535) 0.606 1.002
Post-operative 0.837 (0.821-1) 0.837 (0.735-1) 0.767 (0.633-0.939) 0.260 2.696
EQ-5D VAS Pre-operative 80 (65-80) 80 (50-90) 60 (50-70) 0.139 3.940
Post-operative 80 (74-85) 85 (70-95) 85 (70-90) 0.652 0.856
SF-12 PCS Pre-operative 29.6 (24.8-36.4) 28.2 (23.9-37.8) 27.2 (21.6-29.9) 0.257 2.714
Post-operative 49.0 (44.0-51.7) 46.9 (30.1-53.3) 38.5 (32.5-49.6) 0.379 1.942
SF-12 MCS Pre-operative 48.2 (38.1-54.6) 50.1 (40.0-59.6) 45.0 (38.6-54.1) 0.692 0.737
Post-operative 58.6 (53.4-60.6) 59.3 (44.2-62.3) 57.8 (51.2-60.5) 0.897 0.208
1

Kruskal Wallis H test.

a

Statistically significant P < 0.05.

KOOS: Knee Osteoarthritis Outcome Score; ADL: Activities of daily livin; Sport/Rec: Sports and recreation; QoL: Quality of life; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; EQ-5D: EuroQol-5D index; VAS: Visual Analogue Scale; SF-12: Short Form 12 item survey; PCS: Physical component summary; MCS: Mental component summary.