Observational Study
Copyright ©The Author(s) 2023.
World J Orthop. Dec 18, 2023; 14(12): 853-867
Published online Dec 18, 2023. doi: 10.5312/wjo.v14.i12.853
Table 1 Patient demographics
Total knee replacement (n = 63)
Total hip replacement (n = 68)
Age (yr), mean ± SD72.1 ± 8.368.7 ± 9.4
Gender (male:female)22:4127:41
Laterality (left:right:bilateral)27:34:227:41:0
Height (m), mean ± SD1.62 ± 0.091.66 ± 0.10
Weight (kg), mean ± SD80.2 ± 15.182.6 ± 16.7
BMI (kg/m2), mean ± SD30.4 ± 4.230.0 ± 5.5
ASA median (range)2 (1-3)2 (1-3)
SCQ median (range)4 (0-15)5 (0-18)
Table 2 Comparison of pre-operative and post-operative patient reported outcome measure scores: Total knee replacement

Pre-operative (n = 63), median (IQR)
Post-operative (n = 63), median (IQR)
P value1
Z value
KOOS pain36 (25-44)92 (77 – 98)< 0.001a-6.617
KOOS symptoms36 (21-46)89 (82 – 93)< 0.001a-6.842
KOOS ADL38 (31-44)88 (78-97)< 0.001a-6.902
KOOS Sport/Rec5 (0-25)70 (50-86)< 0.001a-4.571
KOOS QoL13 (6-25)75 (56-93)< 0.001a-6.457
Overall KOOS28.9 (18.2-37.9)80.7 (64.5-89.4)< 0.001a-5.160
WOMAC pain40 (30-50)90 (80-100)< 0.001a-6.575
WOMAC stiffness25 (25-37.5)75 (63-100)< 0.001a-6.708
WOMAC function38.2 (30.9-44.1)91.2 (77.9-97.1)< 0.001a-6.625
Oxford knee score15 (11-19)40 (33-43)< 0.001a-6.618
EQ-5D index0.345 (0.211-0.548)0.821 (0.703-1)< 0.001a-6.237
EQ-5D VAS65 (50-80)83 (71-95)< 0.001a-5.323
SF-12 PCS27.6 (23.2-32.1)43.8 (33.0-50.4)< 0.001a-5.333
SF-12 MCS47.0 (39.3-56.5)58.6 (51.5-61.3)< 0.001a-3.832
Table 3 Comparison of pre-operative and post-operative patient reported outcome measure scores: Total hip replacement

Pre-operative (n = 68), median (IQR)
Post-operative (n = 68), median (IQR)
P value1
Z value
HOOS pain33 (25-40)92 (77-98)< 0.001a-4.868
HOOS symptoms38 (30-49)89 (82-93)< 0.001a-4.909
HOOS ADL37 (26-43)88 (78-97)< 0.001a-4.841
HOOS Sport/Rec19 (6-31)70 (50-86)< 0.001a-4.788
HOOS QoL19 (6-31)75 (56-93)< 0.001a-4.663
Overall HOOS28.9 (18.2-37.9)80.7 (64.5-89.4)< 0.001a-4.681
WOMAC pain40 (30-49)95 (85-100)< 0.001a-4.932
WOMAC stiffness25 (25-50)88 (75-100)< 0.001a-4.760
WOMAC function36.8 (28.3-44.1)91.9 (75.7-98.5)< 0.001a-4.864
Oxford hip score14 (10-20)42 (35-47)< 0.001a-4.912
EQ-5D index0.335 (0.169-0.533)0.857 (0.643-1)< 0.001a-4.918
EQ-5D VAS65 (50-80)90 (79-95)< 0.001a-4.357
SF-12 PCS24.8 (21.7-29.3)50.6 (36.5-55.0)< 0.001a-4.623
SF-12 MCS49.6 (39.9-58.3)57.8 (55.4-59.8)0.076-1.776
Table 4 Comparison of pre-operative and post-operative patient reported outcome measure scores: Total knee replacement vs total hip replacement

TKR (n = 63), median (IQR)
THR (n = 68), median (IQR)
P value1
Z value
U value
KOOS/HOOS
pain
Pre-operative36 (25-44)33 (25-40)0.597-0.5281755
Post-operative92 (77-98)95 (84-100)0.208-0.3701206
KOOS/HOOS
symptoms
Pre-operative36 (21-46)38 (30-49)0.415-0.4151729
Post-operative89 (82-93)90 (80-100)0.629-0.4831189
KOOS/HOOS
ADL
Pre-operative38 (31-44)37 (26-43)0.298-1.0401656
Post-operative88 (78-97)91 (76-98)0.711-0.3701206
KOOS/HOOS Sport/RecPre-operative5 (0-25)19 (6-31)0.030a-2.1641001
Post-operative70 (50-86)75 (56-100)0.158-0.141738
KOOS/HOOS QoLPre-operative13 (6-25)19 (6-31)0.106-1.6161519
Post-operative75 (56-93)84 (58-94)0.499-0.6761030
KOOS/HOOS overallPre-operative28.9 (18.2-37.9)28.0 (21.0-37.6)0.833-0.2111267
Post-operative80.7 (64.5-89.4)88.8 (72.9-95.5)0.140-1.476713
WOMAC painPre-operative40 (30-50)40 (30-49)0.984-0.021886
Post-operative90 (80-100)95 (85-100)0.297-1.041020
WOMAC stiffnessPre-operative25 (25-37.5)25 (25-50)0.583-0.551786
Post-operative75 (63-100)88 (75-100)0.309-1.021114
WOMAC functionPre-operative38.2 (30.9-44.1)36.8 (28.3-44.1)0.639-0.471798
Post-operative91.2 (77.9-97.1)91.9 (75.7-98.5)0.945-0.071151
OKS/OHSPre-operative15 (11-19)14 (10-20)0.859-0.1771826
Post-operative40 (33-43)42 (35-47)0.076-1.775932
EQ-5D indexPre-operative0.345 (0.211-0.548)0.335 (0.169-0.533)0.719-0.361761
Post-operative0.821 (0.703-1)0.857 (0.643-1)0.386-0.87988
EQ-5D VASPre-operative65 (50-80)65 (50-80)0.308-1.021579
Post-operative83 (71-95)90 (79-95)0.374-0.891019
SF-12 PCSPre-operative27.6 (23.2-32.1)24.8 (21.7-29.3)0.073-1.791308
Post-operative43.8 (33.0-50.4)50.6 (36.5-55.0)0.106-1.62690
SF-12 MCSPre-operative47.0 (39.3-56.5)49.6 (39.9-58.3)0.777-0.281574
Post-operative58.6 (51.5-61.3)57.8 (55.4-59.8)0.438-0.78784
Table 5 Comparison of pre-operative and post-operative total knee replacement patient reported outcome measure scores: Cruciate retaining vs posterior stabilised implants


Cruciate retaining (n = 36), median (IQR)
Posterior stabilised (n = 27), median (IQR)
P value1
Z value
U value
KOOS painPre-operative36 (23-44)36 (25-42)0.568-0.57445.0
Post-operative89 (69-100)94 (83-97)0.271-1.10348.5
KOOS symptomsPre-operative36 (26-53)32 (21-43)0.181-1.34390.0
Post-operative86 (80-89)89 (86-93)0.074-1.79358.5
KOOS ADLPre-operative39 (31-46)38 (29-44)0.950-0.06481.5
Post-operative88 (75-96)94 (82-97)0.292-1.05410.5
KOOS Sport/RecPre-operative5 (0-29)5 (0-25)0.721-0.36277.0
Post-operative70 (50-85)70 (60-95)0.671-0.43237.5
KOOS QoLPre-operative6 (2-25)13 (6-27)0.408-0.83411.0
Post-operative75 (56-81)75 (61-94)0.557-0.59354.5
Overall KOOSPre-operative29. 8 (20.8-36.5)27.2 (16.8-38.5)0.880-0.15286.5
Post-operative81.3 (64.0-88.8)80.7 (75.3-90.8)0.730-0.35232.0
WOMAC painPre-operative40 (30-50)35 (30-50)0.867-0.17474.0
Post-operative90 (75-100)95 (85-100)0.376-0.88363.0
WOMAC stiffnessPre-operative25 (25-47)25 (25-38)0.930-0.09480.0
Post-operative75 (63-88)75 (75-100)0.112-1.59374.5
WOMAC functionPre-operative39.0 (30.9-45.2)38.2 (29.4-44.1)0.851-0.19472.5
Post-operative88.2 (73.5-97.1)94.1 (82.4-97.0)0.286-1.07350.5
Oxford knee scorePre-operative14 (11-21)15 (12-18)0.760-0.31451.0
Post-operative41 (33-43)40 (34-44)0.794-0.26408.0
EQ-5D indexPre-operative0.322 (0.217-0.530)0.392 (0.181-0.568)0.747-0.32428.0
Post-operative0.795 (0.679-1)0.829 (0.714-1)0.885-0.15368.5
EQ-5D VASPre-operative65 (50-80)80 (53-83)0.180-1.34348.5
Post-operative85 (79-95)80 (70-86)0.151-1.44346.5
SF-12 PCSPre-operative28.1 (23.2-31.6)25.7 (23.4-32.5)0.653-0.45379.5
Post-operative43.8 (34.9-52.2)44.6 (28.3-50.9)0.572-0.57248.5
SF-12 MCSPre-operative44.0 (38.7-53.9)49.7 (41.6-57.1)0.294-1.05341.5
Post-operative57.5 (49.9-60.6)59.4 (51.4-61.6)0.306-1.02227.0
Table 6 Comparison of pre-operative and post-operative total hip replacement patient reported outcome measure scores: Cemented, uncemented and hybrid fixations


Cemented (n = 36), median (IQR)
Uncemented (n = 28), median (IQR)
Hybrid (n = 4), median (IQR)
P value1
H value
HOOS painPre-operative35 (22.4-44.6)31 (25-38)40 (33-X)0.5121.338
Post-operative95 (70-100)98 (93-100)89 (83- X)0.3322.205
HOOS symptomsPre-operative40 (30-50)35 (29-45)35 (15-X)0.5441.216
Post-operative85 (75-90)95 (85-100)73 (65-X)0.046a6.614
HOOS ADLPre-operative37 (25-43)35 (28-44)40 (35-X)0.8080.425
Post-operative91 (68-96)98 (84-100)80 (66-X)0.1763.479
HOOS Sport/RecPre-operative16 (5-27)25 (6-43)25 (19-X)0.6110.986
Post-operative75 (48-95)94 (75-100)59 (50-X)0.1114.405
HOOS QoLPre-operative19 (6-31)19 (13-38)31 (25-X)0.4011.827
Post-operative75 (50-94)88 (69-100)56 (50-X)0.2592.703
Overall HOOSPre-operative26.1 (19.7-40.0)29.7 (21.5-40.3)35.9 (25.3-X)0.8120.418
Post-operative88.4 (64.8-92.2)95.0 (79.0-98.8)71.4 (65.2-X)0.1304.086
WOMAC painPre-operative45 (25-55)35 (30-40)40 (35-X)0.4971.398
Post-operative95 (65-100)95 (90-100)90 (80-X)0.7640.538
WOMAC stiffnessPre-operative25 (25-50)25 (25-38)25 (25-X)0.9640.074
Post-operative88 (75-88)88 (75-100)69 (63-X)0.1703.540
WOMAC functionPre-operative39.7 (26.5-50.0)34.6 (29.0-44.1)39.7 (35.3-X)0.7900.472
Post-operative91.2 (67.7-95.6)98.5 (83.8-100)80.1 (66.2-X)0.1903.317
Oxford hip scorePre-operative14 (10-19)14 (11-22)19 (17-X)0.2382.872
Post-operative41 (33-46)44 (39-47)38 (34-X)0.3472.118
EQ-5D indexPre-operative0.375 (0.155-0.533)0.314 (0.217-0.535)0.604 (0.482-X)0.1284.106
Post-operative0.836 (0.592-1)1 (0.747-1)0.790 (0.580-X)0.5291.274
EQ-5D VASPre-operative65 (50-80)65 (39-80)60 (60-X)0.9380.127
Post-operative90 (70-95)90 (80-98)80 (65-X)0.7790.499
SF-12 PCSPre-operative25.0 (21.1-27.3)25.3 (21.9-31.1)24.7 (20.4-X)0.5971.030
Post-operative50.6 (32.3-54.8)53.4 (43.3-55.8)42.9 (36.4-X)0.4471.610
SF-12 MCSPre-operative49.5 (41.1-58.2)50.6 (38.7-58.6)50.7 (34.4-X)0.9800.040
Post-operative56.6 (53.7-59.8)59.2 (57.3-60.8)47.1 (36.1-X)0.1284.104
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 painPre-operative41 (22-51)38 (26-49)33 (22-42)0.2302.936
Post-operative97 (95-100)92 (73-97)88 (72-98)0.046a6.160
KOOS symptomsPre-operative32 (23-62)38 (21-56)32 (22-43)0.7010.712
Post-operative91 (86-95)89 (86-93)86 (79-93)0.1294.098
KOOS ADLPre-operative40 (25-53)38 (34-45)40 (26-43)0.4661.527
Post-operative96 (89-99)91 (78-97)87 (76-96)0.2143.079
KOOS Sport/RecPre-operative5 (0-63)8 (0-25)5 (0-20)0.6210.952
Post-operative75 (60-100)73 (51-84)65 (45-88)0.5821.083
KOOS QoLPre-operative19 (0-44)19 (6-31)6 (6-19)0.3022.394
Post-operative91 (75-99)75 (63-100)63 (47-81)0.032a6.881
Overall KOOSPre-operative36.5 (12.1-51.1)32.2 (20.8-43.8)26.6 (16.7-33.7)0.3542.075
Post-operative87 (80-97)81.3 (67.2-92.0)79.9 (64.1-84.8)0.2083.139
WOMAC painPre-operative45 (25-54)40 (30-50)35 (25-50)0.3322.206
Post-operative100 (95-100)90 (75-99)90 (79-100)0.045a6.186
WOMAC stiffnessPre-operative38 (6-59)25 (25-47)25 (25-38)0.7040.702
Post-operative100 (75-100)75 (63-100)75 (63-88)0.0844.960
WOMAC functionPre-operative39.7 (25.0-53.3)38.2 (34.1-45.2)39.7 (26.5-44.1)0.5211.302
Post-operative97.1 (93.0-100)91.2 (78.3-97.1)86.0 (75.7-97.1)0.1254.154
Oxford knee scorePre-operative17 (11-23)15 (11-19)14 (11-19)0.5661.137
Post-operative39 (38-40)42 (33-45)39 (33-43)0.5591.165
EQ-5D indexPre-operative0.502 (0.107-0.630)0.304 (0.215-0.479)0.356 (0.206-0.535)0.6061.002
Post-operative0.837 (0.821-1)0.837 (0.735-1)0.767 (0.633-0.939)0.2602.696
EQ-5D VASPre-operative80 (65-80)80 (50-90)60 (50-70)0.1393.940
Post-operative80 (74-85)85 (70-95)85 (70-90)0.6520.856
SF-12 PCSPre-operative29.6 (24.8-36.4)28.2 (23.9-37.8)27.2 (21.6-29.9)0.2572.714
Post-operative49.0 (44.0-51.7)46.9 (30.1-53.3)38.5 (32.5-49.6)0.3791.942
SF-12 MCSPre-operative48.2 (38.1-54.6)50.1 (40.0-59.6)45.0 (38.6-54.1)0.6920.737
Post-operative58.6 (53.4-60.6)59.3 (44.2-62.3)57.8 (51.2-60.5)0.8970.208
Table 8 Pre-operative and post-operative impact of body mass index category on patient reported outcome measure scores: Total hip replacements


Normal (n = 14), median (IQR)
Overweight (n = 16), median (IQR)
Obese (n = 34), median (IQR)
Morbidly obese (n = 4), median (IQR)
P value1
H value
HOOS painPre-operative38 (23-43)35 (29-44)30 (25-39)22.5 (15-X)0.4052.917
Post-operative99 (65-100)99 (86-100)93 (73-97)97 (97-97)0.3103.582
HOOS symptomsPre-operative40 (28-53)38 (25-53)40 (30-49)35 (25-X)0.7201.339
Post-operative90 (63-100)98 (69-100)85 (78-90)85 (85-85)0.7181.349
HOOS ADLPre-operative39 (23-48)38 (32-42)33 (27-43)18 (18-X)0.2773.860
Post-operative92 (67-99)98 (73-100)84 (63-96)94 (94-94)0.2943.712
HOOS Sport/RecPre-operative28 (20-31)25 (19-44)6 (0-25)13 (6-X)0.0886.536
Post-operative88 (75-100)91 (55-100)63 (34-91)75 (75-75)0.2524.090
HOOS QoLPre-operative25 (6-41)25 (19-31)19 (13-25)13 (0-X)0.4862.443
Post-operative88 (58-100)81 (53-98)69 (38-90)94 (94-94)0.3763.106
Overall HOOSPre-operative35.9 (29.9-41.7)36.0 (24.8-38.5)25.7 (20.7-33.3)25.0 (12.8-X)0.2673.950
Post-operative91.2 (88.8-100)95.1 (68.3-98.6)79.0 (60.4-90.0)89.0 (89.0-89.0)0.2564.047
WOMAC painPre-operative40 (33-63)38 (31-53)38 (30-45)25 (15-X)0.4452.673
Post-operative100 (68.8-100)100 (85-100)90 (75-98)95 (95-95)0.3323.417
WOMAC stiffnessPre-operative38 (19-50)38 (25-50)25 (25-38)25 (13-X)0.3773.099
Post-operative94 (56-100)94 (66-100)75 (75-88)75 (75-75)0.4832.459
WOMAC functionPre-operative39.7 (30.1-54.4)39.7 (32.0-43.8)33.1 (26.8-44.1)17.6 (17.6-X)0.2673.951
Post-operative91.9 (69.1-99.3)98.5 (73.2-99.6)83.8 (63.2-95.6)94.1 (94.1-94.1)0.3133.562
Oxford hip scorePre-operative23 (12-29)18 (13-22)13 (10-19)7 (5-X)0.046a8.001
Post-operative44 (35-47.75)44 (36-48)39 (31-45)47 (47-47)0.2753.882
EQ-5D indexPre-operative0.527 (0.059-0.699)0.481 (0.235-0.568)0.289 (0.210-0.420)0.169 (-0.199-X)0.3053.624
Post-operative1 (0.659-1)1 (0.685-1)0.750 (0.639-0.892)1 (1-1)0.1585.198
EQ-5D VASPre-operative60 (40-80)80 (60-85)65 (40-74)65 (40-X)0.2504.105
Post-operative93 (60-100)94 (71-100)80 (75-84)90 (90-90)0.1066.114
SF-12 PCSPre-operative31.8 (19.7-37.1)26.8 (22.5-37.9)24.1 (21.4-27.6)25.0 (21.7-X)0.3703.144
Post-operative54.8 (40.5-56.0)49.3 (36.4-55.3)43.9 (28.0-54.8)49.3 (49.3-49.3)0.5901.914
SF-12 MCSPre-operative59.5 (51.2-63.1)53.5 (39.9-61.7)47.4 (40.1-52.7)32.3 (16.7-X)0.0756.919
Post-operative57.5 (55.9-59.859.8 (55.7-60.8)57.7 (50.2-59.8)60.8 (60.8-60.8)0.3343.396