Comparison of variables and outcomes between Group TBW and Group PF in the original 107 patients
The variables in the TBW Group and the PF Group in the original 107 patients are shown in Table 1. There were some differences between the TBW Group and the PF Group regarding diabetes, dominant hands and the side of injury. As shown in Table 2, there was no significant difference between the TBW Group and the PF Group in terms of MEPS (91.60 (86.7,94.75) vs 92.2 (77.2,95.2), P = 0.56), flexion of elbow (144 (131,151) vs 145 (1335,153.1), P = 0.36), forearm rotation (146 (135,150) vs 145 (135,150), P = 0.72), and RTW (6 (3,9) vs 5 (3,7), P = 0.13). Interestingly, a significantly different fare was found between the TBW Group and the PF Group: the fare in PF Group was markedly higher than that in the TBW Group (23204.5 (18400, 24847) vs 11592 (9832, 17102), P < 0.001)). The total adverse events rate was higher in the TBW Group than in PF Group (75.93% vs 29.63%, P < 0.001) (Table 3). Moreover, metalwork removal rate was higher in the TBW Group than in the PF Group (48.15% vs 20.37%, P < 0.001), and other adverse events rate was higher in the PF Group than in the TBW Group (12.96% vs 9.25%, P < 0.001).
Table 1
Comparison of variables in Group TB and Group PF in the original 107 patients
| | Group | | | | |
| | TBW | PF | Total | Proportion(%) | Chi-square value/Z | P |
Sex | Men | 24 | 34 | 58 | 41.38 | 0.62 | 0.43 |
Women | 24 | 25 | 49 | 48.98 |
Age | 35(22 ~ 59.8) | 42(32 ~ 56) | | | -1.24 | 0.22 |
Occupation | Heavy worker | 13 | 16 | 29 | 44.83 | 0 | 0.99 |
No heavy worker | 35 | 43 | 78 | 44.87 |
Associated injury | None | 22 | 33 | 55 | 40.00 | 5 | 0.29 |
Ipsilateral shoulder joint injury | 5 | 9 | 14 | 35.71 |
Ipsilateral wrist joint injury | 7 | 2 | 9 | 77.78 |
Minor head injury | 8 | 9 | 17 | 47.06 |
Others | 6 | 6 | 12 | 50.00 |
Mechanism of injury | Fall from standing height | 19 | 22 | 41 | 46.34 | 2.06 | 0.73 |
Fall from height | 6 | 12 | 18 | 33.33 |
Motor vehicle collision | 11 | 15 | 26 | 42.31 |
Sports | 7 | 5 | 12 | 58.33 |
Fight/assault | 5 | 6 | 11 | 45.45 |
Diabetes | No diabetes | 39 | 56 | 95 | 88.79 | 4.96 | 0.03 |
Diabetes | 9 | 3 | 12 | 11.21 |
Dominant hand | Left hand | 0 | 6 | 6 | 0.00 | 5.17 | 0.03 |
Right hand | 48 | 53 | 101 | 47.52 |
Side of injury | Left hand | 24 | 41 | 65 | 36.92 | 4.22 | 0.048 |
Right hand | 24 | 18 | 42 | 57.14 |
ASA grade | 1 | 34 | 41 | 75 | 45.33 | -0.14 | 0.89 |
2 | 10 | 13 | 23 | 43.48 |
3 | 4 | 5 | 9 | 44.40 |
Alcohol consumption | < 21 units/wk | 42 | 55 | 97 | 43.30 | 1.02 | 0.34 |
> 21 units/wk | 6 | 4 | 10 | 60.00 |
Smoking | No smoking | 34 | 41 | 75 | 45.33 | 0.023 | 1.00 |
Smoking | 14 | 18 | 32 | 43.75 |
Fracture | May 2A | 29 | 28 | 57 | 50.88 | 1.79 | 0.24 |
May 2B | 19 | 31 | 50 | 38.00 |
BMI | 23.32 ± 3.29 | 22.47 ± 3.31 | | | 0.04 | 0.19 |
Follow period(month) | 33(14 ~ 65) | 41(16 ~ 55) | | | -0.15 | 0.89 |
Table 2
Comparison of functional effects between Group TB and Group PF in the original 107 patients
| Group | M (25%QSD`75%QSD) | Z | P |
MEPS | Tension band wiring | 91.6(86.7,94.75) | -0.59 | 0.56 |
Plate fixation | 92.2(77.2,95.2) |
Elbow flexion | Tension band wiring | 144(131,151) | -0.93 | 0.36 |
Plate fixation | 145(133.5,153.1) |
Forearm rotation | Tension band wiring | 146(135,150) | -0.37 | 0.72 |
Plate fixation | 145(135,150) |
RTW(month) | Tension band wiring | 6(3,9) | -1.53 | 0.13 |
Plate fixation | 5(3,7) |
Fare(yuan) | Tension band wiring | 11592(9832,17102) | -5.2 | < 0.001 |
Plate fixation | 23204.5(18400,24847) |
Table 3
Comparison of adverse events between Group TB and Group PF in the original 107 patients
| | TBW | PF | Total | Proportion(%) | Chi-square value/Z | P |
Adverse events | Total | 35 | 21 | 51 | 25.49 | 11.5 | < 0.001 |
Infection | 2 | 2 | 4 | 50.00 | 0.44 | 1 |
Metalwork removal | 26 | 11 | 37 | 70.27 | 11.8 | < 0.001 |
Revision | 2 | 1 | 3 | 66.67 | 0,593 | 0.59 |
Others | 5 | 7 | 12 | 41.67 | 18.44 | < 0.001 |
Comparison of functional effects and adverse events between Group TBW and Group PF in 58 patients after propensity score matching.
Propensity score matching resulted in 58 patients being matched to 29 patients in each group (Table 4). As indicated by Table 5, there was no significant difference between two groups in terms of fuctional effects, including MEPS ((93.8 (87.9,95.5) vs 92 (86.8,94.3), P = 0.93), elbow flexion (148 (135,153) vs 144 (134,151), P = 0.62), forearm rotation (145 (135,148.5) vs 148 (135,150), P = 0.5) and RTW (6 (3.5,9) vs 6 (3,9), P = 0.9) (Table 5). Interestingly, the fare was higher in Group PF than in Group TBW(23519 (17232,25424.5) vs 11943 (10201,17978), P < 0.001). However, as indicated by Table 6, total adverse events rates was higher in Group TBW than that in Group PF (79.31% vs 27.59%, P = 0.001). What’s more, metalwork removal was especially higher in Group TBW than that in Group PF (65.56% vs 17.24%, P = 0.03).
Table 4
Comparison of variables in Group TB and Group PF after propensity match scoring
| | Group | | | | |
| | TBW | PF | Sum | Odds(%) | χ2 /Z | P |
Sex | Men (%) | 14 | 18 | 32 | 43.75 | 1.12 | 0.21 |
Women (%) | 15 | 11 | 26 | 57.69 |
Occupation | No heavy labor | 20 | 20 | 40 | 50.00 | 0 | 1 |
Heavy labor | 9 | 9 | 18 | 50.00 |
Associated injury | No | 16 | 13 | 29 | 55.17 | 3.27 | 0.55* |
Ipsilateral shoulder joint injury | 3 | 5 | 8 | 37.50 |
Ipsilateral wrist joints injury | 5 | 2 | 7 | 71.43 |
Minor head injury | 3 | 6 | 9 | 33.33 |
others | 2 | 3 | 5 | 40.00 |
Mechanism of injury | Fall from standing height | 14 | 10 | 24 | 58.33 | 2.08 | 0.75* |
Fall from height | 3 | 5 | 8 | 37.50 |
Motor vehicle collision | 6 | 9 | 15 | 40.00 |
Sports | 4 | 3 | 7 | 57.14 |
Fight/assault | 2 | 2 | 4 | 50.00 |
Diabetes | No | 27 | 29 | 56 | 48.21 | 2.07 | 0.49 |
Yes | 2 | 0 | 2 | 100.00 |
Dominant hand | Right | 29 | 29 | 58 | 50.00 | constant | |
Side of injury | Left | 19 | 17 | 36 | 52.78 | 0.29 | 0.79 |
Right | 10 | 12 | 22 | 45.45 |
Alcohol consumption | < 21 units/wk | 28 | 26 | 54 | 51.85 | 1.07 | 0.61* |
> 21 units/wk | 1 | 3 | 4 | 25.00 |
Smoking | No | 22 | 20 | 42 | 52.38 | 0.35 | 0.78 |
Yes | 7 | 9 | 16 | 43.75 |
Fracture | Mayo 2A | 17 | 16 | 33 | 51.52 | 0.07 | 1 |
Mayo 2B | 12 | 13 | 25 | 48.00 |
ASA_grade | 1(1,1.5) | 1(1,1) | | | -0.23 | 0.97# |
Age | 33(22,51) | 38(30,55.5) | | | -1.386 | 0.17# |
BMI | 22.33(20.85,25.05) | 22.9(19.14,25.15) | | | -0.156 | 0.88# |
Follow period | 39(15,65) | 42(22,53) | | | -0.288 | 0.78# |
Table 5
Compassion of functional effects between Group TB and Group PF after propensity match scoring
| | M(25%QSD,75%QSD) | Z | P |
MEPS | PF | 93.8(87.9,95.5) | -0.09 | 0.93 |
TB | 92(86.8,94.3) |
Elbow of flexion | PF | 148(135,153) | -0.51 | 0.62 |
TBW | 144(134,151) |
Fore arm rotation | PF | 145(135,148.5) | -0.69 | 0.50 |
TBW | 148(135,150) |
RTW (months) | PF | 6(3.5,9) | -0.14 | 0.90 |
TBW | 6(3,9) |
Fare(yuan) | PF | 23519(17232,25424.5) | -3.13 | < 0.001 |
TBW | 11943(10201,17978) |
Table 6
Comparison of adverse events between Group TB and Group PF after propensity match scoring
| PF | TBW | Chi-square value | P |
Total complications (%) | 8(27.59) | 23(79.31) | | 0.001 |
Infection(%) | 0 | 1 | 1.018* | 1 |
Metalwork removal (%) | 5(17.24) | 19(65.56) | | 0.03 |
Revision(%) | 1(34.48) | 1(34.48) | | 1 |
Other complication(%) | 2(6.90) | 2(6.90) | | 1 |
Univariate analysis and multivariate analysis of variables relating to treatment efficacy in 58 patients after propensity match scoring
As indicated by Table 7 and Table 8, the results of univariate analysis of the propensity match scoring revealed that fracture type was significantly correlated with treatment efficacy (as indicated by an excellent MEPS). A multivariate analysis revealed that fracture type was an independent factor that affected the efficacy (regression coefficient=-1.24 < 0, P = 0.03), indicating that fracture severity was inversely proportional to the efficacy of the treatment method for an olecranon fracture. The Mayo 2B efficacy rate was 29% of the Mayo 2A efficacy rate in terms of excellent MEPS.
Table 7
Univariate analysis of variables relating to treatment efficacy in 58 patients after propensity match scoring
| | Excellent | Not excellent | Odds(%) | χ2/Z/F | P |
Sex | Men | 18 | 14 | 54.5 | 0.01 | 1.00 |
Women | 15 | 11 | 45.5 |
Occupation | No heavy labor | 21 | 19 | 63.6 | 1.02 | 0.31 |
Heavy labor | 12 | 6 | 36.4 |
Associated injury | No | 14 | 15 | 42.4 | 2.35 | 0.71* |
Ipsilateral shoulder joint injury | 6 | 2 | 18.2 |
Ipsilateral wrist joints injury | 4 | 3 | 12.1 |
Minor head injury | 6 | 3 | 18.2 |
Others | 3 | 2 | 9.1 |
Mechanism of injury | Fall from standing height | 13 | 11 | 39.4 | 0.95 | 0.95* |
Fall from height | 4 | 4 | 12.1 |
Motor vehicle collision | 9 | 6 | 27.3 |
Sports | 4 | 3 | 12.1 |
Fight/Assault | 3 | 3 | 9.1 |
Diabetes | No | 31 | 25 | 93.9 | 1.57 | 0.501* |
Yes | 2 | 0 | 6.1 |
Dominant hand | Right hand | 33 | 25 | 56.9 | constant | |
Side of injury | Left hand | 19 | 17 | 57.6 | 0.66 | 0.59 |
Right hand | 14 | 8 | 42.4 |
Alcohol consumption | < 21 units/wk | 32 | 22 | 97 | 1.78 | 0.305* |
> 21 units/wk | 1 | 3 | 3 |
Smoking | No | 26 | 16 | 78.8 | 1.56 | 0.25 |
Yes | 7 | 9 | 21.2 |
Group | TBW | 15 | 14 | 45.5 | 0.63 | 0.60 |
PF | 18 | 11 | 54.5 |
Fracture | Mayo 2A | 23 | 10 | 69.7 | 5.12 | 0.03 |
Mayo 2B | 10 | 15 | 30.3 |
Age | 36(25.5,51) | 37(22.5,55) | | | -0.20 | 0.838△ |
ASA grade | 1(1,1) | 1(1,1.5) | | | -0.34 | 0.738△ |
BMI | 22.46 ± 3.12 | 22.67 ± 3.03 | | | 0.31 | 0.58# |
Table 8
Multivariate analysis of variables relating to treatment efficacy in 58 patients after propensity match scoring
| B | Standard error | Wald | DOF | P | OR | 95% confidence interval of OR |
Low limit | Upper limit |
Fracture | Mayo 2B | -1.24 | 0.56 | 4.95 | 1.00 | 0.03 | 0.29 | 0.10 | 0.86 |
Mayo 2A | 0.00 | | | | | 1.00 | | |
| Constant | 0.83 | 0.38 | 4.84 | 1.00 | 0.03 | 2.30 | | |
Univariate analysis and multivariate analysis of variables relating to metalwork removal in 58 patients after propensity score matching.
A univariate analysis of 58 patients after propensity score matching revealed that fracture type and age were correlated with metalwork removal (Table 9). Multivariate analysis demonstrated that group (treatment type) was an independent factor that affected metalwork removal of an olecranon fracture (regression coefficient 2.38 > 0, OR = 10.77, P < 0.01), indicating that the risk of metalwork removal in Group TBW was 10.77 times that that in Group PF. Furthermore, multivariate analysis demonstrated that age was an independent factor that affected metalwork removal (regression coefficient =-0.04 < 0, P = 0.03), indicating that for each additional year of age, the probability of metalwork removal is 96% of the probability of patients 1 year younger (Table 10). In other words, age is a protective factor against metalwork removal.
Table 9
Univariate analysis of variables relating to metalwork removal in 58 patients after propensity match scoring
| | Complication | | |
| | No | Yes | χ2/Z | P |
Sex | Men (%) | 17(53.13%) | 15(46.87%) | 1.24 | 0.27 |
Women%) | 10(38.46%) | 16(61.54%) |
Occupation | Non-heavy labor | 17(42.5%) | 23(57.5%) | 0.85 | 0.40 |
Heavy labor | 10(55.6%) | 8(44.4%) |
Associated injury | No (%) | 9(31) | 20(69) | 7.2* | 0.12 |
Ipsilateral shoulder joint Injury (%) | 6(75) | 2(25) |
Ipsilateral wrist joints injury (%) | 3(42.9) | 4(57.1) |
Minor head injury (%) | 6(66.7) | 3(33.3) |
Others (%) | 3(60) | 2(40) |
Mechanism of injury | No (%) | 13(54.2) | 11(45.8) | 1.35* | 0.90 |
Fall from standing height (%) | 3(37.5) | 5(62.5) |
Fall from height (%) | 6(40) | 9(60) |
Motor vehicle collision (%) | 3(42.9) | 4(57.1) |
Sports (%) | 2(50) | 2(50) |
Others (%) | | |
Diabetes | No (%) | 25(44.6) | 31(55.4) | 2.38* | 0.21 |
Yes (%) | 2(100) | 0(0) |
Dominant hand | Left (%) | 0(0) | 0(0) | constant# | |
Right (%) | 27(46.6) | 31(53.4) |
Side of injury | Left (%) | 15(41.7) | 21(58.3) | 0.91 | 0.42 |
Right (%) | 12(54.5) | 10(45.5) |
Alcohol consumption | < 21 units/wk (%) | 26(48.1) | 28(51.9) | 0.80 | 0.62 |
> 21 units/wk (%) |
Smoking | No (%) | 19(45.2) | 23(54.8) | 0.11 | 0.78 |
Yes (%) | 8(27) | 8(31) |
Group | TBW (%) | 6(21) | 23(79) | 15.59 | < 0.001 |
PF (%) | 21(72) | 8(18) |
Fracture | Mayo 2A (%) | 18(54.5) | 15(45.5) | 1.97 | 0.19 |
Mayo 2B (%) | 9(36) | 16(64) |
Age (QSD) | 43(33,66) | 31(22,42) | -2.794 | 0.005 |
ASA grade (QSD) | 1(1,1) | 1(1,2) | -0.815 | 0.415 |
BMI(M ± SD) | 23.02 ± 0.57 | 22.2 ± 0.56 | 1.02 | 0.99 |
Table 10
Multivariate analysis of variables relating to metalwork removal in 58 patients after propensity match scoring
| B | Standard error | Wald | DOF | P | OR | 95% confidence interval of OR |
Low limit | Upper limit |
Age | -0.04 | 0.02 | 4.86 | 1.00 | 0.03 | 0.96 | 0.93 | 1.00 |
Group TBW | 2.38 | 0.67 | 12.69 | 1.00 | < 0.01 | 10.77 | 2.91 | 39.80 |
Group PF | 0 | | | | | 1 | | |
Constant | 0.71 | 0.83 | 0.73 | 1.00 | 0.39 | 2.04 | | |