Table 4.
Multivariate linear regression model predicting 3-month ROM following primary unilateral total knee arthroplasty.
| Variable | Count % of variable (n) | Adjusted 3-month ROM (degrees) | 95% CI | P-Value |
|---|---|---|---|---|
| Discharge (ref = home) | 77 (331) | |||
| Non-Home | 23 (98) | −2.74 | −6.40 – 0.93 | 0.143 |
| Age Group (ref = <55) | 17 (74) | |||
| 55-59 | 16 (67) | 5.07 | 0.38 – 9.76 | 0.034 |
| 60-64 | 18 (79) | 4.00 | −1.20 – 9.20 | 0.131 |
| 65-69 | 21 (89) | 3.81 | −0.95 – 8.56 | 0.116 |
| 70-74 | 11 (48) | 5.66 | 0.09 – 11.23 | 0.046 |
| 75-79 | 9 (40) | 2.98 | −3.82 – 9.78 | 0.390 |
| 80+ | 8 (32) | 7.62 | 1.63 – 13.61 | 0.013 |
| Gender (ref = Male) | 43 (183) | |||
| Female | 57 (246) | −1.12 | −3.89 – 1.64 | 0.425 |
| Length of Stay (ref 1-2) | 36 (155) | |||
| 3 | 43 (186) | −2.82 | −5.86 – 0.23 | 0.070 |
| 4 | 13 (57) | −0.69 | −5.44 – 4.05 | 0.774 |
| 5+ | 7 (31) | 0.84 | −5.34 – 7.02 | 0.789 |
| VR-12 Pre-Op PCS (ref = 40+) | 20 (86) | |||
| 30-40 | 24 (104) | 1.36 | −2.79 – 5.51 | 0.520 |
| 20-30 | 32 (138) | 2.25 | −1.71 – 6.20 | 0.265 |
| <20 | 10 (41) | 1.52 | −3.89 – 6.93 | 0.582 |
| Surgeon (ref=Surgeon 1) | 7 (31) | |||
| Surgeon 2 | 19 (82) | 10.17 | 2.82 – 17.52 | 0.007 |
| Surgeon 3 | 20 (86) | 9.62 | 2.75 – 16.50 | 0.006 |
| Surgeon 4 | 8 (33) | 4.61 | −3.17 – 12.39 | 0.245 |
| Surgeon 5 | 28 (120) | 5.74 | −1.08 – 12.56 | 0.099 |
| Surgeon 6 | 18 (77) | 6.34 | −1.14 – 13.82 | 0.097 |
| Charlson (ref=0) | 58 (250) | |||
| 1-3 | 14(59) | −1.11 | −4.90 – 2.68 | 0.565 |
| 4-5 | 21 (89) | −0.53 | −4.56 – 3.50 | 0.796 |
| 6-9 | 7 (31) | 3.26 | −0.87 – 7.39 | 0.122 |
| Pre-Op BMI Group (ref = Normal <25) | 43 (81) | |||
| Moderate Obes 30-34 | 42 (79) | −0.09 | −4.20 – 4.01 | 0.965 |
| Morbidly Obes 40+ | 16 (30) | 1.44 | −4.12 – 6.99 | 0.612 |
| Pre-Op ROM Group (ref = >110) | 43 (103) | |||
| 90-110 | 48 (115) | −5.39 | −8.81 – −1.97 | 0.002 |
| <90 | 10 (24) | −15.33 | −23.03 – −7.63 | <0.001 |
| Laterality (ref = Left) | 46 (196) | |||
| Right | 54 (233) | 0.94 | −1.65 – 3.53 | 0.476 |
Due to incomplete follow-up at 3 months, 429 of the initial surgeries are included in this Table. There was no cluster effect because no individual had complete follow-up at 3 months separately for multiple surgeries. Since this is a subpopulation of the original 738 surgeries, we are also reporting the counts.Missing values for each variable were included in the model, but not displayed. Percentages and counts may not add up to 100 and 429, respectively, due to missingness.