Table 3.
Results of adjusted linear regression models to assess the association between grade of lower back pain and pre- and postoperative WOMAC and SF-36 scores
| Low back pain grade | WOMAC pain* | WOMAC function* | SF-36 PCS | SF-36 MCS | ||||
|---|---|---|---|---|---|---|---|---|
| Pre-TKA | 2 years post-TKA | Pre-TKA | 2 years post-TKA | Pre-TKA | 2 years post-TKA | Pre-TKA | 2 years post-TKA | |
| Mild (VAS 0–3) | – | – | – | – | – | – | – | – |
| Moderate (VAS 4–6)† | −5.24 (−12.95 to 2.46) | 4.11 (−2.42 to 10.63) | −5.64 (−12.24 to 1.07) | 0.84 (−5.78 to 7.46) | −1.33 (−3.75 to 1.08) | −1.80 (−5.14 to 1.53) | 3.08 (−0.66 to 6.83) | 2.88 (−1.26 to 7.01) |
| Severe (VAS 7–10)† | −11.66 (−21.50 to −1.82) | 2.41 (−6.80 to 11.62) | −17.8 (−26.36 to −9.24) | 0.57 (−8.75 to 9.90) | −1.61 (−4.74 to 1.52) | −2.51 (−7.44 to 2.42) | −2.48 (−7.33 to 2.37) | −1.40 (−7.50 to 4.71) |
Data are presented as adjusted regression coefficient with 95% confidence intervals in parentheses. Regression coefficients and 95% confidence intervals with statistical significance (p < 0.05) are in bold; * the original WOMAC scores were converted to percentage scores on a worst-to-best scale; †all values are in reference to mild (VAS 0–3) scores; PCS = physical component summary; MCS = mental component summary; VAS = visual analog scale.