Table 3.
Summary of Independent Variables [reported as Odds Ratios (95% CI); bolded and p-value included when significant]
| Category | Variable Comparison | Variable (worse outcome, if significant) | Model 1 (Englund) | Model 2 (KOOS Pain ≤ 72) | Model 3 (KOOS Pain MCID) | Model 4 (Activity Tolerance) | |||
|---|---|---|---|---|---|---|---|---|---|
| 2 Years | 6 Years | 2 Years | 6 Years | 6 Years | 6 Years | ||||
| Number of patients who satisfied criteria for each model | 655/1527 (43%) | 592/1505 (39%) | 141/1528 (9%) | 131/1504 (9%) | 169/1394 (12%) | 159/1495 (11%) | |||
| Baseline Outcome Scores | KOOS | Symptoms | 0.90 (0.69, 1.18) | 0.83 (0.69, 1.09) | 0.78 (0.45, 1.36) | 0.81 (0.45, 1.49) | 0.91 (0.59, 1.40) | 1.27 (0.78, 2.07) | |
| Pain | 0.66 (0.40, 1.07) | 0.78 (0.46, 1.32) | 0.48 (0.17, 1.36) | 0.87 (0.32, 2.37) | 1.45 (0.66, 3.18) | 1.00 (0.40, 2.51) | |||
| ADL | ADL (low) |
0.53 (0.36, 0.79) p<0.001 |
0.67*
(0.45, 0.99) p=0.117 |
0.78 (0.37, 1.62) | 0.89 (0.42, 1.89) | 1.13 (0.61, 2.07) | 0.67 (0.32, 1.41) | ||
| Sports/Rec | Sports/Rec (high) | 1.04 (0.82, 1.32) | 1.01 (0.77, 1.33) |
1.63 (1.13, 2.34) p=0.016 |
0.78 (0.53, 1.16) | 0.90 (0.63, 1.30) | 0.88 (0.60, 1.29) | ||
| Quality of Life | 0.90 (0.76, 1.06) | 0.97 (0.82, 1.15) | 0.96 (0.73, 1.27) | 1.00 (0.73, 1.36) | 0.82 (0.64, 1.04) | 0.79 (0.60, 1.04) | |||
| WOMAC | Pain | 1.18 (0.77, 1.81) | 1.09 (0.69, 1.72) | 0.68 (0.31, 1.47) | 0.46 (0.20, 1.05) | 0.63 (0.29, 1.35) | 1.03 (0.50, 2.13) | ||
| Stiffness | 0.92 (0.74, 1.15) | 0.92 (0.72, 1.16) | 1.06 (0.70, 1.59) | 1.57 (1.00, 2.47) | 1.07 (0.73, 1.58) | 0.92 (0.62, 1.36) | |||
| Patient Characteristics | Age (yrs) | Age | 0.91 (0.55, 1.51) | 0.76 (0.42, 1.37) | 1.65 (0.73, 3.71) | 1.21 (0.48, 3.05) | 0.96 (0.42, 2.17) | 1.43 (0.62, 3.28) | |
| Gender | Females : Males | Males | 1.10 (0.86, 1.40) | 1.00 (0.75, 1.33) | 0.85 (0.54, 1.34) | 0.90 (0.54, 1.51) |
0.67 (0.47, 0.96) p=0.028 |
1.46 (0.89, 2.39) | |
| BMI | BMI | Higher BMI |
1.24 (1.01, 1.53) p=0.004 |
1.28*
(1.01, 1.61) p=0.071 |
1.52 (1.04, 2.20) p=0.003 |
1.30 (0.84, 2.02) | 1.00 (0.71, 1.39) | 1.27 (0.89, 1.83) | |
| Smoking status | Current : Never | Current (compared to never) | 1.45 (0.96, 2.19) | 1.22 (0.81, 1.85) | 1.59 (0.92, 2.75) |
2.83 (1.46, 5.49) p=0.002 |
1.13 (0.62, 2.08) | 1.78 (1.00, 3.18) | |
| Quit : Never | Quitting (compared to never) |
1.66 (1.12, 2.45) p=0.011 |
0.84 (0.54, 1.32) | 0.96 (0.50, 1.83) |
1.96 (1.02, 3.75) p=0.042 |
0.59 (0.32, 1.12) | 1.03 (0.57, 1.89) | ||
| Education (years) | Years of education | Less education years | 1.04 (0.77, 1.41) | 0.80 (0.56, 1.14) | 0.63 (0.38, 1.03) |
0.43 (0.23, 0.79) p=0.022 |
0.72 (0.44, 1.16) |
0.61*
(0.39, 0.98) p=0.126 |
|
| Baseline activity level (Marx) | Marx activity score | 1.31 (0.92, 1.87) | 1.16 (0.80, 1.69) | 1.38 (0.72, 2.65) | 1.39 (0.66, 2.92) | 0.93 (0.53, 1.63) | 1.26 (0.60, 2.67) | ||
| 2 Year activity level (Marx) | Marx activity score | Low score (low activity) |
0.62 (0.48, 0.82) p=0.001 |
0.53 (0.33, 0.86) p=0.032 |
0.91 (0.64, 1.31) |
0.41 (0.26, 0.63) p<0.001 |
|||
| Surgical Factors | Previous meniscal pathology | Yes : No | No (compared to ‘yes’) | 1.48 (0.91, 2.39) | 1.23 (0.76, 1.98) | 1.11 (0.57, 2.16) | 1.13 (0.51, 2.52) |
0.43 (0.19, 0.97) p=0.041 |
1.78 (0.90, 3.51) |
| Previous articular cartilage pathology | Yes : No | 3.98 (0.95, 16.73) | 0.70 (0.20, 2.50) | 2.50 (0.70, 8.86) | 1.79 (0.46, 6.93) | 0.53 (0.08, 3.55) | 3.47 (0.58, 20.63) | ||
| Current Meniscal pathology | |||||||||
| * medial | Repair : Normal | 1.34 (0.94, 1.90) | 1.11 (0.79, 1.55) | 1.53 (0.90, 2.60) | 1.61 (0.91, 2.86) | 0.96 (0.59, 1.59) | 1.21 (0.65, 2.25) | ||
| * lateral | No tear for treatment : Normal | Normal (compared to no tx for tear) |
0.59 (0.39, 0.89) p=0.012 |
0.74 (0.50, 1.10) | 0.97 (0.50, 1.89) | 0.62 (0.28, 1.40) | 0.93 (0.52, 1.67) | 1.22 (0.65, 2.30) | |
| Current Articular cartilage pathology | |||||||||
| * medial femoral condyle (MFC) | Grade 4 : Normal/grade 1 | Grade 4 (compared with normal/grade 1) | 1.62 (0.69, 3.76) | 1.43 (0.65, 3.14) | 1.07 (0.35, 3.32) | 1.28 (0.46, 3.61) | 1.42 (0.50, 3.98) |
2.67 (1.05, 6.80) p=0.040 |
|
| * lateral femoral condyle (LFC) | Grade 2 : Normal/grade 1 | Normal/grade 1 (compared to grade 2) | 0.70 (0.47, 1.05) | 0.73 (0.48, 1.09) | 0.75 (0.36, 1.57) |
0.34 (0.14, 0.82) p=0.016 |
0.83 (0.46, 1.49) | 1.01 (0.53, 1.92) | |
| Grade 3 : Normal/grade 1 | Grade 3 (compared with normal/grade 1) | 1.78 (0.85, 3.73) |
2.58 (1.21, 5.50) p=0.014 |
1.40 (0.54, 3.62) | 1.37 (0.44, 4.29) | 1.89 (0.83, 4.32) | 1.56 (0.47, 5.19) | ||
| * medial tibial plateau (MTP) | Grades 3/4 : Normal/grade 1 | Grades 3/4 (compared with normal/grade 1) | 0.73 (0.24, 2.27) | 2.98 (0.93, 9.50) | 1.26 (0.35, 4.53) | 3.20 (0.76, 13.48) |
4.20 (1.33, 13.25) p=0.015 |
0.86 (0.17, 4.25) | |
| * lateral tibial plateau (LTP) | Grade 2 : Normal/grade 1 | Normal/grade 1 (compared to grade 2) | 0.91 (0.57, 1.46) |
0.46 (0.26, 0.82) p=0.008 |
0.41 (0.15, 1.14) | 1.24 (0.53, 2.93) | 1.15 (0.60, 2.22) | 0.56 (0.24, 1.35) | |
| * patella | Grade 2 : Normal/grade 1 | Grade 2 (compared with normal/grade 1) | 0.95 (0.63, 1.42) |
1.65 (1.06, 2.58) p=0.028 |
1.81 (0.96, 3.39) | 1.59 (0.74, 3.43) | 1.30 (0.66, 2.59) |
3.06 (1.68, 5.56) p<0.001 |
|
| Grades 3/4 : Normal/grade 1 | Grades 3/4 (compared with normal/grade 1) |
1.71 (1.04, 2.80) p=0.033 |
1.55 (0.94, 2.55) | 1.28 (0.60, 2.70) | 2.29 (0.92, 5.68) |
2.10 (1.09, 4.03) p=0.026 |
2.14 (1.07, 4.30) p=0.032 |
||
| * trochlea | Grade 2 : Normal/grade 1 | Normal/grade 1 (compared to grade 2) | 0.93 (0.52, 1.67) | 0.96 (0.54, 1.73) | 0.88 (0.37, 2.10) | 0.44 (0.14, 1.37) | 0.57 (0.22, 1.48) |
0.31 (0.12, 0.82) p=0.017 |
|
| Subsequent Surgery | Ipsilateral knee | Yes : No | yes (compared to ‘no’) |
2.31 (1.35, 3.96) p<0.001 |
2.66 (1.77, 4.01) p<0.001 |
2.20 (1.07, 4.55) p<0.001 |
3.41 (1.72, 6.75) p<0.001 |
1.94*
(1.11, 3.39) p=0.060 |
3.03 (1.59, 5.79) p<0.001 |
| Contralateral knee | Yes : No | 0.62 (0.27, 1.41) | 0.92 (0.50, 1.68) | 0.23 (0.03, 1.88) | 0.90 (0.29, 2.76) | 1.55 (0.54, 4.45) | 0.47 (0.14, 1.64) | ||
Key:
Significant values are depicted in bold
Gray shading indicates outcome is counterintuitive to what one would think
*
Although odds ratio did not cross 1, indicating significance, the p value did not reach 0.05 level of significance.
For Continuous variables, where the Odds ratio < 1.0 --- variables are inversely related.
For Categorical variables, where the Odds ratio > 1.0 --- 1st variable listed is worse than 2nd variable listed
For Categorical variables, where the Odds ratio < 1.0 --- 2nd variable listed is worse than 1st variable listed