Table 2.
Characteristics of the Three Classification Groups
| “Appropriate” Mean (sd) | “Inconclusive” Mean (sd) | “Inappropriate” Mean (sd) | |
|---|---|---|---|
| Age | 69.1 (7.2) | 62.6 (8.6) | 66.4 (10.1) |
| Gender (% female) | 55.1 | 50.0 | 62.2 |
| Body Mass Index | 29.8 (5.0) | 31.1 (5.2) | 29.0 (4.1) |
| Pre-operative Morbidity Scale Score^ | |||
| WOMAC Physical Function+ | |||
| Preoperative (n = 69, 30, 45)* | 30.3 (9.0) | 30.7 (12.6) | 12.8 (9.7) |
| One-year post-operative (n = 68, 30, 44) | 12.5 (12.1) | 12.8 (13.7) | 13.6 (11.7) |
| Two-year post-operative (n = 45, 20, 32) | 9.9 (9.4) | 11.6 (13.6) | 8.1 (10.0) |
| KOOS Symptoms+ | |||
| Preoperative (n = 69, 30, 45) | 56.4 (17.2) | 45.7 (19.6) | 72.6 (17.0) |
| One-year post-operative (n = 68, 30, 45) | 73.9 (18.8) | 72.8 (20.5) | 70.7 (19.9) |
| Two-year post-operative (n = 45, 21, 32) | 82.1 (11.9) | 75.2 (17.6) | 85.2 (13.2) |
| KOOS Pain+ | |||
| Preoperative (n = 69, 30, 45) | 49.4 (14.3) | 44.9 (17.0) | 72.7 (14.3) |
| One-year post-operative (n = 67, 30, 45) | 75.8 (21.4) | 75.2 (22.1) | 75.3 (21.1) |
| Two-year post-operative (n = 45, 21, 32) | 85.7 (17.0) | 78.9 (20.5) | 86.7 (17.3) |
| Time in days from surgery to data collection# | |||
| Pre-operative visit | −167.6 (103.2) | −169.1 (100.1) | −198.8 (94.2) |
| First year post-operative visit | 204.5 (98.2) | 198.7 (101.1) | 166.8 (84.7) |
| Second year post-operative visit | 562.2 (110.3) | 553.9 (116.6) | 537.0 (95.1) |
Morbidity was quantified using the Modified Charlson Comorbidity Index (39).
The sample sizes for each outcome variable and for each year are listed for the appropriate, inconclusive and inappropriate subgroups, respectively.
A series of one-way analyses of variance procedures were used to compare the number of days for each classification for each time period. For the pre-operative visit, F2,141 =1.4, p = 0.23, for the first post-operative visit F2.140 = 2.3, p = 0.10, and for the second year visit, F2.95 = 0.5. p = 0.60.
The WOMAC Physical Function score ranges from 0 to 68 with higher scores equating to worse function. The KOOS Symptoms and Pain scales range from 0 to 100 with higher scores equating to less symptoms and less pain.