Table 1.
Descriptive and clinical data on all patients who received a primary THA using the direct anterior approach in the period 2007–2020 in the 6 participating hospitals (n = 15,875). Values are count (%) and do not add up to total due to unknown or missing values. Smoking, Charnley score, and BMI registered since 2014.
| n (%) | Operation groups | ||||||
|---|---|---|---|---|---|---|---|
| 1–25 | 26–50 | 51–100 | 101–150 | 151–200 | >200 | Total | |
| 1,024 (6.5) | 827 (5.2) | 1,390 (8.8) | 1,111 (7.0) | 1,005 (6.3) | 10,518 (66.3) | 15,875 | |
| Age b | |||||||
| < 60 | 164 (16) | 134 (16) | 232 (17) | 189 (17) | 161 (16) | 1,984 (19) | 2,864 (18) |
| 60–74 | 554 (54) | 463 (56) | 744 (54) | 608 (55) | 520 (52) | 5,627 (54) | 8,516 (54) |
| ≥ 75 | 304 (30) | 230 (28) | 414 (30) | 313 (28) | 323 (32) | 2,907 (28) | 4,491 (28) |
| Sex | |||||||
| Male | 344 (34) | 260 (31) | 460 (33) | 373 (34) | 311 (31) | 3,569 (34) | 5,317 (34) |
| Female | 674 (66) | 566 (69) | 930 (67) | 736 (66) | 694 (69) | 6,947 (66) | 10,547 (66) |
| ASA score b | |||||||
| I | 248 (25) | 192 (24) | 313 (23) | 283 (26) | 257 (26) | 2,636 (25) | 3,929 (25) |
| II | 591 (60) | 519 (65) | 847 (62) | 656 (60) | 571 (58) | 6,418 (62) | 9,602 (62) |
| III–IV | 144 (15) | 83(11) | 197 (15) | 153 (14) | 155 (16) | 1,356 (13) | 2,088 (13) |
| Diagnosis | |||||||
| OA | 947 (94) | 762 (93) | 1,287 (93) | 1,034 (94) | 921 (92) | 9,740 (93) | 14,691 (93) |
| Non-OA | 60 (6.0) | 58 (7.1) | 98 (7.1) | 67 (6.1) | 76 (7.6) | 744 (7.1) | 1,103 (7.0) |
| Previous operation a | |||||||
| Yes | 12 (1.2) | 12 (1.5) | 28 (2.0) | 27 (2.5) | 24 (2.5) | 241 (2.3) | 344 (2.2) |
| No | 1,002 (98) | 807 (99) | 1,351 (98) | 1,072 (98) | 935 (98) | 10,142 (98) | 15,309 (98) |
| Smoking status | |||||||
| Yes | 67 (10) | 54 (11) | 125 (14) | 83 (12) | 92 (12) | 961 (11) | 1,382 (11) |
| No | 584 (90) | 441 (89) | 741 (86) | 635 (88) | 666 (88) | 7,689 (89) | 10,756 (89) |
| BMI | |||||||
| ≤ 18.5 | 5 (0.8) | 2 (0.4) | 6 (0.7) | 1 (0.1) | 9 (1.2) | 72 (0.8) | 95 (0.8) |
| > 18.5–25 | 211 (33) | 189 (38) | 312 (36) | 244 (34) | 262 (34) | 3,127 (36) | 4,345 (36) |
| > 25–30 | 287 (45) | 225 (45) | 373 (44) | 317 (44) | 337 (44) | 3,713 (42) | 5,252 (43) |
| > 30–40 | 130 (20) | 81 (16) | 160 (19) | 146 (20) | 162 (21) | 1,769 (20) | 2,448 (20) |
| > 40 | 3 (0.5) | 1 (0.2) | 6 (0.7) | 9 (1.3) | 3 (0.4) | 72 (0.8) | 94 (0.8) |
| Charnley score a | |||||||
| A | 286 (47) | 224 (47) | 375 (47) | 301 (44) | 276 (41) | 3,370 (41) | 4,832 (42) |
| B1 | 211 (34) | 170 (36) | 267 (33) | 256 (38) | 239 (36) | 2,680 (33) | 3,823 (34) |
| B2 | 104 (17) | 79 (17) | 147 (18) | 113 (17) | 148 (22) | 1,941 (24) | 2,532 (22) |
| C | 13 (2.1) | 6 (1.3) | 11 (1.4) | 10 (1.5) | 7 (1.0) | 187 (2.3) | 234 (2.0) |
| ODEP rating stem | |||||||
| < 5A | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 6 (0.1) | 6 (0.0) |
| ≥ 5A | 1,012 (99) | 819 (99) | 1,380 (99) | 1,100 (99) | 996 (99) | 10,459 (99) | 15,766 (99) |
| Unknown | 12 (1.2) | 8 (1.0) | 10 (0.7) | 11 (1.0) | 9 (0.9) | 53 (0.5) | 103 (0.6) |
| ODEP rating cup a | |||||||
| < 5A | 2 (0.2) | 1 (0.1) | 1 (0.1) | 1 (0.1) | 0 (0.0) | 663 (6.3) | 668 (4.2) |
| ≥ 5A | 1,018 (99) | 825 (100) | 1,389 (100) | 1,110 (100) | 1,001 (100) | 9,820 (93) | 15,163 (96) |
| Unknown | 4 (0.4) | 1 (0.1) | 0 (0.0) | 0 (0.0) | 4 (0.4) | 35 (0.3) | 44 (0.3) |
| Configuration stem a | |||||||
| Anatomic | 683 (67) | 558 (68) | 954 (69) | 823 (74) | 774 (77) | 8,212 (78) | 12,004 (76) |
| Shoulder | 0 (0.0) | 1 (0.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.0) |
| Other c | 341 (33) | 268 (32) | 436 (31) | 288 (26) | 231 (23) | 2,306 (22) | 3,870 (24) |
| Head size, mm a | |||||||
| 22–28 | 422 (41) | 320 (39) | 458 (33) | 349 (31) | 267 (27) | 2,276 (22) | 4,092 (26) |
| 32 | 366 (36) | 297 (36) | 595 (43) | 462 (42) | 456 (45) | 4,789 (46) | 6,965 (44) |
| 36 | 236 (23) | 210 (25) | 334 (24) | 300 (27) | 282 (28) | 3,452 (33) | 4,814 (30) |
| ≥ 38 | 0 (0.0) | 0 (0.0) | 3 (0.2) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 3 (0.0) |
| Fixation a | |||||||
| Cemented | 305 (30) | 242 (29) | 397 (29) | 263 (24) | 210 (21) | 1,959 (19) | 3,376 (21) |
| Cementless | 531 (52) | 470 (57) | 788 (57) | 700 (63) | 663 (66) | 7,390 (70) | 10,542 (67) |
| Reversed hybrid | 167 (16) | 107 (13) | 180 (13) | 138 (12) | 121 (12) | 985 (9.4) | 1,698 (11) |
| Hybrid | 11 (1.1) | 3 (0.4) | 16 (1.2) | 6 (0.5) | 9 (0.9) | 119 (1.1) | 164 (1.0) |
| Unknown | 3 (0.3) | 3 (0.4) | 4 (0.3) | 3 (0.3) | 2 (0.2) | 43 (0.4) | 58 (0.4) |
| Bearing type a | |||||||
| Metal-on-PE | 541 (53) | 388 (47) | 623 (45) | 467 (42) | 411 (41) | 3,786 (36) | 6,216 (39) |
| Cer-on-PE | 314 (31) | 290 (35) | 518 (37) | 437 (39) | 389 (39) | 3,636 (35) | 5,584 (35) |
| Cer-on-cer | 168 (16) | 137 (17) | 241 (17) | 203 (18) | 204 (20) | 2,961 (28) | 3,914 (25) |
| OxZ-on-PE | 0 (0.0) | 12 (1.5) | 7 (0.5) | 2 (0.2) | 1 (0.1) | 135 (1.3) | 157 (1.0) |
| Cer-on-metal | 1 (0.1) | 0 (0.0) | 0 (0.0) | 2 (0.2) | 0 (0.0) | 0 (0.0) | 3 (0.0) |
| Period | |||||||
| 2007–2011 | 310 (30) | 228 (28) | 231 (17) | 145 (13) | 144 (14) | 798 (7.6) | 1,856 (12) |
| 2012–2015 | 306 (30) | 249 (30) | 514 (37) | 489 (44) | 454 (45) | 3,870 (37) | 5,882 (37) |
| 2016–2019 | 408 (40) | 350 (42) | 645 (46) | 477 (43) | 407 (41) | 5,850 (56) | 8,137 (51) |
a
p < 0.0001,
b
p < 0.05.
c
Missing or cemented.
OA: osteoarthritis, ODEP: Orthopaedic Data Evaluation Panel, PE: polyethylene. Cer: ceramic.
OxZ: oxidized zirconium/oxinium.