Figure 1
A 12 × 12 transparent grid was overlayed on coronal MDCT images. Image analysis was performed in every 4 × 4 mm grid box. As an example, grid boxes D2, D3, E2, F2, G2 and H2 contained collapse-related trabecular interruption.
Figure 2
Coronal MDCT reformats of resected femoral head specimens of (A) a 59-year-old woman and (B) an 85-year-old woman, showing interface-related bone sclerosis (thick arrows) and collapse-related bone changes: cortical interruption (arrowheads), trabecular interruption (thin arrows) and bone resorption (asterisks in B).
Figure 3
(A) and (B) Coronal MDCT reformats of a resected femoral head specimen in a 62-year-old man, showing collapse-related trabecular interruption in the superficial (thin white arrows) and deep layers (thick white arrows) of the trabecular bone. Also note cortical interruption (arrowheads) and interface-related bone sclerosis (black arrows).
Table 1
Frequency of grid boxes with cortical and trabecular bone changes on coronal MDCT reformats of 14 femoral head specimens.
| R1 | R2 | ||
|---|---|---|---|
| Necrosis-relatedbone changes | Necrotic lesion | 3442/10596 (32.5%) | 3666/10596 (34.6%) |
| Trabecular sclerosis | 1111/10596 (10.5%) | 1362/10596 (12.9%) | |
| Collapse-relatedbone changes | Cortical interruption | 557/2933 (19%) | 413/2933 (14.1%) |
| Trabecular interruption | 796/10596 (7.5%) | 665/10596 (6.3%) | |
| Trabecular resorption | 331/10596 (3.1%) | 595/10596 (5.6%) |
[i] R1 and R2 represent two readers.
Table 2
Frequency of grid boxes with CRBC and with necrotic lesion in different thirds regions of the FH in the coronal plane on MDCT reformats.
| ANTERO-POSTERIOR DIRECTION | MEDIO-LATERAL DIRECTION | CRANIO-CAUDAL DIRECTION | RADIAL DIRECTION | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ANT | MID | POST | P | MED | CENT | LAT | P | SUP | MID | INF | P | SUPERFICIAL | DEEP | P | ||
| R1 | NecroticLesion* | 782/2159 (36.2%) | 1345/4354 (30.9%) | 623/2419 (25.8%) | P1 < 0.001 P2 < 0.001 P3 < 0.001 | 681/2427 (28.1%) | 1582/4345 (36.4%) | 487/2160 (22.5%) | P4 < 0.001 P5 < 0.001 P6 < 0.001 | 1713/2273 (75.4%) | 1030/4632 (22.2%) | 7/2027 (0.3%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | 823/2232 (36.9%) | 1927/6700 (28.8%) | P < 0.001 |
| Trabecularsclerosis | 324/2562 (12.6%) | 509/5134 (9.9%) | 278/2900 (9.6%) | P1 < 0.001 P2 < 0.001 P3 = 0.664 | 273/2867 (9.5%) | 587/5125 (11.45%) | 251/2604 (9.6%) | P4 = 0.007 P5 = 0.090 P6 = 0.013 | 422/2671 (15.8%) | 650/5447 (11.9%) | 39/2478 (1.6%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | 203/2621 (7.7%) | 908/7975 (11.4%) | P < 0.001 | |
| Corticalinterruption | 213/830 (25.7%) | 236/1199 (19.7%) | 108/904 (11.9%) | P1 = 0.001 P2 < 0.001 P3 < 0.001 | 131/1357 (6.7%) | 252/846 (29.8%) | 174/730 (23.8%) | P4 < 0.001 P5 < 0.001 P6 = 0.007 | 486/1388 (35%) | 71/941 (7.5%) | 0/604 (0%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | NA | NA | ||
| Trabecularinterruption | 243/2562 (9.5%) | 404/5134 (7.9%) | 149/2900 (5.1%) | P1 = 0.02 P2 < 0.001 P3 < 0.001 | 160/2867 (5.6%) | 448/5125 (8.7%) | 188/2604 (7.2%) | P4 < 0.001 P5 = 0.016 P6 = 0.023 | 693/2671 (25.9%) | 99/5447 (1.8%) | 4/2478 (0.2%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | 448/2621 (17.1%) | 348/7975 (4.4%) | P < 0.001 | |
| Trabecularresorption | 162/2562 (6.3%) | 125/5134 (2.4%) | 44/2900 (1.5%) | P1 < 0.001 P2 < 0.001 P3 = 0.007 | 59/2867 (2.1%) | 204/5125 (4%) | 68/2604 (2.6%) | P4 < 0.001 P5 = 0.221 P6 = 0.002 | 171/2671 (6.4%) | 143/5447 (2.6%) | 17/2478 (0.7%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | 50/2621 (1.9%) | 281/7975 (3.5%) | P < 0.001 | |
| R2 | NecroticLesion* | 884/2159 (40.9%) | 1323/4354 (30.4%) | 607/2419 (25.1%) | P1 < 0.001 P2 < 0.001 P3 < 0.001 | 685/2427 (28.2%) | 1585/4345 (36.5%) | 544/2160 (25.2%) | P4 < 0.001 P5 = 0.022 P6 < 0.001 | 1766/2273 (77.7%) | 1036/4632 (22.4%) | 12/2027 (0.6%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | 897/2232 (40.2%) | 1917/6700 (28.6%) | P < 0.001 |
| Trabecularsclerosis | 421/2562 (16.4%) | 616/5134 (12%) | 325/2900 (11.2%) | P1 < 0.001 P2 < 0.001 P3 = 0.284 | 332/2867 (11.6%) | 662/5125 (12.9%) | 368/2604 (14.1%) | P4 = 0.091 P5 = 0.006 P6 = 0.014 | 590/2671 (22.1%) | 732/5447 (13.4%) | 40/2478 (1.6%) | Px < 0.001 Py < 0.001 Pz < 0.001 | 317/2621 (12.1%) | 1045/7975 (13.1%) | P = 0.185 | |
| Corticalinterruption | 168/830 (20.2%) | 179/1199 (14.9%) | 66/904 (7.3%) | P1 = 0.002 P2 < 0.001 P3 < 0.001 | 112/1357 (8.3%) | 186/846 (22%) | 115/730 (15.75%) | P4 < 0.001 P5 < 0.001 P6 = 0.002 | 350/1388 (25.2%) | 60/941 (6.4%) | 3/604 (0.5%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | NA | NA | ||
| Trabecularinterruption | 228/2562 (8.9%) | 306/5134 (6%) | 131/2900 (4.5%) | P1 < 0.001 P2 < 0.001 P3 = 0.004 | 108/2867 (3.8%) | 432/5125 (8.4%) | 125/2604 (4.8%) | P4 < 0.001 P5 = 0.068 P6 < 0.001 | 582/2671 (21.8%) | 83/5447 (1.5%) | 0/2478 (0%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | 389/2621 (14.8%) | 276/7975 (3.5%) | P < 0.001 | |
| Trabecularresorption | 243/2562 (9.5%) | 248/5134 (4.8%) | 104/2900 (3.6%) | P1 < 0.001 P2 < 0.001 P3 = 0.011 | 116/2867 (4.1%) | 334/5125 (6.5%) | 145/2604 (5.6%) | P4 < 0.001 P5 = 0.01 P6 = 0.12 | 353/2671 (13.2%) | 238/5447 (4.4%) | 4/2478 (0.2%) | P7 < 0.001 P8 < 0.001 P9 < 0.001 | 110/2621 (4.2%) | 485/7975 (6.1%) | P < 0.001 | |
[i] *Frequency of grid boxes containing the necrotic lesion was calculated in 12 instead of 14 ONFH because the interface was only partially visible.
The denominators represent the total number of grid boxes in every region. (p1) Anterior versus Middle; (p2) Anterior versus Posterior; (p3) Middle versus posterior. (p4) = Medial versus Central; (p5) = Medial versus Lateral; (p6) = Central versus Lateral. (p7) = Superior versus Middle; (p8) = Superior versus Inferior; (p9) = Middle versus inferior.
Table 3
Comparison of frequency of grid boxes with CRBC on coronal MDCT reformats within or outside the osteonecrotic lesions*.
| COLLAPSE-RELATED BONE CHANGES | OUTSIDE NECROTIC LESION | WITHIN NECROTIC LESION | P VALUE | |
|---|---|---|---|---|
| R1 | Cortical bone interruption | 42/1507 (2.8%) | 415/979 (42.4%) | p < 0.001 |
| Trabecular bone interruption | 18/6182 (0.3%) | 648/2750 (23.6%) | p < 0.001 | |
| Trabecular bone resorption | 20/6182 (0.3%) | 246/2750 (8.9%) | p < 0.001 | |
| R2 | Cortical bone interruption | 24/1507 (1.6%) | 315/979 (32.2%) | p < 0.001 |
| Trabecular bone interruption | 3/6118 (0.05%) | 544/2814 (19.3%) | p < 0.001 | |
| Trabecular bone resorption | 3/6118 (0.05%) | 519/2814 (18.4%) | p < 0.001 |
[i] *Frequency of grid boxes containing the necrotic lesion was calculated in 12 instead of 14 ONFH because the interface was only partially visible.
Table 4
Comparison of frequency of grid boxes with necrotic lesions and CRBC at MDCT between ONFH with limited and advanced collapse.
| FREQUENCY OF GRID BOXES CONTAINING | R1 | R2 | ||||
|---|---|---|---|---|---|---|
| COLLAPSE <1.5 mm | COLLAPSE ≥1.5 mm | P VALUE | COLLAPSE <1.5 mm | COLLAPSE ≥1.5 mm | P VALUE | |
| Necrotic lesion | 1481/4610(32.13%) | 1961/5986(32.76%) | P = 0.503 | 1460/4610(31.67%) | 2206/5986(36.85%) | p < 0.001 |
| Interface-relatedTrabecular sclerosis | 499/4610 (10.82%) | 612/5986(10.22%) | P = 0.318 | 577/4610(12.51%) | 785/5986(13.11%) | P = 0.360 |
| Cortical bone interruption | 216/1269(17.02%) | 341/1664(20.49%) | P = 0.018 | 121/1269(9.54%) | 292/1664(17.55%) | p < 0.001 |
| Trabecular bone interruption | 369/4610(8%) | 427/5986 (7.13%) | P = 0.094 | 299/4610(6.49%) | 366/5986(6.11%) | P = 0.443 |
| Trabecular bone resorption | 99/4610(2.15%) | 232/5986(3.88%) | p < 0.001 | 214/4610(4.64%) | 381/5986(6.36%) | p < 0.001 |
| ARCO: | Association Research Circulation Osseous |
| CRBC: | collapse-related bone changes |
| FH: | femoral head |
| MDCT: | multidetector computed tomography |
| ON: | osteonecrosis |
| ONFH: | osteonecrotic femoral heads |
| µCT: | Microcomputed tomography |