Table 2.
Summary of the effects of a Mg-Ca-Zn alloy pin on the growth plate.
| Follow-Up Period (weeks) |
Group | Rabbits | Physeal Height (µm) | Chondrocyte | Cell Cloning † | Physeal Discontinuity * | Femoral Segment Length | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Orientation | Density † | Percentage (%) | Width (µm) | Interposed Substance | Length (mm) (Ipsilat./Contralat.) | Ratio Compared to Control | |||||
| 3 | PEO-coated | 1 | 302.8 | orderly | 1 | 2 | - | - | - | 78/78 | 1 |
| 2 | 499.9 | orderly | 1 | 0 | - | - | - | 79/79 | 1 | ||
| 3 | 751.2 | orderly | 3 | 4 | - | - | - | 79/79 | 1 | ||
| 4 | 497.4 | orderly | 1 | 0 | - | - | - | 76/76 | 1 | ||
| 5 | 504.3 | orderly | 0 | 1 | - | - | - | 80/80 | 1 | ||
| 6 | 620.8 | orderly | 2 | 1 | - | - | - | 78/78 | 1 | ||
| Non-coated | 1 | 549.4 | orderly | 1 | 4 | - | - | - | 78/78 | 1 | |
| 2 | 631.6 | orderly | 0 | 4 | - | - | - | 79/79 | 1 | ||
| 3 | 666.1 | orderly | 1 | 0 | - | - | - | 74/74 | 1 | ||
| 4 | 630.4 | orderly | 1 | 1 | - | - | - | 76/76 | 1 | ||
| 5 | 303.3 | orderly | 1 | 4 | 1.3 | 492 | Void area (Hydrogen gas) | 77/78 | 0.99 | ||
| 6 | 270.7 | orderly | 0 | 2 | - | - | - | 79/79 | 1 | ||
| Control | (average) | 466.4 | orderly | 0 to 1 | 0 to 1 | 0.8 | 325.3 | Bone bridge | - | - | |
| 6 | PEO-coated | 1 | 403.3 | orderly | 1 | 1 | 0.9 | 511 | Bone bridge | 96/96 | 1 |
| 2 | 0 | disorderly | 2 | 0 | 2.0 | 733 | Bone bridge | 92/92 | 1 | ||
| 3 | 428.7 | orderly | 1 | 0 | 0.8 | 250 | Bone bridge | 90/90 | 1 | ||
| 4 | 706.1 | orderly | 1 | 0 | - | - | - | 99/99 | 1 | ||
| 5 | 756.6 | orderly | 1 | 0 | - | - | - | 97/97 | 1 | ||
| 6 | 441.5 | orderly | 3 | 0 | - | - | - | 79/80 | 0.99 | ||
| Non-coated | 1 | 0 | disorderly | 4 | 4 | 15.8 | 3168 | Bone bridge | 88/92 | 0.96 | |
| 2 | 0 | disorderly | 4 | 4 | 16.5 | 3656 | Bone bridge | 87/91 | 0.96 | ||
| 3 | 0 | N/C | 4 | 4 | Premature physeal arrest | 88/93 | 0.95 | ||||
| 4 | 0 | disorderly | 1 | 1 | 2.3 | 920 | Bone bridge | 89/89 | 1 | ||
| 5 | 391.1 | orderly | 1 | 4 | - | - | - | 87/87 | 1 | ||
| 6 | 333.6 | disorderly | 2 | 4 | - | - | - | 91/91 | 1 | ||
| Control | (average) | 309.7 | orderly | 0 to 1 | 0 to 1 | 0.9 | 351.7 | Bone bridge | - | - | |
| 12 | PEO-coated | 1 | 113.5 | orderly | 0 | 4 | - | - | - | 92/92 | 1 |
| 2 | 0 | disorderly | 2 | 4 | 0.2 | 103 | Bone bridge | 95/96 | 0.99 | ||
| 3 | 0 | disorderly | 2 | 4 | 0.3 | 267 | Bone bridge | 91/93 | 0.98 | ||
| 4 | 0 | disorderly | 2 | 4 | 0.5 | 444 | Bone bridge | 94/96 | 0.98 | ||
| 5 | 0 | orderly | 2 | 2 | 0.5 | 487 | Bone bridge | 96/98 | 0.98 | ||
| 6 | 136.8 | orderly | 0 | 4 | - | - | - | 93/93 | 1 | ||
| Non-coated | 1 | 0 | N/C | 4 | 4 | Premature physeal arrest | 85/96 | 0.89 | |||
| 2 | 0 | N/C | 4 | 4 | Premature physeal arrest | 89/97 | 0.92 | ||||
| 3 | 0 | N/C | 4 | 4 | Premature physeal arrest | 85/92 | 0.92 | ||||
| 4 | 0 | disorderly | 3 | 1 | 1.8 | 467 | Bone bridge | 9.1/9.1 | 1 | ||
| 5 | 0 | disorderly | 4 | 4 | 15.9 | 3487 | Bone bridge | 9.3/9.9 | 0.94 | ||
| 6 | 0 | N/C | 4 | 4 | Premature physeal arrest | 8.8/9.5 | 0.93 | ||||
| Control | (average) | 154.1 | orderly | 0 to 1 | 0 to 1 | 0.9 | 330.5 | Bone bridge | - | - | |
* Physeal discontinuity, except pin remnant, occurred in every growth plate. Premature physeal arrest was defined as the almost complete disappearance of physeal cartilage (except a trace of it in the micro-CT and histologic analyses); † Chondrocyte density and cell cloning adjacent to the insertion site were examined according to the method of the Osteoarthritis Research Society International [19].