Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Badger Athletic Performance Program, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Am J Sports Med. 2022 Jul;50(9):2410-2416. doi: 10.1177/03635465221099456. Epub 2022 Jun 1.
Osteoarthritis (OA) is a significant long term concern after anterior cruciate ligament (ACL) reconstruction (ACLR). A low bone mineral density (BMD), particularly in the subchondral region, has been associated with the development of OA and is evident at the knee in patients long after ACLR. It is unknown if persistent BMD deficits are present in high level collegiate athletes.
PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate bilateral changes in the BMD of the femur and tibia from before the injury to 24 months after ACLR in collegiate athletes. We hypothesized that the BMD of both the distal femur and the proximal tibia would be significantly reduced within the surgical limb initially postoperatively but return to preinjury levels by 24 months after ACLR.
Cohort study; Level of evidence, 2.
A total of 33 Division I collegiate athletes were identified between 2010 and 2021 (13 female) who underwent total body dual-energy X-ray absorptiometry (DXA) before sustaining an ACL injury. DXA was repeated at 6, 12, and 24 months after ACLR. Linear mixed effects models assessed differences in the BMD at 5%, 15%, and 50% of the femur's length (F, F, F) and at 5%, 15%, and 50% of the tibia's length (T, T, T) within each limb from before the injury to 24 months after ACLR, reported as Tukey-adjusted values.
Compared with before the injury, the BMD at F of the surgical limb was reduced by 0.15 g/cm (SE, 0.02 g/cm) at 6 months ( < .001). The BMD at F of the surgical limb was reduced by 0.06 g/cm (SE, 0.01 g/cm), 0.09 g/cm (SE, 0.01 g/cm), and 0.09 g/cm (SE, 0.01 g/cm) at 6, 12, and 24 months, respectively (all < .001). The BMD at T of the nonsurgical limb was reduced by 0.07 g/cm (SE, 0.02 g/cm) at 12 months ( = .02) and 0.10 g/cm (SE, 0.02 g/cm) at 24 months ( = .001). The BMD at T of the surgical limb was reduced by 0.07 g/cm (SE, 0.01 g/cm) at 6 months and 0.08 g/cm (SE, 0.02 g/cm) at 12 months ( < .001).
BMD deficits at F of the surgical limb persisted out to 24 months (-7.1%) after ACLR compared with before the injury in collegiate athletes. The BMD at F and T of the surgical limb was reduced at 6 and 12 months but not at 24 months compared with preinjury levels. For the nonsurgical limb, no significant differences were detected, except for the T region at 12 months (-5.1%) and 24 months (-7.2%). The BMD at F and T of both limbs was not significantly different than preinjury levels at any time after ACLR.
前交叉韧带（ACL）重建（ACLR）后，骨关节炎（OA）是一个长期存在的问题。特别是在软骨下区域，骨密度（BMD）低与 OA 的发展有关，在 ACLR 后很长时间，患者的膝关节都有这种情况。目前尚不清楚高水平大学生运动员是否存在持续的 BMD 不足。
目的/假设：本研究的目的是评估 ACLR 后，大学生运动员在受伤前到 ACLR 后 24 个月，股骨和胫骨的 BMD 双侧变化。我们假设在手术后的最初阶段，手术侧的远端股骨和近端胫骨的 BMD 会显著降低，但在 ACLR 后 24 个月时会恢复到受伤前的水平。
队列研究；证据水平，2。
2010 年至 2021 年期间，共确定了 33 名 I 级大学运动员（13 名女性），他们在 ACL 受伤前接受了全身双能 X 射线吸收法（DXA）检查。在 ACLR 后 6、12 和 24 个月重复进行 DXA。线性混合效应模型评估了受伤前到 ACLR 后 24 个月内，每个肢体的股骨长度（F、F、F）的 5%、15%和 50%处和胫骨长度（T、T、T）的 5%、15%和 50%处的 BMD 差异，报告为 Tukey 调整值。
与受伤前相比，手术侧 F 的 BMD 在 6 个月时降低了 0.15 g/cm（SE，0.02 g/cm）（<.001）。手术侧 F 的 BMD 在 6、12 和 24 个月时分别降低了 0.06 g/cm（SE，0.01 g/cm）、0.09 g/cm（SE，0.01 g/cm）和 0.09 g/cm（SE，0.01 g/cm）（均<.001）。非手术侧 T 的 BMD 在 12 个月时降低了 0.07 g/cm（SE，0.02 g/cm）（=.02），在 24 个月时降低了 0.10 g/cm（SE，0.02 g/cm）（=.001）。手术侧 T 的 BMD 在 6 个月时降低了 0.07 g/cm（SE，0.01 g/cm），在 12 个月时降低了 0.08 g/cm（SE，0.02 g/cm）（<.001）。
与受伤前相比，大学生运动员 ACLR 后 24 个月时，手术侧 F 的 BMD 持续存在（7.1%）。与受伤前相比，手术侧 F 和 T 的 BMD 在 6 个月和 12 个月时降低，但在 24 个月时没有降低。对于非手术侧，除了 12 个月（-5.1%）和 24 个月（-7.2%）的 T 区域外，没有发现显著差异。在 ACLR 后任何时候，双侧 F 和 T 的 BMD 均未显著低于受伤前水平。
