Department of Mechanical Engineering, Columbia University, New York, NY, USA.
Department of Biomedical Engineering, Columbia University, New York, NY, USA.
J Biomech. 2022 Sep;142:111240. doi: 10.1016/j.jbiomech.2022.111240. Epub 2022 Aug 5.
Osteochondral allograft (OCA) transplantation provides a safe and effective treatment option for large cartilage defects, but its use is limited partly due to the difficulty of matching articular surface curvature between donor and recipient. We hypothesize that bendable OCAs may provide better curvature matching for patella transplants in the patellofemoral joint (PFJ). This finite element study investigates PFJ congruence for unbent and bendable OCAs, at various flexion angles. Finite element models were created for 12 femur-patella OCA pairings. Two grooves were cut in each OCA bony substrate, allowing the articular layer to bend. PFJs with either unbent (OCA) or permanently bent (BOCA) allografts were articulated from 40 to 70 degrees flexion and contact area was calculated. OCAs and BOCAs were then shifted 6 mm distally toward the tibia (S-OCA, S-BOCA) to investigate the influence of proximal-distal alignment on congruence. On average, no significant difference in contact area was found between native PFJs and either OCAs or BOCAs (p > 0.25), indicating that both types of allografts restored native congruence. This result provides biomechanical support in favor of an emerging surgical procedure. S-BOCAs resulted in a significant increase in contact area relative to the remaining groups (p < 0.02). The fact that BOCAs produced equally good results implies that bendable allografts may prove useful in future surgical procedures, with the possibility of transplanting them with a small distal shift. Surgeons who are reluctant to use OCAs for resurfacing patellae based on curvature matching capabilities may be more amenable to adopting BOCAs.
异体骨软骨移植（OCA）为治疗大面积软骨缺损提供了一种安全有效的治疗选择，但由于供体和受体关节面曲率匹配困难，其应用受到限制。我们假设可弯曲的 OCA 可能为髌股关节（PFJ）中的髌骨移植提供更好的曲率匹配。本有限元研究调查了在不同弯曲角度下未弯曲和可弯曲 OCA 的 PFJ 吻合度。为 12 个股骨-髌骨 OCA 配对创建了有限元模型。在每个 OCA 骨基质中切割两个凹槽，允许关节层弯曲。从 40 度到 70 度弯曲来铰接具有未弯曲（OCA）或永久弯曲（BOCA）同种异体移植物的 PFJ，并计算接触面积。然后将 OCA 和 BOCAs 向胫骨远端移动 6 毫米（S-OCA、S-BOCA），以研究近端-远端对准对线对吻合度的影响。平均而言，在接触面积方面，天然 PFJ 与 OCA 或 BOCAs 之间没有发现显著差异（p > 0.25），表明这两种同种异体移植物都恢复了天然吻合度。这一结果为一种新兴的手术程序提供了生物力学支持。与其余组相比，S-BOCAs 的接触面积显著增加（p < 0.02）。BOCAs 产生同样良好效果的事实意味着可弯曲同种异体移植物在未来的手术中可能会很有用，并且有可能将其与较小的远端移位一起移植。由于曲率匹配能力而不愿意使用 OCA 进行髌骨表面置换的外科医生可能更容易接受 BOCAs。
