Department of Orthopaedic Surgery, Lahey Clinic Medical Center, 41 Mall Road, Burlington, MA 01805, USA.
Clin Orthop Relat Res. 2012 Jan;470(1):108-16. doi: 10.1007/s11999-011-2124-3.
Modular, metal-backed tibial (MBT) components are associated with locking mechanism dysfunction, breakage, backside wear, and osteolysis, which compromise survivorship. All-polyethylene tibial (APT) components eliminate problems associated with MBTs, but, historically, APT utilization has generally been limited to older, less active patients. However, it is unclear whether APT utilization can be expanded to a nonselected patient population.
QUESTIONS/PURPOSES: We therefore determined the survivorship of APT components compared with MBT components in a non-age- or activity-selected population who underwent TKA.
Using a longitudinal database, we identified 775 patients with primary TKAs utilizing a single implant design between 1999 and 2007. Of these, 558 (72%) patients had APT components (APT2), while 217 (28%) patients with tibial bone loss or defects, contralateral MBT components, or a BMI of greater than 37.5 received MBT components. We determined the survivorship in the two groups. The minimum followup was 2 years for both groups (mean ± SD: MBT, 80 ± 29 months; APT, 63 ± 27 months). The APT group was older (average age: APT2, 70 years; MBT, 64.7 years) and had a lower BMI than the MBT group (APT2, 30.8; MBT, 33.8).
Survivorship, as defined by revision for any reason, was 99% for the APT group and 97% for the MBT group. There were four (2%) tibial failures in the MBT group in patients with a BMI of greater than 40. There were no revisions for loosening or osteolysis in the APT group.
APT implants perform as well as MBT implants in a non-age- or activity-selected TKA population with a BMI of less than 37.5.
模块化金属背托胫骨（MBT）组件与锁定机制功能障碍、断裂、背面磨损和骨溶解有关，这些问题会影响其存活率。全聚乙烯胫骨（APT）组件消除了与 MBT 相关的问题，但从历史上看，APT 的应用通常限于年龄较大、活动量较小的患者。然而，目前尚不清楚是否可以将 APT 的应用扩展到非选择性患者群体。
问题/目的：因此，我们在未进行年龄或活动选择的 TKA 患者中，确定了 APT 组件与 MBT 组件的存活率。
我们使用纵向数据库，确定了 1999 年至 2007 年间接受单一植入物设计的 775 例初次 TKA 患者。其中，558 例（72%）患者为 APT 组件（APT2），217 例（28%）患者因胫骨骨丢失或缺损、对侧 MBT 组件或 BMI 大于 37.5 而使用 MBT 组件。我们对两组患者进行了存活率分析。两组的最低随访时间均为 2 年（平均±标准差：MBT，80±29 个月；APT，63±27 个月）。APT 组年龄较大（APT2 组平均年龄为 70 岁；MBT 组为 64.7 岁），BMI 低于 MBT 组（APT2 组为 30.8；MBT 组为 33.8）。
以任何原因进行翻修为定义的存活率，APT 组为 99%，MBT 组为 97%。在 BMI 大于 40 的 MBT 组患者中，有 4 例（2%）胫骨失败。APT 组无松动或骨溶解的翻修。
在 BMI 小于 37.5 的非年龄或活动选择的 TKA 人群中，APT 植入物与 MBT 植入物的表现相当。
