Siddiqi Ahmed, Mahmoud Yusuf, Manrique Jorge, Molloy Robert M, Krebs Viktor E, Piuzzi Nicolas S
Orthopaedic Institute Brielle Orthopaedics, Manasquan, New Jersey.
JFK University Medical Center, Hackensack Meridian Health, Edison, New Jersey.
JBJS Rev. 2022 Feb 21;10(2):01874474-202202000-00010. doi: e21.00185.
»: As the number of primary total joint arthroplasty (TJA) procedures continues to rise, megaprostheses have found an emerging role in more complex revision arthroplasty cases that require additional reconstruction, stability, and restoration of function.
»: Megaprosthesis options have evolved: in addition to cemented prostheses, cementless and even hybrid fixation designs optimize longevity. Proximal femoral replacement (PFR), distal femoral replacement (DFR), proximal tibial replacement (PTR), and total femoral replacement (TFR) are all limb salvage options in the setting of substantial bone loss, poor bone quality, and soft-tissue compromise.
»: Dislocation is one of the most common complications after PFR, likely due to the loss of soft-tissue integrity, most notably the hip abductor musculature from the greater trochanter. The utilization of dual-mobility constructs, larger femoral heads, elevated acetabular liners, and constrained acetabular liners may reduce the risk of instability and improve overall hip function.
»: Patients with megaprostheses may be more prone to periprosthetic joint infection and surgical site infection given multiple variables, such as the lengthy nature of the surgical procedure, prolonged wound exposure, extensive soft-tissue dissection and resection, poor soft-tissue coverage, and poorer host status.
»: Despite advances in technology, complication and revision rates remain high after megaprosthesis reconstruction. Therefore, thorough attention to patient-specific factors must be considered for appropriate use of these constructs.
随着初次全关节置换术（TJA）手术数量持续增加，大型假体在需要额外重建、稳定性和功能恢复的更复杂翻修关节置换病例中发挥着越来越重要的作用。
除了骨水泥固定假体，非骨水泥甚至混合固定设计优化了使用寿命。股骨近端置换（PFR）、股骨远端置换（DFR）、胫骨近端置换（PTR）和全股骨置换（TFR）都是在大量骨质流失、骨质质量差和软组织受损情况下的肢体挽救选择。
脱位是PFR术后最常见的并发症之一，可能是由于软组织完整性丧失，最明显的是大转子处的髋外展肌。使用双动结构、更大的股骨头、抬高的髋臼衬垫和限制性髋臼衬垫可能会降低不稳定风险并改善整体髋关节功能。
考虑到多个变量，如手术时间长、伤口暴露时间延长、广泛的软组织解剖和切除、软组织覆盖差以及宿主状态较差，使用大型假体的患者可能更容易发生假体周围关节感染和手术部位感染。
尽管技术取得了进步，但大型假体重建后的并发症和翻修率仍然很高。因此，为了合理使用这些假体，必须充分考虑患者的具体因素。
