Yeo Cheng Hong, Jariwala A, Pourgiezis N, Pillai A
Division of Orthopaedics and Trauma, The Queen Elizabeth Hospital, Adelaide, SA 5011, Australia ; Department of Orthopaedic and Trauma Surgery, Toowoomba Hospital, Toowoomba, QlD, Australia.
Department of Orthopaedic and Trauma Surgery, TORT Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK.
ISRN Orthop. 2012 May 20;2012:509750. doi: 10.5402/2012/509750. eCollection 2012.
Introduction. The key to a successful total knee arthroplasty (TKA) is the restoration of the mechanical axis with balanced flexion and extension gaps. Patient-specific cutting block technique has been the latest development in total knee arthroplasty. This technique uses a magnetic resonance image (MRI) of the patient's symptomatic knee to create bone models and cutting jigs. This study was designed to evaluate the intraoperative accuracy of the patient-specific cutting block as compared to the preoperative template. Methods. Visionaire (Smith and Nephew, Genesis 2 Knee Arthroplasty) patient-specific TKA was used in all patients. An independent research officer was responsible for measuring all the resected articular surfaces of femur and tibia during surgery and compared it to the cutting block manufactured according to the preoperative template. Seven different measurements from each patient were obtained; four different measurements from the femur and three from the tibia were recorded. The differences between the actual resections made intraoperatively, as compared to the original pre-operative templates, were noted as the error. The surgical team was blinded to the measurements of the resections and the calculations of the errors. Results. Twenty-six Visionaire patient-specific TKA were included in the study. A total of 182 readings of bone resections made intraoperatively (seven for each patient). Eighty five percent of all collected readings were below the error margin of ≤1.5 mm. Size of resection had no effect on the error margin. All patients had satisfactory post-operative alignment, and at discharge all 26 patients achieved more than 90° of knee flexion. Conclusion. This observational study provides evidence that patient-specific TKA is comparable to other forms of TKA and may have some distinct advantages. In addition, we have shown that the cutting blocks are able to consistently deliver accurate cuts that are reproducible. We recommend intra-operative measurement of the bone resection and its comparison with the cutting block as a routine surgical step to confirm the MRI scan data, block placement, and instant validation of the bony resection before implant placement.
引言。全膝关节置换术（TKA）成功的关键在于通过平衡屈伸间隙来恢复机械轴。患者特异性截骨模板技术是全膝关节置换术的最新进展。该技术利用患者患膝的磁共振成像（MRI）来创建骨模型和截骨导板。本研究旨在评估与术前模板相比，患者特异性截骨模板的术中准确性。方法。所有患者均采用Visionaire（史赛克，创世纪2膝关节置换系统）患者特异性TKA。一名独立的研究人员负责在手术过程中测量股骨和胫骨所有切除的关节面，并将其与根据术前模板制作的截骨模板进行比较。从每位患者获得七种不同的测量值；记录了股骨的四种不同测量值和胫骨的三种测量值。术中实际切除值与原始术前模板之间的差异被记为误差。手术团队对切除测量值和误差计算结果不知情。结果。本研究纳入了26例Visionaire患者特异性TKA。术中总共进行了182次骨切除测量（每位患者7次）。所有收集的测量值中有85%低于≤1.5毫米的误差范围。切除尺寸对误差范围没有影响。所有患者术后对线情况均令人满意，出院时所有26例患者的膝关节屈曲均超过90°。结论。这项观察性研究提供了证据，表明患者特异性TKA与其他形式的TKA相当，并且可能具有一些明显优势。此外，我们已经表明，截骨模板能够始终如一地提供可重复的精确截骨。我们建议将术中骨切除测量及其与截骨模板的比较作为常规手术步骤，以确认MRI扫描数据、模板放置以及在植入假体前对骨切除的即时验证。
