Department of Joint Surgery, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.
Chin Med J (Engl). 2013 Oct;126(20):3840-4.
This study was designed to analyze three tibial axis reference lines including the anterior tibial cortex (ATC) line, the fibular line (FL), and the anatomical axis of tibia (AAT) line, to determine which line most closely parallels the mechanical axis (MA) of the tibia in the sagittal plane. The clinical relevance of the study is that through finding a reliable landmark on the leg, a surgeon may minimize posterior tibial slope measurement errors thereby and improving the technique for assuring proper alignment of total knee arthroplasty.
The material for this study included CT scans of the tibia from 85 consecutive patients and 168 knees (78 without osteoarthritis (OA) and 90 knees with OA). Measurements of the angles between the tibial mechanical axis and each of three reference lines in the sagittal plane were carried out using 3D imaging software.
Mean angles of 168 knees were as follows: aMT (3.96±0.85)°, aMF (0.70±0.58)°, and aMA (1.40±0.66)°, (aMT: an angle between MA and ATC, aMF: an angle between MA and FL, aMA: an angle between MA and AAT. All abovementioned angles were measured in the sagittal plane of tibia) and the aMF was significantly smaller than the others (P < 0.0001). The mean value of the medial tibial slope angle vs. the MA was (9.19±3.97)°, and this was significantly larger than the mean lateral slope angle of (6.62±4.23)° (P < 0.0001). The difference between aMF without OA and with OA was not statistically significant (P = 0.5015) and the association between the aMT and aMA was strong (r = 0.82, P < 0.01).
FL was more closely parallel to the MA of tibia, and more showed less variation between OA and non- OA controls than ATC and AAT lines. Furthermore, the amount of posterior slope in medial plateau was greater than that in lateral plateau. The findings of this analysis suggest that when using the anterior tibial cortex line as is commonly done with extramedullary tibial resection guides, the tibial resection should be sloped approximately four degrees more posteriorly.
本研究旨在分析包括胫骨前皮质（ATC）线、腓骨线（FL）和胫骨解剖轴（AAT）线在内的 3 条胫骨轴线参考线，以确定哪条线在矢状面最接近胫骨的机械轴（MA）。该研究的临床意义在于，通过在腿部找到一个可靠的标志，外科医生可以最大限度地减少胫骨后倾角测量误差，从而提高确保全膝关节置换术正确对线的技术。
本研究的材料包括 85 例连续患者和 168 膝 CT 扫描（78 例无骨关节炎（OA）和 90 例膝 OA）。使用三维成像软件测量胫骨机械轴与矢状面 3 条参考线之间的角度。
168 膝平均角度如下：aMT（3.96±0.85）°、aMF（0.70±0.58）°和 aMA（1.40±0.66）°（aMT：MA 与 ATC 之间的角度，aMF：MA 与 FL 之间的角度，aMA：MA 与 AAT 之间的角度。所有上述角度均在胫骨矢状面测量），且 aMF 明显小于其他角度（P < 0.0001）。内侧胫骨斜率角与 MA 的平均值为（9.19±3.97）°，明显大于外侧斜率角的平均值（6.62±4.23）°（P < 0.0001）。OA 与非 OA 组之间的 aMF 差异无统计学意义（P = 0.5015），且 aMT 与 aMA 之间的相关性较强（r = 0.82，P < 0.01）。
FL 更接近胫骨 MA，与 OA 和非 OA 对照组相比，FL 变化较小。此外，内侧平台的后倾角大于外侧平台。本分析结果表明，当使用胫骨前皮质线（通常用于髓外胫骨切除导向器）时，胫骨切除应向后倾斜约 4 度。
