Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa.
Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa.
J Arthroplasty. 2018 Oct;33(10):3304-3312. doi: 10.1016/j.arth.2018.03.060. Epub 2018 Mar 30.
Obesity has been associated with varying adverse outcomes related to total knee arthroplasty (TKA) and has long been associated with various mechanical complications. Computational modeling holds promise for investigating biomechanical aberrations related to TKA in obese patients. However, basic anthropometric information regarding the shape of the lower extremity in obese patients is lacking. We, therefore, developed a method to determine lower extremity shape both generally and subject specific as a function of body mass index (BMI) and sex.
A unique set of 4 radiographs (knee anteroposterior/lateral; EOS long-leg alignment anteroposterior/lateral) were reviewed for patients with BMI exceeding 30 kg/m before undergoing TKA. Soft tissue thickness in both the coronal and sagittal planes, including anterior adipose tissue thickness overlying the tibial tubercle and patella, was measured. Elliptical parameters were then determined for any distance along the lower extremity. Additional measurements were obtained, including prepatellar thickness and pretubercular thickness and anteroposterior and mediolateral dimensions of the proximal tibia. A total of 232 obese subjects were analyzed.
Girth increased as a function of BMI. Anterior prepatellar and pretubercular subcutaneous fat thickness in females exceeded that in males for all values of BMI. Wide variation was seen with regard to overall patterns of adiposity among same-sex subjects with similar BMI. Proximal tibial osseous dimensions did not demonstrate an association with BMI; however, males were found to have deeper and wider tibias compared with females.
BMI and sex influence lower extremity shape. The prediction algorithms developed here holds implications for future biomechanical studies of TKA in obese patients.
肥胖与全膝关节置换术（TKA）相关的各种不良结果有关，并且长期以来与各种机械并发症有关。计算建模有望研究肥胖患者 TKA 相关的生物力学异常。然而，关于肥胖患者下肢形状的基本人体测量信息却缺乏。因此，我们开发了一种方法，以确定下肢的形状，通常是特定于个体的，作为体重指数（BMI）和性别的函数。
回顾了一组独特的 4 张 X 光片（膝关节前后/侧位；EOS 长腿前后/侧位），这些 X 光片用于 BMI 超过 30 kg/m 的患者，这些患者在接受 TKA 之前。测量了冠状面和矢状面的软组织厚度，包括覆盖胫骨结节和髌骨的前脂肪组织厚度。然后确定了下肢任何距离的椭圆参数。还获得了其他测量值，包括髌前厚度和髌下厚度以及胫骨近端的前后和内外径。共分析了 232 名肥胖患者。
周长随 BMI 的增加而增加。女性的前髌前和髌下皮下脂肪厚度大于男性的所有 BMI 值。对于具有相似 BMI 的同性别受试者，整体肥胖模式存在广泛的差异。胫骨近端骨尺寸与 BMI 没有关联；然而，与女性相比，男性的胫骨更深更宽。
BMI 和性别会影响下肢的形状。这里开发的预测算法对肥胖患者 TKA 的未来生物力学研究具有重要意义。
