The Medical Device Research Institute, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.
Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Adelaide, South Australia, Australia; Centre for Orthopaedic and Trauma Research, The University of Adelaide, Adelaide, South Australia, Australia.
Osteoarthritis Cartilage. 2017 Oct;25(10):1623-1632. doi: 10.1016/j.joca.2017.06.001. Epub 2017 Jun 20.
To (1) stratify patient subgroups according to their distinct walking gait patterns in end-stage knee osteoarthritis (OA); (2) compare measures of joint loading and proximal tibia subchondral trabecular bone (STB) microarchitecture among these gait subgroups.
Twenty-five knee OA patients undergoing total knee arthroplasty (TKA) had pre-operative gait analysis. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four tibial condylar regions of interest. Peak knee moments were input to k-means cluster analysis, to identify subgroups with homogeneous gait patterns. Joint loading and STB microarchitecture parameters were compared among gait subgroups (Kruskal-Wallis, Bonferroni-corrected Mann-Whitney U tests).
Three gait subgroups were revealed: biphasics (n = 7), flexors (n = 9), counter-rotators (n = 9). Peak knee adduction moment (KAM) and KAM impulse were significantly higher (P < 0.05) in biphasics than in flexors and counter-rotators (KAM = -0.65, -0.40 and -0.21 Nm/kg, respectively), suggesting a higher medial-to-lateral tibiofemoral load ratio in biphasics. Interestingly, STB medial-to-lateral bone volume fraction (BV/TV) ratio was also significantly higher (more than double) in biphasics and flexors than in counter-rotators (2.24, 2.00 and 1.00, respectively), whereas in biphasics it was only 10% higher than in flexors and not significantly so.
Within the confines of the limited sample size, data suggests that different mechanisms between the biphasic and flexor gait subroups may generate comparable loads upon the tibial plateau and corresponding bony responses, despite significantly lower KAM indices in flexors. Hence, in flexor gait OA patients, conservative treatments designed to reduce KAM, may not be appropriate. Understanding joint loading among walking gait patterns and relationships to bone microarchitecture may aid at identifying/improving management of persons at risk for developing knee OA.
（1）根据终末期膝骨关节炎（OA）患者不同的行走步态模式对患者亚组进行分层；（2）比较这些步态亚组之间的关节负荷和胫骨近端软骨下骨小梁（STB）微观结构测量值。
25 例接受全膝关节置换术（TKA）的膝关节 OA 患者进行了术前步态分析。手术后，对切除的胫骨平台进行微 CT 扫描，并在四个胫骨髁感兴趣区域分析 STB 微观结构。将峰值膝关节力矩输入到 k-均值聚类分析中，以识别具有同质步态模式的亚组。在步态亚组之间比较关节负荷和 STB 微观结构参数（Kruskal-Wallis，Bonferroni 校正的 Mann-Whitney U 检验）。
揭示了三种步态亚组：双相步态（n=7）、屈肌步态（n=9）、对旋步态（n=9）。双相步态的峰值膝关节内收力矩（KAM）和 KAM 冲量明显高于屈肌步态和对旋步态（KAM=-0.65、-0.40 和-0.21 Nm/kg），表明双相步态中胫骨股骨的内-外侧负荷比更高。有趣的是，双相步态和屈肌步态的 STB 内-外侧骨体积分数（BV/TV）比值也明显高于对旋步态（分别为 2.24、2.00 和 1.00），而在双相步态中，其值仅比屈肌步态高 10%，且差异无统计学意义。
在样本量有限的情况下，数据表明，双相步态亚组和屈肌步态亚组之间的不同机制可能会在胫骨平台上产生类似的负荷，并产生相应的骨反应，尽管屈肌步态的 KAM 指数明显较低。因此，在屈肌步态 OA 患者中，旨在降低 KAM 的保守治疗可能并不合适。了解行走步态模式之间的关节负荷及其与骨微观结构的关系，可能有助于识别/改善有发展为膝骨关节炎风险的人的管理。
