Department of Orthropedics and Traumatology, AUVA UKH Steiermark, Graz, Austria.
Department of Orthropedics and Traumatology, Johannes Kepler University Linz, Linz, Austria.
Knee Surg Sports Traumatol Arthrosc. 2024 Jul;32(7):1734-1742. doi: 10.1002/ksa.12178. Epub 2024 Apr 12.
When planning and delivering total knee arthroplasty (TKA), there are multiple coronal alignment strategies such as functional alignment (FA), kinematic alignment (KA), mechanical and adjusted mechanical alignment (MA, aMA). Recent three-dimensional and robotic-assisted surgery (RAS) studies have demonstrated that KA potentially better restores the trochlear anatomy than MA. The purpose of this study was to compare the restoration of the native trochlear orientation in patients undergoing RAS TKA using four different alignment strategies. It was hypothesised that FA would result in the lowest number of outliers.
This is a prospective study of 200 patients undergoing RAS-TKA with a single implant. All patients were analysed for MA and KA prebalancing, and 157 patients received aMA and 43 patients FA with intraoperative balancing. Preoperative transverse computed tomography scans were used to determine the posterior condylar axis (PCA), lateral trochlear inclination (LTI) angle, sulcus angle (SA) and anterior trochlear line (ATL) angle. Implant measurements were obtained using a photographic analysis. Intraoperative software data combined with implant data and preoperative measurements were used to calculate the differences. Outliers were defined as ≥3° of alteration. Trochlea dysplasia was defined as LTI < 12°.
Native transepicondylar PCA had a median of 2°, LTI 18°, SA 137°, ATL 4°. LTI outliers were observed in 47%-60% of cases, with KA < FA < aMA < MA. For ATL, the range of outliers was 40.5%-85%, KA < FA < aMA < MA. SA produced 81% of outliers. Of all median angle values, only LTI when using KA was not significantly altered compared to the native knee.
There is a significant alteration of trochlear orientation after TKA, regardless of the alignment strategy used. KA produced the lowest, but a substantial, number of outliers. The uniform design of implants causes the surgeon to compromise on balance in flexion versus trochlear position. The clinical relevance of this compromise requires further clinical investigations.
Level II, prospective cohort study.
在规划和实施全膝关节置换术（TKA）时，有多种冠状面对齐策略，如功能对齐（FA）、运动学对齐（KA）、机械和调整机械对齐（MA、aMA）。最近的三维和机器人辅助手术（RAS）研究表明，KA 可能比 MA 更好地恢复滑车解剖结构。本研究的目的是比较使用四种不同对齐策略在接受 RAS-TKA 的患者中恢复原生滑车方向的情况。假设 FA 会导致最少的异常值。
这是一项前瞻性研究，共纳入 200 例接受 RAS-TKA 的患者，使用单一植入物。所有患者均在预平衡时进行 MA 和 KA 分析，其中 157 例患者接受 aMA，43 例患者接受 FA 并进行术中平衡。术前横断 CT 扫描用于确定后髁轴线（PCA）、外侧滑车倾斜角（LTI）、沟角（SA）和前滑车线（ATL）角。使用摄影分析获得植入物测量值。术中软件数据与植入物数据和术前测量值相结合，用于计算差异。异常值定义为≥3°的改变。滑车发育不良定义为 LTI<12°。
原生髁间 PCA 的中位数为 2°，LTI 为 18°，SA 为 137°，ATL 为 4°。LTI 异常值在 47%-60%的病例中观察到，KA<FA<aMA<MA。对于 ATL，异常值范围为 40.5%-85%，KA<FA<aMA<MA。SA 产生 81%的异常值。在所有中位数角度值中，只有使用 KA 时的 LTI 与原生膝关节相比没有显著改变。
无论使用何种对齐策略，TKA 后滑车方向都会发生明显改变。KA 产生的异常值最少，但数量相当多。植入物的统一设计导致外科医生在膝关节弯曲与滑车位置之间平衡妥协。这种妥协的临床意义需要进一步的临床研究。
II 级，前瞻性队列研究。
