Department of Surgery, University of Colorado, Denver, Colorado.
Orlando Health Orthopaedic Surgery, Orlando, Florida.
J Bone Joint Surg Am. 2021 Jan 6;103(1):30-36. doi: 10.2106/JBJS.19.01425.
Adductor canal blocks (ACBs) are commonly employed in multimodal pain control for total knee arthroplasty (TKA) and minimize motor blockade compared with femoral nerve blocks. Quadriceps weakness may be associated with ACBs. The purpose of this study was to quantify the prevalence of clinically relevant quadriceps weakness after a single-shot ACB and to identify the factors that are associated with its diagnosis.
The study group consisted of 1,083 retrospectively reviewed consecutive TKAs that were performed with ACBs at an academic hip and knee center. Quadriceps weakness was quantified with a standardized rating system during the initial physical therapy evaluation, and 23 potential covariates were analyzed.
The prevalence of quadriceps weakness was 9%. Increasing the dose of the ACB anesthetic per unit of body mass index (BMI) increased the probability of quadriceps weakness by 5.0 times (95% confidence interval [CI], 1.9 to 13.3; p = 0.001). The highest probability of quadriceps weakness (52.9%) was associated with women who received the highest anesthetic dose per unit of BMI and an epinephrine extender but no corticosteroid extender.
The optimal volume of local anesthetic in ACBs to maintain pain control while minimizing quadriceps weakness has not yet been defined. Our observation that quadriceps weakness was associated with increasing doses of ACB anesthetic per unit of BMI suggests that more than traditional structural canal-fill parameters (i.e., filling the distal aspect of the adductor canal without spreading to the femoral triangle) should be considered when choosing injectates and injectate volumes for ACBs.
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
在全膝关节置换术（TKA）的多模式疼痛控制中，经常使用收肌管阻滞（ACB），与股神经阻滞相比，其运动阻滞最小化。股四头肌无力可能与 ACB 有关。本研究的目的是量化单次 ACB 后临床相关股四头肌无力的发生率，并确定与诊断相关的因素。
研究组包括在学术髋膝关节中心进行的 1083 例回顾性连续 TKA，均行 ACB 治疗。在初始物理治疗评估时，使用标准化评分系统量化股四头肌无力，并分析了 23 个潜在的协变量。
股四头肌无力的发生率为 9%。每单位体重指数（BMI）增加 ACB 麻醉剂量会使股四头肌无力的概率增加 5 倍（95%置信区间，1.9 至 13.3；p = 0.001）。股四头肌无力的最高概率（52.9%）与接受最高单位 BMI 麻醉剂量和肾上腺素延长剂但无皮质类固醇延长剂的女性相关。
在维持疼痛控制的同时最小化股四头肌无力的 ACB 中最佳局部麻醉剂体积尚未确定。我们观察到股四头肌无力与 ACB 麻醉剂量的增加有关，每单位 BMI 增加，这表明在选择 ACB 的注射剂和注射量时，应考虑超过传统结构管填充参数（即，填充收肌管的远端部分而不扩散到股三角）。
治疗性 IV 级。有关证据水平的完整描述，请参见作者说明。
