Anesthesiology Department, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College, Shuaifuyuan 1#, Dongcheng District, Beijing, 100730, China.
Orthopaedic Department, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College, Shuaifuyuan 1#, Dongcheng District, Beijing, 100730, China.
BMC Anesthesiol. 2020 Oct 9;20(1):260. doi: 10.1186/s12871-020-01165-w.
The optimal position for continuous adductor canal block (ACB) for analgesia after total knee anthroplasty (TKA) remians controversial, mainly due to high variability in the localization of the the adductor canal (AC). Latest neuroanatomy studies show that the nerve to vastus medialis plays an important role in innervating the anteromedial aspect of the knee and dives outside of the exact AC at the proximal end of the AC. Therefore, we hypothesized that continuous ACB at the proximal end of the exact AC could provide a better analgesic effect after TKA compared with that at the middle of the AC (which appeared to only block the saphenous nerve).
Sixty-two adult patients who were scheduled for a unilateral TKA were randomized to receive continuous ACB at the proximal end or middle of the AC. All patients received patient-controlled intravenous analgesia with sufentanil postoperatively. The primary outcome measure was cumulative sufentanil consumption within 24 h after the surgery, which was analyzed using Mann-Whitney U tests. P-values < 0.05 (two-sided) were considered statistically significant. The secondary outcomes included postoperative sufentanil consumption at other time points, pain at rest and during passive knee flexion, quadriceps motor strength, and other recovery related paramaters.
Sixty patients eventually completed the study (30/group). The 24-h sufentanil consumption was 0.22 μg/kg (interquartile range [IQR]: 0.15-0.40 μg/kg) and 0.39 μg/kg (IQR: 0.23-0.52 μg/kg) in the proximal end and middle groups (P = 0.026), respectively. There were no significant inter-group differences in sufentanil consumption at other time points, pain at rest and during passive knee flexion, quadriceps motor strength, and other recovery related paramaters.
Continuous ACB at the proximal end of the AC has a better opioid-sparing effect without a significant influence on quadriceps motor strength compared to that at the middle of the AC after TKA. These findings indicates that a true ACB may not produce the effective analgesia, instead, the proximal end AC might be a more suitable block to alleviate pain after TKA.
This study was registered at ClinicalTrials.gov ( NCT03942133 ; registration date: May 06, 2019; enrollment date: May 11, 2019).
连续收肌管阻滞（ACB）用于全膝关节置换术（TKA）后镇痛的最佳位置仍存在争议，主要是因为收肌管（AC）的定位存在很大差异。最新的神经解剖学研究表明，股内侧肌神经在支配膝关节前内侧方面发挥重要作用，并在 AC 的近端从确切的 AC 之外穿出。因此，我们假设与在 AC 的中间（似乎只能阻滞隐神经）相比，在确切的 AC 的近端进行连续 ACB 可以在 TKA 后提供更好的镇痛效果。
62 例择期单侧 TKA 的成年患者随机分为接受 AC 近端或中间连续 ACB 组。所有患者术后均接受舒芬太尼患者自控静脉镇痛。主要观察指标为术后 24 小时内累积舒芬太尼消耗量，采用 Mann-Whitney U 检验进行分析。P 值<0.05（双侧）认为具有统计学意义。次要观察指标包括术后其他时间点的舒芬太尼消耗量、静息和被动膝关节屈曲时的疼痛、股四头肌肌力以及其他与恢复相关的参数。
60 例患者最终完成了研究（每组 30 例）。24 小时舒芬太尼消耗量分别为 0.22μg/kg（四分位距[IQR]：0.15-0.40μg/kg）和 0.39μg/kg（IQR：0.23-0.52μg/kg），差异有统计学意义（P=0.026）。两组间其他时间点的舒芬太尼消耗量、静息和被动膝关节屈曲时的疼痛、股四头肌肌力及其他与恢复相关的参数均无显著差异。
与 TKA 后 AC 中间部位阻滞相比，AC 近端连续阻滞对阿片类药物的节省作用更好，对股四头肌肌力无明显影响。这些发现表明，真正的 ACB 可能无法产生有效的镇痛效果，相反，AC 的近端可能是缓解 TKA 后疼痛的更合适的阻滞部位。
本研究在 ClinicalTrials.gov 注册（NCT03942133；注册日期：2019 年 5 月 6 日；入组日期：2019 年 5 月 11 日）。
