Is There an Optimal Timing of Adductor Canal Block for Total Knee Arthroplasty?-A Retrospective Cohort Study

Comparison of Adductor Canal Block Before Versus After Total Knee Arthroplasty in Terms of Pain, Stress, and Functional Outcomes: A Double-Blinded Randomized Controlled Trial

BACKGROUND

Whether an adductor canal block (ACB) is more effective when administered before or after total knee arthroplasty (TKA) is unclear. This study compared pain, stress, and functional outcomes between patients who received the block before surgery and those who received the block after surgery.

METHODS

In this double-blinded trial, 100 patients at our hospital were randomized to receive an ACB at either 30 minutes before general anesthesia or postoperatively in the post-anesthesia care unit (PACU). All patients received periarticular local infiltration analgesia during surgery. The 2 groups were compared with respect to the primary outcome, the postoperative consumption of morphine as rescue analgesia, and in terms of the secondary outcomes, including the time from the end of surgery to the first rescue analgesia or discharge, intraoperative and postoperative stress, postoperative pain, functional recovery, the incidence of chronic pain, and complications.

RESULTS

All included patients were Asian (Chinese) in race/ethnicity. The 2 groups had similar demographic information. Compared with the postoperative ACB, the preoperative ACB was associated with significantly lower morphine consumption within the first 24 hours postoperatively and lower total morphine consumption. It was also associated with a longer time until the first rescue analgesia, lower intraoperative consumption of opioids and inhaled anesthetic, fewer episodes of hypertension during surgery, a lower rate of rescue analgesia in the PACU, lower levels of cortisol and adrenocorticotropic hormone in serum on the morning of postoperative day 1, lower pain on a visual analog scale while at rest or during motion within 12 hours postoperatively, better range of knee motion on postoperative day 1, and a lower incidence of chronic pain at 3 months postoperatively. The 2 groups did not differ significantly with respect to postoperative ambulation distance, time until discharge, or complication rates.

CONCLUSIONS

Administering an ACB before rather than after TKA may lead to lower opioid consumption during hospitalization, lower intraoperative and postoperative stress responses, better pain relief during hospitalization, and a lower incidence of chronic pain at 3 months postoperatively.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Early versus delayed postoperative adductor canal block in total knee arthroplasty

Background

We hypothesized that patients who received an adductor canal block (ACB) in the operating room following unilateral total knee arthroplasty would have a lower oral morphine milligram equivalent (MME) consumption during the postanesthesia care unit (PACU) phase 1 recovery period compared to patients who received an ACB in the PACU.

Methods

This was a retrospective cohort study of patients who underwent robotic-assisted unilateral total knee arthroplasty under general anesthesia between March 1, 2020, and February 28, 2021, and received postoperative ACB either in the operating room or the PACU.

Results

A total of 36 and 178 patients received postoperative ACB in the operating room and PACU, respectively, and had median and interquartile range MME consumption in the PACU of 22.5 (20-40) mg and 30.0 (20-40) mg (P = 0.76), respectively. Patients who had an ACB performed in the operating room and PACU had median and interquartile ranges of time spent in the PACU of 101 (75-178) minutes and 186 (125-272) minutes (P < 0.01), respectively.

Conclusion

Patients who received an ACB in the operating room did not have a lower OME consumption than patients who received an ACB in the PACU but did have a shorter PACU length of stay.

Application of Preoperative Adductor Canal Block Coupled with General Anaesthesia in Elderly Patients Undergoing Total Knee Arthroplasty

Objective

To investigate the clinical application of preoperative adductor canal block combined with general anaesthesia in elderly patients with total knee arthroplasty.

Methods

Seventy-four patients scheduled for elective TKA in Shaanxi Nuclear Industry Hospital No. 215 were selected and were assigned into group A (continuous ACB prior to the induction of anaesthesia) and group B (continuous ACB after extraction of the tracheal catheter post-operatively) according to the random number table method. Pre and postoperative plasma adrenaline and noradrenaline levels were measured; mean arterial pressure (MAP) and heart rate (HR) were recorded at the admission and the surgical skin incision; intraoperative sufentanil dosage, number of analgesic pump presses at 48 h postoperatively; postoperative adverse effects and length of stay were recorded; resting and active VAS pain scores were assessed at 4, 8, 12, 24, and 48 h postoperatively.

Results

Group B experienced a substantial increase in MAP and HR at the time of surgical skin incision, while group A registered a smaller change and a stable haemodynamic profile (P < 0.05). The plasma adrenaline and norepinephrine concentrations in group B were elevated compared to the preoperative period, differentially with group A. Group A received less intraoperative sufentanil than Group B (P < 0.05).

Conclusion

Collectively, postoperative resting VAS scores and active VAS scores remained lower in TKA patients who were subjected to preoperative and postoperative ACB, while preoperative ACB in conjunction with general anaesthesia decreased intraoperative sufentanil dosage, contained the surgical stress response, and maintained a stable intraoperative haemodynamic state, in what is probably a preferable option for elderly patients undergoing TKA. This study has served as a reference for postoperative patients to reduce their medication and for clinicians in the treatment going forward.

Improved Deep Convolutional Neural Network to Classify Osteoarthritis from Anterior Cruciate Ligament Tear Using Magnetic Resonance Imaging

Anterior cruciate ligament (ACL) tear is caused by partially or completely torn ACL ligament in the knee, especially in sportsmen. There is a need to classify the ACL tear before it fully ruptures to avoid osteoarthritis. This research aims to identify ACL tears automatically and efficiently with a deep learning approach. A dataset was gathered, consisting of 917 knee magnetic resonance images (MRI) from Clinical Hospital Centre Rijeka, Croatia. The dataset we used consists of three classes: non-injured, partial tears, and fully ruptured knee MRI. The study compares and evaluates two variants of convolutional neural networks (CNN). We first tested the standard CNN model of five layers and then a customized CNN model of eleven layers. Eight different hyper-parameters were adjusted and tested on both variants. Our customized CNN model showed good results after a 25% random split using RMSprop and a learning rate of 0.001. The average evaluations are measured by accuracy, precision, sensitivity, specificity, and F1-score in the case of the standard CNN using the Adam optimizer with a learning rate of 0.001, i.e., 96.3%, 95%, 96%, 96.9%, and 95.6%, respectively. In the case of the customized CNN model, using the same evaluation measures, the model performed at 98.6%, 98%, 98%, 98.5%, and 98%, respectively, using an RMSprop optimizer with a learning rate of 0.001. Moreover, we also present our results on the receiver operating curve and area under the curve (ROC AUC). The customized CNN model with the Adam optimizer and a learning rate of 0.001 achieved 0.99 over three classes was highest among all. The model showed good results overall, and in the future, we can improve it to apply other CNN architectures to detect and segment other ligament parts like meniscus and cartilages.

Is Prevention of Postoperative Vomiting Surgery Dependent? A Retrospective Cohort Study of Total Knee Arthroplasty

The study of postoperative nausea and vomiting (PONV) has been ongoing since the early days of general anesthesia. The search for risk factors of PONV and the development of new agents to treat PONV are the two main strategies to combat the adverse side effects of general anesthesia. Female sex, non-smoking status, a history of PONV/motion sickness, and postoperative opioid use are the four independent risk factors for PONV derived after a series of prospective studies, evidence-based systematic reviews, and meta-analyses. The two frequently asked questions that arise ask whether risk factors apply to different clinical settings and whether prevention measures of PONV can be surgery dependent. We conducted a comprehensive review of 665 patients who underwent primary total knee arthroplasty (TKA) between January and December 2019. As nausea is subjective and its measurement is not standardized, postoperative vomiting (POV) was used as a study endpoint. The exclusion criteria were desflurane anesthesia, spinal anesthesia, anesthesia without bispectral index monitoring, and day surgery. Three well-recognized risk factors, consisting of body weight, sevoflurane consumption, and postoperative opioid consumption, were not considered as independent risk factors of POV, while female sex, preoperative adductor canal block (ACB), and dexamethasone were identified as being so in this study. The risk of POV in the female sex was 2.49 times that in the male sex; however, when dexamethasone was used, this risk was reduced by >40% compared with no antiemetic use, and by >50% when patients received preoperative ACB compared with those without the block. The clinical characteristics of our TKA patients—female dominance, old age, and their fairly constant body weights that were distinct from those of other surgical patients—suggested that age may play a crucial role in determining the relative contributions of the different risk factors of POV. We concluded that risk factors of POV are dependent on clinical settings. Based on these results, it is reasonable to speculate that a surgery-dependent plan for the prevention of POV is feasible for patients in similar clinical settings.