Wide-Awake Local Anesthesia With no Tourniquet Versus General Anesthesia for the Plating of Distal Radius Fracture: A Systematic Review and Meta-Analysis

Background Distal radius fractures are treated using open reduction and internal fixation and using general anesthesia (GA) or regional blocks. A new technique, wide-awake local anesthesia with no tourniquet (WALANT), allows this operation to be conducted in nonsedated patients without the use of tourniquets. Objective We analyzed whether WALANT yields better outcomes than GA in the treatment of patients with distal radius fractures. Evidence Review We searched the PubMed, Cochrane Library, Embase, and Scopus databases for cases of distal radius fractures treated using WALANT or GA. The outcomes of interest were duration of preparation for surgery, duration of surgery, blood loss, and length of postoperative hospitalization; visual analog scale (VAS), Mayo wrist score, and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire score on postoperative day 1; range of motion (ROM); time until bone union; and complication rate. Findings We systematically reviewed 4 studies with a total of 263 patients (128 with WALANT and 135 with GA). In comparison with GA, WALANT required less time for preparation for surgery, shorter postoperative hospitalization, and lower postoperative day 1 VAS scores; however, blood loss was greater. Functional outcomes (ROM, QuickDASH score, and Mayo wrist score), complication rates, and times until union did not differ considerably between the two methods. Conclusion The included studies demonstrated that durations of preparation for surgery and postoperative hospitalization were shorter and pain on postoperative day 1 was less severe with WALANT than with GA. Although blood loss in surgery was greater with WALANT, this technique is a novel and promising alternative to GA.


HIGHLIGHTS
• A meta-analysis and systematic review compared wide-awake local anesthesia with no tourniquet (WALANT) versus general anesthesia (GA) in patients with a distal radius fracture. • WALANT is a promising alternative to GA for its reliable, cost-effective, and time-saving qualities, especially in older patients and those with various comorbidities. • Durations of preparation for surgery and postoperative hospitalization were shorter and pain on postoperative day

INTRODUCTION
Distal radius fracture, a common upper-limb injury worldwide, has a bimodal age distribution pattern: It tends to occur in young adults with high-energy trauma and in older adults with osteoporosis (1). Open reduction and internal fixation provide immediate stability to support patients' quick return to daily life and regular work. Such fixation with plates can be performed by administering regional blocks (e.g., Bier's block and brachial plexus block) or general anesthesia (GA) to patients. With both types of anesthesia, a tourniquet can be used to control bleeding and provide a clear surgical field. However, administering regional blocks is technically demanding and requires special equipment, and GA can be dangerous in patients at high risk for complications (2). A new method of administering anesthesia, wide-awake local anesthesia with no tourniquet (WALANT), was conceived by Lalonde et al. (3) The WALANT technique involves the local administration of lidocaine and epinephrine into the surgical field, thereby allowing to conduct the operation without using sedation or tourniquets (4). It is used mainly in numerous hand and wrist procedures such as trigger finger (5), carpal tunnel release (6), wrist arthroscopy for triangular fibrocartilage complex repair (7), radial forearm perforator flap (8), tendon repair or transfer (9,10), and internal fixation or implant removal for metacarpal fractures (11).
In comparison with GA, WALANT can be performed in older patients and in those with various comorbidities. Intraoperative anesthetic monitoring is not required, and hand or wrist function can be assessed in real time with the cooperation of nonsedated patients (12). Furthermore, it precludes not only postoperative pain and swelling of soft tissues caused by the tourniquet (13) but also anesthetic care after surgery and complications such as nausea and vomiting caused by GA. Therefore, WALANT is more cost-effective because postoperative hospitalization is reduced (14) and the services of anesthesiologists and preoperative testing for sedation are not required (15).
Fixation of distal radius fractures necessitates a wide surgical field and complicated bony procedures. Therefore, our concern is whether WALANT is a feasible alternative to GA in surgical treatment. To compare the effectiveness of WALANT with that of GA in surgical treatment, we conducted a systematic review and meta-analysis. The outcomes of interest were duration of preparation for surgery, duration of surgery, blood loss, and duration of postoperative hospitalization; visual analog scale (VAS) score, Mayo wrist score, and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire score on postoperative day 1; range of motion (ROM), measured by wrist flexion and wrist extension; time until bone union; and complication rate.

Search Strategy
The study was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. We searched the PubMed, the Cochrane Library, Embase, and Scopus databases for publications up to February 10, 2021, with the following search terms: "distal radius fracture," "wide-awake local anesthesia no tourniquet," and "WALANT" (search details are listed in the supplement). Randomized controlled trials (RCTs) and cohort studies were included, as were studies in which distal radius fractures were treated using a surgical intervention and WALANT or GA. Perioperative variables and clinical outcomes were included. Comments, letters, case reports, case series, editorials, proceedings, and personal communications were excluded. The search strategies are illustrated in the supplement. We also manually searched the reference lists of the relevant studies to retrieve additional studies. No language or date restriction was applied in this systematic search.
Because a meta-analysis does not involve human subjects, institutional review board review, ethical approval, and informed consent were not required.

Study Selection and Data Extraction
Studies were reviewed and selected by two independent reviewers. When study eligibility was uncertain, a third reviewer was consulted. The following information was extracted from the included studies: the name of the first author, year of publication, study design, sample size, participants' ages, follow-up period, distal radius fracture classification, WALANT solutions, injection procedure, postoperative medication regimen, and surgical outcomes.

Quality Assessment
Two independent reviewers used the Newcastle-Ottawa Scale to assess the quality of the included retrospective cohort studies in terms of the selection bias (four items), comparability bias (one item), and outcome bias (three items). With the exception of one comparability item that was rated a maximum of two stars, each item was assigned one star at most if the quality of the study was high. The highest possible rating on the Newcastle-Ottawa Scale is 9 stars. A study with a score of 8 or 9 stars was recognized as high quality; 5-7 stars, as moderate or low quality; and fewer than 5 stars, as poor quality. After reviewers independently rated all studies, any disagreements were resolved through discussion.
RCTs were appraised by the Cochrane Collaboration's Risk of Bias Tool (16) in the following six categories: (1) selection bias (use of random sequencing generation), (2) selection bias (use of allocation concealment), (3) detection bias (degree of "blinding" of outcome assessment), (4) performance bias (degree of "blinding" of participants and personnel), (5) attrition bias (presence of incomplete outcome data), and (6) reporting bias (as selective reporting). Each category was provided with one of three ratings: low, high, and unclear risk of bias. The overall risk of bias was considered low when all domains were rated as having a low risk of bias. It was considered unclear if at least one domain was considered to have an unclear risk of bias, but no domain was rated as having a high risk of bias; the overall risk of bias was otherwise considered high. After all studies were rated independently, any disagreements were resolved through discussion.

Outcome Measures
Outcomes of interest were perioperative variables and clinical outcomes such as duration of preparation for surgery, duration of surgery, blood loss, and length of postoperative hospitalization; VAS score, Mayo wrist score, and QuickDASH score on postoperative day 1; ROM, measured by wrist flexion and wrist extension; time to bone union; and complication rate.

Statistical Analysis
For the assessment of continuous data, we used mean differences (MDs) with corresponding 95% confidence intervals (CIs). For the assessment of dichotomous data, we used relative risk and 95% CIs. A p value of <0.05 was considered statistically significant. To assess the heterogeneity of the studies, we used Cochran's Q test with the Ι 2 statistic. The Ι 2 values were defined as follows: 0%-24% heterogeneity was considered low; 25%-49% heterogeneity was considered moderate; 50%-74% heterogeneity was considered high; and 75%-100% heterogeneity was considered extremely high. Because the number of studies included in the meta-analysis was small, heterogeneity tests had low statistical power (17), and because we observed heterogeneity between studies, random-effects models were conservatively applied for the meta-analysis (18). In addition, the National Research Council recommended the use of random-effects approaches for metaanalyses and the exploration of sources of variation in study results (19). Pooled effects sizes were calculated, and a twosided p value of <0.05 was considered to indicate statistical significance. We used the statistical software Comprehensive Meta-Analysis, version 3.0 (Biostat, Englewood, NJ, USA) to perform all analyses.

Search Results
We identified 42 potentially eligible studies in the initial search ( Figure 1). We excluded 22 duplicates and 9 irrelevant studies by reviewing titles and abstracts. The remaining 11 studies underwent full-text review, and 7 were excluded because they were case series or one-arm studies or had different inclusion criteria. Four studies (2,(20)(21)(22) were thus included in the systematic review. Table 1 Table 2 lists the outcomes of interest in each study. Preparation time for surgery was considerably shorter with WALANT than with GA in the studies conducted by Tahir (20); in all these studies, Mayo wrist scores, wrist flexion, wrist extension, time to bone union, and complication rates did not differ between patients who underwent surgery using WALANT and surgery using GA. The total complication rate was 0.8% after surgery using WALANT (1 of 128 patients) and 5.9% after surgery using GA (8 of 135 patients). The proportions of patients requiring revision surgery were 0.8% after initial surgery with WALANT (1 of 128 patients) and 1.5% after surgery with GA (2 of 135 patients).
a At each dot, 10 mL of the WALANT solution was injected at different angles into the volar (4 mL), lateral (2 mL) and posterior (4 mL) aspects of the radius within the periosteal layer.  (23,24) proposed waiting approximately 30 min after administering the injection to maximize hemostasis before making an incision. The widely accepted maximal dose of lidocaine that is believed to be safe for upper extremity surgery is 7 mg/kg (25). The addition of epinephrine prolongs the duration of action of lidocaine from 30-60 min to 120-360 min (26). The acidity of the solution (pH: 4.2) is likely to cause pain to the patient during injection; therefore, buffering the WALANT solution (1% Frontiers in Surgery | www.frontiersin.org 8 lidocaine with 1:100,000 epinephrine) with 8.4% sodium bicarbonate at a ratio of 1:20 to reach the physiologic pH of 7.4 was recommended (27,28). According to a Cochrane review (29), patients favor buffered lidocaine over unbuffered lidocaine. WALANT appears to be a safe, cost-effective, and timeefficient technique. Compared with GA, the primary advantages of WALANT are that (1) because a tourniquet is not required, postoperative discomfort, muscle necrosis, and nerve injury can be avoided. (2) Deep sedation is not essential; thus, recovery is faster, fewer side effects such as nausea and vomiting occur, and the anesthesia risk in older patients with multiple comorbidities is lower. (3) Patients do not need to fast overnight, which minimizes the risk of glycemic change in patients with diabetes before surgery. (4) Preoperative testing-such as blood tests, chest radiographs, electrocardiography, and medical clearance-and the services of an anesthesiologist and postoperative anesthetic care are not required, which thereby saves time and decreases costs (30). However, WALANT application was restricted in case of patients with needle phobia, peripheral vascular diseases or active infection, bleeding tendency, abnormal clotting profile, and hypersensitivity to lidocaine (2).
A mean saving of USD 1320 in health care costs, including anesthesia cost, preoperative cost, and postoperative cost, was noted in an American study in which the cost of WALANT was compared with that of GA in surgery for carpal tunnel syndrome (31). Furthermore, despite the MDs in annual household incomes between the United States and Pakistan, Tahir et al. demonstrated that WALANT costs less in hospital spending (USD 202.10; p < 0.001) compared with GA in terms of repairs of distal radius fracture in both countries (2). In contrast, Caggiano et al. (32) showed that the choice of anesthesia considerably affected total nonsurgical time, room turnover time, in-room presurgical time, and in-room postsurgical time; for instance, local Frontiers in Surgery | www.frontiersin.org anesthesia reduced the total nonsurgical time by 40% in comparison with GA. In the repair of distal radius fractures, WALANT, a safe, cost-effective, and time-efficient technique, resulted in better patient satisfaction ( p < 0.001) compared with GA (2). In this quantitative, comparative meta-analysis of four studies (two retrospective cohort studies and two RCTs) with a total of 263 patients, C2 and A2 were the most common types of distal radius fractures according to the AO/OTA classification. With WALANT, preparation for surgery and postoperative hospitalization were shorter and VAS scores on postoperative day 1 were lower, but blood loss was greater in comparison with GA. For conventional GA, an anesthesiologist and nursing staff must be available, in addition to information about the patient's medical history and vital sign monitoring equipment, before and after anesthesia induction, and the patient needs to be intubated. WALANT does not require the abovementioned staff and procedures, and surgical preparation time can thus be substantially shortened. Because a tourniquet is not used, the pain in the upper arm is reduced, and the painful swelling and ecchymosis caused by the immediate venous return after release of the tourniquet can be avoided. When pain decreases and the effects of deep sedation, including nausea, vomiting, and dizziness, do not occur, hospitalization is considerably shortened. However, no significant differences were found between the two techniques in terms of the functional outcome (ROM, QuickDASH score, and Mayo wrist score), complication rate, and time to bone union. The total complication rates were lower after surgery using WALANT (0.8%) than after surgery using GA (5.9%), and the proportions of patients requiring revision surgery using WALANT (0.8%) were lower than those using GA (1.5%).
Complications with GA occurred in three patients in the study by Yi et al. (20), who experienced nausea and vomiting for 1 day; in one patient with attrition injury and two patients with mild wound inflammation in the study by Tahir et al. (2); and in one patient with screw penetration of the wrist joint and another with distal radioulnar joint dissociation (both of whom underwent subsequent revision surgery) in the study by Hamid et al. (20). Conversely, complications with WALANT-a reduction in radial inclination and an increase in dorsal tilt, treated using revision surgery with K-wire augmentation-were noted in   one patient in the study by Yi et al.. The definitive functional outcome and complication rate after surgery should depend on the severity of the fracture in terms of whether it involves the joint surface, the appropriate selection and placement of an implant, and the reduction and surgical technique. In addition to disparate surgery-related problems, different postoperative rehabilitation protocols and medications may have contributed to the discrepancies in functional outcomes among the studies. Therefore, the present study of these two different anesthesia approaches revealed only differences in immediate recovery and pain after surgery but not in different functional outcomes and complication rates. This study had several limitations. First, the follow-up periods in most studies varied and were no more than 1 year; several outcomes and complications may have emerged during a more extended follow-up period. Second, these four studies with small sample sizes (two nonrandomized controlled studies and two randomized controlled studies with an overall high risk of bias) may have been affected by various biases and a low statistical power. Third, the high heterogeneity among studies that was observed for some outcomes may be attributable to different covariates. Incongruous distribution among different types of distal radius fractures and different WALANT solution formulas presumably resulted in heterogeneity in surgery duration and blood loss among studies. Last, despite the apparently lower complication rate using WALANT compared with GA, some of the complications that necessitated secondary revisions were associated with technical problems rather than problems associated with anesthesia. The misattribution of these complications might cause misclassification bias. There are still some distinctions in the anesthesia methods used in these included articles. Moreover, different epinephrine and xylocaine concentrations were administered. Further research is essential for further investigation and objective observations of factors such as oozing status, difficulty of reduction, patients' pain perceptions, and variation in vital signs during surgery.
In summary, this systemic review and meta-analysis demonstrated that WALANT, in comparison with GA, shortened the time required for the preparation of surgery, shortened postoperative hospitalization, and resulted in less pain 1 day after distal radius fracture fixation; however, blood loss was greater with WALANT, which is a drawback. According to some studies (2,21), even if blood loss is greater without the use of a tourniquet, it is still minimal and does not affect the operation. Otherwise, the final functional outcome and complication rates did differ considerably between the two different anesthetic approaches. Although this study showed that WALANT is a favorable alternative to GA in terms of reliability, cost-effectiveness, and time saved, each patient should be treated on a case-by-case basis because both treatments have benefits and drawbacks.

DATA AVAILABILITY STATEMENT
The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author/s.

AUTHOR CONTRIBUTIONS
Study conception and design: C-YC; Acquisition of data: T-YT; Analysis and interpretation of data: T-YT, C-YH, P-CL, C-YC; Writing (original draft preparation): T-YT; Writing (review and editing): C-YH, P-CL, C-YC; Guarantor: C-YC. All authors contributed to the article and approved the submitted version.