WALANT vs standard anaesthesia in the management of flexor tendon injuries: A systematic review and meta-analysis

Abstract

Wide awake local anaesthesia no tourniquet (WALANT) surgery has gained increasing popularity in recent years for hand surgery fast-tracked by the COVID pandemic. It involves infiltration of lidocaine with adrenaline to the operative region ensuring a good visual field owing to the vasoconstrictive effects of epinephrine. It has numerous advantages over traditional anaesthetic (TA) for flexor tendon repairs including testing of tendon strength on table as well as immediate revision of the repair if needed. Currently there are a number of studies in the literature evaluating WALANT versus TA in flexor tendon injuries with continuing debate on the optimal modality but no amalgamated synthesis of data. The authors report the first systematic review and meta-analysis on the topic. The authors conducted the review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards (PRISMA) guidelines. All studies comparing flexor tendon repairs under WALANT versus TA were included. The primary outcome measure was range of movement (ROM) with secondary outcomes including adhesions/tenolysis, rupture as well as re-operation rates. OpenMeta[Analyst] software was utilised for data synthesis. Five studies in total met the inclusion criteria with an overall assessment of 624 fingers. There was no significant difference observed between WALANT and TA for tendon rupture; odds ratio 1.027 (0.450, 2.342) p-value = 0.950, the incidence of adhesions/tenolysis; odds ratio 0.601 (0.172, 2.093) p-value = 0.424 or re-operation rates; odds ratio 1.193 (0.544, 2.618) p-value = 0.659. ROM was reported to be better in the WALANT cohort; odds ratio: 1.641 (1.010, 2.669) p-value = 0.046. WALANT offers a safe and effective mode of anaesthetic over traditional modalities with comparable outcomes for flexor tendon repairs. Although ROM appears superior, the number of randomised control trials are currently low and more high quality studies are necessitated to enhance the current evidence base.

1. Introduction

Currently almost 20 % of injuries presenting to the emergency department involve the hand placing a significant financial burden on the health service¹ with 1–2% affecting tendons² most often on the flexor aspect. Flexor tendon repairs can be fraught with complications³ despite meticulous tissue handling and optimizing rehabilitation protocols.³ Adhesions and stiffness in particular are some of the adverse sequelae that can occur in the post operative period compromising outcomes.⁴ Wide awake local anaesthesia no tourniquet surgery has gained increasing popularity in recent years for hand surgery fast-tracked by the COVID pandemic.^5,6 It involves infiltration of lidocaine with adrenaline to the operative region⁷ ensuring a good visual field owing to the vasoconstrictive effects of epinephrine.⁸ The selection of the appropriate anaesthesia method is pivotal in optimizing outcomes for precise tendon repair, patient satisfaction and postoperative recovery.⁷ WALANT enables tendon strength to be tested on the table and the repair revised if needed with release of pulleys to improve excursion⁹(10). Patients can therefore actively participate in postoperative rehabilitation based on confidence of the intra-operative repair integrity¹¹ leading to improved functional outcomes compared to traditional anaesthesia. It has gained increased popularity in various forms of hand and wrist surgery^12,13 circumventing the drawbacks of traditional anaesthetic with a reduced burden on resources as well as facilitating quicker hospital discharges.^7,14,15 To the authors knowledge, there is currently however no systematic review and meta-analysis within the literature on WALANT versus traditional anaesthesia in assessing outcomes for flexor tendon repairs in the hand. The authors aim to report the first one and enhance the current evidence base.

2. Methodology

This systematic review and meta-analysis was conducted according to the Preferred.

Reporting Items for Systematic Reviews and Meta-Analyses statement standards.¹⁶

3. Eligibility criteria

All comparative studies including randomized as well as nonrandomized controlled trials and

observational studies which compared flexor tendon repairs under WALANT versus traditional anaesthesia (TA) were included. There was no restriction on age, sex, or comorbidity status. Studies where there was no comparison to WALANT in the form of either regional block or general anaesthesia were excluded from the review process as well as articles not reported in English.

4. Outcome measures

The primary outcome measure was range of movement (ROM) with secondary outcomes

assessing flexor tendon rupture, presence of adhesions or a need for tenolysis as well as the re-operation rate and other miscellaneous outcomes.

5. Literature search strategy

Two authors (B.S. and S.R.) independently searched the electronic databases of MEDLINE, Embase, CINAHL, PUBMED, Google scholar, and the Cochrane Central Register of.

Controlled Trials (CENTRAL). The last search was conducted on 27th April 2024 with

terminologies consisting of “WALANT”, “wide awake local anaesthesia no tourniquet, “routine anaesthesia”, “general anaesthesia”, “regional block” and “flexor tendon injuries”. All terms were combined with adjuncts of “and” as well as “or.” The authors extended the screening for eligible articles by reviewing the bibliographic lists relevant articles also.

6. Selection of studies

Two authors (B.S. and S.R.) independently assessed the titles and abstracts of articles retrieved from the literature and the full texts were reviewed for articles which met the eligibility criteria.

7. Data extraction and management

A Microsoft Excel spreadsheet was developed for data extraction following Cochrane's data

collection form for intervention reviews. The authors ran a pilot test in randomly selected articles and made necessary adjustments accordingly. The data extraction process was carried out independently by two authors (A.A. and S.S.S.) and any discrepancies were resolved by discussion with a third author (M.Y.R.).

8. Data synthesis

For data synthesis, OpenMeta[Analyst] software was utilised. The odds ratio (OR) was applied for the assessment of all dichotomous variables. Results were presented in forest plots with 95 % confidence intervals (CIs). Heterogeneity was evaluated using the Cochran Q test (χ2) supplemented by calculating the I2 for additional quantification of inconsistency. Interpretation of the I2 test results were as follows: 0 %–25 % (low heterogeneity), 25 %–75 % (moderate heterogeneity), and 75 %–100 % (considerable heterogeneity).

9. Methodological quality and risk of bias assessment

Two authors (A.S. and S.R.) independently assessed the methodological quality and risk of

bias for articles that met the inclusion criteria. The Cochrane collaboration tool was utilised

For randomized control trials to assess domains of selection, performance, detection, attrition, reporting bias as well as others types. Studies were categorized as having either low, unclear, or a high risk of bias. In instances where there was disagreement a third author (M.Y.R.) was recruited to act as an adjudicator. Additionally, the Newcastle-Ottawa Scale was used to assess bias in nonrandomized studies across three domains: selection, comparability, and exposure. This scale employs a star scoring system, with a maximum total score of nine stars for each study.¹⁷

10. Results

The screening process retrieved 244 articles of which 5 in total met the eligibility criteria for both qualitative and quantitative synthesis of outcomes.

11. Primary outcome

11.1. Range of movement

Range of movement assessment was conducted by four studies in total with a significantly higher proportion of fingers experiencing good ROM (Fig. 1) in the WALANT cohort with also a lower incidence of fair or poor movement outcomes(Fig. 2 compared to routine anaesthesia. Bamal¹⁸ and Kiran¹⁹ used the Strickland score^20,21 to categorise the range of movement whilst Kadhum²² utilised Global Outcome Grading Criteria adapted from Shewring.²³ The degree of movement was subsequently categorized into fair/poor as well as good/excellent. Townsend²⁴ however reported outcomes for range of finger movement as total active motion in degrees at different joints for both flexion and extension as well as the extent of digit movement to the distal palmar crease(DPC). No significant differences were identified for either outcome between WALANT or TA (see Fig. 3).

Fig. 1.

PRISMA flow chart depicting article screening and selection for assessment of flexor tendon repair under WALANT vs traditional anaesthesia.

Fig. 2.

Forest plot depicting good range of movement outcomes comparing WALANT with TA (traditional anaesthesia). Odds ratio: 1.641 (1.010, 2.669) p-value = 0.046.

Fig. 3.

Forest plot depicting fair or poor range of movement outcomes comparing WALANT with TA(traditional anaesthesia. Odds ratio 0.609 (0.375, 0.990) p-value = 0.046.

12. Secondary outcomes

12.1. Adhesions/tenolysis

Four studies overall assessed the development of adhesions in fingers as well as those necessitating tenolysis surgery to improve the range of movement. Equivocal outcomes were identified between the two study arms with no significant difference seen between the WALANT or TA groups (p value 0.424). (see Fig. 4)

Fig. 4.

Forest plot depicting the presence of adhesions or fingers necessitating tenolysis with WALANT and TA(traditional anaesthesia). Odds ratio is 0.601 (0.172, 2.093) p-value = 0.424.

12.2. Rupture

No significant difference was seen in the rupture rates between the two study groups on odds ratio assessment with negligible heterogeneity giving further consistency to the outcome. (Fig. 5)

Fig. 5.

Forest plot depicting rupture rates comparing WALANT with Traditional Anaesthesia. Odds ratio 1.027 (0.450, 2.342) p-value = 0.950.

12.3. Re-operation rates

Three studies in total assessed the re-operation incidence between WALANT and TA groups with comparable rates identified in both cohorts. No significant difference was seen on odds ratio assessment (p-value = 0.659). A generic inverse variance function was adopted to circumvent moderate heterogeneity of 60.6 % on initial analysis with a random effects model. (Fig. 6)

Fig. 6.

Forest plot depicting re-operation outcomes comparing WALANT with Traditional Anaesthesia. Odds ratio 1.193 (0.544, 2.618) p-value = 0.659.

12.4. Miscellaneous outcomes

Townsend reported on quick disabilities of the arm, shoulder and hand (qDASH) scores (2022) with the final qDASH score in the WALANT group being 17.2 (SD: 14.4) versus 23.3 (SD: 18.5) in the TA group (P = 0.255) but no significant difference was seen. Pain was reported by Srisai²⁵ with a ten point scale to quantify outcomes between the two study groups with no significant difference seen between the WALANT and TA cohorts. This was also comparable to the findings in the study by Townsend²⁴ who used a visual analogue scale with no difference in the degree of pain experienced. Townsend²⁴ also measured grip strength as a percentage relevant to the uninjured side with comparable strength levels between the two treatment groups. Srisai²⁵ measured overall patient satisfaction with a 5 point Likert Scale as well but found no differences between the WALANT and TA groups. No significant differences were also reported by Srisai²⁵ for operative time as well as blood loss (see Table 1).

Table 1.

Risk of bias assessment for randomized controlled trials utilising the Cochrane Collaboration's Tool.

First author	Bias	Authors judgement	Support for judegemnt
SRISAI	Random sequence generation (selection bias)	Low risk	Systematic random sampling technique usedNot clearly describedAll outcomes reportedNot blindedAll outcomes reported
	Allocation concealment (selection bias)	Unclear
	Selective reporting (reporting bias)	Low risk
	Blinding of participants and personnel (performance bias)	High risk
	Blinding of outcome assessment (detection bias)	Low risk
	Incomplete outcome data (attrition bias)	Low risk
KIRAN	Random sequence generation (selection bias)	Unclear risk	Not described in enough detail – random number allocationNot described All data reportedNot blindedAll outcomes reported
	Allocation concealment (selection bias)	Unclear risk
	Selective reporting (reporting bias)	Low risk
	Blinding of participants and personnel (performance bias)	High risk
	Blinding of outcome assessment (detection bias)	Unclear risk
	Incomplete outcome data (attrition bias)	Low risk

The methodological quality for all observational studies was assessed using the Newcastle-Ottawa scale¹⁷ (Table 2).

Table 2.

Newcastle Ottawa Scale assessing all observational studies for domains of selection, comparability and outcome.

Study	Selection	Comparability	Outcome
Townsend	∗∗∗∗	∗∗	∗∗
Bamal	∗∗∗∗	∗∗	∗∗
Kadhum	∗∗∗∗	∗∗	∗∗

13. Discussion

The results of this review has evidenced comparable outcomes for WALANT to standard anaesthesia in flexor tendon injuries for rupture, re-operation rates as well as needing tenolysis or suffering from adhesions. A higher proportion of patients however reported good range of movement outcomes under WALANT. Heterogeneity was low giving further consistency to the quantified outcomes. Secondary miscellaneous outcomes including qDASH scores, grip strength, patient satisfaction as well as pain were also found to be equivocal between the two treatment arms. WALANT however provides effective anaesthesia with a chemical tourniquet mitigating the discomfort of mechanical pressure.²² Lalonde has advocated its importance in terms of enabling testing glide for flexor tendons as well as strength intra-operatively.¹⁰ This can improve the surgical decision process for venting of pulleys to increase tendon excursion as well as initiating early active mobilisation protocols post operatively knowing the robustness of the intra-operative strength. Intraoperative assessment of flexor tendon movement is an integral component of WALANT allowing an immediate opportunity for revision of the repair, identifying any difficulties with glide as well as tendon gap therefore mitigating poor outcomes.⁹ In addition, intra-operative evaluation of total active movement is reported to be an effective indicator for patients necessitating tenolysis as well.⁹ WALANT avoids many drawbacks encountered with conventional modes of anaesthetic including service cost and any deleterious side effects from anaesthetic medication²⁶ with a quicker postoperative recovery.²⁷ There is also the additional benefit of avoiding any pre-operative anaesthetic work up as routinely conducted with conventional forms which can reduce the number of patient reviews as well as save time minimising the burden on health services.²⁸ Lalonde and Martin have²⁹ previously highlighted that surgical time can be reduced by adopting a WALANT based approach however the study by Srisai²⁵ showed that there was no significant advantage to TA.

Some hand surgeons have raised concerns when using WALANT given the propensity for flexor tendons to retract proximally necessitating additional incisions. In the analysis by Kadhum,²² there were three flexor tendons that had retracted all of which were however successfully retrieved by additional local anaesthetic infiltration using remote incisions and utilising a push pull technique.³⁰ Concerns regarding epinephrine use in fingers have also been refuted and proven to be a safe adjunct in local anaesthetic usage for the application of WALANT(29). Mann and Hammert reported one of the largest data sets disproving any risks regarding finger necrosis using lidocaine with epinephrine evidencing its safety.³¹

The authors report the first systematic review and meta-analysis within the literature assessing the outcomes for WALANT versus traditional anaesthesia in flexor tendon repairs, however not without inherent limitations. The number of randomised control trials in the literature are currently low although an overall 5 study inclusion has enabled the analysis of 624 fingers in total (Table 3). None the less, the authors advocate for more high quality studies to enhance the current evidence. At present, the WAFER trial is being conducted which is a multicentre study in the United Kingdom assessing WALANT in flexor tendon repairs compared to conventional anaesthetic. It is assessor blinded across three centres with computerised randomisation.³² Total active motion is being utilised to ascertain range of movement outcomes. The results of this meta-analysis has advocated improved range of movement in the WALANT group and although a negligible heterogeneity on analysis provides consistency, results of further randomised trials should be awaited to better guide clinical decisions. All observational studies within this review achieved satisfactory scores on the Newcastle Ottawa scale for selection, comparability and outcome domains as did all randomised control trials when assessed for risk of bias with minimal reports of high risk. Generally, outcomes were consistently reported amongst all studies with negligible heterogeneity evidenced on I2 assessment at 0 % for range of movement, re-operation, rupture as well as adhesion/tenolysis rates. Equally, the Cochran Q test drew insignificant heterogeneity results for all outcomes providing additional reliability of the effect estimates. Further high quality trials are still however needed to provide more robust data and the authors advocate for better reporting of injury zone and consistency in the repair technique used to enable more specific data synthesis.

Table 3.

Amalgamation table depicting author & year, study design, sex distribution, age, control/intervention treatment, number of fingers, zone of injury, mechanism and repair technique. SD = standard deviation, NR = not reported, RCT = randomised control trial.

Author & Year	Study Design	Intervention group age (mean/years +SD)	Intervention group sex (M:F)	Intervention treatment	Control group age (mean/years + SD)	Control group sex (M:F)	Control treatment (anaesthetic)	Number of fingers	Zone of injury	Mechanism of injury (n)	Repair technique (n)
Kadhum et al., 2021	Retrospective cohort study	38.5 ± 14.4	41:12	WALANT	32.1 ± 15.2(GA) 34.5 ± 12.4 (RA)	31:10 (GA) 42:15 (RA)	General/Regional	251	1-5 (sub zones not reported)	NR	4-strand Cruciate (41)
											Adelaide28
											Modified Kessler (4-strand) (60)
											Modified Kessler(2-strand)21
											Horizonal Mattress13
											Mitek bone anchor3
											Unspecified (85)
Kiran et al., 2021	RCT	28.51 ± 5.01	51:14	WALANT	28.39 ± 9.54/	46:19	General	130	1–5	Glass 90	NR
										Sharp cut 10
										Knife 4 Machine 1
Srisai et al., 2020	RCT	47.08 ± 15.79	29:17	WALANT	46.13 ± 18.97	31:15	General/Regional	92	1–5	Knife 83	NR
										Scissors 3
										Glass 6
Townsend et al., 2023	Retrospective cohort study	41.3 ± 14.1	18:5	WALANT	45.0 ± 18.6	22:20	General/Regional	65	1 & 2	NR	Core and epitendinous suture techniques for zone 2.
											Pull-out suture over an acrylic button or bone tunnels or suture anchors for zone 1
											(numbers not specified)
Bamal et al., 2023	Retrospective Cohort Study	43.9 ± 15.8	36:8	WALANT	34.2 ± 13.5/	17: 7	General/Regional	86	1 & 2	NR	Cruciate core and epitendinous
											Modified Kessler
											Transosseous with Bunnell or or Krackow-type stitch
											Numbers not specified

14. Conclusion

This is the first systematic review and meta-analysis within the literature assessing outcomes for flexor tendon injuries utilising WALANT versus TA. Comparable outcomes were seen in relation to tendon rupture, adhesions/tenolysis as well as re-operation rates. Although better range of movement was evidenced in the WALANT group, the number of randomised control trials are currently low and the authors advocate for further high quality studies to enhance the current evidence base.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Informed consent

Not applicable.

Contributorship

Rahy Farooq (R.F.) and Muhammad Yasir Raufi (M.Y.R.) have contributed equally to this article and should be considered joint first authors. R.F. and M.Y.R conceived of the presented idea. All authors discussed the results and contributed to the final manuscript which was mainly written by R.F. and M.Y.R with support and supervision from Shafiq Rahman (S.R.) and Waseem Bhatt (W.B.). Bryan Soe (B.R.) was involved in the screening and selection of articles. B.R. also contributed towards data extraction and analysis. Amir-Humza Suleman (A.S.) was involved in the methodology review, data analysis, generating the amalgamation table and drafting the results with support from R.F. and M.Y.R. Shaikh Sanjid Seraj (S.S.S.), Abida Arif (A.A.) contributed in data extraction and analysis as well as drafting of the results and manuscript write-up with support from R.F. and M.Y.R. S.R. and W.B. supervised and supported the project and contributed to the design and write-up.

Ethical approval

Not applicable.

Declaration of competing interest

The authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.