Reverse Anterolateral Thigh Flap for Lower Extremity Reconstruction: A Scoping Review

Abstract

Background:

There are several reconstructive methods in a plastic surgeon’s toolbox for reconstruction of soft tissue deficits in the lower extremity. This study presents a comprehensive review of literature pertaining to reconstruction of the lower extremity with the reverse anterolateral thigh flap.

Methods:

A scoping review was conducted based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews methodology. A total of 4 databases were used for the literature search. Main outcomes measured included procedure performed, region of soft tissue deficit, complications, follow-up, and the need for reoperation.

Results:

A total of 985 studies were imported for screening, of which 6 studies were selected based on our inclusion and exclusion criteria. Sixty-nine patients were included, with the majority of defects involving the peripatellar region, followed by the proximal and middle third of the lower extremity, and the thigh. The aggregate complication rate was 21.7% with flap loss occurring in 3 (4.3%) patients. Nine (12.9%) patients required reoperation due to complete flap loss or delayed healing.

Conclusions:

The reverse anterolateral thigh flap is a versatile option for reconstruction of defects localized to the knee and the proximal and middle third of the lower extremity. Particularly, the flap should be considered in patients that are otherwise not candidates for typical forms of reconstruction with the gastrocnemius or soleus muscles or with a free flap.

Takeaways.

Question: In which patients should the reverse anterolateral thigh (ALT) flap be considered for lower extremity reconstruction?

Findings: The reverse ALT should be considered in patients that are not candidates for free flap reconstruction or have had prior reconstruction with local muscle flaps.

Meaning: The reverse ALT flap is a versatile option for reconstruction of defects localized to the knee and the proximal and middle third of the lower extremity.

INTRODUCTION

Reconstruction of the knee and proximal two-thirds of the lower extremity can be challenging secondary to the presence of infection, hardware, exposed structures such as bone and tendon, or an open joint. There are several reconstructive techniques that may provide vascularized tissue that is both functional and aesthetically pleasing including muscle flaps (gastrocnemius), local perforator flaps (medial/lateral sural artery flap), musculocutaneous flaps, free flaps, or even staged reconstruction with wound matrixes followed by a skin graft.^1–3 Ultimately, the goal of a lower extremity reconstructive surgeon is to provide adequate and durable soft tissue coverage while also attempting to deliver a cosmetically appealing surgical result.

Locoregional perforator-based flaps often have suboptimal vascular reliability, which can be further complicated by a lack of adequate soft tissue coverage secondary to traumatic defects and the risk of venous congestion.⁴ The gastrocnemius flap is traditionally used for knee and proximal third defects of the lower extremity but is limited by a short pedicle, bulk which can lead to contour deformities, and mobility.^5,6 Finally, autologous free tissue transfer, although effective, can lead to donor site morbidity (applies to regional or pedicled flaps as well), need for advanced surgical experience, increased operating times, bulky contour, and possibility of flap failure secondary to zone of injury.^7–9

The reverse anterolateral thigh (ALT) flap was introduced by Zhang et al in 1990, in which the flap is raised on the anastomosis between the descending branch of the lateral circumflex femoral artery and the lateral superior genicular artery.¹⁰ Since the initial publication by Zhang et al, there have been various case series and reports along with anatomical studies that have found the reverse ALT flap to have reliable perforator sites.¹¹ There are several advantages to the reverse ALT flap including flap volume, ability to use the fascia lata in flap construct to aid with patellar tendon reconstruction, and capability to provide coverage to the knee and proximal third of the lower extremity.¹²

Despite the reverse ALT flap having been described for several decades, there is a lack of prospective or retrospective review studies, with the majority of the literature limited to case reports and case series. Given the absence of a comprehensive and synthesized outcome-based paper, the goal of this study was to perform a scoping review of the surgical technique, utility, and associated outcomes of the reverse ALT flap for lower extremity reconstruction in adult patients.

METHODS

Design

This scoping review was conducted using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR).¹³ A review protocol does not exist. (See figure, Supplemental Digital Content 1, which displays the PRISMA-ScR checklist, https://links.lww.com/PRSGO/F302.)

Information Sources

The online databases used include PubMed, Cochrane, Embase, and CINAHL. The literature search was conducted on December 22, 2025.

Eligibility Criteria

There were no restrictions when conducting the initial search regarding publication date, study language, or study type. Following the collection of studies, the inclusion/exclusion criteria consisted of publication after the year 2000, English language only, no systematic reviews, no case reports, and no cadaveric studies.

Search Strategies

A search strategy with keyword search terms was built to identify articles pertaining to the reverse ALT flap for reconstruction of lower extremity defects, complications, and other associated procedural effects. Our search strategy relied on the following keywords: distally based anterolateral thigh flap, distally based anterolateral thigh, distally based ALT flap, distally based ALT, reconstruction, defect, and wound. The formal search strategy that was used for PubMed is shown in Supplemental Digital Content 2. (See appendix, Supplemental Digital Content 2, which displays the search strategy from PubMed, https://links.lww.com/PRSGO/F303.)

Study Selection

The identified articles were then imported into the COVIDENCE software, an online application tool used for primary screening and data extraction. Once all duplicates were removed, studies were selected based on our inclusion/exclusion criteria. Two independent reviewers selected the studies through title and abstract screening. All conflicts were resolved by a third-party individual. Once irrelevant studies had been removed from the study group, the articles underwent full-text review by two independent reviewers, with a third reviewer resolving any conflicts.

Data Extraction

Our data extraction forms recorded authorship, year of publication, procedural details, complications, and other study details based upon our inclusion/exclusion criteria. Whenever possible, the following information was recorded:

1. Methods: study type, level of evidence (based on the Oxford Centre for Evidence-Based Medicine), quality of the study (Methodological Index for Nonrandomized Studies [MINORS]), and sample size.^14,15 Level of evidence and MINORS scores were conducted by 2 independent reviewers, with all conflicts resolved by a third-party individual.

2. Participants: year of study, sample size, age of participants, gender, and procedural indication.

3. Intervention: the technique used, details of the procedure, and follow-up period.

4. Outcomes: postprocedural complications, reoperations, aesthetic outcome, patient satisfaction, and long-term complications.

Data Analysis

Once all of the data had been extracted, it was then imported into Microsoft Excel (Microsoft Office Excel 2022, Redmond, WA). Microsoft Excel was then used to compile data and create tables for the article.

RESULTS

General Overview

The study selection PRISMA-ScR flow diagram is shown in Figure 1. A total of 985 studies were imported for screening, of 954 studies were screened as not relevant to this study. Thirty-one full-text studies were assessed, and 6 articles met our final inclusion/exclusion criteria.^12,16–20 Several studies included operative indication, complication profile, demographic details, and long-term follow-up. Seldom, there were studies that discussed operative techniques. Quality assessment was performed on selected studies (Table 1), as described previously. There was a generalized lack of control groups within the included studies that prevented a meta-analysis from being performed.

Fig. 1.

Inclusion flowchart based on PRISMA-ScR guidelines.

Table 1.

Articles Included Within Scoping Review

Study	Study Design	Level of Evidence*	Indications for Surgery	MINORS Score15	Statistical Analysis
Akhtar et al16	Prospective review	IV	Peripatellar, thigh, and lower extremity proximal third wounds	6	No
Bekarev et al17	Retrospective chart review	IV	Peripatellar wounds	5	No
Demirseren et al18	Case series	IV	Peripatellar wounds	7	No
Du et al12	Retrospective chart review	III	Peripatellar, thigh, and lower extremity proximal third wounds	9	Yes
Liu et al19	Case series	IV	Peripatellar wounds	7	No
Wang et al20	Case series	IV	Peripatellar and lower extremity proximal third wounds	7	No

^*Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence.¹⁴

Clinical Characteristics Analysis

In total, 6 studies were included in the analysis, of which 3 were case series, 2 were retrospective reviews, and 1 was a prospective review study. Although surgical technique was not discussed in 5 of the studies, it had been broadly described in the introduction of each paper, giving us the confidence that the flap techniques were similar between the articles (Table 2). Within the studies, the number of patients ranged from 3 to 36. The patient age range was vast, spanning 20–85 years of age. Flap survival varied between studies and all included papers reported both short- and long-term complications. Follow-up ranged from 1 to 52 months and there were 2 articles (Akhtar et al and Wang et al) that did not disclose follow-up.

Table 2.

Characteristics and Outcomes of Included Studies.

Study	Study Period	Indication for Surgery	No. Patients	Age (y)	Sex	Defect Size	Complications	Follow-up (mo)	Conclusion
Akhtar et al16	2011–2013	Peripatellar, thigh, and lower extremity proximal third wounds	4	20–30	Not provided	20 × 9 cm to 28 × 10 cm	● Distal flap loss treated conservatively (1)	Not provided	The inferiorly based thigh flap is a reliable flap to cover the defect over the proximal one-third of the leg, peripatellar region, and inferior thigh. The main advantages of this flap are its ability to cover a large area with a hidden donor site
Bekarev et al17	2011–2015	Peripatellar wounds	5	50–85 (69 mean)	1 male, 4 female	Not provided	● Flap loss (1) ● Infection (1) ● Delayed healing requiring debridement (2)	11–36 (24.5 mean)	The inferiorly based thigh flap is useful for reconstruction of peripatellar wounds due to minimal donor site morbidity and predictive pedicle anatomy. However, weaknesses include unreliable venous drainage and the possible need to delay or perform venous outflow anastomosis
Demirseren et al18	2006–2010	Peripatellar wounds	17	26–82 (64.3 mean)	9 male, 8 female	6 × 8 cm to 10 × 14 cm	● Distal flap loss treated conservatively (2)	5–27 (11 mean)	The reverse ALT flap can be technically challenging but can provide adequate soft tissue coverage to the knee and proximal third of the lower extremity
Du et al12	2010–2021	Peripatellar, thigh, and lower extremity proximal third wounds	35	28.9 ± 22.7	23 male, 12 female	Not provided	● Flap loss (2) ● Venous congestion (3)	1–52 (8.2 mean)	The reverse ALT is a useful flap but surgical resection or trauma can render it less likely to succeed. As a result, surgeons can often pivot to another flap from the same surgical incision
Liu et al19	2005–2008	Peripatellar wounds	3	24–45 (32.3 mean)	3 male, 0 female	2 × 3 cm to 23 × 6 cm	● Distal flap loss treated conservatively (1) ● Distal flap loss treated operatively (1)	4–6	The reverse ALT flap has a wide arc of rotation, reliable anatomy, and sufficient skin paddle. However, surgeons may have to consider delaying the flap if there is a large skin paddle
Wang et al20	2006–2007	Peripatellar and lower extremity proximal third wounds	5	25–72 (40 mean)	1 male, 4 female	6 × 8 cm to 12 × 13 cm	● Delayed healing (1)	Not provided	The reverse ALT flap is effective for coverage of peripatellar and lower extremity wounds due to its long pedicle, soft tissue coverage, minimal donor-site morbidity, and possible composite transfer with the fascia lata

The aggregate data comprised a total of 69 patients that were included in the review. Akhtar et al did not provide gender information for their included patients (4), bringing the gender dataset to 65 patients, of which 37 were male (56.9%). Indications for surgery were most commonly wounds secondary to complications from total knee arthroplasty, trauma, or following resection of malignancy. Although not specified throughout the included studies, wounds included the peripatellar region, thigh, proximal third of the lower extremity, and middle third of the lower extremity.

The defect size was vast, ranging from 2 × 3 cm to 28 × 10 cm. Bekarev et al and Du et al did not provide specific defect size measurements within their articles. The aggregate complication rate was 21.7% (15 of 69), ranging from delayed healing to flap loss. Delayed healing requiring local wound care was most common, which was seen in 5 (33.3%) patients, followed by venous congestion in 3 (20%), and flap loss in 3 (20%). Complications were further stratified into minor (delayed healing, infection, or congestion treated nonoperatively) and major (any complication requiring operative intervention). There were a total of 9 major complications (60%) and 6 minor complications (40%). Of the major complications, there were a total of 3 flap losses, with a flap success rate of 95.7%. Postoperatively, most patients were placed in a knee immobilizer without need for frequent flap monitoring.

Critical Appraisal Within Sources of Evidence

The included sources of evidence consisted of articles with inconsistencies of the information provided, including patient gender, defect size, surgical technique, and follow-up duration. Currently, there are no comparative studies or randomized controlled trials that are available within the literature. The level of evidence in the reviewed literature in the included studies were typically level 4, with the exception of 1 level 3 study, demonstrating the limited literature present. This is further exemplified by an average MINORS score of 6.83 (range 5–9), suggesting substantial methodological weakness in the included studies.

DISCUSSION

This study looked to perform a comprehensive review of reported literature on patients that have undergone reconstruction for lower extremity defects with the reverse ALT flap. To the best of our knowledge, there have been no published studies that have performed a scoping review evaluating the efficacy of the reverse ALT flap for lower extremity reconstruction. A total of 6 studies were examined with a wide range of defects and outcomes that were addressed, reflecting the versatility of this reconstructive technique.

Typically, soft tissue reconstruction of knee defects involves local muscle flaps such as the gastrocnemius or perforator flaps such as the medial sural artery flap.^1,21,22 Distal to the knee, reconstruction of the lower extremity has historically been divided into thirds, with the gastrocnemius flap being used for proximal third defects, the soleus flap for middle third defects, and fasciocutaneous or free flaps for lower third defects.^7,23 However, limitations of the gastrocnemius and soleus as local flaps for reconstruction include the arc of rotation and the possibility of insufficient coverage.²⁴

The reverse ALT flap was found to be used for several lower extremity defects, primarily in the peripatellar region. Akhtar et al, Du et al, and Wang et al were able to extend the utility of this flap to include the distal thigh, proximal third of the lower extremity, and middle third of the lower extremity for reconstructive purposes.^12,16,20 Additional studies, including a paper by Sadigh et al, have demonstrated the reverse ALT flap to be useful for revision cases and reaching the mid-tibial region.²⁵ The ability of the reverse ALT flap to provide coverage from the peripatellar region to the middle third of the lower extremity demonstrates the effectiveness of the flap in patients that would otherwise be unable to undergo complex reconstruction with autologous tissue.

Unlike some free flaps, the reverse ALT can be harvested, and defects can be reconstructed in the supine position without the need for a possible position change, should a free flap be harvested.²⁶ Other comparative benefits to a free flap include decreased operating time, lack of need for microsurgical expertise, and ability to perform the procedure in patients with significant co-morbidities.^27,28 In addition, the fascia lata can be harvested with the reverse ALT flap to provide reconstruction to the extensor function of the knee, further demonstrating the effectiveness of the reverse ALT flap.^20,29 Furthermore, a study by Boucher et al found that in their radiological study, a tensor fasciae latae perforator was present in all cases with an average pedicle length of 32 cm, demonstrating its suitability for perigenicular reconstruction.³⁰

Our study demonstrated an overall complication rate 21.4%, with a total of 9 major complications requiring reoperation and 6 minor complications, which were treated nonoperatively. Flap loss occurred in 3 patients (4.3%). A systematic review by Serra et al found a total flap necrosis rate of 7.78% and an operating room takeback rate of 13.79% for vascular compromise in a total of 5133 free flap reconstructions (5061 patients).⁹ An additional systematic review by Chandra et al found a complication rate of 59.9% for gastrocnemius flaps, 55.6% for gracilis flaps, and 19.2% for fasciocutaneous flaps.³¹ Thus, the reverse ALT flap is a comparable flap to be used for peripatellar and lower extremity soft tissue defects.

Venous congestion was seen in 3 patients, along with 5 patients who experienced distal tip necrosis. Komorowska-Timek et al found that supercharging the flap through anastomosis of the lateral femoral circumflex to the anterior tibial vessels led to improved reliability and coverage up to the proximal two-thirds of the tibia.³² Bøkset et al determined that supercharging the flap to the great saphenous vein optimized flap survival by decreasing the rate of venous congestion.²⁶

Although this scoping review offers valuable insight into the utility of the reverse ALT flap and complications, there are several limitations that must be acknowledged. Primarily, the included studies in this article are mainly composed of case series rather than large retrospective/prospective review studies or randomized controlled trials. Thus, it is possible that the study population and surgical procedure may impact the generalizability of the study. In addition, due to the included studies, we were unable to perform a meta-analysis, which may further impact the reliability of our findings. In addition, based on our MINORS score, the quality of studies varied widely, which is critical to consider. Finally, across the included studies, there was not a uniform method by which data were presented, limiting the analysis that could be performed for this study.

CONCLUSIONS

The reverse ALT flap has the potential to be a versatile and effective flap that may be considered for soft tissue reconstruction of the peripatellar region and proximal lower extremity distal to the knee. Complications include delayed healing and venous congestion, which can be alleviated by supercharging to both arterial and venous vasculature in the distal extremity to improve flap caliber. This flap may be considered in patients who are unable to undergo autologous free flap based reconstruction or other work-horse local flaps.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.

ETHICAL APPROVAL

This study did not require approval by the institutional review board.