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Journal of Wound Management and Research > Volume 20(2); 2024 > Article
Khurram and Karad: Versatility of Proximal Sural Island Sensate Fasciocutaneous Flap in Reconstruction of Soft Tissue Defects of Knee and Proximal Leg



The proximal sural island sensate (PSIS) fasciocutaneous flap presents an ideal alternative in reconstruction of defects of the knee and proximal leg. It provides a thin sensate flap with good aesthetic outcomes and reduced donor site morbidity. However, only limited reports exist in the literature about this flap.


This is a retrospective study done between December 2018 and December 2021 including 30 patients, among which seven cases had defects located on the knee and 23 cases in the proximal part of the leg. Mean age of the study population was 41 years. The maximum flap size was 8×12 cm, while the maximum pedicle length was 15 cm.


All 30 flaps survived well with only minimal complications occurring in a few patients such as epidermal loss and distal tip necrosis. No arterial or venous crisis occurred postoperatively in any case. Donor sites were managed with one-stage primary closure or split-thickness skin grafts. Functional deficits were not detected in any of the cases.


We found the PSIS fasciocutaneous flap to be a simple and reliable technique to perform. The flap offers extensive coverage, reaching from the knee to the proximal leg, and provides thin, pliable, and sensate skin, resulting in excellent aesthetic and functional outcomes.


Soft tissue defects in the knee and proximal leg, stemming from various causes such as trauma, postoperative wound gaping, and tumor excision, are problems commonly encountered by reconstructive surgeons [1]. Successfully addressing these defects is crucial for achieving optimal aesthetic and functional outcomes. Several reconstruction methods exist, including adjacent local muscle flaps, fasciocutaneous flaps, cross-leg flaps, and free flaps [2-4].
However, each method comes with its own set of disadvantages. Muscle flaps, for instance, can result in a bulky appearance and significant discomfort because of muscle twitching and contractions. Similarly, cross-leg flaps may cause severe discomfort because of the need to maintain a fixed posture, and free flaps demand significant microsurgical expertise. Island fasciocutaneous flaps based on the median sural artery, transferred through a subcutaneous tunnel to the defect, offer a promising solution in overcoming these disadvantages. This approach provides satisfactory coverage while maintaining superior aesthetic and functional outcomes [5,6]. However, the dissection of the vascular pedicle through the gastrocnemius muscle is tedious and time-consuming.
This study focuses on exploring the potential of a proximally based sural artery flap for reconstructing soft tissue defects in the knee and proximal leg following trauma. Unlike other methods, this approach offers satisfactory coverage with a thin, supple, and sensate skin flap, leading to improved aesthetic and functional outcomes. Despite its promise, the use of a proximally based sural artery flap for such reconstructions is underexplored, with only limited studies documenting its application [1,3,7]. Therefore, the primary objective of this research is to evaluate the versatility of the proximally based sural artery flap in addressing post-traumatic soft tissue defects in the knee and proximal leg, shedding light on its potential as a valuable reconstructive option.


This is a retrospective study of 30 patients who were managed between December 2018 and December 2021, at the department of plastic surgery. All patients underwent surgery for reconstruction of soft tissue defects using a proximally based sural fasciocutaneous flap after providing written and informed consent. The study has been approved by the Institutional Ethical Committee of Jawaharlal Nehru Medical College (IECJNMC/1100, dated 26 August 2023). All surgeries were performed by the same surgeon.

Surgical technique

All cases were done under spinal anesthesia and tourniquet control. The wound bed was prepared after thorough debridement (Fig. 1). Patients were kept in either lateral decubitus or prone position during flap surgery.
To mark the required flap, a reference line was drawn on the posterior calf extending from the midpoint of the lateral malleolar tip and Achilles tendon to the midpoint of the skin crease in the popliteal fossa (Fig. 2). The donor site was positioned at the midpoint of this line, aligning with the approximate path of the sural nerve (pedicle). Typically, the pivotal point of the pedicle was positioned on the line approximately 1.5 to 2 cm distal to the popliteal skin crease. Then, the flap was marked by planning in reverse with the help of a lint piece template of the defect, followed by distal to proximal flap harvest. From an anatomical perspective, the proximal based sural fasciocutaneous island flap comprises a region of skin and subcutaneous fat along with the superficial and deep fascia, the sural nerve, the lesser saphenous vein, and the superficial sural artery. Flap circulation mainly depends on the median superficial sural artery, which usually originates from the popliteal artery. The skin paddle was incised at the distal margin, after which the lesser saphenous vein was identified, dissected, divided, and tacked to the dermis of the skin paddle. Similarly, the sural nerve was also ligated and tacked to the dermis. The sural nerve was incorporated into the flap to avoid the risk of damaging the superficial sural artery during dissection, which is in close proximity to the nerve. Additionally, including the nerve in the flap design was done to confer sensory functionality to the flap. Ultimately, flap elevation was performed beneath the subfascial plane, with special attention given to incorporating both vessels and nerve into the flap. A skin incision was made up to the pivot point, and skin flaps were elevated on both sides, ensuring a minimum of 1.5 cm of soft tissue was left on each side to protect the vascular pedicle (Fig. 3).
Once the flap was entirely raised, the tourniquet was deflated to check flap circulation. Then the flap was delivered into the defect through a subcutaneous tunnel avoiding tension or kinking of the pedicle (Fig. 4). If any compression of the pedicle was noted, the subcutaneous tunnel was incised open and the exposed pedicle was covered with a split-thickness skin graft. The flap was inset partially at the defect with 3-0 and 4-0 non-absorbable nylon sutures and a negative suction drain was placed underneath, carefully avoiding direct placement on the pedicle. After placing the drain, flap inset was completed, and the posterior calf incision used to elevate the flap pedicle was also closed (Fig. 5). The donor site of the flap was constricted and subsequently either closed primarily or underwent skin grafting, depending on the size of the defect (Fig. 6). Simple adhesive dressings were done to permit easy flap monitoring and the knee was immobilized in skin grafted patients until complete skin graft take. Subjective satisfaction was collected using Likert scale ratings (satisfaction rating of the surgical outcome using a scale from 1 to 10, where 1 is “Not Satisfied at All” and 10 is “Extremely Satisfied”) through questionnaires describing the user’s perceived satisfaction with the interaction experience. Sensory function was assessed using Semmes–Weinstein monofilaments and static 2-point discrimination (s2-PD) testing. Cortical reorientation was assessed using four modalities—hot and cold temperatures, superficial touch, and superficial pain—over the skin paddle at 1 month, 3 months, and 12 months after surgery. During the assessment, the patient was asked about the perceived origin of the stimulus, specifically whether it felt as though it were coming from the recipient site or the donor area. If the stimulus was identified from the recipient site rather than the donor site, it was deemed as complete cortical reorientation. Conversely, if the stimulus was perceived from the donor site or both sites, it signified incomplete cortical reorientation. Fig. 7 shows a well-settled flap with adequate range of motion at the knee joint and Fig. 8 is a follow-up image of the donor area which was covered with a skin graft showing excellent take of the graft.


The research involved a cohort of 30 patients, comprising 25 males and five females, presenting with defects primarily situated around the knee in seven cases and on the proximal half of the leg in 23 cases. The soft tissue defects were primarily attributed to road traffic accidents, encompassing acute soft tissue necrosis in 22 cases and postoperative implant exposure in eight cases. Associated risk factors included diabetes, advanced age, cigarette smoking, and high blood pressure. The mean age of patients at the time of surgery was 38.6 years. Flap procedures were performed on the left limb in 14 cases and on the right limb in the remaining 16 patients. Flap sizes ranged from 5×8 to 8×12 cm, and pedicle lengths varied from 8 to 15 cm, with a mean of 11 cm. The mean duration of the operation was 89.9 minutes, ranging from 68 to 105 minutes (Table 1).
All donor sites were closed in one stage with either primary closure or split-thickness skin (Figs. 9, 10). All 30 flaps survived and yielded satisfactory coverage. The study investigated only the sensory component of cortical reorientation of the proximal sural fasciocutaneous flaps. Cortical reorientation was complete in 20 (70%) patients and incomplete in 10 (30%) patients at the end of 12 months. The findings revealed a sequential recovery pattern, with crude touch being the first sensation to recover at 3 months, followed by fine touch at 6 months, and then pain sensation at 1 year postoperation.
s2-PD was measured at 3 months, 6 months, 1 year, and 1.5 years postoperatively. The measurements were compared with the opposite leg along the same dermatomal area as that of the leg defect which was covered with the flap. In 21 patients, the s2-PD of the flap area was comparable to the counterpart dermatomal area of the normal leg, indicating complete cortical reorientation. However, in the remaining nine patients, s2-PD over the flap was greater than that of the normal leg, suggesting incomplete cortical reorientation. This suggests that while some patients experienced complete cortical reorientation following the procedure, others did not achieve the same level of sensory recovery, indicating variability in outcomes.
After surgery, there were no significant issues related to arteries or veins in any of the cases. Two patients experienced distal tip necrosis and partial superficial epidermal necrosis, which were treated conservatively with regular dressings. There were no complications at the donor site, and no functional problems with the knee or ankle were observed. Although all patients experienced sensory loss in the dorsolateral aspect of the foot, they tolerated it well. Overall, patients expressed satisfaction with both the aesthetic appearance and functional results of the flap during the 1-year follow-up, with a mean subjective satisfaction score of 8.3.


Although reconstruction of knee and proximal lower leg soft tissue defects is one of the most common procedures performed by reconstructive surgeons, it is still considered a challenging procedure. Numerous techniques exist for addressing these defects, encompassing options such as local muscle flaps, perforator-based flaps, axial pattern fasciocutaneous flaps, cross-leg flaps, and free flaps. Other regional flaps have restricted utility when it comes to providing coverage for sizable oncosurgical defects in the knee region, particularly in the case of supra-patellar defects. The use of local muscle or musculocutaneous flaps, such as the gastrocnemius muscle flap, can impact lower limb function and may not provide an optimal match for the native tissue. Opting for a random pattern fasciocutaneous flap is a preferred choice, but challenges arise in terms of availability, mobility, and the tendency to create a dog-ear deformity, which negatively influences the aesthetic outcome. Both perforator-based propeller flap and free flap procedures require advanced microsurgical technique [8,9]. The cross-leg flap involves immobilizing both the healthy contralateral leg and the injured leg for around 3 weeks, leading to significant discomfort. Additionally, as a two-stage procedure, it necessitates extended hospital stay. Consequently, these approaches may not always be well-received or deemed acceptable.
Since Ponten’s landmark report [10], fasciocutaneous flaps have been widely used in leg reconstruction. But there are very few reports on the use of proximally based pedicled fasciocutaneous flaps from the posterior calf region. Moscona et al. [11] introduced an island posterior calf fasciocutaneous flap for reconstructing knee defects. However, in their description, they did not acknowledge the involvement of the median sural artery in the blood supply, attributing it to the fascial plexus. Satoh et al. [12] explored the utilization of sural fasciocutaneous flaps in different configurations, including pedicled, island, and free flaps. Their findings indicated that the island sural fasciocutaneous flap in particular exhibits notable versatility in effectively reconstructing soft tissue defects around the knee joint.
Cariou et al. [13] suggested a posterolateral sural fasciocutaneous island flap with a proximal adipofascial pedicle in a study involving nine patients. Their findings indicated that the resulting skin cover exhibited excellent quality, stability, and sensitivity. In a similar study, Li et al. [14] utilized lateral sural artery-based flaps in 17 patients for knee defect reconstruction, concluding that this approach was adequate for achieving the desired purpose.
In a study conducted by Suri et al. [1], proximally based sural artery flaps were utilized for the repair of soft tissue defects in 10 cases. The researchers found that these flaps were a dependable choice for reconstructing soft tissue around the knee and the proximal lower leg. Notably, the procedure resulted in minimal complications, including minor tip necrosis, grafted skin necrosis, and superficial infection.
In a comparable study involving 37 patients, Cheon et al. [3] reached the conclusion that soft tissue defects around the knee and on the proximal lower leg can be effectively addressed by using proximally based sural fasciocutaneous flaps.
Anatomically, the flap comprises the skin, subcutaneous tissue, superficial and deep fascia, the sural nerve, short saphenous vein, and superficial sural artery as a single unit. The blood supply to the flap primarily relies on the consistent median superficial sural artery, which typically arises from the popliteal artery. The median superficial sural artery traverses the popliteal fossa and courses between the heads of the gastrocnemius muscle. Upon penetrating the deep fascia, this artery runs in close proximity just medial to the lesser saphenous vein, extending toward the lateral malleolus [15]. Following this course, the median superficial sural artery either concludes its path or forms anastomoses with the supramalleolar branch of the peroneal artery and the posterior tibial artery. In our present study, the flap and its pedicle consistently incorporated the lesser saphenous vein, sural nerve, and the superficial sural artery. The arteries accompanying the lesser saphenous vein were also regarded as an additional reservoir of cutaneous branches supplying the posterior skin of the leg [16,17]. In the context of our study, all cases were associated with acute traumatic injury and postoperative wound dehiscence. Nevertheless, it is worth noting that a proximally based pedicled flap could also be a viable and effective option for reconstructing defects arising from chronic infection or post-oncologic excision.
The proximally based sural fasciocutaneous island flap presents a compelling option for addressing soft tissue defects around the knee, thanks to its thin and pliable skin characteristics. An added advantage of this flap is the provision of sensate skin, offering a degree of protective sensation, albeit rudimentary. There are very few studies reporting on cortical reorientation with respect to soft tissue reconstruction of the knee region to compare with the results of this series. Though utilized in the hand instead of the knee region, Littler's flap also offers the transfer of similar sensate skin, therefore requiring cortical reorientation, which was demonstrated in the studies of Muyldermans et al. [18], Aharrama et al. [19], and Wang et al. [20]. Additionally, the flap boasts a long arc of rotation, minimizing donor site morbidity and allowing for enhanced mobility of the affected knee joint. Being a flap with a lengthy pedicle, it can also be used for coverage of lower thigh defects. Other benefits include a shorter operative time, reduced duration of hospital stay, and the reliable sourcing of tissue from a donor area distant from the injury site. The ultimate clinical outcomes proved to be gratifying and promising, characterized by favorable functional and aesthetic results. The occurrences of minor complications, such as epidermal loss and distal tip necrosis, were the only noteworthy issues.
The drawbacks associated with the proximally based sural fasciocutaneous island flap encompass sensory loss in the dorsolateral aspect of the foot and scarring of grafted skin at the donor site, resulting in a less favorable cosmetic appearance. However, these issues were deemed minor and well-tolerated by the patients.
In our experience, the proximally based sural fasciocutaneous island flap can be considered a versatile and dependable option providing thin, pliable skin coverage with good functional and aesthetic outcomes at the expense of minimal donor site morbidity for the coverage of defects of the knee and proximal leg. The primary advantage of the proximally based sural fasciocutaneous island flap is its ability to retain sensory function which is quite desirable at the knee region.

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Fig. 1.
Defect with implant exposed. The patient had an exposed tibial implant in the proximal tibial region. The whole area was cleaned and debrided.
Fig. 2.
Markings for the proximal sural island sensate flap. The flap is marked on the posterior aspect of the leg after planning in reverse.
Fig. 3.
Harvesting of the flap. The flap is harvested under tourniquet control with identification of the pedicle.
Fig. 4.
Delivery of the flap. The flap is tunneled under the skin bridge to the recipient site after adequate pocket creation.
Fig. 5.
Insetting of the flap. The flap is inset over the defect and drains may or may not be placed under the flap.
Fig. 6.
Donor area. The donor area of this flap may be closed primarily if the size of the flap is less than 5–6 cm in width, otherwise a split-thickness skin graft (STSG) is necessary. In this case it was covered partially with primary closure and the remaining donor area was covered with a STSG.
Fig. 7.
Follow-up image. This picture shows a well-settled flap with adequate range of motion at the knee joint.
Fig. 8.
Follow-up image, donor site. The donor which was covered with skin graft also shows a well healed area.
Fig. 9.
Case 2. Patient with defect on anterior aspect of the upper tibial region. Wound bed created after thorough debridement (A), flap markings done (B), flap insetting (C), and donor area closed primarily (D).
Fig. 10.
Case 3. Similar case involving defect around the lower knee region with exposed implant. Wound bed created after thorough debridement (A), flap markings done (B), flap insetting, (C) and donor area covered with a split-thickness skin graft (D).
Table 1.
Data information sheet
Case No. Age (yr) Sex Site of defect Side of defect Defect size/ flap size (cm) Operative time (min) Pedicle length (cm) Complication Subjective satisfaction score Cortical reorientation
1 25 Male Knee Right 5×8 90 8 Nil 9 Complete
2 34 Male Leg Left 5×9 85 12 Nil 8 Complete
3 22 Male Leg Right 8×12 68 15 Nil 9 Incomplete
4 45 Male Knee Left 7×12 86 13 Nil 9 Complete
5 56 Male Leg Left 7×11 105 9 Nil 7 Incomplete
6 34 Male Leg Left 8×11 95 11 Epidermal loss 7 Complete
7 45 Male Knee Right 6×10 100 10 Nil 10 Incomplete
8 38 Male Leg Left 6×11 105 12 Nil 8 Complete
9 46 Male Leg Left 7×8 80 8 Nil 9 Complete
10 33 Male Leg Left 6×8 105 12 Nil 7 Complete
11 44 Female Knee Right 5×11 75 15 Nil 8 Incomplete
12 53 Male Leg Left 5×8 80 13 Nil 9 Complete
13 24 Male Leg Right 5×9 90 9 Nil 8 Incomplete
14 45 Male Leg Left 8×12 100 11 Distal tip necrosis 7 Incomplete
15 46 Male Knee Right 7×12 102 10 Epidermal loss 7 Complete
16 64 Male Knee Right 7×11 80 12 Nil 10 Incomplete
17 53 Male Leg Right 8×11 105 10 Nil 8 Complete
18 43 Female Leg Right 6×10 75 12 Nil 9 Complete
19 44 Male Leg Left 6×11 80 8 Nil 7 Incomplete
20 53 Male Leg Right 7×8 90 12 Nil 9 Incomplete
21 38 Male Leg Left 6×8 100 10 Nil 7 Complete
22 37 Female Leg Left 5×11 68 12 Nil 8 Complete
23 41 Male Leg Right 8×11 86 10 Distal tip necrosis 7 Incomplete
24 36 Male Leg Left 6×10 105 12 Nil 8 Complete
25 40 Male Leg Right 6×11 95 8 Nil 9 Complete
26 39 Male Leg Right 7×8 100 15 Nil 10 Complete
27 42 Female Leg Left 5×11 102 13 Nil 8 Complete
28 38 Male Leg Right 8×11 75 9 Nil 9 Complete
29 35 Female Knee Right 6×10 80 11 Nil 8 Complete
30 37 Male Leg Right 8×12 90 10 Nil 7 Complete
Mean 41 89.9 11 8.3


1. Suri MP, Friji MT, Ahmad QG, et al. Utility of proximally based sural artery flap for lower thigh and knee defects. Ann Plast Surg 2010;64:462-5.
crossref pmid
2. Zheng HP, Lin J, Zhuang YH, et al. Convenient coverage of soft-tissue defects around the knee by the pedicled vastus medialis perforator flap. J Plast Reconstr Aesthet Surg 2012;65:1151-7.
crossref pmid
3. Cheon SJ, Kim IB, Park WR, et al. The proximally-based sural artery flap for coverage of soft tissue defects around the knee and on the proximal third and middle third of the lower leg: 10 patients followed for 1-2.5 years. Acta Orthop 2008;79:370-5.
4. Hong JP, Koshima I. Using perforators as recipient vessels (supermicrosurgery) for free flap reconstruction of the knee region. Ann Plast Surg 2010;64:291-3.
crossref pmid
5. Leclere FM, Eggli S, Mathys L, et al. Anatomic study of the superficial sural artery and its implication in the neurocutaneous vascularized sural nerve free flap. Clin Anat 2013;26:903-10.
crossref pmid
6. Zhang YX, Zhang YG, Yang J, et al. Anatomy and clinical application of posterior calf fasciocutaneous flap. Zhonghua Zheng Xing Wai Ke Za Zhi 2008;24:192-5.
7. Dai J, Chai Y, Wang C, et al. Proximal-based saphenous neurocutaneous flaps: a novel tool for reconstructive surgery in the proximal lower leg and knee. J Reconstr Microsurg 2013;29:373-8.
crossref pmid
8. Rajacic N, Gang RK, Darweesh M, et al. Reconstruction of soft tissue defects around the knee with the use of the lateral sural fasciocutaneous artery island flap. Eur J Plast Surg 1999;22:12-6.
crossref pdf
9. Shim JS, Kim HH. A novel reconstruction technique for the knee and upper one third of lower leg. J Plast Reconstr Aesthet Surg 2006;59:919-27.
crossref pmid
10. Ponten B. The fasciocutaneous flap: its use in soft tissue defects of the lower leg. Br J Plast Surg 1981;34:215-20.
crossref pmid
11. Moscona AR, Govrin-Yehudain J, Hirshowitz B. The island fasciocutaneous flap; a new type of flap for defects of the knee. Br J Plast Surg 1985;38:512-4.
crossref pmid
12. Satoh K, Fukuya F, Matsui A, et al. Lower leg reconstruction using a sural fasciocutaneous flap. Ann Plast Surg 1989;23:97-103.
crossref pmid
13. Cariou JL, Lambert F, Arcila M, et al. Posterolateral sural fasciocutaneous island flap with proximal aponeurotic pedicle: anatomical study and use for cutaneous cover of the knee: apropos of 9 clinical cases. Ann Chir Plast Esthet 1995;40:148-61.
14. Li Z, Liu K, Lin Y, et al. Lateral sural cutaneous artery island flap in the treatment of soft tissue defects at the knee. Br J Plast Surg 1990;43:546-50.
crossref pmid
15. Chang SM, Zhang K, Li HF, et al. Distally based sural fasciomyocutaneous flap: anatomic study and modified technique for complicated wounds of the lower third leg and weight bearing heel. Microsurgery 2009;29:205-13.
crossref pmid pdf
16. Nakajima H, Imanishi N, Fukuzumi S, et al. Accompanying arteries of the lesser saphenous vein and sural nerve: anatomic study and its clinical applications. Plast Reconstr Surg 1999;103:104-20.
crossref pmid
17. Rajendra Prasad JS, Cunha-Gomes D, Chaudhari C, et al. The venoneuroadipofascial pedicled distally based sural island myofasciocutaneous and muscle flaps: anatomical basis of a new concept. Br J Plast Surg 2002;55:203-9.
crossref pmid
18. Muyldermans T, Hierner R. First dorsal metacarpal artery flap for thumb reconstruction: a retrospective clinical study. Strategies Trauma Limb Reconstr 2009;4:27-33.
crossref pmid pmc pdf
19. Aharram A, Mohammed S, Aamahtil M, et al. Littler neurovascular island flap in the loss of pulp substance of the thumb. Eplasty 2022;22:ic11.
pmid pmc
20. Wang H, Yang X, Chen C, et al. Modified Littler flap for sensory reconstruction of large thumb pulp defects. J Hand Surg Eur Vol 2018;43:546-53.
crossref pmid pdf
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